Appendices Appendix a Values of Constants Symbol Value

APPENDICES

APPENDIX A

VALUES OF CONSTANTS

SYMBOL NAME VALUE UNIT -12 €o Permittivity of free space 8.85 x 10 farad/meter (F/m) -6 JL o Permeability of free space 1.26 x 10 henry/meter (Him)

e Elementary charge 1.60 F< 10-19 coulomb (C) -24 JL B Bohr magneton 9.27 x 10 joule/tesla (J/T) -15 ~o Flux quantum 2.07 x 10 weber (W) -34 h Planck constant 6.63 x 10 . joule' second (J's) 8 c Speed of light in vacuum 3.00 x 10 meter/sec (m/s) -23 kB Boltzmann constant 1.38 x 10 joule/kelvin (J/K) -8 0 Stefan-Boltzmann constant 5.67 x 10 watt(m2 'K' (w/m 'K')

1\ 23 1 NA Avogadro number 6.02 x 10 mole- (mole -1 )

633 634 APPENDICES

R Universal gas constant * 8.31 joule/mole'kelvin (J/mole'K)

* The word "mole" means a gram-mole in both cgs and SI units. The definition has not been changed to kilogram-mole. Thus one mole of a substance comprised of molecules is an amount whose mass in grams is numerically equal to its molecular weight, or if comprised of atoms its atomic weight.

APPENDIX B

CONVERSION BETWEEN CG5 AND SI UNITS Many scientists who deal with magnetic quantities and measurements still use the so-called unrationalized electromagnetic units in the centimeter-gram-second system ("cgs" or "cgs-emu" system). Therefore a conversion table is given here. This in no way consti- tutes a recommendation for the use of these units. Multiply the value in cgs units by the number in the fourth column to obtain the value in 51 units.

SYMBOL QUANTITY CGS UNIT FACTOR SI UNIT

B flux dens.tty gauss 10-4 tesla (G) (T) -3 H field strength oersted 411 Ie 10 ampere/meter (oe ) (Ajm) -8 ~ flux maxwell 10 weber 2 (G'em ) (W or T'm ) 3 X susceptibility emu/em 411 dimensionless -3 3 Xp mass emu/g 411 x 10 m /kg susceptibilty

-6 3 Xm molar .,. emu/mole 411 x 10 m /mole susceptibility

* One mole of a substance comprised of molecules is an amount whose mass in grams is numerically equal to its molecular weight, or if comprised of atoms its atomic weight. APPENDICES 635

APPENDIX C

CALCULATION OF INDUCTANCE

P. Carelli, I. Modena, G.L. Romani

Istituto di Elettronica dello Stato Solido - C.N.R. Rome, Italy

S.J. Williamson

New York University New York, New York, U.S.A.

Most biomagnetic research is now done with commercial SQUIDs, and the only component of the field-sensing system that the experi- menter is free to design is the detection coil of the flux transformer. As explained in Chapter 5, the geometry and size of the coil should be chosen to maximize sensitivity for the biomagnetic source of interest while minimizing sensitivity for interfering "noise" sources. In relatively quiet environments, the intrinsic noi.se of the SQUID or SQUID electronics limits the sensitivity of the field-mesuring system, in which case greater sensitivity is achieved by increasing the radius of the pickup coil and number of turns of wire to increase the total magnetic flux of the signal within it. However as the size of the coil increases there is a corresponding degredation in the lateral resolution, which may be- come intolerable if a field pattern having fine detail is to be measured. Consequently a compromise must be made between sensitivity and spatial resolution. Some analysis to help with this choice has been provided by Williamson and Kaufman (1981b) and by Romani et al. (1982e).

An additional consideration when designing a coil for maximum sensitivity is the desire to transfer the greatest possible signal energy from the detection coil to the input coil of the the SQUID. To accomplish this, the detection coil's inductance Ld should match the input coil's inductance L .. The match need not De done very l. precisely because a small mis-match (up to ~20') has a comparative- ly small effect (see Eq. 5.3.2). Thus when designing a detection coil for a particular application, it is necessary to calculate its inductance. This appendix shows how to do that ..

C.l. MAGNETOMETER

The first example of a d.etection coil is a simple pickup coil 636 APPENDICES of one turn of wire (a "magnetometer"). We recall from Section 2.6.2 that the inductance L of a coil specifies the magnetic flux ~ within it when a current I flows in the wire, as given by ~ .. LI. For a single-turn coil of radius "a" and wire radius "c" the inductance is

-7 L (C.1 ) o 47TxlO a[ Ln( sa/c) - 1. 75] This gives L in the SI unit of the henry (H) when "a" and "c" are o expressed in meters; and "Ln" indicates the natural logarithm (to the base e = 2.171S ... ), which can be found in standard tables. To illustrate the use of this formula, we take typical values of a = 2 em and b .. 0.1 mm and obtain Lo .. 0.141 ~H. The value of inductance is insensitive to the wire radius "b" since the radius enters log- arithmically in the formula. For instance, if "c" is doubled to the size c .. 0.2 mm, L decreases by only 13'. o For a given coil diameter, the total signal flux increases with increasing number of turns N of wire. However the total inductance should not appreciably exBeed that of the SQUID'S input coil. If turns of the same radius are wound close to one another, the total inductance increases by more than a factor of N expected if the individual self inductances were simply to add. TRis is because of the mutual inductance between the various pairs of turns: the flux within a given turn is enhanced by a factor of N owing to the contribution of the other turns. Therefore the total ~nductance L of the closely-wound coil is proportional to N 2: c p L .. N 2 L (C.2 ) cpo

Accordingly, if the coil of the preceding example is wound with N P .. 3 turns its inductance becomes L a 1.27 ~H. P It should be noted that winding turns close to one another is not the most advantageous way to increase the inductance of a pickup coil. If instead a separation is allowed between adjacent turns, the mutual inductance is reduced and therefore more turns can be added while still respecting the condition for inductance matching to the SQUID. The additional turns are an advantage because they increase the total signal flux within the coil. We let "s" denote the separation distance (between wire centers) and for convenience introduce as a parameter the "reduced" separation distance x s/2a, where "a" is the coil's radius. The mutual inductance between two coaxial, single-turn coils of equal radii varies with "x" as shown in Fig. C.l. By conSidering the mutual inductances between all pairs of turns for a multiple-turn coil, it is found that the total inductance L can be expressed as p

L N 2-a L (C.3 ) P p 0 APPENDICES 637

IU5+-______~------_+------~~------~

-6 10 E "- I

0 "- ~ Qj u c 0 t; :> -7 "0 E 10 (5 :> "S ~ "0 Q) u :> "0 n:Q)

10- 8

169+-~------~------~------_+------~--~ 10-3 10- 1 10 Reduced separation, x Fig. <':.1. Reduced mutual inductance (mutual inductance divided by the coil radius "a") versus reduced separation distance x = s/2a between two coaxial, single-turn coils of equal radius.

For a coil whose turns are closely spaced, a = 0, and so the formula reduces to that in Eq. C.2; for a coil with turns far apart, a = I, and the total inductance is just the sum of the individual self inductances of the turns. A general expression for a is

N -2 P 2 - !n{2 + L 2[N -n] K[(n+I)X]}/!n(Np ) (C.4 ) n=O p 638 APPENDICES

The function K(x) is the coupling coefficient of mutual inductance between two turns of reduced separation "x" (Grover 1962), which is approximately

K(X) = - 0.08 - 0.139 Ln(x) (C.s)

This expression is valid for values of x that range between 10- 3 and 2X10- 2 , covering the range appropriate for most coils used for biomagnetic measurements.

As an example of using Eqs. C.3 - C.S we consider the three- turn coil of radius a = 2 cm discusssed earlier, but now we allow a separation s = 1 mm between the adjacent turns. Thus only two terms appear in the sum of Eq. C.4, and we have x - 0.025. Adding terms gives a(3, 0.025) = 0.23. With this calculated a, Eq. C.3 then gives an inductance of 0.99 #H. This is a substantial reduction from the close-wound value of 1.27 ~H. The decrease of inductance by separating turns allows the addition of one more turn without appreciably exceeding the inductance.of the closely-wound case, assumed to match the input coil of the SQUID. A four-turn coil of s = 1 mm and a = 2 cm has a = 0.31 and a total inductance of 1.29 ~H. This is virtually the same inductance as for the three-turn closely wound coil. The extra turn permitted by separating turns thus en- hances the coil's sensitivity by 33\ over that of the closely wound geometry.

calculations of this sort can be carried out to optimize coil size and number of turns once the general desired features of a pickup coil have been selected. However, increasing the separation by more than a millimeter or so may be undesirable, because it shifts the geometrical center of the coil further from the source to the measured, with a corresponding decrease in the detected flux.

C. 2 • GRADIOMETERS

We turn now to consider the inductance of detection coils having gradiometer geometries such as the first-order configuration in Fig. C.2a and second-order configuration in Fig. C.2b. The baseline "b" between adjacent coils is assumed to be long in comparison with the overall separation between the end turns of an individual coil. Then the inductance L of an individual coil labeled "n" can be calculated as explained ~ve, and the only new feature to be taken into account is the mutual inductance M between one turn of coil "m" and one turn of coil "n". For the s~etrical first-order gradiometer the total inductance is

(C.6 ) APPENDICES 639

Fig. C.2. (a) symmetric first-order grad10meter and (b) second- order gradiometer illustrating the notation for coil di- mens ions as well as the self inductances L and mutual inductances M ; (c) asymmetric first-ordeP gradiometer. mn

We use the convention where all values of mutual inductance are positive, so that the signs of their effects are explicitly shown in the formulas. The minus sign appears in Eq. C.6 because the two coils are wound in opposite directions, so the field from one op- poses the self-generated field in the other. The factor of "2" appears in front of M12 because each coil affects the flux in the other. The value of M12 can be calculated from the curve in Fig. C.l. If each coil has N turns instead of a single turn, this for- p mula becomes

(C.7 )

where the factor N 2 represents the product of the number of turns in each coil to acc8unt for the enhanced flux that one coil pro- duces in the other. Thus for a gradiolReter of b = 5 em baseline consisting of two coils of 2 cm radius, each of which has four turns spaced by 1 mm, the total inductance is -6 -9 (2 x 1.29x10 ) - (2 x 6.8x10 ) -6 2.571(10 B

Because of the relatively large baseline in this example the mutual inductance has only a meager effect on the total inductance.

A similar procedure can be used for a second-oraer gradiometer (Fig. C.2b). The total inductance of the configuration having one turn for each of the end coils and two for the center coil is 640 APPENDICES

Ld - 2Ll + L2 - 4Ml2 + 2Ml3 (C.S) If instead the end coils each have N turns, the generalization of this would have Ml2 and Ml3 each multiBlied by Np 2 • In the preceding illustrations we assumed that the overall coil lengths were much shorter than the baseline "b". If on the other hand the lengths of the coils are not negligible, the appropriate formulas are invalid and the actual mutual inductances between all pairs of turns must be calculated. Fig. C.I can be used for this, or if greater precision is desired, the tables given in the next section.

C.2.1. Tables for Coils of Unequal Radii

It is common to design gradiometers with an asymmetric geometry to improve the transfer of flux from the pickup coil to input coil of the SQUID. Then the calculation of the mutual inductance between turns of differing radii may be necessary. We consider two one-turn coils of radii a. and a , separated by the distance "s" as illustrated in Fig. C.2c. 1The mu~ual inductance, as shown by Grover (1946), depends on the two parameters P - a~/a2 and ~ - s/a2 and is proportional to the coils' linear size. Tfie mutual inductance M (in henrys) can be written as 12

(C.9)

Here again, the coil radius a2 must be expressed in meters. The parameter "f" is to be obta1ned from an appropriate table corresponding to the value of the variable K2 defined by

(1 p)2 + ~2 2 K (C.10) (1 + p)2 + ~2

Thus, once the values 20f P and ~ are calculated for a given set of coils, the value of K can be calculated from Eq. C.IO and the corresponding value of "f" can be obtained from the appropriate table. Table C.1 is useful for most radii and separations met in biomagnetic applications. Table C.2 lists values when the coils' separation is very small, and Table C.3 when very large. For obtaining approximate values, a linear interpolation between the tabulated numbers will suffice; but for more accurate values second differences should also be taken into account. When entries in these tables are very small, the logarithm (to the base 10) is given. An underline indicates a negative value for the characteristic. APPENDICES 641

Table C.l. values of the parameter "f" in Eq. C. 9 for coils of differing radii. (From "Inductance Calculations," 1946, 1973, Fre- derick W. Grover, published by the Instrument Society of America under an arrangement with Dover Publications, Inc., New York. Tables used with the permission of Dover Publications, Inc.)

f f

0.010 0.021474 0.260 0.003805 .020 .017315 .270 .003649 .030 .014937 .280 .003500 .040 .013284 .290 .003359

0.050 0.012026 0.300 0.003224 .060 .011017 .310 .003095 .070 .010179 .320 .002971 .080 .009464 .330 .002853 .090 .008843 .340 .002740

0.100 0.008297 0.350 0.0026317 .110 .007810 .360 .0025276 .120 .007371 .370 .0024276 .130 .006974 .380 .0023315 .140 .006611 .390 .0022391

0.150 0.006278 0.400 0.0021502 .160 .005970 .410 .0020646 .170 .005685 .420 .0019821 .180 .005420 .~30 .0019026 .190 .005173 .440 .0018259

0.200 0.004941 0.450 0.0017519 .210 .004723 .460 .0016805 .220 .004518 .470 .0016116 .230 .004325 .480 .0015451 .240 .004142 .490 .0014808 0.250 0.003969 0.500 0.C014186 642 APPENDICES

Table C.l. ( Continued)

k 2 f k 2 f

0.500 0.0014186 0.750 0.0003805 .510 .0013585 .760 .0003545 ;520 .0013004 .770 .0003295 .530 .0012443 .780 .0003054 .540 .0011900 .790 .0002823

0.550 0.0011374 0.800 0.00025998 .560 .0010865 .810 .00023859 .570 .0010373 .820 .00021806 .580 .0009897 .830 .00019840 .590 .0009436 .840 .00017959

0.600 0.0008990 0.850 0.00016162 .610 .0008558 .860 .00014450 .620 .0008141 .870 .00012821 .630 .0007736 .880 .00011276 .640 .0007345 .890 .00009815

0.650 0.0006966 0.900 0.00008438 .660 .0006600 .910 .00007146 .670 .0006246 .920 .00005940 .680 .0005903 .930 .00004824 .690 .0005571 .940 .00003798

0.700 0.0005251 0.950 0.00002866 .710 .0004941 .960 .00002035 .720 .0004642 .970 .00001312 .730 .0004353 .980 .00000708 .740 .0004074 .990 .00000249 0.750 0.0003805 1.000 0 APPENDICES 643

Table C.2. Values of the parameter "f" for coils very close to- 2 gether: K "1. (From "Inductance calculations," 1946, 1973, Fre- derick W. Grover, published by the Instument Society of America under an arrangement with Dover Publications, Inc., New York. Tables used with permission of Dover Publications, Inc.)

6.0 0.079093 4.5 ~.042938 6.1 .077647 4.6 .041494 6.2 .076200 4.7 .040051 6.3 .074753 4.8 .038608 6.4 .073306 4.9 .037167

6.5 0.071860 3.0 0.035727 6.6 .070413 3.1 .034288 6.7 .068966 3.2 .032851 6.8 .067520 3.3 .031416 6.9 .066073 3.4 .029984

5.0 0.064626 3.5 0.028554 5.1 .063180 3.6 .027128 5.2 .061733 3.7 .025707 5.3 .060287 3.8 .024291 5.4 .058840 3.9 .022881

5.5 0.057394 2.0 0.021478 5.6 .055947 2.1 .020084 5.7 .054500 2.2 .018700 5.8 .053055 2.3 .017329 5.9 .051609 2.4 .015972

4.0 0.050163 2.5 0.014632 4.1 .048717 2.6 .013311 4.2 .047272 2.7 .012013 4.3 .045827 2.8 .010742 4.4 .044382 2.9 .009502 4.5 .042938 1.0 .008297 644 APPENDICES

Table C.3. Values of the parameter "f" for coils very far apart: 1(2 (1. (From "Inductance calculations," 1946, 1973, Frederick W. Grover, published by the Instrument Society of America under an arrangement with Dover Publications, Inc., New York. Tables used with the permission of Dover Publications, Inc.)

2 2 10g10( I( ) 10g1O(£) 10g10( I( ) 10g10(f)

4.0 9.39227 3.5 7.64327 '4.1 9.54228 3.6 7.79354 4.2 9.69229 3.7 7.94388 4.3 9.85230 3.8 6.09430 4.4 9.99232 3.9 6.24484

!.5 8.14234 2.0 6.39551 4.6 !.29237 2.1 6.54636 4.7 8.44240 2.2 6.69744 4.8 8.59244 2.3 6.84879 4.9 8.74250 2.4 5.00051

3.0 8.89257 2.5 5.15268 3.1 7.04265 2.6 5.30542 3.2 7.19276 2.7 5.45891 3.3 7.34289 2.8 5.61334 3.4 7.49306 2.9 5.76899 3.5 7.64327 1.0 5.92622 REFERENCES

Abildskov, J.A. 1975, The sequence of normal recovery of excitability in the dog heart, Circulation, 52:442-446. Abramowitz, M. and stegun, I.A. 1972, Handbook of Mathematical Functions, Dover Publications, New York. Addison, G.M., Beamish, M.R., Hales, C.N. et al. 1972, An immunora- diometric assay for ferritin in the serum of normal subjects and patients with iron deficiency and iron overload, J. Clin. Pathol. 25:326-329. Adey, W.R. and Bawin, S.M. 1974, Brain interactions with weak electric and magnetic fields, Neurosciences B!!. Prog., Bull. 15, No.1. Ahopelto, J., Hukkinen, K., Katila, T.E., Laine, H. and Kariniemi, V. 1975a, Detection of fetal QRS complexes by external methods, Ann. Chir. Gyn. ~. 64:152. Ahopelto, J., Karp, P.J., Katila, T.E., Lukander, R. and Makipaa, P. 1975b, An UHF SQUID gradiometer for biomagnetic measurements, in Low Temperature Physics - LT14, M. Krusius and M. Vuorio, eds., North Holland, Amsterdam, Vol. 4, pp. 262-265. Aittoniemi, K., Karp, P.J., Katila, T., Kuusela, M-L. and Varpula, T. 1978a, On balancing superconducting gradiometric magnetometers, ~. de Physique 39(C6):1223-1225. Aittoniemi, K., Katila, T., Kuusela, M-L. and Varpula, T., 1978b, On the evaluation of magnetic lung contamination, in ~. Third Natl. Meeting ~ Biophysics and Medical Engineering in Finland, Ch. A2. Aittoniemi, K., Katila, T., Kuusela, M-L. and Varpula, T. 1979, Magnetoretinography: Detection of the transient magnetic field of the eye, Proc. 12th IntI. Conf. on Medical and Biological Engineering, Jerusalem, Ch. 96.4. Aittoniemi, K., Hari, R., Jarvinen, M-L., Katila, T. and Varpula, T. 1981a, Localization of neural generators underlying auditory evoked magnetic fields of human brain, in Erne' et al. ( 1981a, pp. 415-422). Aittoniemi, K., Jarvinen, M-L., Katila, T., Maniewski, R. and varpula, T. 1981b, Magnetoretinogram and magneto-oculogram in man, in Erne' et al. (19Bla, pp. 463-472). Aittoniemi, K., Kalliomaki, K., Katila, T. and Varpula, T. 19B1c, Practical magnetopneumography using fluxgate magnetometers, in

645 646 REFERENCES Erne' et al. (1981a, pp. 475-484). Albert, R.E., Lippman, M. 1972, Factors influencing dust retention in the pulmonary parenchyma, ~. ~ York Acad. Sci. 200:37-47. Albrecht, G., Hiibert, A., Kirsch, G., Nowak, H., Vodel, W. and Zach, H.G. 1981, Application of flat dc-thin film SQUIDs and techniques for biomagnetic measurements, Cryogenics 21:607-608. Ammala, P. and Kariniemi, V. 1981, Short term variability of fetal heart rate in cholestasis of pregnancy, Am. ~. Obstet. Gynecol. 141:217. Arden, G.B. and Kelsey, J.H. 1962a, Brit. ~. Ophthal. 46:449. Arden, G.B. and Kelsey, J.H. 1962b, Changes produced by light in the scaning potential of the human eye, ~. Physiol. (London) 161:189. Arezzo, J. and vaughan, H.G. 1975, Cortical potentials associated with voluntary movements in the monkey, Brain Res. 88:99-104. Arezzo, J., Vaughan, H.G., Jr. and Koss, B. 1977, Relationship of neuronal activity to gross movement-related potentials in monkey pre- and postcentral cortex, Brain Research 132:362-369. Arezzo, J. and vaughan, H.G., Jr. 1980, Intracortical sources and surface topography of the motor potential and somatosensory evoked potential in the monkey, Progress in Brain Research 54:77-83. Awano, I., Muramoto, A., Awano, N., Koja, S. 1978, Low Temperature Med. 4:89-100 (In Japanese). Bak, C., Kofoed, B., Lebech, J., Saermark, K. and Elberling, C. 1981, Auditory evoked magnetic fields from the human brain: Source localization in a single-dipole approximation, Phys. Lett. 82A:57-60. Baker, R.R., Mather, J.G. and Kennaugh, J.H. 1982, The human compass?, Trans. ~. Geoph. Union (EfBS) 63:156. Ba1kwi11, D.L., Maratea, D. and Blakemore, R.P. 1980, Ultrastruc- ture of a magnetotactic spirillum,~. Bacteriology 141:1399- 1408. Barach, J.P., Freeman, J.A. and Wikswo, J.P., Jr. 1980, Experiments on the magnetic field of nerve action potentials, ~. of ~. Phys. 51:4532-4538. Barbanera, S., Carelli, P., Leoni, R., Romani, G.L., Bordoni, F., Modena, I., Fenici, R.R. and zeppilli, P. 1981a, Biomagnetic measurements in unShielded, normally noisy environments, in Erne' et al. (l98la, pp. 139-149). Barbanera, S., Carelli, P., Leoni, R., Romani, G.L., Bordoni, F., Modena, I., Fenici, R.R. and Zeppilli, P. 1981b, Magnetocardio- graphic study of some human cardiac electrophysiological phenomena: Preliminary observation, in Erne' et al. (1981a, pp. 283-290) . Barbanera, 5., Carelli, P., Fenici, R.R., Leoni, R., Modena, I. and Romani, G.L. 1981c, Use of a superconducting instrumentation for biomagnetic measurements performed in a hospital, IEEE Trans. Magn. MAG-17:849-852. Bardeen, J., Cooper, L.N., Schrieffer, J.R. 1957, Theory of super- REFERENCES 647

conductivity, Phys. Rev., 108:1175-1204. Barlow, H.B. 1972, Single units and sensation: A neuron doctrine for perceptual psychology?, Perception 1:371-394. Barlow, H.B., Blakemore, C. and pettigrew, J.D. 1967, The neural mechanism of binocular depth discrimination. J. Physiol. 193:327-42. Barlow, H.B. and Levick, W.R. 1969, Changes in the maintained discharge with adaptation level in the cat retina, ~. Physiol. 202:699-718. Barlow, H.B., Levick, W.R. and Yoon, M. 1971, Responses to single quanta of light in retinal ganglion cells of the cat, Vision Res. Supplement No. 3:87-101. Barnard, A.C.L., Duck, I.M., Lynn, M.S. and Timlake, W.P. 1967, The application of electromagnetic theory to electrocardiology: II Numerical solution of the integral equations, Biofys.~. 7:463- 491. Barnard, A.C.L., Holt, J.R., Jr. and Kramer, J.O .., Jr. 1976, Models and methods in inverse electrocardiology: The UAB choice, in The Theoretical Basis of Electrocardiology, C.V. Nelson and D.B. Ge- selowitz, eds., Clarendon Press, Oxford, pp. 305-322. Barr, R.C. and Spach, M.S. 1976, Inverse solutions directly in terms of potentials, in The Theoretical Basis of Electrocardiology, C.V. Nelson and D.B. Geselowitz, eds., Clar- endon Press, Oxford, pp. 294-304. Barry, W.H., Fairbank, W.M., Harrison, D.C., Lehrman, K.L., Malmi- vuo, J.A.V. and Wikswo, J.P., Jr. 1977, Measurement of the human magnetic heart vector, Science 198:1159-62. Barth, D.S., Sutherling, W., Engel, J. ,Jr. and Beatty, J. 1982, Neuromagnetic localization of epileptiform spike activity in the human brain, Science 218:891-894. Bastuscheck, C.M., Brenner, D., Williamson, S.J. and Kaufman, L. 1981a, Susceptometer for in vivo measurement of iron stored in human tissue, in Erne' et al. (1981a, pp. 519-532). Bastuscheck, C.M. and Williamson, S.J. 1981b, AC susceptibility measurements with a biomedical SQUID system, Physics 107B:27-28. Baule, G.M. 1963, Detection of the magnetic field of the heart, Ph.D. thesis, Department of Electrical Engineering, Syracuse Un- iversity. Baule, G.M. 1965, Instrumentation for measuring the heart's magnetic field, Trans. ~.!. Acad. of Sciences Ser. II 27:689-700. Baule, G.M. 1974, Some considerations for magnetic lead systems, Adv. Cardiol. 10:304-310. Baule, G.M. and McFee, R. 1963, Detection of the magnetic field of the heart, Am. Heart ~. 66:95-96. Baule, G.M. and McFee, R. 1965, Theory of magnetic detection of the heart's electrical activity, ~. ~. Phys. 36:2066-2073. Baule, G.M. and MCFee, R. 1970, The magnetic heart vector, Am. Heart J. 79:223-236. Bauman, J.H. and Harris, J.W. 1967a, Estimation of hepatic iron stores by in vivo measurement of magnetic susceptibility, ~. 648 REFERENCES

Lab. Clin. Med. 70:246-257. Bauman, --J.H. and-- Hoffman, R.W. 1967b, Magnetic susceptibility meter for in vivo estimation of hepatic iron stores, IEEE Trans. Biomed. Eng. BME-14:239~243 Bayes, A. and Cosin, J. (eds.) 1978, Diagnostico Z Tratamiento de las Arritmias cardiacas, Ediciones Doima, S.A., Barcelona, Spain. Baylor, D.A. and Fuortes, M.G.F. 1970, Electrical responses of single cones in the retina of the turtle, ~. Phzsiol. 207:77-92. Benett, W.R. 1948, spectra of quantized signals, Bell szstem Techn. J. 27:446-472. Berbari, E.J., Lazzara, R., samet, P., Sherlag, B.J. 1973, Noninva- sive technique for detection of electrical activity during the PR segment, Circulation 48:1005-1013. Bercy, C., Duret, D., Karp, P. and Teszner, D. 1981, Installation of a biomagnetic measurement facility in a hospital environment, in Erne' et al. (1981a, pp. 95-106). Berger, H. 1929, On the electroencephalogram of man, Archiv. fUr pszchiatrie und Nervenkrankheiten 87:527. Blakemore, R.P. 1975, Magnetotactic bacteria, Science 190:377-379. Blakemore, c. and Campbell, F.W. 1969, On the existence of neurons in the h~man visual system selectively sensitive to the orientation and size of the retinal images. ~. Physiol. 203:237-60. Blakemore, R.P., Maratea, D. and Wolfe, R.S. 1979, Isolation and pure culture of a freshwater magnetic spirillum in chemically defined medium, ~. Bacteriology 140:720-729. Blakemore, R.P., Frankel, R.B. and Kalmijn, A.J. 1980, south-seeking magnetotactic bacteria in the southern hemisphere, Nature 286:384-385. Blakemore, R.P. and Frankel, R.B. 1981, Magnetic navigation in bacteria, Scientific Am. 245:58-65. Bleaney, B.I. and Bleaney, B. 1976, Electricitz and Magnetism, 3rd edition, Oxford University Press, London. Blinkov, S.M. and Glezer, 1.1., 1968, The Human Brain in Figures and Tables: ! Quantitative Handbook, Plenum Press, New York. Bodis-Wollner, I., ed. 1982, Evoked Potentials, Annals !.!. Acad. of Sciences 388. Boismier, G., Hlatky, L. and Tepley, N. 1979, Magnetocardiography in weak dc ambient magnetic fields, ~. ~. Phys. 50:2490-2493. Bolte, A. 1969, Die pranatale fetale Elektrokardiographie, Gynakologe 2:63. Boring, E.G. 1933, The Phzsical Dimensions of Consciousness, centu- ry, New York. Brain, J.D., valberg, P.A. 1979, Deposition of aerosol in the respiratory tract, Am. Rev. Resp. Dis. 120:1325-1373. Braun, v., Hornback, V., Hopp, H.W., Behrenbeck, D.W., Tauchert, M. and Hilger, H.H. 1981, Preatrial activity recorded from intracardiac and surface leads by signal averaging, Intl. Symposium ~ the Signal Averaging Technique in Clinical cardiology, Col- ogne. REFERENCES 649

Breitmeyer, B. 1975, Simple reaction time as a measure of the temporal response properties of transient and sustained channels, Vision Res. 15:1411-1412. Brenner, D., Williamson, S.J. and Kaufman, L. 1975a, Visually evoked magnetic fields of the human brain, Science 190:480. Brenner, D., Williamson, S.J. and Kaufman, L. 1975b, SQUID system for detecting evoked magnetic fields of the human brain, in Low Temperature Physics-LT14, M. Krusius and M. Vuorio, eds., North Holland, Amsterdam, Vol. 4, pp. 266-269. Brenner, D., Kaufman, L. and Williamson, S.J. 1977, Application of a SQUID for monitoring magnetic response of the human brain, IEEE Trans. Magn. MAG-13:365-368. Brenner, D., Lipton, J., Kaufman, L. and Williamson, S.J. 1978, So- matically evoked magnetic fields of the human brain, Science 199:81-83. Brenner, D., Okada, Y., Maclin, E., Williamson, S. J . and Kaufman, L. 1981, Evoked magnetic fields reveal different visual areas in human cortex, in Erne' et al. (1981a, pp. 431-444). Brigham, E.O. 1974, The Fast Fourier Transform, Prentice-Hall Inc., Englewood Cliffs. Brittenham, G.M., Danish, E.H. and Harris, J.W. 1981, Assessment of bone marrow an~body iron stores: Old techniques and new tech- nologies, Seminars in Hematology 18:194-221. Brittenham, G.M., Farrell, D.E., Harris, J.W., Feldman, E.S., Dan- ish, E.H., Muir, W.A., Tripp, J.H., Brennan, J.N. and Bellon, E.N. 1982, MagnetiC susceptibility measurement of human iron stores, submitted for publication. Brodal, A. 1981, Neurological Anatomy, Oxford University Press, 3rd edition, New York. Brown, R.C., Chamberlain, M., Davies, R., Cormley, I.P. (eds.) 1980, The In Vitro Effects of Mineral Dusts, Academic Press, London, pp. 272-315. Brown, W.F. 1962, Magnetostatic principle~ in ferromagnetism, in Selected Topics in Solid State Physics Volume 1, E.P. Wohlfarth, ed., North-Holland, Amsterdam. Butler, R.F. and Banerjee, S.K. 1975, Theoretical single-domain grain size range in magnetite and titanomagnetite, ~. Geophys. Res. 80:4049-4058. campbell, F.W. and Maffei, L. 1970, Electrophysiological evidence for the existence of orientation and size detectors in the human visual system, ~. Physiol. 207:635-652. campbell, F.W. and Kulikowski, J.J. 1972, The visual evoked potential as a function of contrast of a g~ating pattern, ~. Physiol. 222:345-356. Carbonin, P.U., Di Gennaro, M., Furlanello, F. 1980, Variant Angina and reperfusion ventricular tachyarrhythmias, Circulation 62:1389. Carbonin, P.U., Di Gennaro, M., Valle, R. et al. 1981, Inhibitory effect of anoxia on reperfusion - and digitalis - introduced ventricular tachyarrhythmias, Am. ~. Physiol. 240:H730. 650 REFERENCES carbonin, P.U., Bernabei, R., Cocchi, A. and Di Gennaro, M. 1982, L'invecchiamento Fisiologico del Cuore, Schiapparelli S.P.A., Torino, p. 52. Carmeliet, E. and Vereecke, J. 1979, Electrogenesis of the action potential and automaticity, in Handbook of Physiology part II, Cardiovascular System, Volume !: The Heart, R.M. Berne and N. Sperelakis, eds., Am. Physiol. Soc., Bethesda, pp. 269-334. Casella, C. 1980, Principi di Fisiologia, La Goliardica pavese, Pavia, Italy. Chiyotani, K., Saito, K., Kotani, M., Uchikawa, Y. and Turukawa, H. 1981, Measurement of lung's magnetic field in workers of steel- work, XX Intl. Congress of Occup. Health, Cairo, pp. 538. Cisowski, S. 1981, Interacting vs. non-interacting single domain behavior in natural and synthetic samples, Phys. Earth. Plan. Int. 26:56-62. Clark, J.W., Greco, E.C. and Harman, T.L. 1978, Experience with a Fourier method for determing the extracellular potential field of excitable cells with external geometry, CRC Critical Reviews in Bioeng. 3:1-22. Clarke, J. 1974, Josephson junction detectors, Science 184:1235- 1242. Clarke, J. 1977, Superconducting quantum interference devices for low frequency measurements, in supercond'uctor Applications: SQUID'S and Machines, B.B. Schwarz and S. Foner, eds. , Plenum Press, New York, pp. 67-124. Clarke, J. 1980, Fluctuations analySiS, in SQUID '80: Superconducting Quantum Interference Devices and Their Applications, 8-D. Hahlbohm and H. LUbbig, eds., Walter de Gruy- ter, Berlin, pp. 187-205. Clarke, J., Goubau, W.M. and Ketchen, M.B. 1975, Thin-film dc SQUID with low noise and drift, ~. Phys. Lett. 27:155. Clave, c. 1977, Le magnetocardiogramme du sujet normal, These Docteur en Medecine, Universite' Scientifique et Medicale de Grenoble. cohen, D. 1967a, A shielded facility for low-level magnetic measurements, ~. ~. Phys. 38:1295-1296. Cohen, D. 1967b, MagnetiC fields around the torso: Production by electrical activity of the human heart, Science 156:652-654. Cohen, D. 1967c, Enhancement of ferromagnetic shielding against low-frequency magnetic fields, ~. Phys. Lett. 27:67-69. Cohen, D. 1968, Magnetoencepha10graphy: evidence of magnetic fields produced by alpha rhythm currents, Science 161:784-786. Cohen, D. 1969, Detection and analysis of magnetic fields produced by bioelectric currents in humans, ~. ~. Phys. 40:1046-1048. Cohen, D. 1970a, Review of measurements of magnetic fields produced by natural ion currents in humans, IEEE Trans. Magn. MAG-6:344- 345. Cohen, D. 1970b, Large-volume conventional magnetic shields, Rev. de Physique~. 5:53-58. Cohen, D. 1972, Magnetoencephalography: detection of the brain's REFERENCES 651

electrical activity with a superconducting magnetometer, Science 175:664-666. Cohen, D. 1973, Ferromagnetic contamination in the lungs and other organs of the human body, Science 180:745-748. Cohen D. 1975a, Measurements of the magnetic fields produced by the human heart, brain, and lungs, IEEE Trans. Magn. MAG 11:694-700. Cohen, D. 1975b, Magnetic fields of the human body, Physics Today 28:34-43. Cohen, D., ed. 1976, Report of the low-field group: the magnetocardiogram, Publication MIT/FBNML-76/1, National T~chnical Informa- tion Service, Springfield, VA, 22161. Cohen, D., ed. 1978, Report of the low-field group: The magnetic field of the lung, Publication MIT/FBNML-78/1, National Techni- cal Information Service, Springfield, VA, 22161. Cohen, D. 1979a, Magnetic measurement and display of current generators in the brain: part I. The 2-D detector, Digest of 12th IntI. Conf. ~ Medical and Biological Engineering (Jerusalem) Beilinson Medical Center, Petah Tikva, Israel. Cohen, D. 1979b, Magnetic measurement and display of current generators in the brain: Part II. Polarization of the alpha rhythm, Digest of 12th IntI. Conf. on Medical and Biological Engi- neering, (Jerusalem) Beilinson Medical Center, Petah Tikva, Israel. Cohen, D. and Chandler, L. 1969, Measurements and a simplified interpretation of magnetocardiograms from humans, Circulation 39:395-402. Cohen, D., Edelsack, E.A. and Zimmerman, J.E. 1970, Magnetocardio- grams taken inside a shielded room with a superconducting point- contact magnetometer, ~. Phys. Lett. 16:278-280. Cohen, D. and Hood, W.B. 1971a, Magnetocardiography, Arch. of Surg. 103:429. Cohen, D., Norman, F., Molokhia, F. and Hood, w. 1971b, Magnetocar- diography of direct currents: S-T segment and baseline shifts during experimental myocardial infarction, Science 172:1329- 1333. Cohen, D. and Givler, E. 1972a, Magnetomyography: Magnetic fields around the human body produced by skeletal muscles, ~. Phys. Lett. 21:114-116. Cohen, D. and Mccaughan, D. 1972b, Magnetocardiograms and their variation over the chest in normal subjects, Am. J. cardiol. 29:678-685. Cohen, D. and Kaufman, L.A. 1975, Magnetic determination of the relationship between the S-T segment shift and the injury current produced by coronary artery occlusion, Circulation Research 36:414-424. Cohen, D. and MacArthur, J. 1976a, Magnetocardiograms from an insu- lated in vivo canine heart, in Cohen (1976, pp. 117-122). Cohen D. and Hosaka, H. 1976b, Magnetic field produced by a current dipole, ~. Electrocardiol. 9:409-417. Cohen D., Lepeschkin, E., Hosaka, H., Massell, B.F. and Myers, G. 652 REFERENCES

1976C, Abnormal patterns and physiological variations in magnetocardiograms, ~. Electrocardiology 9:398-409. Cohen, D., Arai, S.F. and Brain, J.D. 1979, Smoking impairs long- term dust clearance from the lungs, Science 204:514-517. Cohen, D., palti, Y., Cuffin, B.N. and Schmid, S.J. 1980, Magnetic fields produced by steady currents in the body, Proc. Natl. Acad. sci, U.S.A. 77:1447-1451. Cohen, D., Crowther, T., Gibbs, G. and Becklake, M. 1981, Magnetic lung measurements in relation to occupational exposure in asbestos miners and millers of Quebec, Environ. Res. 26:535-550. Cohen, D. and Nemoto, I. 1983a, Ferrimagnetic particles in the lung: Part I. The magnetizing process, IEEE Trans. Biomed. Eng., in press. Cohen, D., Nemoto, I., Kaufman, L.A. and Arai, S. 1983b, Ferrimag- netic particles in the lung: Part II. The relaxation process, IEEE Trans. Biomed. Eng., in press. Cohen, D. and Cuffin, B.N. 1983c, Demonstration of useful differences between magnetoencephalogram and electroencephalogram, Electroenceph. Clin. Neurophysiol., in press. Cohen, D., Savard, P., Rifkin, R.D. and Strauss, W.E. 1983d, Mag- netic measurements of ST and TQ segment shifts in humans: Part II. Exercise-induced ST segment depression, in press. Cole, K.S. 1968, Membranes, Ions and Impulses, University of Cali- fornia Press, Berkley, pp. 142-143. Colli-Franzone, P., Guerri, L., Taccardi, B. and viganotti, c. 1982a, The inverse potential problem applied to the human case, in Models and Measurements of the Cardiac Electric Field, E. Schubert, ed., Plenum Press, New York, pp. 19-33. Colli-Franzone, P., Guerri, L., Viganotti, C., Macchi, E., Baruffi, S., spaggiari, S. and Taccardi, B. 1982b, Potential fields generated by oblique dipole layers modeling excitation wave fronts in the anisotropic myocardium, Circ. !!!. 51:330-346. Cook, A.M. and Long, F.M. 1970, Magnetic fields associated with nervous conduction, in The Nervous System and Electric Currents, N.L. wulfsohn and A. Sances, Jr., eds., Plenum, New York, pp. 9- 13. Cooley, J.W. and Tukey, J.W. 1965, An algorithm for the machine calculation of complex Fourier series, Math. Compo 19:297-301. Cooper, L.N. 1956, Bound electron pairs in a degenerate fermi gas, Phys. Rev. 104:1189. Coraboeuf, E. 1960, Aspects of cellulaires de l'electrogenese cardiaque chez las vertebres, ~. Physiol., Paris 52:363. Coraboeuf, E. 1978, Electrofisiologia de la cellula cardiaca, Diagnostico ~ Tratamiento de las Arritmias Cardiacas, A. Bayes and J. Cosin, eds., Ediciones Doima, S.A., Barcelona. Corbin, L.V., III and Scher, A.M. 1977, The canine heart as an electrocardiographic generator: Dependence on cardiac cell orientation, Circ. Res. 41:58-67. Cowey, A. 1979, cortical maps and visual perception, Quart. J. ~. Psychol. 31:1-17. REFERENCES 653

Cowey, A. and Rolls, E.T. 1974, Human cortical magnification factor and its relation to visual acuity, ~. Brain Res. 21:447-454. cowey, A. and perry, V.H. 1980, The projection of the fovea to the superior colliculus in rhesus monkeys, Neuroscience 5:53-62. Cowmel, P., Flammang, D. and Attuel, P. 1978, Intraatrial reentry tachycarcia, The cardiac Arrhythmias, P. Puech and R. Slama, eds., Roussel-Uclaf, Cinton-Vanves, France, p. 108. Cragg, B.G. 1967, The density of synapses and neurons in the motor and visual areas of the cerebral cortex, ~. Anat. 101:639-654. Cranefield, P.F. 1975, The Conduction of the Cardiac Impulse, Futu- ra Publishing , New York. Cranefield, P.F. 1977, Action potentials, amplitudes and arrhythmias, Circ. Res. 41:415-423. Cranefield, P.F. and Hoffman, B.F. 1958, Electrophysiology of single cardiac cells, Physiol. Rev. 38:41. Cranefield, P.F., Wit, A.L. and Hoffman, B.P. 1972, Conduction of the cardiac impulse: III Characteristics of very slow conduction, ~. Gen. Physiol. 59:277. Creutzfeldt, 0.0., Watanabe, S. and Lux, H.D. 1966a, Relations between EEG phenomena and potentials of single cortical cells: I. Evoked responses after thalaamic and epicortical stimulation, Electroenceph Clin. Neurophysiol. 20:1-18. Creutzfeldt, 0.0. Watanabe, S. and Lux, H.D. 1966b, Relations between EEG phenomena and potentials of Single cortical cells: II. Spontaneous and convulsoid activity, Electroenceph. Clin. Neurophysiol. 20:19-37. Creutzfeldt, 0.0. and Houchin, J. 1974, Neuronal basis of EEG waves, in Handbook of Electroenceph. Clin. Neurophysiol., A. Redmond, ed., Elsevier, Amsterdam, 2C:5-55. Cromar, M.W. and carelli, P. 1981, Low-noise tunnel junction dc SQUIDs, ~. Phys. Lett. 38:723. Crownfield, F.R., Jr. 1964, Optimum spacing in coil pairs, Rev. Sci. Instrum. 35:240. Cuffin, B.N. 1974, Model Studies of Electrocardiograms and Magneto- cardiograms Using Realistic Torso Boundaries, Ph.D. thesis, The pennsylvania State University. Cuffin, B.N. 1978, On the use of electric and magnetic data to de- termine electrical sources in a volume conductor, Annals of Biomed. Eng. 6:173-193. Cuffin, B.N. 1981a, The effects of torso geometry on magnetocardiographic lead fields, IEEE~. Biomed. Eng. BME-28:741-749. Cuffin, B.N. 1981b, Effects of modeling errors on least squares error solutions to the inverse problem of electrocardiology, Annals Biomed. Eng. 9:364-382. Cuffin, B.N. 1982, Effects of inhomogeneous regions on electric potentials and magnetic fields, ~. ~. Phys., in press. Cuffin, B.N. and Cohen, D. 1977a, MagnetiC fields produced by models of biological current sources, ~. ~. Phys. 48:3971-3980. Cuffin, B.N. and Cohen, D. 1977b, MagnetiC fields of a dipole in special volume conductor shapes, IEEE Trans. Biomed. Eng. BME- 654 REFERENCES

24: 372-381. Cuffin, B.N. and Gese10witz, D.B. 1977, computer model studies of the magnetocardiogram, ~. Biomed. Eng. 5:164-178. Cuffin, B.N. and Cohen, D. 1979, Comparison of the magnetoencepha1- ogram and electroencephalogram, E1ectroenceph. C1in. Neurophys- io1. 47:132-146. Dahn, D.C. 1980, Detection of Ferromagnetic Dust in the Human Lung, Dalhousie University, March 1980, p. 125. Darcy, T.M., Ary, J.P. and Fender, D.H. 1980a, Methods for the localization of electrical sources in the human brain, Progress in Brain Research 54:128-134. Darcy, T.M., Ary, J.P. and Fender, D.H. 1980b, Spatio-tempora1 visually evoked scalp patterns in response to partial-field pat- terned stimulations, Electroenceph. Clin. Neurophysio1. 50:348- 355. de Mello, W.C. 1972, Electrical Phenomena in the Heart, Academic Press, New York. de Monasterio, F.M. and Gouras, P. 1975, Functional properties of ganglion cells of the rhesus monkey retina, ~. Physio1. 251:167- 195. de Weerd, J.P.C. and Martens, W.L.J. 1978, Theory and practice of a posterior "Wiener" filtering of average evoked potentials, Biol. Cybernetics 30:81-94. Deck, K.A., Kern, R. and Trautwein, W. 1964, voltage clamps technique in mammalian cardiac fibers, Pf1ugers Arch. 280:50. Deecke, L., Scheid, P. and Kornhuber, H.H. 1969, Distribution of readiness potential, pre-motion positivity, and motor potential of the human cerebral cortex preceding voluntary finger movements, Exp. Brain Res. 7:158-168. Deecke, L., Grozinger, B. and Kornhuber, H.H. 1976, Voluntary finger movement in man: Cerebral potentials and theory, Biological Cybernetics 23:99-119. Deecke, L., EiSinger, H. and Kornhuber, H.H. 1980, Comparison of bereitschaftspotential, pre-motion positivity, and motor potential preceding voluntary flexion and extension movements in man. Progress in Brain Research 54:171-176. Delmas, A. and Petuiset, D. 1959, cranio-cerebra1 Topometry in Man, C.C. Thomas, springfield, Illinois. Demit rack, A. 1981, A search for bacterial magnetite in the sedi- ments of a freshwater marsh, Trans. Am. Geoph. Union (E.S) 62:850. Denham, C.R., Blakemore, R.P. and Frankel, R.B. 1980, IEEE Trans. Magn. MAG-16:1006. Denis, B., RoSSignol, B., Favier, C., Le1as, J.F. and Martin-Noel, P. 1972, Enregestrement du champ magnetique cardiaque: considerations techniques, Lyon Med. 228:13-18. DeniS, B., Favier, C. and Mate1in, D. 1974, Magnetocardiographe a bobines, ~. de Physiologie de ~, 69:179-190A. Denis, B., Matelin, D., Favier, C., Tanche, M. , Martin-Neel, P. 1976, L'enregistrement du champ magn6tique cardiaque: Consider- REFERENCES 655

ations techniques et premiers resultats en milieu hospitalier, Arch. Mal. Coeur 69(3):299-304. Denis, B., Machecourt, J., Favier, C. and Martin-Neel, P. 1978, In- terpr~tation du magn~tocardiogramme normal et pathologie a partier de 140 cartographies thoraciques, Ann, Cardiol. Angelol. 27:81-86. Denny-Brown, D. and Chambers, R.A. 1958, The parietal lobe and behavior, Res. Pub. Assoc. Res. Nerv. Ment. Dis. 36:35. Desmedt, J.F. (Ed.) 1977, Visual Evoked Potentials in Man: New Developments, Oxford, Clarendon Press, New York. Dobreva, M., Burilkov, T., Kolev, K. and Lalova, P. 1977., Charac- teristics of lung dusts and their relationship dust exposure and pathological findings in the lungs, in Inhaled Particles IV: Part ~, Pergamon Press, Oxford, pp. 717-725. Donald, M.W. 1976, Topography of evoked potential amplitude fluctuations, in The Responsive Brain, W.C. McCallum and J.R. Knott, eds., J. Wright and Sons, Ltd., Bristol. Donchin, E. 1981, Presidential Address, 1980: Surprise I Sur- prise?, psychophysiology, 18:493-512. Donchin, E., Ritter, W. and McCallum, W.C. 1978, Cognitive cycle Physiology: the Endogenous Components of the ERP, in Event- Related Brain Potentials in Man, E. Callaway, P. Tueting and S.H. Koslow, eds., Academic Press, New York, pp. 349-412. Dreher, B., Fukada, Y. and Rodieck, R.W. 1976, Identification, classification and anatomical segregation of cells with X-like and Y-like properties in the lateral geniculate nucleus of old- world primates, i!.. Physiol. 258: 433-452. DuBois-Reymond, E. H. 1849, in untersuchungen Uber tierische Elektrizitat, Berlin. Duncan-Johnson, C.C. and Donchin, E. 1977, On quantifying surprise: The variation in event-related potentials with subjective proba- bility, psychophysiology 14:456-467. Dunlop, D.J., Hanes, J.A. and Buchan, K.L. 1973, Indices of multidomain magnetic behavior in basic igneous rocks: alternating field demagnetization, hysteresis and oxide petrology, ~. Geoph. Res. 78:1387-i393. Duret, D., Bernard, P. and Zenatti, D. 1975, A uhf superconducting magnetometer utilizing a new thin film sensor, Rev. Sci. Instrum. 46:474-480. Durrer, D., van Dam, R.T., Freud, G.E., Janse, M.J., Meijler, F.L. and Arzbaecher, R.C. 1970, Total excitation of the isolated human heart, Circulation 41:899-912. Edelberg, R. 1972, Electrical activity of the skin, in Handbook of psychophysiology, N.S. Greenfield and R.A. sternbaCh, eds., Holt, Rinehart and Winston, pp. 367-417. Eghrari, I.R., von der Weld, J.P., costa Ribeiro, P. and Symko, O. 1981, On the recording of phase and amplitude relationships between electrical and magnetic cardiac events, in Erne' et al. (1981a, pp. 303-308). Ehnholm, G.J., Ilmoniemi, R.J. and wiik, T.O. 1981, A seven channel 656 REFERENCES

SQUID magnetometer for brain research, Physics 107B:29-30. ETher ling, C., Bak, C., Kofoed, B., Lebech, J. and Saermark, K. 1980, Magnetic auditory responses from the human brain. A preliminary report, Scand. AudioI. 9:185-190. Elberling, C., Bak, C., Kofoed, B., Lebech, J. and Saermark, K. 1981, Auditory magnetic fields from the human cortex: Influence of Stimulus Intensity, Scand. Audiol., 10:203. ETher ling, C., Bak, C., Kofoed, B., Lebech, J. and Saermark, K. 1982a, Auditory magnetic fields from the human cerebral cortex: Location and strength of an equivalent current dipole, Acta Neurol. Scandinav. 65:553-569. Elberling, C., Bak, C., Kofoed, B., Lebech, J. and Saermark, K. 1982b, Auditory magnetic fields: Source location and "tonotopi- cal organization" in the right hemisphere of the human brain, Scand. Audiol. 11:61-65. Enroth-cugell, C. and Robson, J.G. 1966, The contrast sensitivity of retinal ganglion cells of the cat, ~. Physiol. 187:517-552. Erne', S.N., Hahlbohm, H-D. and LObbig, H., eds. 1981a, Biomag- netism, Walter de Gruyter, Berlin. Erne', S. N., Hahlbohm, H-D., Scheer, H., Trontelj, Z. 1981b, The Berlin magnetically shielded room (BMSR) section B: Perfor- mances, in Erne' et al. (1981a, pp. 79-87). Erne', S. N., Fenici, R. R., Hahlbohm, H-D., Lehmann, H. P. and Tron- telj, Z. 1982a, Beat to beat surface recording versus averaging of His-Purkinje activity in man, 9th IntI. Congo on Electrocardiology, Tokyo (abstract No. 149). Erne', S.N., Fenici, R.R., Hahlbohm, H-D., Lehmann, H.P., Leitner, E.R.V. and Oeff, M. 1982b, Beat to beat surface recording of electrical late potentials in man, 9th IntI. Cong. on Electrocardiology, Tokyo (abstract No. 176). Erne', S.N., Fenici, R.R., Hahlbohm, H-D., Lehmann, H.P. and Tron- telj, Z. 1982c, High resolution magnetocardiography: Recording of His-Purkinje activity in man, 9th IntI. Cong. on Electrocardiology, Tokyo (abstract No. 32). Erne', S.N., Fenici, R.R., Hahlbohm, H-D., Lehmann, H.P., Trontelj, Z., 1982d, Beat to beat surface recording of His-Purkinje activity in man, ~. of Electrocardiology. Farrell, D.E., Tripp, J.H. and Norgren, R. 1978a, Non-invasive information on the PR segment of the cardiac cycle: An assessment of the clinical potential of the electric and magnetic methods, Proc. SPIE 167:173-177. Farrell, D.E., Messer, M.J., Tripp, J.H., Brittenham, G.M., Danish, E.H. and Muir, W.A. 1978b, Assessment of human iron stores by magnetic susceptibility measurements, Clin. Res. 26:504A. Farrell, D.E., Tripp, J.H. and Norgren, R. 1980a, Magnetic study of the His-Purkinje conduction system in man, IEEE ~. Biomed. Eng. BME-27:345-350. Farrell, D.E., Tripp, J.H., Zanzucchi, P.E., Harris, J.W., Britten- ham, G. and Muir, W.A. 1980b, Magnetic measurement of human iron stores, IEEE Trans. Mag. MAG-16:818-823. REFERENCES 657

Farrell, D.E., Tripp, J.H., Nogren, R. and Teyler, T.J. 1980C, A study of the auditory evoked field of the human brain, Electroenceph. Clin. Neurophysiol. 49:31-37. Farrell, D.E., Tripp, J.H. and VanDoren, C.L. 1981a, High resolution cardiomagnetism, in Erne' et al. (1981a, pp. 273-282). Farrell, D.E., Tripp, J.H., Patrick, J. and Hess, D. 1981b, Tran- sient evoked responses: Some comments on the use of magnetic recording, in Erne' et al. (1981a, pp. 403-413). Farrell, D.E., Tripp, J.H., Zanzucchi, P.E., Harris, J.H., Britten- ham, G.M. and Muir, W.A. 1981c, Non-invasive SQUID diagnosis of liver iron overload, in Erne' et al. (1981a, pp. 507-518). Farrell, D.E., Tripp, J.H., Zanzucchi, P.E., Harris, J.H., Britten- ham, G.M., Bellon, E.M. and Muir, W.A. 1981d, An application of superconductivity to medical diagnostics, ~. Phys. Commun. 1:1-7. Farrell, D.E. and Zanzucchi, P.E. 1982, SQUID biomagnetic instrumentation, CRC Critical Reviews in Solid state Physics, in press.

Fenici, R.R., Marcheil M., Bellocci, F. and Zecchi, P. 1977, Effect on bunaphtine on right atrial repolarization in man, Brit. Heart J. 38:787-794. Fenici, R.R., Bel10cci, F., Marchei, M., Gabrielli, L., Zecchi, P. and Zeppilli, P. 1980a, Tecniche di rilevamento e di calcolo e risultati della registrazione esterna del potenziale del fascio di His, Min. Med. 71, p. 3329. Fenici, R.R., Romani, G.L., Barbanera, S., Zeppilli, P., Carelli, P. and Modena, I. 1980b, High resolution magnetocardiography: Non-invasive investigation of His-Purkinje system activity in man, Q. Ital. Cardiol. 10:1366-1372. Fenici, R.R., Masselli, M., Zeppilli, P. and Pirrami, M.M. 1981, Clinical recordings of monophasic action potentials: Demonstra- tion of intraatrial conduction block in the sinus node region and possible role in reentrant supraventricular tachycardia, Am. Heart ~. 102(1):124-128. Fenici, R.R., Erne', S.N., Hahlbohm, H-D., Masselli, M., Modena, J. and Romani, G.L. 1982a, Computer analysis of high resolution magnetocardiographic signals: A new method for non-invasive electrophysiological investigation in man, 5th Seminario Inter- nazionale di Cardiologia, Trento, to be published in Le Nuove Frontiere delle Aritmie, Piccin, Padova. Fenici, R.R., Romani, G.L., Leoni, R., Masselli, M. and Modena, I. 1982b, Magnetocardiographic recording of the His Purkinje system in man, 9th IntI. Cong. of Electrocardiology, Tokyo (abstract No. 34). Ferrara, E.R. and Widrow, B. 1982, Fetal electrocardiogram enhancement by time-sequenced adaptive filtering, IEEE Trans. Biomed. Eng. BME 29:458-460. Ferrier, G.R. 1977, Digitalis arrhythmias: Role of oscillatory after potentials, Progr. cardiovasc. Dis. 19:459-474. Fishman, H.M. 1964, A study of the induced magnetic field during 658 REFERENCES

impulse propagation along nerve fibers, M.S. thesis, Department of Electrical Engineering, University of California, Berkley. Flowers, N.C., Hand, R.C., Orander, P.C., Miller, C.B., Walden, M.O. and Horan, L.G. 1974, Surface recording of electrical activity from the region of the bundle of His, Am. ~. of Cardiol. 32:384-389. Flowers, N.C., Schvartsman, V., Kennelly, B.M., Sohi, G.S. and Horan, L.G. 1981, Surface recording of His-Purkinje activity on an every-beat basis without digital averaging, Circulation 63:948-952. Fontaine, G., Guirardon, G. and Frank, R. 1976, Epicardial mapping and surgical treatment in 6 cases of resistant ventricular tachycardia not related to coronary heart disease, Conduction System of the Heart, H.J.J. Wellens, K.I. Lie and M.J. Janse, eds., stenfert Kroese B.V. Pub., Leiden, p. 545. Fontaine, G., Guirardon, G., Frank, R., Vedel, J., Grosgogeat, Y. and Cabrol, C. 1978, The value of electrocardiological investigations and delayed potentials in ventricular tachycardia of ischemic and nonischemic etiology (31 operated cases): Modern con- cepts of ventricular tachycardia, Europ. ~. of Cardiol. 8/4-5, 565-580. Fozzard, H.A. 1979, Conduction of the action potential, in Handbook of Physiology, Part II, The Cardiovascular System, Volume I: The Heart, R.M. Berne and N. Sperelakis, eds., Am. Physiol. soc., Bethesda, pp. 335-356. Frankel, R.B., Blakemore, R.P. and Wolfe, R.S. 1979, Magnetite in freshwater magnetotactic bacteria, Science 203:1355. Frankel, R.B. and Blakemore, R.P. 1980, Navigational compass in magnetic bacteria, ~. Mag. Mat. 15-18:1562-1564. Frankel, R.B., Blakemore, R.P., Torres de Araujo, F.F., Esquivel, D.M.S. and Danon, J. 1981, Magnetotactic bacteria at the geomagnetic equator, Science 212:1269-1270. Fraser-Smith, A.C. and Buxton, J.L. 1975, superconducting magnetometer measurements of geomagnetic activity in the 0.1 to 14 Hz frequency range, ~. Geophys. Res. 80:3141-3147. Freedman, A.P., Robinson, S.E., Johnston, R.E. 1979a, Non-invasive magnetopneumographic estimation of lung dust loads and distribution in bituminous coal workers, ~. Occup. Med. 22:613-618. Freedman, A.P., Robinson, S.E., Goodman, L., Stellman, J.M. and O'Leary, K. 1979b, Non-invasive magnetopneumographic determination of lung dust loads in steel arc-welders, Chest 76, p. 352. Freedman, A.P., Robinson, S.E. and Green, H.Y. 1981a, Magnetopneu- mography as a tool for the study of dust retention in the lungs, in Inhaled Particles, A. Critchlow, ed., pergamon, Oxford. Freedman, A.P., Robinson, S.E., O'Leary, K., Goodman, L. and stellman, L.M. 1981b, Non-invasive magnetopneumographic determination of lung dust loads in steel arc welders, Br. ~. of Ind. Med. 38: 384-388. Friedman, H.H. 1977, Diagnostic Electrocardiography and Vectocar- diography, MCGraw-Hill, New York. REFERENCES 659

Furth, H.P. and Waniek, R.W. 1956, Production and use of high transient magnetic fields I. Rev. Sci. Instru. ~7:195-203. Gaffey, C.T. and Mullins, L.J. 1958, Ionic fluxes during the action potential in Chara, ~. Physiol. 144:505-524. Gallangher, J.J., Smith, W.M., Kerr, C.R., Kasel, J., Cook, L., Reiter, M., Sterba, R. and Harte, M. 1982, Esophageal pacing: A diagnostic and therapeutic tool, Circulation 65(2):336-341. Gengerelli, J.A., Holter, N.J. and Glassock, W.R. 1961, Magnetic fields accompanying transmission of nerve impulses in the frog's sciatic, ~. psych. 57:202-212. Gengerelli, J.A., Holter, N.J. and Glassock, W.R. 1964, Further observations on magnetic fields accompanying nerve transmission and tetanus, ~. Psych. 57:202-212. Gerbrandt, L.K., Goff, W.R. and Smith, D.B. 1973, Distribution of the human average movement potential, Electroenceph. Clin. Neurophysiol. 34:461-474. Geschwind, N. 1965, Disconnection syndrome in animals and man, Brain 88:237-294. Geselowitz, D.B. 1967, On bioelectric potentials in an inhomogeneous volume conductor, Biophys. ~. 7:1-11. Geselowitz, D.B. 1970, On the magnetic field generated outside an inhomogenous volume conductor by internal current sources, IEEE Trans. Mag. MAG-6:346-347. Geselowitz, D.B. 1973, Model studies of electric and magnetic fields of the heart, ~. Franklin Inst. 296:379-391. Geselowitz, D.B. 1979, Magnetocardiography: An overview, IEEE Trans. Biomed. Engr. BME-26:497-504. Geselowitz, D.B. 1980, Computer simulation of the human magnetocardiogram, IEEE Trans. Magn. MAG-16:812-817. Geselowitz, D.B. and Miller, W.T., III 1973, Extracorporeal magnetic fields generated by internal bioelectric source, IEEE Trans. Magn. MAG-9:392-398. Giallorenzi, T.G., Bucaro, J.A., Dandridge, A., Siegal, Jr., G.H., Cole, J.H., Rashleigh, S.C. and Priest, R.G. 1982, Optical-fiber sensor technology, ~~. of Quantum Electronics Q-18:634. Giffard, R.P., Webb, R.A. and Wheatley, J.C. 1972, Principles and methods of low-frequency electric and magnetic measurements using an rf-biased point-contact superconducting device,~. Low Temp. Phys. 6:533-610. Giffard, R.P. 1978, RF SQUIDS: The state of the science, A.I.P. Conf. Proc. 44:11-21. Giffard, R. 1980, Fundamentals of SQUID applications, in Hahlbohm and LUbbig (1980, pp. 445-471). Goff, W.R., Allison, T. and Vaughan, H.G., Jr. 1978, The functional neuroanatomy of event-related potentials, in Event-Related Brain Potentials in Man, E. callaway, P. Tueting and S.H. Koslow, eds., Academic Press, New York. Goff, W.R., Williamson, P.O., Van Gilder, J.C., Allison, T. and Fisher, T.C. 1980, Neural origins of long latency evoked potentials recorded from the depth and cortical surface of the brain 660 REFERENCES

in man, in P~ogress in Clinical Neurophysiology, Vol. 7, J.E. Desmedt, ed., Karger, Basel, pp. 126-145. Goree, W.S. and Fuller, M. 1976, Magnetometers using rf-driven SQUIDS and their applications in rock magnetism and paleomagnetism, Revs. of Geoph. and Space Physics 14:591-267. Gould, J.L. 1980, The case for magnetic sensitivity in birds and bees (such as it is), American Scientist 68:256-267. Gould, J.L. 1982a, Ethology, The Mechanisms and Evolution of Behavior, W.W. Norton, New York. Gould, J.L. 1982b, The map sense of pigeons, Nature 296:205-211. Gould, J.L., Kirschvink, J.L. and Deffeyes, K.S. 1978, Bees have magnetic remanence, Science 201:1026-1028. Graham, N. and Nachmias, J. 1971, Detection of grating patterns containing two spatial frequencies: A comparison of single- channel and multiple-channel models. Vis. Res. 11:251-59. Granit, R. 1933, The components of the retinal action potential in mammals and their relation to the discharge in the optic nerve, ~. Physiol. 77:207. Gray, H. 1977, Anatomy: Descriptive and Surgical, T.P. Pick and R. Howden, eds., Bounty Books, New York. Green, D.M. and swets, J.A. 1966, Signal Detection Theory and psychophysics, Wiley, New York. Grover, F.W. 1962, Inductance calculations, Working Formulas, and Tables, Dover, New York. Grynszpan, F. 1971, Relationship Between the Surface Electromagnet- ic Fields and the Electrical Activity of the heart, Ph.D. Dissertation, University of Pennsylvania. Grynszpan, F. and Geselowitz, D.B. 1973, Model studies of the magnetocardiogram, Biophys. ~. 13:911-925. Hahlbohm, H-D. and LUbbig, H. 1977, SQUID superconducting Quantum Interference Devices and their Applications, De Gruyter, Berlin. Hahlbohm, H-D. and LUbbig, H., eds. 1980, SQUID '80 - Superconduct- ing Interference Devices and Their Applications, De Gruyter, Berlin. Halgren, E., Squires, N.K., Wilson, C.S., Rohrbaugh, J.W., Babb, T.L. and Crandall, P.H. 1980, Endogenous potentials generated in the human hippocampal formation and amygdala by infrequent events, Science 210:803-805. Halliday, A.M. and Micheal, W.F. 1970, Changes in pattern-evoked responses in man associated with the vertical and horizontal meridians of the visual field, ~. Physiol. 208:499-513. Halperin, M., Williamson, S.J., Spektor, D.M., Schlesinger, R.B. and Cippmann, M. 1981, Remanent magnetic fields for measuring particle retention and distribution in the lungs, Exp. Lung Res. 2:27-35. Hari, R., Aittoniemi, K., Jarvinen, M-L., Katila, T. and Varpula, T. 1980, Auditory evoked transient and sustained magnetic fields of the human brain, ~. Brain Res. 40:237-240. Hari, R., Antervo, A., Katila, T., Poutanen, T., Seppanen, M., Tu- omisto, T. and Varpula, T. 1982, Cerebral magnetic fields REFERENCES 661

preceding voluntary foot movements, 4th IntI Workshop on Biomagnetism, Rome, Italy, II Nuovo Cimento Q, in press. Harimann, R.J., Krongrad, E., Boxer, R.A., Weiss, M.B., steeg, C.N. and Hoffman, B.F. 1980, Method for recording electrical activity of the sinoatrial node and automatic atrial foci during cardiac catheterization in human subjects, Am. ~. cardiol. 45:775. Hatch, T.F. and Gross, P. 1964, pulmonary Deposition and Retention of Inhaled Aerosols, Academic Press, New York. Hecht,S., Shlaer, S. and Pirenne, M. 1942, Energy, quanta and vision, ~. Gen. Physiol. 25:819-840. Heinonen, P., Tuomola, M., r.ekkala, J. and Malmivuo, J. 1980, Pro- perties of a thick-walled conducting enclosure in low-frequency, ~. Phys. !. Sci. Instrum. 13:569-570. Helmholtz, H. 1853, Uber einige Gesetz der verteilung elektrischer StrOme im kOrperlichen Leitern, mit Anwendung auf die thieris- chelektrischen Versuche, Ann. Phys. Chem. 29:211-233 and 353- 377. Helmholtz, H. 1962, Treatise on Physiological optics, vol. 3 Trans. from 3rd German edition. J.P.C. Southall, Ed. opt. Soc. Amer. (1925), Republished Dover, New York. Hess, D.W. 1980, Estimation of the magnetoencephalogram power spectrum, in Erne' et al. (1981a, pp. 423-430). Ho, A.M-H., Fraser-Smith, A.C. and Villard, Jr., O.G. 1979, Large amplitude ULF magnetic fields produced by a rapid transit system: Close-range measurements, Radio science 14:1011-1015. Hochberg, J.E. and Brooks, V. 1960, The psychophysics of forms: Re- versible perspective drawings of spatial objects, Amer.~. Psychol. 73:337-54. Hocking, W.G., Golde, D.W. 1979, The pulmonary-alveolar macrophage, ~. Engl. ~. Med. 301:580-587. Hodgkin, A.L. and Katz, B. 1949, The effect of sodium ions on the electrical activity of the giant axon of the SQUID, ~. Physiol. London 108:37-77. Hodgkin, A.L. and Huxley, A.F. 1952a, A quantitative description of membrane current and its application to conduction and excitation in nerve, Q. Physiol. London 117:500-544. Hodgkin, A.L., Huxley, A.F. and Katz, B. 1952b, Measurement of current-voltage relations in the membrane of the giant axon of Loligo, ~. Physi01. London, 116:424-448. Hodgkin, A.L. and Horowicz, P. 1959, The influence of potassium and chloride ions on the membrane potential of single muscle fibers, ~. Physiol. London 148:127-160. Hoegstedt, P., Kadefors, R. and Naslund, P-E. 1982, Magnetopu1mo- graphy; Non-invasive measurement of iron oxide retained in the lungs, to be published. Hoffman, B.F. 1960, Physiological basis of disturbances of cardiac rhythm and conduction, Progr. Cardiovasc. Dis. 2:319-333. Hoffman, B.F. and Crane field , P.F. 1960, Electrophysiology of the Heart, MCGraw-Hill. Hoffman, B.F., Rosen, M.R. and Wit, A.L. 1975, Electrophysiology 662 REFERENCES

and pharmacology of cardiac arrhythmias: III. The cause and treatment of cardiac arrhythmias, Part A., Am. Heart J. 89(1): 115-122. Hoffman, B.F. and Rosen, M.R. 1981, Cellular mechanisms for cardiac arrhythmias, Circ. Res. 49(1):1-15. Hollenhurst, J.N. and Giffard, R.P. 1979, High sensitivity microwave SQUID, IEEE Trans. Magn. MAG-15:474-477. Hollman, R. and Little, W.A. 1980, Progress in the development of microminiature refrigerators using photolithographic fabrication techniques, NBS Special Publication 607. Holmgren, A.F. 1865, Lakaref~reningens F~rhandlingar (Uppsala, Sweden) 1:177. Horacek, M. 1973, Digital model for studies in magnetocardiography, IEEE Trans. Magn. MAG-9:440-444. Hosaka, H., Cohen, D., Cuffin, B.N. and Horacek, B.M. 1976a, The effect of torso boundaries on the magnetocardiogram, J. Electrocardiography 9:418-425. Hosaka, H. and Cohen, D. 1976b, Visual determination of generators of the magnetocardiogram, ~. Electrocardiology 9:426-432. Hubel, D.H. and Wiesel, T.N. 1962, Receptive fields, binocular in- teraction and functional architecture in the cat's visual cortex, ~. Physiol. 160:105-154. Hubel, D.H. and Wiesel, T.N. 1965, Receptive fields and functional architecture in two non-striate visual areas (18 and 19) of the cat, ~. Neurophysiol. 28:229-289. Hubel, D.H. and Wiesel, T.N. 1968, Receptive fields and functional architecture of monkey striate cortex, ~. Physiol. 195:215-243. Hubel, D.H. and Wiesel, T.N. 1970, Stereoscopic vision in macaque monkey, Nature 225:41-42. Hubel, D.H. and Wiesel, T.N. 1974, Uniformity of monkey striate cortex: A parallel relationship between field size, scatter and magnification factor, ~. Camp. Neural. 158:295-306. Hubel, D.H. and Wiesel, T.N. 1977a, Ferrier lecture: Functional architecture of macaque monkey visual cortex, Proc. ~. Soc. Lond. B 198:1-59. Hubel, D.H., Wiesel, T.N. and Levay, S. 1977b, Plasticity of ocular dominance columns in monkey striate cortex, Phil. Trans. ~. ~. Lond. B 278:131-163. Hughes, J.R., Hendrix, D.E., Cohen, J., Duffy, F.H., Mayman, C.I., scholl, M.L. and Cuffin, B.N. 1976, Relationship of the magnetoencephalogram to the electroencephalogram: Normal wake and sleep activity, Electroenceph. Clin. Neurophysiol. 40:261-278. Hughes, J.R., Cohen, J., Mayman, C.I., Scholl, M.L. and Hendrix, D.E. 1977, Relationship of the magnetoencephalogram to abnormal activity in the electroencephalogram, ~. Neurol. 217:79-93. Hukkinen, X., Xariniemi, V., Xatila, T.E., Laine, H., Lukander, R. and Makipaa, P. 1976, Instantaneous fetal heart rate monitoring by electromagnetic methods, Am. ~. Obstet. Gynecol. 125: 1115-1120. Hukkinen, X., Xatila, T.E., Laine, H., Lukander, R., Makipaa, P. REFERENCES 663

and Kariniemi, V. 1977, Instantaneous fetal heart rate monitoring by electromagnetic methods, Am. ~. obstet. Gynecol. 128:526. Ibuka, M. Hosomatsu, H. and Naito S. 1981, A SQUID magnetometer using a niobium thin-film microbridge, reprinted from IEEE Trans. ~ Instr. and Measurements, Vol. IM-30, No.4. International Atomic Energy Agency, 1973, Inhaled risks from radi- oactive contaminants, Technical Report Series, 142, Vienna, p. 146. Jaffe, L.F. 1979, Control of development by ionic currents, in Membrane Transduction Mechanisms, R.A. Cone and J.E. Dowling, eds., Raven, New York, pp. 199-231. Jaklevic, R.C., Lambe, J., Silver, A.M. and Mercereau, J.E. 1964, Quantum interference effects in Josephson tunnelling, Phys. Rev. Lett. 12:159-160. Janse, M.J. and KI$ber, A.G. 1981, Electrophysiological changes and ventricular arrhythmias in the early phase of regional myocardial ischemia, Circ. Res. 49:1069-1081. JarVinen, M.-L., Katila, T., Maniewski, R., Siltanen, P. and Varpu- la, T. 1980, Measurement of biomagnetic fields in a hospital environment, Post. Fiz. Med. 15:201-210. Jasper, H.H. 1958, Electroenceph. Clin. Neurophysiol. 10:321-375. Johnson, H.P., Lowrie, W. and Kent, D.V. 1975, Stability of ARM in fine and course grained magnetite and maghemite particles, Geophys. J. R. Astron. Soc. 41:1-10. Jones, 0.5. and MacFadden, B.J. 1982, Induced magnetization in the monarch butterfly, Danaus Plexippus (insecta, Lepidoptera), ~. Exp. BioI. 96:1-9. Josephson, B.D. 1962, Possible new effects in superconductive tunnelling, Phys. Rev. Lett. 1:251. Josephson, B.D. 1964, Coupled superconductors, Rev. Mod. Phys. 36:216-220. Josephson, B.D. 1974, The discovery of tunnelling supercurrents, Rev. Mod. Phys. 46:251-254. Julesz, B. 1971, Foundations of Cyclopean perception Univ. of Chi- cago Press, Chicago. Ju1esz, B. and Kropf1, W. 1982, Binocular neurons and cyclopean visually evoked potentials in monkey and man, in Evoked Poten- tials, I. Bodis-Wollner, ed., Annals ~. !. Acad. Sci. 388:37-44. Jungerman, R.L. and Rosenblum, B. 1980, Magnetic induction for the senSing of magnetic fields by animals: An analysis, ~. Theor. BioI. 87:25-32. Kaas, J.H., Huerta, M.F., Weber, J.T. and Harting, J.K. 1978, Pat- terns of retinal terminations and laminar organization of the lateral geniculate nucleus of primates,~. Compo Neurol. 182: 517-554. Kaden, H. 1959, WirbelstrOme und schirmung in ~ Nachrich- tentechnik, springer verlag, Berlin. Kalliomllki, K., Kalliomllki, P-L., Kelha, V. and Vaaranen, V. 1980, Instrumentation for measuring the magnetic lung contamination of steel welders, Ann. Occup. ~. 23:175-184. 664 REFERENCES

Kalliomaki, K., Aittoniemi, K., Kalliomaki, P-L. and Moilanen, M. 1981, Measurement of lung-retained contaminants in vivo among workers exposed to metal aerosols, Am. Ind. ~. Assoc. J. 42: 234-238. Kalliomaki, P-L. 1977, Measurement of Magnetic Lung Contamination in vivo: Evaluation of the Method and its Application to Arc Welders, Academic dissertation, Helsinki. Kalliomllki, P-L., Alanko, K., Korhonen, 0., Mattsson, T., Vaara- nen, V. and Koponen, M. 1978a, Amount and distribution of welding fume lung contaminations among arc welders, Scand. J. Work Environ. Health 4:122-130. Kalliomaki, P-L., Korhonen, 0., Vaaranen, V., Kalliomaki, K. and Koponen, M. 1978b, Lung retention and clearance of shipyard arc welders, Int. Arch. Occup. Environ. Heath 42:83-89. Kalliomliki, P-L., Sutinen, S., Kelhll, V., Lakomaa, E-L., Sortti, V. and Sutinen, S. 1979a, Amount and distribution of fume contaminants in the lungs of an arc welder post mortem, Br. ~. Ind. Med. 36:224-230. Kalliomliki, P-L., Korhonen, 0., Mattsson, T. , Sortti, V. , Vaara- nen, V. , Kalliomliki, K. and Koponen, M. 1979b, Lung contamination among foundry workers, Int. Arch. occup. Environ. Health 43:85-91. KalliomlllC'i P-L., Huuskonen, M., Korhonen, 0., Mattsson, T., Sort- ti, V., Vaaranen, V., Kalliomaki, K. and Koponen, M. 1979C, Lung contamination of workers exposed to dust with an iron component, Arch. Hig. Rada Toksikol 30: Suppl. 893-902. Kalliomliki, P-L., Aittoniemi, K., Gustafsson, T., Kalliomliki, K., Koponen, M. and vaaranen, V. 1981a, Research on industrial fer- rous metal aerosols, Ann. occup. ~. (in print). Kalliomaki, P-L., Rahkonen, E., Vaaranen, V., Kalliomaki, K. and Aittoniemi, K. 1981b, Lung-retained contaminants, urinary chromium, and nickel among stainless steel welders, Int. Arch. Occup. Environ. Health 49:67-75. Kalliomaki, P-L., Kalliomaki, K., Korhonen, 0., Nordman, H., Rah- konen, E. and Vaaranen, V. 1982, Respiratory status of stainless steel and mild steel welders, Scand. ~. Work Environ. Health 8: suppl. 117-121. Kalmijn Ad, J. 1978, Experimental evidence of geomagnetic orientation in elasmobranch fishes, in Animal Migration, Navigation and Homing, Schmidt-Koenig and Keeton, eds., Springer-Verlag, New York, pp. 135-142. Kalmijn Ad, J. and Blakemore, R.P. 1978, The magnetic behavior of mud bacteria, in Animal Migration, Navigation and Homing, schmidt-Koenig and Keeton, eds., Springer-Verlag, New York, pp. 354-356. Kariniemi, V., Ahopelto, J., Karp, P.J. and Katila, T.E. 1974, The fetal magnetocardiogram, ~. Perinat. Med. 2:214-216. Kariniemi, V. and Hukkinen, K. 1977, Quantification of fetal heart rate variability by magnetocardiography and direct electrocardiography, !!. ~. obstet. Gynecol. 128:526-530. REFERENCES 665

Kariniemi, v., Katila, T., Laine, H. and Ammala, P. 1980, On-line quantification of fetal heart rate variability, ~. Perinat. Med. 8:213. Kariniemi, V. and Ammala, P. 1981a, Short term variability of fetal heart rate during pregnancies with normal and insufficient placental function, Am. ~. Obstet. Gynecol. 139:33. Ka.riniemi, V., and Ammala, P. 1981b, Effect of intramuscular pethidine on fetal heart rate variability during labor, Brit. ~. obstet. Gynecol. 88:718. Kariniemi, V., Paatero, H. and Ammala, P. 1981c, Effects of oxy~ tocin on fetal heart rate variability during labor, ~. Perinat. Med. 9: 251. Kariniemi, V., Siimes, A. and Ammala, P. 1982, Abdominal electrocardiography in the antepartal analysis of fetal heart rate variability, ~. Perinat. Med. 10:114. Karp, P.J. 1977, Biomagnetic Fields - Measurements and Analysis, Ph.D. thesis, Department of Technical Physics, Helsinki Univer- sity of Technology. Karp, P.J. 1981, Cardiomagnetism, in Erne' et al. (1981a, pp. 219- 255) . Karp, P.J., Katila, T., Makipaa, P. and Saar, P. 1976, Proc. 11th IntI. Conf. on Medical and Biological Engineering, ottawa, pp. 504-505. Karp, P.J., Katila, T.E., Saarinen, M., siltanen, P. and Varpula, T.T. 1978, Etude comparative des magnetocardiogrammes normaux et pathologiques, Ann. Cardiol. Ageiol. 27:65-70. Karp, P.J. and Duret, D. 1980a, Unidirectional magnetic gradiometers, ~. ~. Phys. 51:1267. Karp, P.J., Katila, T.E., saarinen, M., Siltanen, P. and Varpula, T.T. 1980b, The normal human magnetocardiogram: II A multipole analysis, Circ. Res. 47:117-130. Karp, P.J., Katila, T., Maniewski, R., Poutanen, T. and Varpula, T. 1981, Magnetic fields produced by the human eye, ~. ~. Phys. 52:2565-2571. Kati1a, T. 1981, Instrumentation for biomedical applications, in Erne' et al. (1981a, pp. 4-31). Katila, T. 1983, On the current multipole expansions of the biomagnetic field, Acta Polytechn. Scand., to be published. Katila, T., Maniewski, R., Poutanen, T., Varpula, T. and Karp, P.J. 1981, Magnetic fields produced by the human eye, ~. ~. Phys. 52:2565-2571. Katila, T., Maniewski, R., Tuomisto, T., Varpula, T. and Siltanen, P. 1982a, Magnetic measurements of cardiac volume changes, IEEE Trans. Biomed. Eng. BME-29:16-25. Katila, T. and salkola, M. 1982b, On the Multipole Expansion of Bi- oelectromagnetic Fields, Technical Report TKK-F-A472, Helsinki University of Technology, Espoo, Finland. Katz, A.H. 1977, Physiology of the Heart, Raven Press, New York, p. 262. Kaufman, L. 1974, Sight and Mind, Oxford, New York. 666 REFERENCES

Kaufman, L. 1979, The World Transformed, Oxford, New York. Kaufman, L. 1982, Neuromagnetic analysis of sensory systems, in Overviews of Emerging Research Techniques in Hearing, Bioacous- tics, and Biomechanics, ~. 1981 Meeting of CHABA, National Research CounCil, National Academy of science, washington, DC., pp. 68-84. Kaufman, L. and Price, R. 1967, The detection of cortical spike activity at the human scalp, IEEE Trans. BME 14:84-90. Kaufman, L. and Locker, J. 1970, Sensory modulation of the EEG, Proc. 78th Annual ~. Amer. Psychol. ~. 179-80. Kaufman, L. and Williamson, S.J. 1980, Evoked magnetic field of the human brain, Ann. New York Acad. of Sci. 340:45-65. Kaufman, L., Okada, Y.C., Brenner, D. and Williamson, S.J. 1981, On the relation between somatic evoked potentials and fields, Intl. J. Neuroscience 15:223-239. Kaufman, L. and Williamson, S.J. 1982a, Magnetic location of cortical activity, Ann. New York Acad. of Sci. 388:197-213. Kaufman, L., Okada, Y.C., Tripp, J. and Weinberg, H. 1982b, Evoked neuromagnetic fields, Ann. ~. !. Acad. Sci., in press. Keeton, W.T. 1971, Magnets interfere with pigeon homing, Proc. ----Natl. ----Acad. ---Sci. 68:102-106. Kehla, V.O. 1981, Construction and performance of the Otaniemi magnetically shielded room, in Erne' (1981a, pp. 33-50). Kelha, V.O., Pukki, J.M., Peltonen, R.S., penttinen, A.J., Ilmoni- emi, R.J. and Heino, J.J. 1982, DeSign, construction, and performance of a large-volume magnetic shield, IEEE Trans. Magn. MAG-18 , 260-270. Kelly, D.H. 1966, Frequency doubling in visual responses, J. opt. ---Soc. Am. 56:1628-1633. Kelly, J.P.-- and Van Essen, D.C. 1974, Cell structure and function in the visual cortex of the cat, ~. Physiol. 238:515-547. Ketchen, M.B., Gobau, W.M., Clarke, J. and Donaldson, G.B. 1977, Thin film dc SQUID gradiometer, IEEE Trans. Magn. MAG 13:372. Kimura, S., Hoboyaski, M.H., Godar, T. and Minato, S. 1979, Inves- tigation of chromium in stainless steel welding fumes, Presented at the AES 60th Annual Meeting, Detroit, Michigan, April 1979. Kirschvink, J.L. 1980, South-seeking magnetic bacteria, ~. ~. BioI. 86:345-347. Kirschvink, J.L. 1981a, The horizontal magnetic dance of the honey- bee is compatable with a Single-domain ferromagnetic magnetore- ceptor, BioSystems 14:193-203. Kirschvink, J.L. 1981b, Biogenic magnetite (Fe 0 ): A ferrimagnetic mineral in bacteria, animals, and man, in Pe~rites: ~. IntI. Conf. (September-October 1980, Japan), pp. 135-137. Kirschvink, J.L. 1982a, Birds, bees and magnetism: a new look at the old problem of magnetoreception, Trends in Neurosciences 5:160-167. Kirschvink, J.L. 1982b, Paleomagnetic evidence for fOSSil biogenic magnetite in western Crete, Earth Planet. SCi. Lett. 59:388-392. Kirschvink, J.L. and Lowenstam, H.A. 1979, Mineralization and mag- REFERENCES 667

netization of chiton teeth: paleomagnetic, sedimentologic and biologic implications of organic magnetite, Earth Planet Sci. Lett. 44:193-204. Kirschvink, J.L. and Gould, J.L. 1981, Biogenic magnetite as a basis for magnetic field sensitivity in animals, BioSystems 13:181-201. Kirschvink, J.L., Tabrah, F.L. and Batkin, S. 1982, Ferromagnetism in two mouse tumors, ~. Exp. BioI., in press. Kittel, C. 1976, Introduction to Solid State Physics, 5th Edition, John Wiley and Sons, New York. Kitzman, G.A., Droll, P.W. and Iufer, E.J. 1971, A theoretical a- nalysis of neuronal biogenerated magnetic fields, in ~ Nervous System and Electric Currents, Vol. 2, N.L. Wulfsohn and A. Sances, Jr., eds., Plenum Press, New York, pp. 87-91. Klinke, R., Fruhstorfer, H. and Finkenzeller, P. 1968, Evoked responses as a function of external and stored information, Electroenceph. Clin. Neurophysiol. 25:119-122. Kolin, A. 1968, Magnetic fields in biology, Phys. Today, 21:39-50. Kooi, K.A., Tipton, A.C. and Marshall, R.E. 1971, Polarities and field configurations of the vertex components of the human auditory evoked responses: A reinterpretation, Electroenceph. Clin. Neurophysiol. 31:166-169. Koponen, M., Gustafsson, T., Kalliomaki, K., Kalliomaki, P-L., Moilanen, M. and Pyy, L. 1980, Dusts in steel making plant; lung contamination among iron workers, Int. Arch. Occup. Environ. Health 47: 35-45. Kornhuber, H.H. and Deecke, L. 1964, Hirnpotentialanderungen beim Neschen vor und nach Willkurbewegungen, dargesllt mit Magnet- bandspeicherung und Ruckwartsana1'yse, Pflugers Arch. Ges. Physiol. 281:52. Kornhuber, H.H. and Deecke, L. 1965, Hirnpotentialanderungen bei Willkurbewegungen und passiven Bewegungen des Menschen: Bereit- schaftspotential und reafferente Potentiale, Pflugers Arch. Ges. Physiol. 284:1-17. Kotani, M., Cohen, D. and cuffin, B.N. 1978, Difficulties in the solution of the inverse problem of the lung, in Report of the Low-Field Group: The Magnetic Field of the Lung, Publication MIT/FBNML~78/1, National Technical Information Service, Spring- field, VA, 22161, pp. 257-268. Kropschot, R.H., Birmingham, B.W. and Mann, D.B. (eds.) 1968, Technology of Liquid Helium, NBS Monograph Ill, Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. Kuffler, S.W. 1953, Discharge patterns and functional organization of mammalian retina, ~. Neurophysiol. 16:37-68. Lambe, J., Silver, A.M., Mercereau, J.E. and Jaklevic, R.C. 1964, Microwave observation of quantum interference effects in superconductors, Phys. Lett. 11:16. Lammrre, Y., Spidalieri, G., Busby, L. and Lund, J.P. 1980, Pro- gramming of initiation and execution of ballistic arm movements 668 REFERENCES

in the monkey, Progress in Brain Research 54:157-169. Lancaster, P. 1974, TTL Cookbook, H.A. Sams, Indianapolis. Lautner, G.M., Carver, J.C. and Konzen, R.B. 1978, Measurement of chromium VI and chromium III in stainless steel welding fumes with electron spectroscopy for chemical analysis and neutron ac- tivation analysis, Am. rnd. ~. Assoc. ~. 39:651-659. Lazaroff, N., warren, S. and Wasserman, A. 1982, Iron oxidation and precipitation of ferric hydroxysulfates by resting thiobacillus ferrooxidans cells, ~. Environ. Microbiol. 43:924-938. Leifer, M.C. 1981, superconducting magnetometry for cardiovascular studies and an application of adaptive filtering, Ph.D. thesis, Department of Physics, stanford University. Leifer, M.C., Griffin, J.C., rufer, E.J., Wikswo, J.P., Jr., Fair- bank, W.M. and Harrison, D.C. 1981, An integrated system for magnetic assessment of cardiac function, in Erne' et al. (1981a, pp. 123-137). Leiteritz, H., Bauer, D. and Bruckmann, E. 1971, Mineralogical characteristics of airborne dust in coal miner of west Germany and their relation to pulmonary changes of coal dust, in Inhaled Particles, Volume II, Pergamon Press, Oxford, pp.729-743. Lennie, P. 1980, Parallel visual pathways: A review, Vision Res. 20:561-594. Leoni, R. and Romani, G.L. 1982, Computer simulation of magnetic field patterns from the human cardiac conduction system, II Nuovo Cimento Q, in press. Lepeschkin, E. 1974, Tentative analysis of the normal magnetocardiogram, Advan. in Cardio. 10:325-332. Levy, R.I. and Moskowitz, J. 1982, Cardiovascular research: Decades of progress, a decade of promise, science 217:121-129. Lin, Li-He and Gasparini, F.M. 1982, Construction and performance of a simple multi-shielded dewar, Rev. Sci. lnst. 53(2):236. Lins de Barros, H.G.P., Esquivel, J.D. and de Oliveira, L.P.H. 1981, Magnetotactic algae,_ CBPF Notas de fisica 48:1. Little, W.A. 1977, Scaling of miniature cryocoolers to microminiature size, NBS special Publication 508. Little, W.A. 1981, Design considerations for microminiature refrigerators using laminar-flow heat exchangers, NBS Special Publication 607, pp. 154-159. Little, W.A. 1982, Microminiature refrigerator - small is better, Physica 109-110B:2001-2009. Llinas, R. and Nicholson, C. 1974, Analysis of field potentials in the central nervous system, in Handbook of Electroenceph. Clin. Neurophysiol., A. Redmond, ed., Elsevier, Amsterdam, 2B:61-83. Lorente de No' 1947, Analysis of the distribution of the action currents of nerve as volume conductors, in: ~ Study of Nerve Physiology Part ~ 132:384-477. Lowenstam, H.A. 1962, Magnetite in denticle capping in recent chitons (Polyplacophora), Geol. Soc. Am. Bull. 73:435-438. Lowenstam, H.A. 1981, Minerals formed by organisms, Science 211: 1126-1130. REFERENCES 669

Lowenstam, H.A. and Weiner, S. 1982, Mineralization by organisms and the evolution of biomineralization, in Proc. 4th Intl. Symposium ~ Biomineralization, P. Westbroek and E.W. deJong, eds., Kreidel Press, in press. Lowrie, W. and Fuller, M. 1971, On the alternating field demagnetization characteristics of multidomain thermoremanent magnetization in magnetite, ~. Geophys. Res. 76:6339-6349. Lupp, V., Hauske, G. and Wolf, W. 1976, Perceptual latencies to sinusoidal gradings, Vision Res. 16:969-972. Maas, J.A. and Maxim, M. 1970, contactless nerve stimulation and signal detection by inductive transducer, IEEE Trans. Mag., MAG- 6:322-326. Maclin, E.L. 1982, Visually Evoked Magnetic Fields of the Human Brain, Ph.D. Thesis, Department of Psychology, New York Univer- sity. Mager, A. 1981, The Berlin magnetically shielded room (8MSR), section A: Design and performance, in Erne' et al. (1981a, pp. 51- 79 ) Malmivuo, J.A.V. 1976, On the detection of the magnetic heart vector - an application of the reciprocity theorem, Acta polytechn. scand., El. Eng. ser. No 39, The Finnish Academy of Technical Sciences, Helsinki. Malmivuo, J.A.V. 1980, Distribution of m.e.g. detector sensitivity: An application of reciprocity, Med. and BioI. Eng. and Comput. 18:365-370. Malmivuo, J.A.V. and Wikswo, J.P., Jr. 1977, A new practical lead system for vector magnetocardiography, Proc. IEEE 65:809-811. Malmivuo, J.A.V., Heinonen, P., TUomola, M. and Lekkala, J. 1980, Thick-walled conducting shield in biomagnetic experiments, in Erne' et al. (1981a, pp. 107-112). Malmqvist, K., Johansson, G., Bohgard, M. and Akselsson, R. 1980, Luftf~roreningar vid svetsning; Karakterisering av svetsr~k. Institutionen for karnfysik vid Lunds Tekniska H~gskolan, Lund, 1980. Slutraport f~r del 2 av ASF-projekt Dnr 74/198, p. 113 (Swedish). Marr, D. 1982, Vision, W.H. Freeman, San Francisco. Marr, D. and Poggio, T. 1979, A computational theory of human ster- eo vision, Proc. !. Soc. Lond. B 204:301-28. Martin, H. and Lindauer, M. 1977, Der Einfluss des Erdsmagnetfeldes auf die schwereorientierung der Honigbiene (Apis Mellifica), ~. Compo Physiol. 122:145-187. Matelin, D. 1974, La magnetocardiographie realization d'un magnetocardiographie a bobine: premiers resultats obtenus en milieu urban, These de M4!ldecine, Universite scientifique et Medicale de Grenoble, Grenoble . .Mather, J.G. and Baker, R.R. 1981, Magnetic sense of direction in woodmice for rpute-based navigation, Nature 291:152-155. Mather, J.G., Baker, R.R. and Kennaugh, J.H. 1982, Magnetic field direction by small mammals, Trans. ~. Geoph. Union (E.S) 63: 156. 670 REFERENCES

McBrooks, C.C., Hoffman, B.C., Suckling, E.E. and Orias, C. 1955, Excitability of the Heart, Grune Stratton, New York. Mccarthy, G. and Donchin, E. 1981, A metric for thought: A comparison of P300 latency and reaction time, Science 211:77-80. Mccarty, R.D. 1972, Thermophysical Properties of Helium, NBS Technical Note 631, Superintendent of Documents, U.S. Govern- ment Printing Office, Washington, D.C. 20402. McElhinny, M.W. 1973, Paleomagnetism and Plate Tectonics, Cambridge University Press, Cambridge, U.K. McFee, R. and Baule, G.M. 1972, Research in electrocardiography and magnetocardiography, Proc. IEEE 60:290-322. Meere, C. 1979, Proceeding of the VI world symposium on cardiac pacing, Pace Symposium, Montreal. Meissner, W. and Ochsenfeld, R. 1933, Ein neurer Effekt bei Ein- tritt der supraleitfahigkeit, Naturwissenschaften 21:787. Messer, M.J. and Harris, J.W. 1967, Magnetic susceptibility and he- patiC iron stores: The correlation between quantitative determination of susceptibility and iron in human liver specimens, ~. Lab. Clin. Med. 70:1008-1009. Middlebrooks, J.C., Dykes, R.W. and Merzenich, M.M. 1980, Binaural response-specific bands in primary auditory cortex (Al) of the cat: Topographical organization orthogonal to isofrequency con- tours, Brain Res. 181:31-48. Miller, W.T., III and Geselowitz, D.B. 1974, Use of electric and magnetic data to obtain a multiple dipole inverse cardiac generator: A spherical model study, Ann. Biomed. Eng. 2:343-360. Miller, W.T., III, and Geselowitz, O.B. 1978, Simulation studies of the electrocardiogram I-II, Circ. Res. 43:301-323. Milner, B. 1972, Disorders of learning and memory after temporal lobe lesions in man, Clinical Neurosurgery 19:421-446. Mitzdorf, U. and Singer, W. 1978, Prominent excitatory pathways in the cat visual cortex (A17 and Al8): A current source density analysis of electrically evoked potentials. Exp. Brain Res. 33:371-394. Modena, I., RiCCi, G.B., Barbanera, S., Leoni, R., Romani, G.L. and carelli, P. 1982, Biomagnetic measurements of spontaneous brain activity in epileptic patients, Electroenceph. Clin. Neurophysiol., in press. M011anen, M., xalliomaki, X., xalliomaki, P-L. and Aittoniemi, X. 1982, Measurement of the magnetic properties of metal dusts and fumes, IEEE Trans. Magn. 18:788-789. MOrse, P.M. and Feshbach, H. 1953, Methods of Theoretical Physics, Part II, McGraw-Hill, New York, Ch. 13. Mountcastle, V.B. 1957, Modality and topographic properties of single neurons of eat's somatic sensory cortex, ~. Neurophysiol. 20:408. Mountcastle, V.B., and Poggio, G.F. 1974, Structural organization and general physiology of thalamotelencephalic systems, in Medical Physiology, Volume 1, V.B. Mountcastle, ed., Mosby, Saint Louis, pp. 227-253. REFERENCES 671

Musso, E., De Ambroggi, L. and Taccardi, B. 1972, Potential distri- butions generated by isolated dog hearts after occlusion of an- terior or posterior coronary branches, in ~. Satellite ~. XXC Int!. Congress. Physio!. SC.: The Electrical Field of the Heart, P. Rijlant, ed., Presses Academiques Europennes, Brux- elles, pp. 390-394. Myrtle, K., Winter, C. and Gygax, S. 1982, A 9-K conical stirling- cycle cryocooler, cryogenics 22(3):39. Nakayama, K. 1982, The relationship of visual evoked potentials to cortical physiology, in Bodis-Wollner (Ed.) Evoked Potentials, Annals ~. y. Acad. SCiences, New York. Narula, 0.5., Samet, P. and Javier, R.P. 1972, Significance of the sinus node recovery time, Circulation 45:140. Nernst, W. 1969, Z. Physik. Chem. 2: (1888) 613, quoted by R.M. Dowben, in Gen~ral Physiology, Harper Row, Ne~ York, p. 359. Netter, F.H. 1969, The Ciba Collection of Medical Illustration, Vol. 5: The Heart, Ciba Pharmaceutical Company, Summit, New Jer- sey. Netzer, Y. 1980, Negative resistance amplifier improves current probes low frequency performance, Electron Devices Newsletters. Nicholson, C. 1980, Dynamics of the brain cell microenvironment, Neurosciences Res. Prog. Bull. 18:177-322. Nunez, P.L. 1981, Electric Fields of the Brain, Oxford University Press, New York. Odehnal, M., Petricek, V., Tichy, R. and Tomasek, F. 1978, Low- level SQUID magnetometry of the human heart in a small ferromagnetic enclosure, cryogenics 18:427-431. Ohmichi, H., Ibuka, M., Naitoh, S., Kotani, M., Uchikawa, Y. and Atsumi, K. 1981, A method of magnetocardiography for clinical use, in Erne' et al. (1981a, pp. 309-318). Ohmichi, H., Uchikawa, Y., Kotani, M., Atsumi, K. 1983, in Proc. 4th IntI. Workshop on Biomagnetism, Rome, Italy, II Nuovo Cimen- to~, in press. Okada, Y.C. 1983, Inferences concerning the anatomy and physiology of the human brain based on its magnetic field, II ~ Cimento ~, in press. Okada, Y.C., Kaufman, L., Brenner, D. and Williamson, S.J. 1981, Application of a SQUID to measurements of somatically evoked fields: Transient responses to electrical stimulation of the me- dian nerve, in Erne' (1981, pp. 445-456). Okada, Y.c., Kaufman, L., Brenner, D., and Williamson, S.J. 1982a, Modulation transfer functions of the human visual system re- vealed by magnetic field measurements, Vision Research 22:319- 333. Okada, Y.C., Williamson, S.J. and Kaufman, L. 1982b, Magnetic field of the human sensorimotor cortex, IntI. ~. Neurosciences 17:33- 38. Okada, Y.C., Kaufman, L. and Williamson, S.J. 1983a, Hippocampal formation as a source of endogenous slow potentials, Electroen- ceph. Clin. Neurophysiol., in press. 672 REFERENCES

Okada, Y.C., Tanenbaum, R., Kaufman, L. and Williamson, S.J. 1983b, Projection areas of human primary somatosensory cortex deter- mined by neuromagnetic techniques, to be published. Olsson, S.B. and Edvardsson, N. 1981, Clinical electrophysiologic study of antiarrhythmic properties of flencainide: Acute intra- ventricular delayed conduction and prolonged repolarization in regular paced and premature beats using intracardiac monophasic action potentials with programmed stimulation, Am. Heart J. 102(5):864-71. Olsson, B., varnavskas, E. and Korsgren, M. 1971, Further improved method for measuring monophasic action potentials of the intact human heart, ~. Electrocardiol. 4(1):19-23. Onnes, H.K. 1913, Comm. Leiden, suppl. Nr. 34. Opfer, J.E., Yeo, Y.K., Pierce, J.M. and Rorden, L.H. 1974, A superconducting second-derivative gradiometer, IEEE Trans. Magn. MAG 9:536-539. Ossenkopp, K.P. and Barbeito, R. 1978, Bird orientation and the geomagnetic field: A review, Neuroscience and Biobehavioral Review 2:255-270. Overweg, J.A. and Walter-Peters, M.J. 1978a, A miniature SQUID magnetometer for biomagnetic measurements with improved selectivity, ~. de Physique 39(C6):1226-1227. Overweg, J.A. and walter-Peters, M.J. 1978b, The design of a system of adjustable superconducting plates for balancing a gradiometer, Cryogenics 18:529-534. Ozima M. and Nagata, T. 1954, Low temperature treatment as an ef- fective means of magnetic cleaning of natural remanent magnetization, ~. Geomag. Geoelect. 16:37-40. palti, Y., Gold, R. and stampfli, R. 1979, Diffusion of ions in my- elinated nerve fibers, Biophys. ~. 25:17. panofsky, W.K.H. and Phillips, M. 1955, Classical Electricity and Magnetism, Addison-wesley, Reading, Massachusetts. pantle, A. and Sekuler, R.W. 1968, Contrast response of human visual mechanisms to orientation and detection and velocity, Vision ~. 9:397-406. Parker, D.M. and Salzen, E.A. 1977, Latency changes in the human visual evoked response to sinusoidal gratings, Vision Res. 17:1201-1204. Parkes, W.R. 1982, Occupational Lung Disorders, Butterworths, Lon- don, pp. 1-30, 45-88. Parks, R.D., ed. 1969, Superconductivity, Marcel Dekker, New York. patrick, J.L.M., Hess, D.W., Tripp, J.H. and Farrell, D.E. 1983, The magnetic field produced by the conduction system of the human heart, Proc. 4th IntI. Workshop on Biomagnetism, Rome, Italy, II ~ Cimento ~, in press. penfield, W. and Rasmussen, T. 1950, The Cerebral Cortex of Man, Macmillan, New York. peon, J., Ferrier, G.R. and Moe, G.K. 1978, The relationship of excitability to conduction velocity in canine Purkinje tissue, Circ. Res. 43:125-135. REFERENCES 673

Perrault, N., Wolfe, R. and Picton, T. 1981, Nasopharyngeal recordings of endogenous event-related potentials, Sixth IntI. Conf. ~ Event-Related Slow Potentials of the Brain, (EPIC VI), June, Lake Forest, Illinois; Ann. ~. !. Acad. Sci., in press. Peters, M.J., Dunajski, Z., Meyssen, T.E.M., Breukink, E.W. and Wevers-Henke, J.J. 1982, Measuring miniature eye movements by means of a SQUID magnetometer, Cryogenics, submitted. Phillips, J.B. and Adler, K. 1978, Directional and discriminatory responses of salamanders to weak magnetic fields, in Animal Migration, Navigation and Homing, K. Schmidt-Koenig and W.T. Keeton, eds., springer-verlag, New York, pp. 325-333. Picton, T.W. and Hillyard, S.A. 1974, Human auditory evoked potentials: II. Effects of attention, Electroenceph. Clin. Neurophysiol. 36:191-199. Plonsey, R.W. 1969, Bioelectric Phenomena, MCGraw-Hill, New York, P. 215. Plonsey, R.W. 1971, The biophysical basis of electrocardiography, CRC Crit. Rev. Bioeng. 1:1-48. Plonsey, R.W. 1972a, Capability and limitations of electrocardiography and magnetocardiography, IEEE~. Biomed. Eng. BME- 19:239-244. Plonsey, R.W. 1972b, Comparative capabilities of electrocardiography and magnetocardiography, Am. ~. of Cardiol. 29:735-736. Plonsey, R.W. 1981a, The magnetic field resulting from action currents on cylindrical fibers, Med. BioI. Eng. and Compo 19:311-- 315. Plonsey, R.W. 1981b, Generation of magnetic fields by the human body' (theory), in Erne' et al. (1981a, pp. 177-205). Plonsey, R.W. 1982, On the nature of sources of bioelectric and biomagnetic fields, Biophys. ~. 39:309-312. Poggio, G.F. and Talbot, W.H. 1981, Mechanisms of static and dynamic stereopsis in foveal cortex of the rhesus monkey, ~. Physiol. 315:469-492. Polyak, S.L. 1957, The Vertebrate Visual system, University of Chi- cago Press, Chicago. poussart, D.J-M. 1973, Low-level average power measurements: Noise figure improvements through parallel or series connection of noisy amplifiers, Rev. Sci. Instr. 44:1049-1052. Puech, P. and Slama, R. 1978, The Cardiac Arrhythmias, Roussel- Uclaf, Citon-vanves (France). Purcell, E.M. 1965, ElectriCity and Magnetism, Berkeley Physics Course, Volume 2, McGraw-Hill, New York. Quinn, T.P. 1980, Evidence for celestial and magnetic compass orientation in lake migrating sockeye salmon fry, ~. Compo Physiol. 137:243-248. Rabiner, L.R. and Gold, B. 1975, Theory and Application of Digital Signal Processing, Prentice-Hall, Englewood Cliffs. RaIl, W. 1962, Theory of physiological properties of dendrites. Annals ---New ----York ----Acad. -----of Sci. 96:1071-1092. Ramon y Cajal, S. 1933, Histology, W. Wood and Company, Baltimore. 674 REFERENCES

Regan, D. 1972, Evoked potentials in Psychology, Sensory Physiology, and Clinical Medicine, Chapman and Hall, London. Regan, D. 1978, Assessment of visual acuity by evoked potential recording: Ambiguity caused by temporal dependence of spatial frequency selectivity, Vis. ~. 18:439-443. Regan, T. 1981, Electronics Design News, June, pp. 183-191. Reiffel, J.A., Gang, E., Gliklich, J., Weiss, M.B., Davis, J.C., patton, J.N. and Bigger, J.T. 1980, The human sinus node electrogram: A transvenous catheter technique and a comparison of directly measured and indirectly estimated sinoatrial conduction time in adults, Circulation 62:1324-1334. Reite, M., Zimmerman, J.E., Edrich, J. and Zimmerman, J.T. 1976, The human magnetoencephalogram: Some EEG and related correla- tions, Electroenceph. Clin. Neurophysiol. 40:59-66. Reite, M., Edrich, J., Zimmerman, J.T. and Zimmerman, J.E. 1978a, Human magnetic auditory evoked fields, Electroenceph. Clin. Neurophysiol. 45:114-117. Reite, M. and Zimmerman, J.E. 1978b, Magnetic pheonomena of the central nervous system, Ann. Rev. Biophys. Bioeng. 7:167-188. Reite, M., Zimmerman, J.T. and Zimmerman, J.E. 1981, MagnetiC auditory evoked fields: Interhemispheric asymmetry, Electroenceph. Clin. Neurophysiol. 51:388-392. Reitz, J.R. and Milford, F.J. 1967, Foundations of Electromagnetic Theory, 2nd ed., Addison-wesley, Massachusetts. Ricci, G.B., Romani, G.L., Modena, I., Barbanera, S., Leoni, R. and Carelli, P. 1981a, MEG and EEG measurements and their correlation in man: Preliminary observation, Electroenceph. Clin. Neurophysiol. 52:595. Ricci, G. B., Romani, G. L., Modena, I., Barbanera, S., Leoni, R. and Carelli, P. 1981b, Magnetic recording in epilepsy, Electro- enceph. Clin. Neurophysiol. 52:595. Rickayzen, G. 1965, Theory of Superconductivity, Interscience Pub- lisher, wiley, New York. Roberts, D.E., Hersh, L.T. and Scher, A.M. 1979, Influence of cardiac fiber orientation on wavefront voltage, conduction veloCity and tissue resistivity in the dog, Circ. ~. 44:701-702. Roberts, D.E. and scher, A.M. 1982, Effect of tissue anisotropy on extracellular potential fields in canine myocardium in situ, Circ. Res. 50:342-351. Robinson, S.E. and Freeman, A.P. 1979, Direct magnetopneumographic measurement of particle concentrations and clearance in the lung, in Proc. IEEE Conf. Frontiers ~ Eng. in Health Care, 183- 188. Robson, J.G. 1966, spatial and temporal contrast-sensitivity functions of the visual system, ~. 2E!. ~. Am. 56:1141-1142. Robson, J.G. 1975, Receptive fields: Neural representation of the spatial and intensive attributes of the visual image, in ~ book ~ Perception, Vol. 5, E.C. Carterette and M.P. Friedman, eds., Academic Press, New York, pp. 81-116. Rodieck, R.W. 1965, Quantitative analysis of cat retinal ganglion REFERENCES 675

cells response to visual stimuli, Vision Res. 5:583-601. Rodieck, R.W. 1979, Visual pathways, Ann. Rev. Neurosci. 2:193-225. Rodieck, R.W. and Dreher, B. 1979, Visual suppression from nondomi- nant eye in the lateral geniculate nucleus: A comparison of cat and monkey, ~. Brain ~. 35:465-477. Romani, G.L. and Fenici, R.R. 1982a, study of the human heart con- duct jon system by the biomagnetic method, U.S.A. - Italy Joint Symposium ~ Methods of Non-Invasive Diagnosis in Cardiovascular Disease, Bethesda, 12-13 November, 1981, in press. Romani, G.L., Modena, I. and Leoni, R. 1982b, Biomagnetism: Recent progress in Italy, Proc. IntI. Conf. ~ Applications of Physics to Medicine and Biology, Trieste, Italy, March, 1982. Romani, G.L., Williamson, S.J. and Kaufman, L. 1982C, Tonotopic organization of the human auditory cortex, Science, 216:1339-1340. Romani, G.L., Williamson, S.J. and Kaufman, L. 1982d, Characteriza- tion of the human auditory cortex by the neuromagnetic method, Exp. Brain Res. 47:381-393. Romani, G.L., Williamson, S.J. and Kaufman, L. 1982e, Biomagnetic instrumentation, Rev. sci. Instrum. 53:1815-1845. Romani, G.L. and Williamson, S.J., eds. 1983, Proc. 4th IntI. Work- shop on Biomagnetism, Rome, Italy, september 1982, 11 Nuovo Cimento~, in press. Rosen, A., Inouye, G.T., Morse, A.L. and Judge, D.L. 1971, Magnetic recordings of the heart·s electrical activity with a cryogenic magnetometer, ~. ~. Phys. 42:3682-3684. Rosen, A., Inouye, G.T., Morse, A.L. and Judge, D.L. 1972, Ultra- sensitive magnetic field measurements in the presence of high ambient noise levels-- application to magnetocardiography, J. ~. Phys. 43:1908-1914. Rosen, A. and Inouye, G.T. 1975, A study of the vector magnetocardiographic waveform, ~ Trans. Biomed. Engr. BME-22:167-174. Rosen, M.R., Fish, C., Hoffman, B.F., Danilo, P., Lovelace, P.E. and Knoebel, S.B. 1980, Can accelerated atrioventricular junc- tional escape rhythms be explained by delayed after-polariza- tions?, Am. ~. Cardiol. 45:1272-1284. Rossiter, C.E., Rivers, D., Bergman, I •• Casswell, C. and Nagel- schmidt, G. 1965, Dust content, radiology and pathology in simple pneumocosiosis of coal miners, Inhaled particles and vapors, II, Pergamon Press, Oxford, pp. 419-434. Rowland, D.J. 1980, Understanding the Electrocardiogram: A ~ Approach, Sect. 1: The Normal ECG, ICI Pharmaceuticals Division, Manchester (England). Rubens, S.M. 1945, Cube-surface coil for producing a uniform magnetic field, Rev. Sci. Instrum. 16:243. Ruch, T.C. and patton, H.D. 1965, PhYSiology and Biophysics, 19th edition, W.B. Saunders, Philadelphia, pp. 31-38. Rudd, M.E. and craig, J.R., Optimum spacing of square and circular coil pairs, ~. Sci. Instrum. 39:1372. Rush, S. 1975, On the independence of magnetic and electric body surface recordings, IEEE Trans. Biomed. Eng. BME-22:157-167. 676 REFERENCES

Rush, S. and Driscoll, D.A. 1968, Current distribution in the brain from surface electrodes: Anesthesia and analgesia, Current Researches 47:717-723. Rushton, W.A.H. 1961, Peripheral coding in the nervous system, in Sensory Communication, W.A. Rosenblith, ed., M.I.T. Press, Cam- bridge, Mass. Saarinen, M., Karp, P.J., Katila, T.E. and Siltanen, P. 1974, The magnetocardiogram in cardiac disorders, cardiovascular Res. 8:820-834. saarinen, M., Siltanen, P., Ahopelto, J. and Katila, T.E. 1975, Magnetocardiograms in healthy men and women, in Proc. III Nordic Meeting ~ Medical and Biological Engineering, A. Uusitalo and N. saranummi, eds., Tampere, Finland, Ch. 55. Saarinen, M., siltanen, P., Katila, T., Karp, P.J. and Varpula, T.E. 1978a, The morphological and multiple analysis of the normal magnetocardiogram, in Modern Electrocardiology, A. Antaloc- zy, ed., Akad$miai Kiado', Budapest, Excerpta Medica, Amster- dam. Saarinen, M., siltanen, P., Karp, P.J. and Katila, T.E. 1978b, The normal magentocardiogram I: Morphology, Ann. Clin. Res. 10(S21): 1-43. Safonov, ¥u.D., Provotorov, V.M., Lube, V.M. and Yakimentov, L.T. 1967, Method of recording the magnetic field of the heart (magnetocardiography), Bull. ~. BioI. and Med. 64:1022-1024. Sandoe, E., Julian, D.G. and Bell, J.W. 1978, Management of ventricular tachycardia: Role of mexiletine, Excerpta Medica, Amsterdam-oxford. Sarwinski, R.E. 1977, Superconducting instruments, Cryogenics 17: 671-679. Savard, P. and Cohen, D. 1979, Magnetic measurements of the dc of the human heart: Coping with extraneous fields from other organs, Digest of 12th IntI. Conf . ~ Medical and Biological Engineering, Jerusalem, Beilinson Medical center, Petah Tikva, Israel, pp. 365. savard, P., Cohen, D. Rifkin, R.D., Lepeschkin, E. and Strauss, W.E. 1981, Magnetic detection of injury current in the human heart, Circ. 64:329 (abstract). Savard, P., Cohen, D., Lepeschkin, E., Cuffin, B.N. and Madias, J.E. 1983, Magnetic measurement of ST and TQ segment shifts in humans, Part 1: Early repolarization and LBBB, submitted for publication. Scher, A.M. and Corbin, L.V. 1976, Cardiac fiber direction and electrocardiographic potentials, Circulation 54, Suppl. 1I-131. Scher, A.M. and Spach, M.S. 1979, Cardiac depolarization and repolarization and the electrocardiogram, in Handbook of Physiology, Part II, The Cardiovascular System, Volume!: The Heart, Berne and N. Sperelakis, eds., Am. Physiol. Soc., Bethesda, pp. 357-392. scherlag, B.J., Helfant, R.H. and Law, S. 1968, Catheter technique for His bundle stimulation and recording in the intact dog, ~. REFERENCES 677

~. Physiol. 25:425. Scherlag, B.J., Law, S., Helfant, R.H., Berkovitz, W.D., stern, E. and Damato, A.N. 1969, Catheter technique for recording His bundle activity in man, Circulation 39:13. Schiller, P. and Malpeli, J.G. 1977, Properties and retinal projections of monkey retinal ganglion cells, ~. Neurophysiol. 40:428- 445. Schwartz, E. 1977, spatial mapping in the primary sensory projection: Analytic structure and relevance to perception, Biological Cybernetics 25:181-194. Schwartz, B.B. and Foner, S., eds. 1976, superconductor Applica- tions: SQUIDS and Machines, Plenum Press, New York. scott, B.I.H. 1962, Electricity in plants, Scientific American 204( 4): 107-117. scott, G.R. and Frohlich, C. 1980, Constructing a magnetically shielded room with transformer steel, Trans. Am. Geoph Union (EIDS) 61:942. Scurlock, R.G. and Saull, B. 1976, Development of multilayer insu- lations with thermal conductivities below 0.1 ~W/cm'K, Cryogenics 16:303. Seipel, J.H. and Morrow, R.D. 1960, The magnetic field accompanying neuronal activity: A new method for the study of the nervous system, ~. wash. Acad. Sci. 50(6):1-4. seppunen, M., Duret, D., Karp, P., Katila, T., Tuomisto, T. and varpula, T. 1982, Measurement of biomagnetic fields using multichannel superconducting magnetometer techniques, Proc. 4th IntI. Workshop on Biomagnetism, Rome, Italy, II Nuovo Cimento Q, in press. Shabetai, R., Surawicz, B., Hammill, W. 1968, Monophasic action potential in man, Circulation 38:341. Shirae, K., Furukawa, H. and Kishida, K. 1981, A new multi-element rf SQUID system and its application to the magnetic vector gradiometer, cryogenics 21:707-710. Shvartsman, V., Barnes, G.R., Shvartsman, L. and Flowers, N.C. 1982, Multichannel signal proceSSing based on logiC averaging, IEEE Trans. Biomed. Eng. BME-29:531-536. Sidman, R.D., Giambalvo, V., Allison, T. and Bergey, P. 1977, A dipole localization method for the localization of sources of human cerebral evoked potentials, Am. EEG Soc., Miami. Sidman, R.D., Giambalvo, V., Allison, T. and Bergey, P. 1978, A method for localization of sources of human cerebral potentials evoked by sensory stimuli, Sensory Proc. 2:116-129. Siltanen, P., Katila, T., poutanen, T., Seppanen, M. and Varpula, T. 1982, Proc. 4th IntI. Workshop on Biomagnetism, Rome, Italy, II Nuovo Cimento Q, to be published. Simson, R., vaughan, H.G., Jr. and Ritter, W. 1976, The scalp topography of potentials associated with missing visual or auditory stimuli, Electroenceph. Clin. Neurophysiol. 40:33-42. Simson, R., Vaughan, H.G., Jr. and Ritter, W. 1977, The scalp topography of potentials in auditory and visual discrimination 678 REFERENCES

tasks, Electroenceph. Clin. Neurophysiol. 42:528-535. Singer, D.H., Lazzara, R. and Hoffman, B.F. 1967, Interrelationship between automaticity and conduction in Purkinje fibers, Circ. Res. 21:537-558. Singer, S.J. 1975, Architecture and topography of biological membranes, Cell Membranes, G. Weissman and R. Cleiborne, eds., HP Publishing, New York, p. 35. Sommers, J.R. and Johnson, E.A. 1979, Ultrastructure of cardiac muscle, in Handbook of Physiology, Section 2, Volume 1, R.M. Berne, ed., pp. 113-186. Spach, M.S., Barr, R.C., Serwer, G.A., Kootsey, J.M. and Johnson, E.A. 1972, Extracellular potentials related to intracellular action potentials in the dog Purkinje system, Circ. Res. 30:505- 519. Spach, M.S., Barr, R.C., Johnson, E.A. and Kootsey, J.M. 1973, Car- diac extracellular potentials, Circ. Res. 33:465-473. Spach, M.S., Miller, W.T., Barr, R.C. and Geselowitz, D.C. 1979a, Influence of cardiac cell-to-cell connections on action potential shape and propagation, Circ. Res. 60:11-208. Spach, M.S., Miller, W.T., Miller-Jones, E., warren, R.B. and Barr, R.C. 1979b, Extracellular potentials related to intracellular action potentials during impulse conduction in anisotropic canine cardiac muscle, Circ. Res. 45:188-204. spach, M.S., Miller, W.T., Geselowitz, D.B., Barr, R.C., Kootsey, J.M. and Johnson, E.A. 1980, The discontinuous nature of propagation in normal canine cardiac muscle, Circ. Res. 87:129-152. spataru, A. 1973, Theorie der Informationsuebertragung, Vieweg Ver- lag, Braunschweig. Spekreisje, H., Estevesz, O. and Reits, D. 1977, Visual evoked potentials and the physiological analysis of visual processes in man, in J.E. Desmedt (Ed.) Visual Evoked Potentials in Man: New Developments, Oxford, Clarendon press, New York. Spekreisje, H. and Reits, D. 1982, Sequential analysis of the evoked potential system in man: Nonlinear analysis of a sandwich system, in Evoked potentials, I. Bodis-Wollner, ed., Annals N. Y. Acad. Sciences 388:45-71. Sperelakis, N. 1979a, Propagation mechanisms in the heart, Ann. Rev. Physiol. 41:441-457. Sperelakis, N. 1979b, Origin of the cardiac resting potential, in Handbook of Physiology, Section 2, Volume 1, R.M. Berne, ed., William and Wilkins, Baltimore, pp. 187-268. Squires, K.C., Wickens, C., Squires, N.K. and Donchin, E. 1976, The effect of stimulus sequence on the waveform of the cortical event-related potential, Science 193:1142-1146. Squires, N.K., squires, K.C. and Hillyard, S.A. 1975, Two varieties of long-latency positive waves evoked by unpredictable auditory stimuli in man, Electroenceph. Clin. Neurophysiol. 38:387-401. Steketee, J., Roggeveen, H. and Kingura, Y.J. 1980, Measurement of magnetic susceptibility in living rats, Med. BioI. Eng. Comput. 18:253-259. REFERENCES 679 sterling, T.D. 1981, Possible risks to human lungs from magnetome- tric dust clearance experiments, ~. ~. Phys. 52:2575-2577. stern, R.M. 1977, A chemic~l, physical and biological essay of welding fumes, publication 77.05, The Danish Welding University, Copenhagen, p. 78. stevens, S.S. 1970, Neural events and the psychophysical law, Science 170:1043-1050. StOber, W., Einbrodt, J. and KlosterkOtter, W. 1965, Quantitative studies of dust retention in animal and human lungs after chron- ic inhalation, Inhaled Particles and vapors II, pergamon Press, Oxford, pp. 409-418. Stockard, J.J. 1982, Brainstem auditory evoked potentials in adult and infant sleep apnea syndromes, including sudden infant death syndrome and near-miss for sudden infant death, in Evoked Potentials, I. Bodis-Wollner, ed., Annals ~. !. Acad. sciences 388:443-465. stone, J. 1972, Morphology and physiology of the geniculocortical synapse in the cat: The question of parallel input to the striate cortex, Invest. ophthal. 11:338-346. Stratbucker, R.A., Hyde, C.M. and Wixon, S.E. 1963, The magnetocardiogram: A new approach to the field surrounding the heart, IEEE Trans. Biomed. Eng. BME-I0:145-149. strauss, H.C., saroff, A.L., Bigger, J.T. and Giardina, E.G.V. 1973, Premature atrial stimulation as a way to the understanding of sinoatrial conduction in man, Circulation 47:86. Streeter, D.D. 1969, Gross morphology and fiber geometry of the heart, in Handbook of Physiology, Section 2, Volume 1, R.M. Berne, ed., William and Wilkins, Baltimore, pp. 61-112. Stroink, G., Dahn, D. and Holland, J. 1981a, Magnetopneumographic estimation of lung dust loads and distribution in asbestos miners and millers, Am. Rev. of Resp. Disease 123/4:144. Stroink, G., Dunlap, A. and Hutt, D. 1981b, Room temperature magnetization measurements of some Canadian chrysatiles and UICC* asbestos samples, ~. Minerology 19/4. stroink, G. and Dahm, D. 1981C, Magnetic field measurements on lungs: A comparison between two methods, in Erne' et al. (1981a, pp. 485-488). Stroink, G., Blackford, B., Brown, B. and Horacek, M. 1981d, Alumi- num shielded room for biomagnetic measurements, ~. Sci. tn- strum. 52:463-468. Stroink, G., Dahn, D. and Braver, F. 1982, A lung model to study the magnetic field of lungs of miners, IEEE Trans. Magn. MAG-18: 1791-1793. stuart, C.l.J.M., Woods, S.B., Crawford, A.C., Thomas, N.R. and Newbound, K.B. 1981, Rand T waves in the MCG and ECG, in Erne' et al. (1981a, pp. 291-301). Sullivan, D.B., Zimmerman, J.E. and Ives, J.T. 1981, Operation of a practical SQUID gradiometer in a low-power Stirling cryocooler, Refrigeration for Cryogenic Sensors and Electronic Systems, J.E. Zimmerman, O.B. Sullivan and S.E. MCCarthy, eds., NBS special 680 REFERENCES

Publication 607, pp. 186-194. Suomaa, L., Lekkala, J. and Malmivuo, J. 1980, A coil system for compensating earth's magnetic field, Research Report No. 13/1980, Electronics Laboratory, Tampere University of Technolo- gy, Finland. sutton, S., Braren, M., Zubin, J. and John, E.R. 1965, Evoked- potential correlates of stimulus uncertainty, Science 150:1187- 1188. sutton, S., Tueting, P., Zubin, J. and John, E.R. 1967, Information delivery and the sensory evoked potentials, Science 155:1436- 1439. Swinney, K.R. and Wikswo, J.P., Jr. 1980, A calculation of the magnetic field of a nerve action potential, Biophys. ~. 32:719-732. swithenby, S.J. 1980, SQUIDS and their applications in the measurement of weak magnetic fields, ~. Phys. Sci. Instrum. 13:801-813. Taccardi, B., De Ambroggi, L. and viganotti, C. 1976, Body surface mapping of heart potentials, in The Theoretical Basis of Elec- trQcardiology, C.V. Nelson and D.B. Geselowitz, eds., Clarendon Press, Oxford, pp. 436-466. Taccardi, B., MuSSO, E. and De Ambroggi, L. 1971, Potential fields of normal and ischemic hearts during rest, ventricular excitation and recovery, in vectorcardiography £, I. Hoffman, ed., North Holland, Amsterdam, pp. 142-145. Task Group on Lung Dynamics 1966, Deposition and retention models for internal dOSimetry of the human respiratory tract, Health Physics 12:173-207. Tesch, F-W. 1980, Migratory performance and environmental evidence of orientation, in Environmental Physiology of Fishes, M.A. Ail, ed., Plenum Press, New York, pp. 589-612. ~eyler, J.T., Cuffin, B.N. and Cohen, D. 1975, The visual evoked magnetoencephalogram, Life Sci. 17:683-692. Tinkham, M. 1975, Introduction to Superconductivity, McGraw-Hill, New York. Tolhurst, D.J. and Thompson, 1.0. 1981, On the variety of spatial frequency selectivities shown by neurons in area 17 of the cat, ----Proc. -R. ---Soc. ----Lond. B 213:183-199. Tossavainen, A. 1976, Metal fumes in foundries, Scan. ~. Work Envi- ~. Health (Suppl.) 1:42-49. Touboul, P., Huerta, F., Porte, J. and Delahaye, J.P. 1976, ReCip- rocal rhythm in patient with normal electrocardiogram: Evidence for dual conduction pathways, Am. Heart ~. 91(1):3-10. Towe, K.M. and Lowenstam, H.A. 1967, Ultrasonic and development of iron mineralization in the radular teeth of Chryptochiton Stelleri (mollusca), ~. Ultrastruct. Res. 17:1-13. Towe, K.M. and Moench, T.T. 1981, Electron-optical characterization of bacterial magnetite, Earth Planet. Sci. Lett. 52:213-220. Trautwein, W. 1963, Generation and conduction of impulses ,in the heart as affected by drugs, Pharmacol. Rev. 15:277. Tripp, J.H. 1977, Effects of torso geometry on the magnetocardiogram, Biophys. ~. 18:269-273. REFERENCES 681

Tripp, J.H. 1979a, The theory of the magnetocardiogram, Adv. Cardi- ~. Phys. 1:29-46. Tripp, J.H. 1979b, Eff.ect of torso geometry on the magnetocardiogram, Biophys. ~. 18:269-273. Tripp, J.H. 1981, Biomagnetic fields and cellular current flow, in Erne' et al. (198la, pp. 207-215). Tripp, J.H. 1982, Biomagnetic fields sources and significance, Phys. Bull. 33:175-178. Tripp, J.H. and Farrell, D.E. 1981a, Magnetic field of the cardiac conduction system, ~. ~. Phys. 52:2560-2564. Tripp, J.H. and Farrell, D.E. 1981b, Theory of the PR segment of the human magnetocardiogram, in Erne' et al. (198la, pp. 259- 271) • Tuomisto, T., Hari, R., Katila, T., Poutanen, T. and Varpula, T. 1982, Effect of stimulus repetition rat on the auditory vertex response and its magnetic counterpart, Proc. 4th IntI. Workshop on Biomagnetism, Rome, Italy, II Nuovo Cimento ~, in press. Ueno, S. and Fukui; Y. 1978, Current dipole model for the electroencephalogram and the magnetoencephalogram, with application to diagnosis of the central nervous diseases, Memoirs of the Faculty of Engineering, Kyushu University, 38:207-217. Ulfvarson, M., Hallne, U., Bellander, T., SjOgren, B. and Svens- son, A. 1978, ArbetsmiljOproblem vid svetsning. Del 5. Svetsn- ing av rostfrittstal med metallbagsvetsning och gasbagsvetsning. I Karlaggning av luftroreningar II. Medicinsk undersOkning av svetsare. Arbeta och Halsa 1978/8. Stockholm (in Swedish). van der Tweel, L.H., Estevez, O. and Cavonius, C.R. 1979, Invari- ance of the contrast evoked potential with changes in retinal illuminance, Vision Res. 19:1283-1287. Van Essen, D.C. 1979, Visual areas of the mammalian cereral cortex, Ann. Rev. Neurosci. 2:227-263. Varpula, T. 1982, studies of weak magnetic fields: Application of superconducting magnetometry for monitoring ocular, cerebral and cardiac function in man, Ph.D. thesis, Helsinki University of Technology. Vaughan, H.G., Jr., Costa, L.D. and Ritter, W. 1968, Topography of the human motor potential, Electroenceph. Clin. Neurophysiol. 25:1-10. Vaughan, H.G., Jr., Gross, E.G. and Bossom, J. 1970a, Cortical motor potential in monkeys before and after upper limb deaffer- entation, Exp. Neurology 26:253-262. Vaughan, H.G., Jr. and Ritter, W. 1970b, The sources of auditory evoked responses recorded from the human scalp, Electroenceph. Clin. Neurophysiol. 28:360-367. Vedenski, V.L. and Ozhnogin, V.I. 1981, superconducting magnetometry and biomagnetism, Priroda 7:23-31. Vrba, J., Fife, A.A., Burbank, M.B., Weinberg, H. and Brickett, P.A. 1982, spatial discrimination in SQUID gradiometer and 3rd order gradiometer performance, Can. ~. Phys. 60, 1-12. Walcott, C. 1980, Magnetic orientation in homing pigeons, IEEE 682 REFERENCES

Trans. ~ Magnetics MAG-16:1008-1013. Walcott, C. and Green, R.P. 1974, Orientation of homing pigeons al- tered by a change in the direction of an applied magnetic field, Science 184:180. Walcott, C., Gould, J.L. and Kirschvink, J.L. 1979, pigeons have magnets, Science 205:1027-1029. Walker, M.M. and Dizon, A.E. 1981, Identification of magnetite in tuna, Trans. Am. Geoph. Union (EIDS) 62:850. Wallach, H. and Zuckerman, C. 1963, The constancy of stereoscopic depth, Amer. ~. Psychol. 76:404-12. Walter, D.O. 1969, A posteriori "Weiner filtering" of average evoked responses, Electroenceph. Clin. Neurophysiol. suppl. 27:61-70. Walter, W.G., cooper, R., Aldridge, V.J., MCCallum, W.C. and Winter, A.L. 1964, contingent negative variation: An electric sign of sensorimotor association and expectancy of the human brain, Nature 203:380-384. Walton, D. 1977, Aracheomagnetic intensity measurements using a SQUID magnetometer, Archaeometry 19:192-200. Warren, J.M. and Akert, K., eds. 1964, The Frontal Granular Cortex and Behavior, McGraw-Hill, New York. Watanabe, A. and Grundfest, H. 1961, Impulse propagation at the septral and commissural junctions of crayfish lateral axons, J. Gen. Physiol. 45:267-308. Weidmann, S. 1955, The effect of the cardiac membrane potential on the rapid availability of the sodium carrying system, J. Physiol., London, 127:213. Weidmann, S. 1969, Electrical coupling between myocardial cells, Prog. Brain Res. 31:275-281. Weinberg, H., Deecke, L., Brickett, P. and Boschert, J. 1983, Slow magnetic fields of the brain preceding voluntary movement, Proc. 4th IntI. Workshop on Biomagnetism, Rome, Italy, II Nuovo Cimento Q, in press. Wellens, H.J.J. and DUrrer, D.R. 1975, The role of an accessory atrioventricular pathway in reciprocal tachycardia: Observations in patients with and without the Wolf-Parkinson-White syndrome, Circulation 52:58. Wellens, H.J.J., DUrrer, D.R. 1976, Observations on mechanisms of ventricular tachycardia in man, Circulation 54:237. Wheatstone, C. 1838, On some remarkable, and hitherto unresolved, phenomena of binocular vision, Roy. Soc. of London, Philosoph. Trans., 371-94. Whitteridge, D. and Daniel, P.M. 1961, The representation of the visual field on the calcarine cortex, in The Visual System: Neurophysiology and Psychophysics, J. Jung and H. Kornhuber, eds., springer, Berlin, pp. 221-227. Wiener, N. 1949, Extrapolation, Interpolation and Smoothing of stationary Time Series, Wiley, New York. Wiesel, T.N. and Hubel, D.H. 1966, spatial and chromatic interactions in the lateral geniculate body of the rhesus monkey, J. REFERENCES 683

Neurophysiol. 29:1115-1156. Wikswo, J.P., Jr. 1975, Non-Invasive Magnetic Measurement of the Electrical and Mechanical Activity of the Heart, Ph.D. dissertation, Department of Physics, Stanford University, California. Wikswo, J.P., Jr. 1978a, optimization of SQUID differential magnetometers, AlP Conf. Proc. 44:145-149. Wikswo, J.P., Jr. 1978b, The calculation of the magnetic field from a current distribution: Application to finite element techniques, IEEE Trans. Magn. MAG-14:1976-1977. Wikswo, J.P., Jr. 1978c, A guide to scalar multipole expansions, Report PAS-78-36, David W. Taylor Naval Ship Research and Devel- opment Center, Bethesda, Md. Wikswo, J.P., Jr. 1979, Clinical magnetocardiography, in Non- invasive Cardiovascular Measurements, Society of Photo-optical Instrumentation Engineer, Bellingham, WA, USA, pp. 181-193 Wikswo, J.P., Jr. 1980a, Non-invasive magnetic detection of cardiac mechanical activity: Theory, Med. Phys. 7:297-306. Wikswo, J.P., Jr. 1980b, Measurements of magnetic field of isolated nerves, IEEE 1980 Frontiers of Engineering in Health Care 141- 144. Wikswo, J.P., Jr. 1981, Recent developments in the measurement of magnetic fields from isolated nerves and muscles, ~. ~. Phys. 52:2554-2559. Wikswo, J.P., Jr. 1982, Improved instrumentation for measuring the magnetic field of cellular action currents, Rev. Sci. Instrum .. 53:1846-1850. Wikswo, J.P., Jr., opfer, J.E. and Fairbank, W.M. 1974, Observation of human cardiac blood flow by non-invasive measurement of magnetic susceptibility changes, AlP Conf. Proc. 18:1335-1339. Wikswo, J.P., Jr. and Fairbank, W.M. 1977, Application of superconducting magnetometers to the measurement of the vector magnetocardiogram, IEEE Trans. Magn. MAG-13 354-357. Wikswo, J.P., Jr., Griffin J., Leifer, M., Barry, W.M. and Harri- son, D.C. 1978, vector magnetocardiography: The effect of the heart-lung boundary, Clinical Research 26:486A. Wikswo, J.P., Jr., Malmivuo, J.A.V., Barry, W.H., Lefier, M.C. and Fairbank, W.M. 197·9, The theory and application of magnetocardiography, in Cardiovascular Physics, D.N. Ghista, ed., S. Karger, Basel, pp. 1-67. Wikswo, J.P., Jr., Barach, J.P. and Freeman, J.A. 19S0a, MagnetiC field of a nerve impulse: First measurements, Science 208:53-55. Wikswo, J.P., Jr. and Barach, J.P. 19S0b, An estimate of the steady magnetic field strength required to influence nerve conduction, IEEE Trans. Biomed. Eng. BME-27, 722-723. Wikswo, J. P ., Jr., Opfer, J. E. and Fairbank, W. M. 19S0C, Non-invasive magnetic direction of cardiac mechanical activity: Experi- ment, Medical Physics 7:307-314. Wikswo, J.P., Jr., palmer, J.O. and Barach, J.P. 19S1, MagnetiC measurements of action currents in single isolated nerve axons, Bull. Am. Phys. Soc. 26: 1223.. 684 REFERENCES

Wikswo, J.P., Jr. and Barach, J.P. 1982a, Possible sources of new information in the magnetocardiogram, J. Theoretical BioI. 95:721-729. Wikswo, J.P., Jr., Samson, P.C. and Giffard, R.P. 1982b, A low- noise, low input impedance amplifier for general measurements of nerve action currents, IEEE Trans. Biomed. Eng., in press. Wikswo, J. P ., Jr., McLean, M. J ., Barach, J. P . , Freeman, J . A. and Gundersen, S.C. 1983a, First magnetic measurements of action currents in cardiac Purkinje fibers, in Proc. 4th IntI. Workshop on Biomagnetism, II Nuovo Cimento Q, in press. Wikswo, J.P., Jr., Palmer, J.O., Barach, J.A. and Gundersen, S.C. 1983b, Magnetic measurements of action currents in an isolated lobster axon, in Proc. 4th IntI. Workshop on Biomagnetism, II Nuovo Cimento Q, in press. Willey, J. 1982, Magnetic properties of asbestos fibers, IEEE Trans. Magn. MAG-18:1794-1795. Williamson, S.J., Kaufman, L. and Brenner, D. 1977, Biomagnetism, in sUperconductor Applications: SQUIDS and Machines, B.B. Schwartz and S. Foner, eds., Plenum, New York, pp. 355-402. Williamson, S.J., Brenner, D., and Kaufman, L. 1978a, Biomedical applications of SQUIDS, AlP Conf. Proc. 44:106-116. Williamson, S.J. and Kaufman, L. 1978b, Applications of SQUID detectors in biomagnetism, in NBS Special Publication 508, pp. 177-204. Williamson, S.J., Kaufman, L. and Brenner, D. 1978C, Latency of the neuromagnetic response of the human visual cortex, Vision Res. 18: 107-110. Williamson, S.J., Kaufman, L. and Brenner, D. 1979, Evoked neuromagnetic fields of the human brain, ~. ~. Phys. 50:2418-2421. Williamson, S.J. and Kaufman, L. 1980a, Le magn~tisme du cerveau, La Recherche 112:722-724. Williamson, S.J. and Kaufman, L. 1980b, Magnetic fields of the human brain, ~. Magn. Mat. 15-18, Part III, 1548-1550. Williamson, S.J. and Kaufman, L. 1981a, Biomagnetism, J. Magn. Mat. 22:129-201. Williamson, S.J. and Kaufman, L. 1981b, Magnetic fields of the'cerebral cortex, in Erne' et al. (1981a, pp. 353-402). Wilson, F.N. and Bayley, R.H. 1950, The electric field of an eccen- tric dipole in a homogeneous spherical conducting medium, Circulation 1:84-92. Wilson, M.E. and Cragg, B.G. 1967, Projections from the lateral geniculate nucleus in the cat and monkey, ~. Anat. 101:677-692. Wiltschko, W. and Wiltschko, R. 1972, Magnetic compass of European robins, Science 176:62-64. Wise, S.P. and Evarts, E.V. 1981, The role of the cerebral cortex in movement, Trends in Neurosciences 4:297-300. Wit, A.L., Rosen, M.R. and Hoffman, B.F. 1974, Electrophysiology and pharmacology of cardiac arrhythmias: II Relationship of normal and abnormal electrical activity of cardiac fibers to the genesis of arrhythmias, Am. Heart ~. 88(4):515-524. REFERENCES 685

Wohlfarth, E.P. 1958, Relations between different modes of acquisi- tion of remanent magnetization of ferromagnetic particles, ~. ~. Phys. 29:595-596. Wood, C.C. 1982, Application of dipole localization methods to source identification of human evoked potentials, ~. ~. Y. Acad. SCi., in press. Wood, C.C., Allison, T., Goff, W.R., Williamson, P.D. and Spencer, D.B. 1980, On the neural origin of P300 in man, Progress in Brain Res. 54:51-56. Wood,----- C.C.--- and Allison, T. 1981, Interpretation of evoked potentials: A neurophysiological perspective, Canad. ~. of psychology 35:113-135. Wood, C.C., Macarthy, G., Squires, N.K., Vaughan, H.G., Woods, D.L. and Mccallum, W.C. 1982, Anatomical and physiological substrates of event-related potentials: TWo case studies, Ann. ~.!. Acad. Sci., in press. Woosley, C.N. 1947, Patterns of sensory representation in the cerebral cortex, Fed. ~. 6:437-441. Woosley, C.N., Marshall, W.H. and Bard, P. 1942, Representation of cutaneous tactile sensibility in the cerebral cortex of the monkey as indicated by evoked potentials, Bull. Johns Hopkins Hosp. 70:399-441. woosley, J.K. and Wikswo, J.P., Jr. 1982, A general technique for calculation of magnetic fields of active biological fibers, in preparation. Wynn, W.M., Frahm, C.P., Carroll, P.J., Clark, R.H., Welhoner, J. and Wynn, M.J. 1975, Advanced superconducting gradiometer/magnetometer arrays and a novel signal processing technique, IEEE Trans. Magn. MAG-11:701-707. Yeagley, H.L. 1947, A preliminary study of a physical basis of bird navigation, ~. ~. Physics 18:1035-1063. Yeh, H.C., Phalen, R.F. and Raabe, O.G. 1976, Factors influencing the deposition of inhaled particles, Environ. Health perspect. 15:147-156. Yeh, S-Y., Forsythe, A. and Hon. E.H. 1973, Quantification of fetal heart beat-to-beat interval differences, Obstet. Gynecol. 41: 255. Yorke, E.D. 1979, A possible magnetic transducer in birds, J. Theor. BioI. 77:101-105. Yorke, E.D., 1981, Sensitivity of pigeons to small magnetic field variations, ~. Theor. Biol. 89:533-537. Zijlstra, H. 1967, Experimental Methods in Magnetism, Volume IX, Part 1, E.P. Wohlfarth, ed., North-Holland, Amsterdam, p. 38. Zimmerman, J.E. 1971, Sensitivity enhancement of superconducting quantum interference devices through the use of fractional-turn loops, ~. ~. Phys. 42:4483-4487. Zimmezman, J.E. 1972, Josephson effect devices and low-frequency field sensing, Cryogenics 12:19-31. Zimmerman, J.E. 1977, SQUID instruments and shielding for low-level magnetic measurements, ~. ~. Phys. 48:702-710. 686 REFERENCES Zimmerman, J.E. 1980, cryogenics for SQUIDs, in Hahlbohm and LUbbig (1980, pp. 423-443). Zimmerman, J.E. and Silver, A.H. 1966, Macroscopic quantum interference effects through superconducting point contacts, Phys. Rev. 141:367-375. Zimmerman, J.E., Thiene, P. and Harding, J.T. 1970, Design and operation of stable rf-biased superconducting pOint-contact quantum devices, and a note on the properties of perfectly clean metal contacts, ~. ~. Phys. 41:1572-1580. Zimmerman, J.E. and Frederick, N.V. 1971a, Miniature ultra-sensitive magnetic gradiometer and its use in cardiography and other applications, ~. Phys. Lett. 1:16-19. Zimmerman, J.E. and Frederick, N.V. 1971b, Ultrasensitive superconducting magnetic gradiometer, National Bureau of Standards Report 10:736. Zimmerman, J.E. and Sullivan, D.B. 1972, A study of design principles for refrigerators for low-power cryoelectronic devices, NBS Technical Note No. 1049, National Technical Information Service, springfield, VA 2·2161. Zimmerman, J.E. and Siegwarth, J.D. 1973, Portable helium dewars for use with superconducting magnetometers, Cryogenics 12:158. Zimmerman, J.E. and Campbell, W.H. 1975, Tests of cryogenic SQUID for geomagnetic field measurements, Geophys. 40:269-28. Zimmerman, J.T. 1981, Magnetic Investigations of Cortical Excita- tion and Inhibition Preceeding Voluntary Movement: A Test of Levi and Reid's IpSilateral Motor Cortical Hypothesis, Ph.D. TheSis, University of Colorado, Boulder. Zimmerman, J.T., Edrich, J., Zimmerman, J.E. and Reite, M.L. 1978a, The human magnetoencephalogram averaged visual evoked field, in Proc. ~ Diego Biomed. Symposium, J.T. Martin and E.A. Calvert eds., Academic Press, New York, Vol. 17, pp. 217-221. Zimmerman, J.T. and Radebaugh, R., Operation of a very low-power cryocooler, in Applications of Closed Cycle Cryocoolers to Small sUperconducting Devices, J.E. Zimmerman and T.M. Flynn, eds., NBS Special Publication No. 508:59-65. Zimmerman, J.T., Reite, M. and Zimmerman, J.E. 1981, Magnetic evoked fields: Dipole orientation, Electroenceph. Clin. Neurophysiol. 52:151-156. Zoeger, J., Dunn, J.R. and Fuller, M. 1981, MagnetiC material in the head of a common Pacific dolphin, Science 213:892. LECTURERS AND DIRECTORS

Dr. Pasquale Carelli Istituto di Elettronica dello stato Solido, C.N.R. Via Cineto Romano 42 00156 Rome, Italy (L)

Dr. David Cohen Francis Bitter National Magnet Laboratory M.I.T. 170 Albany Street Cambridge, MA, 02139, U.S.A. (L)

Dr. sergio Erne Physikalische-Technische Bundesanstalt-IB Abbestrasse 2-12 1 Berlin 10, west Germany (L)

Prof. David E. Farrell Physics Department Case western Reserve University Cleveland, OH, 44106, U.S.A. (L)

Dr. Riccardo Fenici Biomagnetic Unit, 1st Patologia Medica Facolta' di Medicina e Chirurgia Universita' Cattolica del Sacro Cuore 00168 Rome, Italy (L )

Dr. Pirkko-Liisa Kalliomaki Institute of occupational Health Haartmanink 1 SF-00290 Helsinki. 29, Finland (L) Dr. Veikko Kariniemi Department of Obstetrics and Gynocology Helsinki UniverSity Central Hospital Haartmanink 2 00290 Helsinki 29, Finland (L)

Prof. Toivo E. Katila Department of Technical Physics Helsinki University of Technology 02150 Espoo 15, Finland (L) 687 688 LECTURERS AND DIRECTORS

Prof. Lloyd Kaufman Department of Psychology New York University 6 washington Place New York, NY, 10003, U.S.A. (D)

Prof. .Joseph L. Kirschvink Division of Geological and Planetary Sciences California Institute of Technology pasadena, CA, 91125, U.S.A. (L)

Dr. Hans Lehmann Physikalische-Technische BUndesanstalt IB Abbestrasse 2-12 1 Berlin 10, west Germany (L)

Prof. Peter Lennie center for Visual Science University of Rochester Rochester, NY, 14627, U.S.A. (L)

Prof. Ivo Modena Istituto di Elettronica dello Stato Solido, C.N.R. Via Cineto Romano 42 00156 Rome, Italy (D)

Prof. Yoshio Okada Department of Psychology New York University 6 washington Place New York, NY, 10003, U.S.A. (L)

Dr. Gian-Luca Romani Istituto di Elettronica dello Stato Solido, C.N.R. Via Cineto ~.ano 42 00156 Rome, Italy (D)

Prof. Bruno Taccardi Istituto di Fisiologia Generale Via Gramsci, 14 43100 parma, Italy (L)

Dr. John H. Tripp Physics Department Case Western Reserve University Cleveland, OH, 44106, U.S.A. (L)

Dr. John P. Wikswo, Jr. Department of Physics and Astronomy Vanderbilt University Box 1807, Station B Nashville, TN, 37235, U.S.A. (L)

Prof·. Samuel J. Williamson Department of Physics New York University 4 Washington Place New York, NY, 10003, U.S.A. (D) LECTURERS AND DIRECTORS 689

Dr. James E. Zimmerman Cryoelectronic Metrology Group Division 724 National Bureau of standards Boulder, CO, 80303, U.S.A. (L) INDEX

Accommodation, 144, 151 Action potential (continued) Action current, 173, 187, 196, response of cel1s (continued) 205 slow, 212, 214 dipole model, 106, 175-176 in skeletal muscle, 156 Action field, 173-207 threshold, 149 of isolated axon, 196-197 Adaptive filter, 624 origin, 174-182 Alpha rhythm, 473-475 pattern, 176 Aluminum of Purkinge fiber resistivity, 571 in vitro, 205 skin depth, 571 in vivo, 275-279, 295-298 susceptibility, 29 recording instrumentation, Alveoli, 535-537 187-201 macrophages, 542-543 of sciatic nerve, 192 Ampere, Andre' strength estimate, 176-178 law, 19, 21, 107 Action potential, 149-150 unit of current, 21, 27 and cable model, 176-182 Amplitude response, of filter, in cardiac conduction 580, 582 system, 159, 202, 212- Analog-to-digital conversion, 216 599-600 current densities, 179, 196, Antiferromagnetism, 33, 509 156, 205 Arrhythmia, 219-222, 230 and current dipole source, magnetic studies, 292, 294, 175-176 298 and dynamic range, 364-365 Asbestos miners, electrical model, 154-156 lung contamination, 560 extracellular potential, 155 Atrioventricular node, 157, equivalent current dipole 163, 214-215 source, 106, 175-176 response to stimulation, monophasic, 228-229 232-233 in myocardial fibers, 158, Attenuation 160-161 of field, 118 in nerve fibers, 154-156 by eddy currents, 118, 570- in pacemaker fibers, 159 572 refractory period, 144, 150 by feedback, 576 response of cells by magnetic shielding, 572- fast, 212-213 576

691 692 INDEX

Attenuation (continued) Biomagnetic field (continued) of electrical signal brain (continued) by analog filter, 580-587 spontaneous activity by digital filter, 614-624 (continued) 469-482 Audition breast, 334 sound localization, 388-389 eye, 341-351 Auditory evoked field, 433-442 heart, 8-9, 237-298 hemispheric asymmetry, 436- perinatal, 299-307 438 isolated tissue, 173-207 pattern, 433-436 limbs, 333-334 tonotopic representation, liver susceptibility, 483-499 438-441 lung, 545-568 Automaticity, 159, 213 scalp, 332-333 disturbances of, 220-222 skeletal muscle, 11 Avogadro number, 46 torso, 334 Axon action field, 196-197 Biomagnetism definition, vii Bacteria, magnetism of, 502, Biomineralization, 502-508 504, 512-513 Biopsy, ~ Magnetic biopsy Balancing procedure Biot-Savart law, 105 for gradiometer, 97-99 Bipolar leads, 217 Bardeen, John, 72 Black-body radiation, 51 Barlow, H.B., 371, 375 Boltzmann, Ludwig, 45 specific nerve energies, Boltzmann's constant, 45 370-371, 390 Brain Baseline of gradiometer, 91 cortex, 356 Bee cytoarchitecture, .357-358 magnetic dance, 515 somatic area, 362 magnetic particles, 530- visual area, 360-362 531 evoked fields Bereitschaftspotential, 424, psychophysical thresholds, 460 396 Bessel filter, 582-583 hemispheric asymmetry, 363 Beta rhythm, 476 single-unit activity, 364, B field, 17, 22 378 Biogenic ferrimagnetism, 13, evoked potentials, 382-383 501-531 psychophysical thresholds, crystal morphologies, 505- 390-382 507 structural features, 355-363 detection of, 522-531 (~ also Perception) distribution among phyla, Brain activity 503 evoked responses, 399-468 functions, 512-516 spontaneous activity, 9-10, Biomagnetic field 469-482 abdomen, 329 Breast field, 334 biogenic materials, 501- Bronchioles, 535 531 Bundle branches, 157, 163 brain, 9-10, 399-482 branch block, 270-271, .290- evoked responses, 399-468 291 spontaneous activity, 9-10, in vector cardiograms, 313 INDEX 693

Butterworth filter, 582 Coil detection, for SQUID, 70, 85, Cable model 89-95 for action potential, 182-187 Helmholtz geometry, 97 for graded potential, 151-154 induction, 6, 37, 46 Cardiac field (~ also Induction coil) of conduction system Rubens geometry, 97 in vitro fiber, 204-205 Comb filter, 281, 584-587 in vivo, 275-284, 295-298 Compass, biological, 513 of fetus, 300-302 European robin, 515 of myocardium, 201-202, 241- homing pigeon, 514 245, 265-274, 287-294, honey bee, 515 298 other species, 516, 519 of neonate, 302-305 Compass, field indicator, 102 (see also Computer simulations Magnetocardiography) His-Purkinje activity, 296- Cardiac potential, 202-204 298 Ca~diac electrophysiology, 211 magnetocardiogram, 243-245 clinical aspects, 227 Conduction, cellular invasive, 228-233 of cardiac activity, 215-217 late potential, 298 decremental, 216 non-invasive, 233 disturbances of, 223 Cardiac stimulation, 230-233 of excitable cell, 143, 213 Carnot, Sadi, 61 saltatory, 156 coefficient of efficiency, 61 Conduction cells, 143, 213 Catheter techniques, 227 Conduction system of heart, Cellular excitations, 141-142 157, 216-217 Cellular fields Conductivity observation, 187-192, 196- electrical, 35 197, 201-206 anisotropic, 160, 324-325 Ceramic magnets, 34 thermal, 50 Charge dipole, 108 Contamination and current dipole, 108-109 magnetic, 521 Chebyschev filter, 582 Contingent negative variation, Chemical transmitters, 142 460 Chitons, 502, 512 Cooper, Leon, 72 Cilia, 540 Copper Clearance, of lung particles resistivity, 571 540-543 skin depth, 571 from alveoli, 540-543 Core conductor model, 151-154, isotope studies, 542 182-187 mechanisms, 541-543 Coronary artery disease from tracheobronchial tree, ST depression, 270 540 Coronary artery occlusion Closed-field neuron, 402-403 current of injury, 265 Coal miners Cortex, 356-363 lung contamination, 560, 566 structure, 357-358, 403-405 Coercive field, 512 (~ also the specific and sample treatment, 546 sensory area) spectrum, particles, 526-528 Coulomb, Charles, 21 694 INDEX

Coulomb, Charles (continued) Current quadrupole, 246 unit of charge, 21 of action potential, 177 Coupling coefficient coefficients, 249 of mutual inductance, 90 tensor, 249, 255-256 Cruciform model, 443 cylindrical conductor model, 128 Cryocoolers, 60-67 cryogenics, 43, 49 Dc fields, !!! steady fields Cryostat, 49, 54-58 Dc magnetocardiogram, 265-273 Curl, Ill, 315 Decay time, 48 Current, 17-18 RlL, 48 cellular, for graded De-gaussing, 520 potential, 399-402 Delta rhythm, 476 density Demagnetizing, 520 current dipole density, 106 alternating field, 527-529 sheet, 20 Demagnetization volume, 22 of magnetic contaminants, 271 displacement, 104 Dendrites, 357-358, 400, 404 induced, 24-26 graded potential, 400 impressed, 117 Depolarization, of injury, 161 cellular, 149, 155 primary, 123, 314, 317 late, in heart, 298 volume, 106, 117 of myocardium, 163-166 Current dipole, 104 slow phase-4, 214 and charge dipole, 108 Deposition of particles in deduced from field data, 130- lung, 537-540, 563 132, 406-408 Detection coil, 70, 85, 89-95 multiple dipoles, 132-133 gradiometers, 330-332 field pattern of, 11, 105-108 inductance, 635-638 in a half space, 130-132, for localized sensitivity, 406-408 551, 492-496 in a sphere, 406-407 magnetometer, 90-91 and magnetic dipole, 315 2-D system, 268, 330-332 of injury current, 265 for uniform sensitivity, 548 layer of myocardium, 161 Dewar, 54-58 moment, 105 Dewar, James, 54 and cellular parameters, Diamagnetism, 30, 485 407-408 Diastole, 161 multiple dipole model of Dielectric constant, 102 heart, 243-245 Digital filtering, 614-624 potential pattern, 105-108 ! posteriori, 614, 621 source strength, 119 frequency response, 617 vector potential, III impulse response, 615-617 vorticity, 119 non-recursive, 615-617 Current of injury, 161-163, windowing technique, 612- 265-266, 338 613, 619-622 measurement of, 265-272 recursive, 615, 621-624 Current multipole expansion, Dipole, !!! Current dipole and 319-321, 245-252 !!! Magnetic dipole for field., 250-252 Displacement current, 102, 116 for potential, 246-250 and ohmic current, 117 INDEX 695

Divergence, 118, 315 Electrolytic gradients,. 335 Domain, magnetic, 31, 510 magnetic fields, 335 growth, 547 Electromyogram, 425 in magnetite, 510 Electronic filtering reorientation, 547 active, 598 single, 511, 519, 527 adaptive, 624 Double layer model, 318-319 amplitude response, 580, 582 Dust, magnetic properties, 547 analog, 579-589 artifacts, 587 Eddy currents, 24-26 digital, 614-624 attenuation of field frequency response, 579, 588, in body, 118 617 in magnetic shield, 8, 519- general theory, 588-589 521, 570-572 group delay, 579, 582 for cylinder, 570 order of filter, 581, 588 shielding, 569-572 phase response, 580 shielding factor, 571 signal averaging, 592-598 skin depth, 570, 574 types of filters, 582-584 Einthoven's hypotheses, 216 Electrotonic spread, 154 triangle, 217 Endogeneous field, 460-468 Electric heart vector, 248 components, 463-465 bundle branch block, 313 pattern, 465-466 and magnetic heart vedtor, source localization, 465-468 322-323 Endogeneous potential, 460-463 Electric potential components, 460-462 of current dipole, 105, 108 source localization, 462-463 of current distribution, 112 Energy sensitivity of current element, 105 definition, 41 dependence on solid angle, for SQUID system, 70, 83 124-126, 164-165 Epilepsy of impressed current, 118 magnetic activity, 479-482 in inhomogeneous medium, 122 Equipartition theorem, 45, 47 in homogeneous medium, 119 Evoked field relationship to electric latency, 450-452 field, 105 neurogenesis, 399-408 Electrocardiography, 216, 227 primary source, 400, 404-405 for bundle branch block, and psychophysics, 396 261-262 secondary source, 405 comparison with MeG, 311-314, steady-state response, 394- 317-321 395 current dipole source, phase information, 450 257-259 transient response, 393-394 genesis, 166 (see also specific normal morphology, 167, 216 modalities) 12-lead recordings, 218 Evoked potential, 391 vector cardiogram, 256 averaging, 392 Electroencephalography neurogenesis, 399-402 spontaneous activity and psychophysics, 383, 395- and MEG, 474-475 396 pathological activity, 478-482 and Single-unit activity, 696 INDEX

Evoked potential (continued) Fluxgate magnetometer and single-unit activity ( continued) (continued), 382-383 in lung studies, 548-553, 557 steady-state response, 394- Flux-locked mode, 81-82 395 Flux quantum, 24, 41 transient response, 393-394 Flux transformer, 69, 89-90 (see also specific Flow field, 317 modalities) Follicle, 11 Excitability, 143, 149 field of, 332-333 Excitable cell Force, magnetic properties, 143-144 on current, 22, 26 electrical model, 147-156 on compass, 102-103 Excitations Forward problem, 170, 173 action potential, 149-150, multipole representations, 202-204 237 cardiac sequence, 163-166 Foundry workers graded potential, 151-154 lung contamination, 566 Eye Fourier series, 601 associated fields coefficients, 602, 606 oculogram, 343, 346-348, sampling theorem, 604-605 351 Fourier transform, 600-614 model for sources, 343-345 aliasing, 606-607 retinogram, 348-351 discrete, 605-606 structure, 341-345 power spectrum, 607-608 Frequency compensation circuit, Faraday, Michael, 24 197-200 law of induction, 24, 116 Frequency response, of filter, Fast-Fourier transform, 601, 580 609-613 aperiodic signals, 610-613 Galvanic skin potential, 327 windowing, 612-613 Gamma rhythm, 476 Ferrimagnetism, 33, 509 Gap junctions, 142, 160 Ferrite, 34 Gas constant, 46 Ferritin, 483, 48.6-487 Gastro-intestinal field, 11, Ferromagnetism, 32, 485, 509 268-269, 329 magnetically "soft", 572 Gates, in membrane, 148, 213 Fetal magnetocardiography, 299- Gauss, Karl F. 302 unit of field, 23, 634 heart rate variability, 300, Gaussian filter, 582-583 309 Geomagnetic field, 87 interval index, 308-310 Goldman equation, 146 instrumentation for, 301, Graded field, 401 305-310 Graded potential, 151, 400 Field, 17, 102 and dynamic ranqe, 364-365 !!! Magnetic field Gradient, lOS Field potential, 400-402 definition, 34 Filtering, see Electronic Gradiometer filtering first-order, 91-92 Fissure, of cortex, 356, 405 inductance, 638-640 Fluxgate magnetometer, 36-37 off-diagonal, 6 INDEX 697

Gradiometer (continued) Hippocampal formation second-order, 92-95 ( continued) SQUID-system, 7 and endogeneous activity, Grinders 465-468 lung contamination, 560 His bundle, 157, 163 Group delay, 580, 583 electrogram, 228 Grover, F.W. invasive recording, 228-230 inductance tables, 641-644 magnetocardiogram, 277-279 magnetic activity, 295-298 Hair follicle, 11 model, 296-297 field of, 332-333 non-invasive recording, Half-space model, 126, 130-132 233-235 Hall-effect magnetometer, 38 His-Purkinje field, 275-284, Hamming window, 620 295-298, 593-598 Heart Hodgkin-Huxley model, 148 anatomy, 157-158 Honey bee conduction system, 157, 216 magnetic compass, 515 displacement, 289 superparamagnetism, 530 excitation, 163-166, 318 Hysteresis loop, 32, 36 multipole expansion, 319- 321 Ideal gas law, 52 fetal rate variability, 300 Impedance, electrical, 48 instrumentation, 305-308 Impressed current, 117 field, see cardiac field Impulse response of filter, muscle, 157-162 615-616 tangential currents, 319 Indifferent electrode (~ also Myocardium) and ECG, 217 Heart studies, see Inductance, 46 Magneotcardiography calculations, 635-644 Heat conduction, 50 mutual, 90, 638-640 Heat convection, 52-53 tables, 641-644 Helium, properties, 59 unit of, 26 Helmholtz, Hermann von, 168 Induction coil, 24, 37 coils, 97 inductance calculation, 635- current decomposition, 316 638 specific nerve energies, 370- toroidal, 187, 190 371 Induction, of voltage, 24 non-uniqueness theorem, 169 Infarction of the myocardium Hematite, 546 magnetic studies, 291-293 Hemochromatosis, 483, 496-498 Inhomogeneities, in conducting Henry, Joseph, 26 bodies unit of inductance, 26, 46 cylindrical, 128 Hertz, Heinrich, 25 half-space, 126 unit of frequency, 25 spherical, 126-128 High-pass filter, 581 Injury current, see Current High-resolution MCG, 276-284, of injury 295-297 Input coil, 69 clinical evaluation, 295-296 Iron oxides, 5.6 instrumentation for, 279-282 Iron workers Hippocampal formation, 467 lung contamination, 560, 565 698 INDEX

Isolated active tissue Lead field theory (continued) first measurements, 10 electric lead field, 135 Intercalated disks, 143, 160 lead currents, 311-312 Intracellular action current magnetic lead field, 137 measurement of, 186 uniform field, 138 source of field, 106, 175-182 unipositional lead, 261 Inverse problem, 102, 129-133, for remanent moment studies, 173 549-553 current dipole model, 130- for susceptibility, 138-139, 132, 407-408 492-495 in electrocardiology, 168-171 Lenz, Heinrich, 24 multipole expansions, 237 law, 24 Ionic channels, 148, 213 Limb field, 333-334 Ionic concentrations Liver magnetic susceptibility resting condition, 145 and chemical biopsy, 496-498 Ionic current clinical studies, 496-498 source of steady field, 334- instrumentation, 494-496 338 methodology, 484-489 Ionic pumps, 146 Lock-in amplifier, 595 Ischemia of the heart, 161, 222 noise bandwidth, 598 magnetic studies, 291-293 Low-pass filter, 581 Isolated preparations, 189-190, digital recursive filter, 201-205 622-624 frequency response, 623 Johnson noise, 49 Lungs of toroidal coil, 192 magnetic contaminants Josephson, Brian, 42 clearance, 540-543 effects, 74 depoSition, 537-540, 559 frequency, 74 detection methods, 548-557 junction, 42 magnetic properties, 547 current bias, 75 occupational exposure, 561- parametric effect, 77 568 Joule, James, 25 total lung burden, 556-557 unit of energy, 25 respiratory system, 535-537 Joule-Thomson effect, 64 ventilation, 537 refrigerator, 64-67 Lung studies, see Magnetopneumography Kelvin, Lord, 45 unit of temperature, 45 Machinists Kepler, Johannes, 386 lung contamination, 560 projection theory, 386-387 Macrophages, 542-543 Maghemite, 502 Langevin function, 516 Magnet Latency of evoked response permanent, 524 from steady-state responses, ceramiC, 34 451-452 pulsed, 524-525 of visual evoked response, superconductivity, 517-519 450-45) Magnetic biopsy, 483-499 Lateral inhibition, 366-367 clinical studies, 496-498 Lead field theory, 133-139 instrumentation, 494-496 INDEX 699

Magnetic biopsy (continued) Magnetic measurements methodology, 484-489 ( continued) quantitative aspects, 489-492 instrumentation, torso contribution, 487-489 field detection, 35-42 Magnetic contaminants moment measurement, 517-519 detection methods, 548-557 remanent moment measurement, localized sensitivity, 551- 548-553 553, 557 susceptibility measurement, uniform sensitivity, 548- 494-496 551, 556 (~ also SQUID system) in dewars, 31, 56 sensitivity pattern, 311-312 of lungs, 547-548 (see also Lead field theory) in subjects, 267 Magnetic moment, 28, 509 Magnetic dipole, 27, 102, 112 remanent, 523 current dipole in sphere, 128 isothermal, 523, 526 field pattern, 28, 112-113 Magnetic multipole expansion, moment, 28 252-257 of ferromagnet, 509 and current multipoles, 254- scalar potential, 114 256, 320-321 sum of current quadrupoles, generators for adult MeG, 257- 254-256 259 vector potential, 113 generators for neonatal MeG, Magnetic field, 17, 102 304-305 of action potential, 176-182 quadrupole coefficients, 320- as ambient noise, 86-87 321 of earth, 86 Magnetic navigation, 513 flux density, 22-23 homing pigeon, 514 of power lines, 87 Magnetic particles, sources of, II, 103-104 magnetic characterization, current element, 104 525-531 current distribution, 110 (~ also Ferrimagnetism impressed current, 118-121 and Ferromagnetism) homogeneous medium, 119 Magnetic relaxation, 554-556 inhomogeneous medium, 121 Magnetic scalar potential, 114 magnetic materials, 27-30 of magnetic dipole, 114 and scalar potential, 114 of magnetization, 115 strength or intensity, 17, 19 Magnetic shielding, 7-8 and vector potential, III active, 576-577 Magnetic flux, 24 room, 569-578 Magnetic flux density, 17, 22 shielding factor, 572 Magnetic heart vector, 260-261 skin depth, 574 adult MeG, 263, 313 soft iron, 519-521 bundle branch block, 263, 313 "soft" materials, 8, 570-572 and electric heart vector, Magnetic susceptibility, 28 263, 322-323 in vivo studies, 10, 483-499 neonatal MeG, 304-305 mass, 29 Magnetic induction, 17, 22 molar, 29 Magnetic materials Magnetic vector potential, III "soft" materials, 572 of current dipole, Magnetic measurements III 700 INDEX

Magnetic vector potential Magnetocardiography (continued) ( continued) current of injury, 265-274 current multipole expansion, fetal, 300-302, 309-310 250-252 instrumentation for, 301 of magnetic dipole, 113 first recording, 8 Magnetic viscosity, 553-554 by SQUID, 9 Magnetically clean room, 521- fetal, 11 522 high resolution, 275-284 Magnetism His-Purkinje system, 275-279, antiferromagnetism, 509 295-298 diamagnetism, 30-31 instrumentation for, 278-282 ferrimagnetism, 33-34, 509 magnetic dipole source, 259 ferromagnetism, 31, 509 for mass screening, 286 paramagnetism, 31 morphology, 238-241 superparamagnetism, 510 neonatal, 302-305 Magnetite, 33, 545 morphology, 303 coercive field, 523 multipole generators, 304- domains, 510-512 305 magnetic tracer, 560-567 numerical predictions, 241 oxidation of, 502 perinatal, 299-310 physical properties, 508-512 quadrupole sources, 258-260 saturation magnetization, 510 simulated infarction, 244 single-domain condition, 511, standard grid, 238 519, 527 steady field, 265-274 specific remanent moment, vector cardiography, 257-261 545-546 Magnetoencephalography unblocking field, 527-530 endogeneous activity, 460- Magnetization, 28, 114 468 easy direction, 505 evoked responses, see isothermal remanent moment, specific modality 523-526 first measurements, 9 Magnetobiology, 501 spontaneous activity, 469-482 magnetic compass, 513-515 and EEG, 474-475 magnetotaxis, 512-513 instrumentation for, 470- Magnetocardiography 471 and atrial repolarizatiQn, normal activity, 471-476 279, 282, 296 pathological activity, 476- for bundle branch block, 261- 482 263, 290-291, 313 Magnetometer clinical assessment, 285-298 detection coil, 90-91 bundle branch block, 290- inductance of, 635-638 291 moment measurement, 517-519, delayed depolarization, 298 525-526 premature beats, 294 Magneto-oculogram, 343, ventricular hypertrophy, 346-348, 351 287-289 Magnetopneumography, 545-568, comparison with ECG, 311-314, instrumentation for, 548- 317-321 553 current dipole source, 257- magnetizing time, 553-554 259 relaxation, 554-556 INDEX 701

Magnetopneumography (continued) Multipo1e expansions total lung burden, 556-557 ( continued) occupational groups, 559- magnetic, 252-254 568 Muscle field and radiological findings, skeletal, 11 564-565 (see also viscosity, 553 Magnetocardiography Magnetoretinogram, 11, 348-351 and Myocardium) Magnetosome, 505 Mutual inductance Magnetostriction magnetometer, coupling coefficient, 90 38 Myocardium, 157 Magnetotaxis, 512-513 circuit model, 162 Magnetotactic bacteria, 502, excitation, 158, 160-161 503, 512-513 pattern, 314, 318, 319, 324 Maximum diastolic potential, magnetic studies 214 infarction, 291-293 Maxwell, James Clerk ischemia, 291-293 unit of flux, 634 source equation, 116 Neonatal heart rate, 307 Medium, conducting interval index, 308 effect on field, 119, 121 Neonatal magnetocardiogram, effect on potential, 118, 122 302-305 Meissner, Hans, 72 morphology, 303 effect, 72 multipole generators, 303- Membrane structure, 212-213 305 Models, of sources Nernst equation, 145 current dipole, 104 Nerve in half space 130-132, 406- specific nerve energies, 370- 408 371 in sphere, 406-407 Nerve fibers current multipoles, 246-252, action potential, 154 319-321 Neuron magnetic dipole, 27, 102, 112 morphology, 402-403 magnetic multipoles, 252-257 Newton, Isaac, 23 Modulation transfer function, unit of force, 23 448-450 Nodes of Ranvier, 142, 156 Molypermalloy core, 194 Noise, electronic Motor cortex, 361 from induction coil, 48 function, 422 and measuring bandwidth, 35- Motor field, 422-432 36, 46-49, 598 characteristics, 425-428 power line compensation, and somatotopic projection, 200-201, 584-587 431 as Signal interference, 591 source location, 428-432 Noise, magnetic Motor potential, 422-425 ambient field, 86-87 MUller, J. NyqUist, 37, 43-49, 193 specific nerve energies, 370- power lines, 87 371 compensation for, 200-201 Multipole expansions in SQUID, 70-71, 83-84 current, 254-259, 319-321 of subject, 268, 271, 282- 702 INDEX

Noise, magnetic (continued) Pial somatically evoked of subject (continued), 283, potential, 420 329 and evoked field, 420 Noise, sensory Pickup coil and sensitivity, 367-370 of detection coil, 89, 91 threshold measures, 377, inductance of, 636 380 toroidal, 187, 190 Notch filter, 583-584 circuit model, 193 pigeon Oculogram, 343, 346-348, 351 magnetic navigation, 514 oddball paradigm, 461 pigment epithelium Oersted, Hans, 1, 19 field sources, 344-345 unit for field strength, 634 Planck, Max, 40 Ohm, Georg, 34 Planck's constant, 40 law of conductance, 34 Polio patients' field, 334 unit of resistance, 26, 34 Point contact, superconducting, Ohmic current, 34, 117 75 and displacement current, 117 post-synaptic potential, 400 Onnes, Kamerlingh, 72 potential, see Electric Open-field neuron, 402-403 potential Optical magnetometer, 38 Power spectrum of Fourier transform, 607-608 pacemaker, 157 scaling factors, 613-614 Paleomagnetism, 517 Premature beats Paramagnetic amplification, 71 magnetic studies, 294 in Josephson junction, 77 Pre-motor potential, 424 Paramagnetism, 31, 484 Primary source, 123, 314, 317 Pascal, Blaise, 52 of action field, 106, 175-176 unit of pressure, 52 in myocardium, 314, 318 Perception, 385 of neuromagnetic field, 399- binocular stereopsis, 386 402 disparity detection, 387- Proprioceptive evoked field, 389 430-431 psychophysical thresholds Proprioceptive evoked and evoked fields, 396 potential, 424-425 and evoked potentials, 383 Proprioceptors, 424 size constancy, 389 Psychophysics, 375 permeability reaction times ionic, 146 and evoked fields, 396, magnetic, 27 450-452 of free space, 26 threshold measures, 375 relative, 27, 29 and evoked field, 452 of "soft" materials, 572 and evoked potential, 383, Phase response, of filter, 580 395-396, 452 Phase-sensitive detection, 595- and noise, 377 598 P300, 461-462, 464-468 noise bandwidth, 598 Pump, of parametric amplifier, Photoreceptors 71 field source, 343-344 Purkinje system, 157, 163 response to light, 364 magnetic activity, 295-298 INDEX 703

Purkinje system (continued) Retinogram (continued) model of, 296-297 magnetic, 11 Pyramidal cells, 358, 404 Retinotopic representation, 443-448 Quality factor Rhythm strip, 219 of filter, 584, 587 Right-hand rule, 20, 23, 26 of lock-in, 596 Robin Quadrupole coefficients magnetic navigation, 515 magnetic, 256, 258 Rubens coils, 97-99 current, 248-250, 254-256, 320-321 Salmon Quasi-static regime, 117 magnetic particles, 528-529 Saltatory conduction, 156 Radiation shield, 56 Sampling theorem, 604-605 Reaction time Saturation, magnetic, 33 and evoked field, 396, 450- isothermal remanent moment, 452 523-526 Readiness field, 425 Scalar potential source location, 428 electric, 105 Readiness potential, 424, 460 of current dipole, 105 Receiver operating magnetic, 114 characteristics, 380- of magnetic dipole, 114 381 of magnetization, 115 Reciprocity, 133 Scaling factors, 613-614 lead currents, 311-312 Schrieffer, John, 72 lead magnetic field, 492 Sciatic nerve for susceptibility, 138 action field, 192 Recursive filter, 615, 621-624 Secondary source, 123, 316, 317 Reentry, 223-226 cylinder, 128 functional, 226 half space, 126 micro, 224 sphere, 126-128 Refractoriness, 144, 150 Semiconductor amplifier, 194- Refrigerators, 60-67 195 Joule-Thomson, 64-67 sensitivity, magnetic stirling, 61-64 of induction coil, 37, 48-49 Rejection factor of filter, 584 of SQUID sensor, 94 Relaxation, magnetic, 554-556 Shielded room Remanent moment, 546-547 active method, 576-577 of industrial dusts, 547, 561 applications, 577-578 specific, 546 eddy-current, 569-572 Repolarization, 150, 155 magnetic, 8, 519-521, 572-576 of atria, 279, 282 Shielding early, 270-271 eddy current, 7 of myocardium, 165-166 magnetic, 7 Resistance, 34 Siemens family Resistivity, 35 unit of conductance, 35 Resonance magnetometer, 38 Signal averaging, 592-598 Respiratory system, 535-537 Signal processing, 591-624 Resting potential, 144 averaging, 592 Retinogram, 348-351 backward, 593 704 INDEX

Signal processing (continued) Spontaneous brain activity averaging (continued) ( continued) forward, 592 pathological (continued) template trigger, 594 epilepsy, 479-482 Signal-to-noise improvement, Jacksonian disease, 479 592 theta, 475 Sinus node, 157, 163, 214 SQUID detector, 7 response to stimulation, multiloop, 89 230-232 types of, 76 Skeletal muscle, II, 156-157 SQUID system, 38-42, 69-71, action potential, 156 81-84 Skin depth dc bias, 39, 79-81 and eddy currents, 570 (see also Detection coil) of magnetic materials, 574 energy sensitivity, 41 Slew rate, 83 feedback loop, 40, 81-83 Solid angle formalism, 124-126 gradiometers, 91-95 applied to heart, 164-165 input impedance, 70 Somatic evoked field, 409-421 input energy sensitivity, field pattern, 409-410 70-71, 83 latency, 410 magnetometer, 91 .lateralization, 411 moment magnetometer, 517-519, somatotopiC prOjection, 413- 525-526 419 rf bias, 39, 77-91 somatotopic representation, slew rate, 83 413-219 steady field Sound applications, 338 localization, 388-389 electrophysiological source, Source models, !!! Current 335-337 dipole, !!! Magnetic and muscle morphology, 337- dipole 338 Source strength, 119 instrumentation, 330-332 Space constant, 153 measurement Spatial discrimination, 91 eye, 346-348 Spatio-contrast sensitivity, gastrOintestinal system, 368-370 329 and visual evoked field, 448- heart, 265-274 450, 452 limbs, 333-334 Spectral density scalp, 332-333 definition, 36 torso, 334 for induction coil, 48 steel workers spherical model, 126-128 lung contamination, 560-565 Spontaneous brain activity Stefan-Boltzmann law, 51 alpha, 472-475 Stefan, Josef, 51 beta, 476 stirling, Robert, 61 delta, 476 refrigerator, 61-64 gamma, 476 ST shift, 265-274 normal activity, 471-476 primary, 265, 270 power spectrum, 472-473, secondary, 265, 268-269 475, 480-481 Subcortical activity, 460-468 pathological, 476-482 Subject noise, 268, 271, 282- INDEX 705

Subject noise (continued) Threshold measures (continued) 283 psychophysical vs. evoked abdominal, 329 field, 452 cold water reflex, 329 psychophysical vs. evoked torso diamagnetism, 488-489, potential, 383, 395- 492-496 396, 452 Sulcus, of cortex, 357, 405 receiver operating superconducting transformer, characteristics, 380- 191 381 superconductivity on single neurons, 378-383 Josephson effects, 73-74 single-unit vs. Meissner effect, 72 psychophysical, 380- quantum state, 73 382 zero resistance, 72 single-unit vs. evoked superconductor potential, 382-383 diamagnetism of, 30 Tidal volume of lung, 537 transtion temperature, 43 and particle deposition, 539- superinsulation, 56-57 540 superparamagnetism, 510 Time constant, 48 of worker bee, 530 L/R, 48, 152 susceptibility Tonotopic representation, 438- in vivo measurements 441 ---ac technique, 488-489 Torque, on compass, 102 dc technique, 487-489, 494- Transformer 497 electrical analysis, 192-194 SQUID moment magnetometer, Translocation in the lung, 567 518-520 Transmembrane conductance, 147 Synapses gates, 148, 213 chemical, 143 determination, 186 Systeme International, 18 Transmembrane current Systole, 162 of action potential, 179 theory, 186 Tabs, superconducting Transmembrane potential Tacconis oscillations, 53-54 resting, 146 Tachycardia, 221 (~ also Action potential) Tesla, Nicola, 23 Trigger, electronic unit of flux density, 23, 26 template, 594 Thalassemia, 483, 497 threshold, 595 Thermal conductivity, 50 Tumor Thermal noise, 49 associated field, 479-482 Thermal oscillations, 53 Tunnelling, 73 Thermal radiation, 46, 51 2-D system, 330-332 Theta rhythm, 475 Thomson, William, see Kelvin Unblocking field, 526-530 Threshold Unipolar leads, 217 of excitable cell, 143, 149 Unipositional lead system, 261 Threshold measures, 375-383 Units of measure, 20 and noise, 377 parallel channels, Vacuum techniques, 57 390 Vapor-cooled shield, 56 706 INDEX

Variometer, 36 Visual system, 359-362 vector cardiography, 259-261 cortex, 357-358, 360-362, electric heart vector, 248, 372-374 263, 313 lateral geniculate nucleus, magnetic heart vector, 260, 359, 371 263, 313 lateral inhibition, 366-367 vector potential, magnetic 111 parallel pathways, 371, 390 of current dipole, 111 photoreceptors of magnetic dipole, 113 noise, 368 ventilation of lungs, 537 receptive field, 365 ventricular hypertrophy, 287- response to light, 36 290 spatio-contrast sensitivity, Viscosity, magnetic, 553-554 368-370 Visual cortex Volt, unit of potential, 25 cruciform model, 443 Volta, Alesandro, 25 cytoarchitecture, 357-358 voltage clamp method, 147 various projections, 360- Volume conductor 362 effect on field, 11 functional specialization, homogeneous medium, 119 372-374 inhomogeneous medium, 121 disparity detection, 387 Volume current, 106 feature detection, 390-391 Vortex field, 317 retinotopic representation, Vorticity, 119 443-448 Visual evoked field, 444-459 watt, James, 50 compared with potential, 454, unit of power, 50 456-459 Weak link, 73 functional properties Weber, Wilhelm, 24 luminance coding, 453-455 unit of flux, 24, 26 spatio-contrast Welders sensitivity, 444-452, lung contamination, 560-565 454 welding fumes latency, 450-452 magnetic properties, 561 retinotopic representation, Wenckebach phenomenon, 232 445-448 White noise, 36 source Window function, 612-613 multiple, 445, 447 Windowing technique, 612-613, single 619-622 strength, 454-455 Wolf-Parkinson-White syndrome orientation, 455 magnetic studies, 294 Visual evoked potential compared with field, 454, 456-459