(19) TZZ Z_¥ T

(11) EP 2 601 863 A2

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication: (51) Int Cl.: 12.06.2013 Bulletin 2013/24 A47C 27/10 (2006.01) A61G 7/10 (2006.01)

(21) Application number: 13157857.7

(22) Date of filing: 16.08.2007

(84) Designated Contracting States: (72) Inventor: Davis, David T. AT BE BG CH CY CZ DE DK EE ES FI FR GB GR Bethlehem, PA Pennsylvania 18017 (US) HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR (74) Representative: Weyand, Tim et al Leonhard & Partner (30) Priority: 15.09.2006 US 532132 Patentanwälte Postfach 10 09 62 (62) Document number(s) of the earlier application(s) in 80083 München (DE) accordance with Art. 76 EPC: 07814160.3 / 2 063 741 Remarks: This application was filed on 05-03-2013 as a (71) Applicant: Woodlark Circle, Inc. divisional application to the application mentioned Bethlehem, PA 18017 (US) under INID code 62.

(54) Double chambered air mattress

(57) Adouble chambered transfer mattress (2)is pro- A one-way valve (31) is positioned through the common vided capable of partial deflation that includes a top in- wall (5) so as to provide selective air flow communication flatable mattress and a bottom inflatable mattress that between the top inflatable mattress and the bottom in- are separated by a common wall (5) from one another. flatable mattress so that when the inlet/outlet valve is A selectable inlet/outlet valve (50,34) is arranged for air- closed, air continues to escape from perforations in the flow communication between an interior chamber of the bottom inflatable mattress and the one-way valve is ac- top inflatable mattress and a source of pressurized air. tuated so as to prevent deflation of the top inflatable mat- tress. EP 2 601 863 A2

Printed by Jouve, 75001 PARIS (FR) 1 EP 2 601 863 A2 2

Description patient rolling chambers are disclosed on the top of the transfer apparatus to provide assistance to medical per- Cross-Reference to Related Applications sonnel in beginning to roll patients reclining or lying upon the transfer apparatus, particularly in a deflated condition [0001] This application is a continuation-in-part appli- 5 on a hospital bed. cation of copending U.S. Application Serial No.[0007] All of the foregoing devices have suffered from 11/191,674, filed on 07/28/2005, which itself claims pri- an inability to be used during X-ray imaging of a patient ority from co- pending Provisional Patent Application Se- lying upon the mattress. Proper X-ray imaging requires rial No. 60/592,251, filed July 28, 2004, and entitled DOU- that the patient remain motionless during the exposure. BLE CHAMBERED AIR MATTRESS. 10 Prior art transfer mattresses tend to drift or move, and are easily moved by even small perturbations. Thus, they Field Of The Invention are required to be deflated prior to effecting X- ray imaging of the patient. Unfortunately, when deflated, the patient [0002] The present invention generally relates to pa- is forced to lie upon a very stiff table that can be quite tient transfer devices and, more particularly to a patient 15 uncomfortable for heavier patients. transfer apparatus which employs an air bearing to facil- [0008] Many of the foregoing devices also suffer from itate the transfer. the fact that when uninflated they tend to bunch causing photo images to appear upon the x-ray exposures that Background Of The Invention mask underlying physiological features of the patient. 20 There is a continuing need to be able to easily and safely [0003] Patient handling mattresses are known in the x-ray a patient on an inflated transfer mattress. art which include at least two flexible material sheets, that together define a plenum chamber, with at least one Summary Of The Invention sheet being perforated with small pinholes over at least a central surface area, and which open up directly to the 25 [0009] The present invention provides a double cham- interior of the plenum chamber. Such prior art mattresses bered transfermattress that is capable of partialdeflation. are used by arranging the perforated sheet so that it faces In one embodiment, a transfer mattress is provided that an underlying fixed, generally planar support surface, includes a top inflatable mattress and a bottom inflatable such as a floor or table. When the mattress is charged mattress that are separated by a common wall from one with pressurized air, the escape of air under pressure 30 another. The bottom inflatable mattress includes a plu- through the pinholes acts initially to jack a load placed rality of holes or perforations disposed in a bottom panel. upon the mattress above the perforated flexible sheet, A selectable inlet/outlet valve is arranged for airflow com- and thereby creates an air bearing of relatively small munication between an interior chamber of the top inflat- height between the underlying fixed, generally planar able mattress and a source of pressurized air. A one- way support surface and the perforated flexible sheet. 35 valve is positioned through the common wall so as to [0004] For example, in U. S. Patent No. 4,517,690, is- provide selective air flow communication between the sued to Wegener, an air pallet is disclosed that is formed top inflatable mattress and the bottom inflatable mattress from upper and lower thin flexible film sheets sealed at so that when said inlet/ outlet valve is closed-off from the their edges to form a plenum chamber. Wegener’s air source of pressurized air, the bottom inflatable mattress pallet functions to move a load with minimal friction over 40 deflates by air escaping through the plurality of holes or an underlying generally planar fixed support surface. The perforations whereby the one-way valve is actuated so bottom thin flexible material sheet is perforated by small as to prevent deflation of the top inflatable mattress. diameterperforations such as pin holes at theload imprint [0010] In another embodiment a top sheet is provided area. having a width, a length, and peripheral edges, an inter- [0005] In U. S. Patent No. 5,561,873, issued 45 to mediate, barrier sheet having the same width, the same Weedling, provides an inflatable flexible pallet within length, and peripheral edges, and a bottom sheet having which an array of structurally interrelated inflatable cham- the same width, the same length, peripheral edges and bers are formed to support a load when inflated. The a plurality of perforations. A first perimeter band is seal- flexible pallet is configured to resist lateral and longitudi- ingly fastened between the peripheral edges of the top nal shrinkage of the load support surface, as well as bal- 50 and barrier sheets and a second perimeter band is seal- looning and hot dogging. Rotational instability is also re- ingly fastened between the peripheral edges of the bar- duced by providing a greater load surface support area. rier and bottom sheets. The peripheral edges of the top, [0006] In U.S. Patent No. 6,073,291, issued to Davis, barrier, and bottom sheets are sealingly fastened to the an inflatable medical patient transfer apparatus is dis- respective perimeter bands by heat sealing. A plurality closed that has a combination of transverse partition55 of baffles, each having a width and a length, are attached members and a raised perimeter section to reduce del- to an inner surface of the top sheet and the barrier sheet eterious ballooning and uneven inflation as well as quick so as to be oriented between the top sheet and the barrier emergency deflation. Additional differentially inflatable sheet. A second plurality of baffles, each having a width

2 3 EP 2 601 863 A2 4 and a length, are attached to an inner surface of the bar- well as derivatives thereof (e.g., "horizontally," "down- rier sheet and an inner surface of the bottom sheet so as wardly," "upwardly," etc.) should be construed to refer to to be oriented between the barrier sheet and the bottom the orientation as then described or as shown in the draw- sheet. One or more inlet/ outlet openings are located with- ing figure under discussion. These relative terms are for in the perimeter bands so that the double chambered 5 convenience of description and normally are not intended transfer mattress may be inflated or deflated. Advanta- to require a particular orientation. Terms including "in- geously, oneor more one- wayvalves are locatedthrough wardly" versus "outwardly," "longitudinal" versus "lateral" the barrier sheet so as to provide selective air flow com- and the like are to be interpreted relative to one another munication between a first chamber formed between the or relative to an axis of elongation, or an axis or center top sheet, the barrier sheet, and the first perimeter band 10 of rotation, as appropriate. Terms concerning attach- and a second chamber formed between the barrier sheet, ments, coupling and the like, such as "connected" and the bottom sheet, and the second perimeter band. In this "interconnected," refer to a relationship wherein struc- way, an inlet/outlet located in the first perimeter band tures are secured or attached to one another either di- may be closed-off from the source of pressurized air so rectly or indirectly through intervening structures, as well that the second chamber deflates by air escaping through 15 as both movable or rigid attachments or relationships, the plurlaity of holes or perforations. As the second cham- unless expressly described otherwise. The term "opera- ber deflates, the one or more one-way valves are actu- tively connected" is such an attachment, coupling or con- ated so as to present deflation of the first chamber. nection that allows the pertinent structures to operate as intended by virtue of that relationship. In the claims, Brief Description Of The Drawings 20 means-plus-function clauses, if used, are intended to cover the structures described, suggested, or rendered [0011] These and other features and advantages of obvious by the written description or drawings for per- the present invention will be more fully disclosed in, or forming the recited function, including not only structural rendered obvious by, the following detailed description equivalents but also equivalent structures. of the preferred embodiment of the invention, which is to 25 [0013] Referring to Figs. 1-5, a double chambered be considered together with the accompanying drawings transfer mattress 2 formed in accordance with the wherein likenumbers referto likeparts and further where- present invention comprises a top panel 4, an internal in: barrier panel 5, a bottom panel 6, a top perimeter band 8, a bottom perimeter band 10, and a plurality of baf- Fig. 1 is a perspective view of a double chambered 30 fle-panels 11. More particularly, top panel 4 comprises a transfer mattress formed in accordance with the head portion 12, a foot portion 14, and a peripheral edge present invention; 16. Top panel 4 is formed from a sheet of fabric, e.g., scrim or the like, that may be coated on at least its Fig. 2 is a cross-sectional view of the transfer mat- outer surface 18 with a water proof coating. Inner surface tress shown in Fig. 1; 35 19 of top panel 4 may also be coated with a water proof coating as well. The water proof coating may be any of Fig. 3 is a broken-away, cross-sectional view of a the well known polymeric or elastomeric compounds that portion of Fig. 2; are known to be impervious to semi-solids and liquids, such as, blood, urine, feces, hospital strength disinfecting Fig. 4 isa cross-sectional view of thedouble chamber 40 compounds, alcohol, or the like. For example, a nylon transfer mattress shown in Fig. 2, with the second fabric that is coated on one side with a heat sealable, chamber deflated and the mushroom valve actuated polyurethane coating (e.g., an inner side) and the outer to a closed position; and side coated with a Durable Water Repellant (patient side). The presence of polyurethane on the interior sur- Fig. 5 is a broken-away, cross-sectional view of a 45 faces allows for heat sealing, eliminating needle holes. portion of Fig. 4. [0014] Barrier panel 5 comprises a head portion 17, a foot portion 19, a top inner surface 20, a bottom inner Detailed Description Of The Preferred Embodiment surface 21, and a peripheral edge 23, and is often formed from a sheet of fabric, e.g., nylon scrim or the like. One [0012] This description of preferred embodiments is in- 50 or more openings 27 are defined through the peripheral tended to be read in connection with the accompanying side surface of barrier panel 5 so as to provide for air flow drawings, which are to be considered part of the entire communication. In one embodiment of the invention, a written description of this invention. The drawing figures one way valve 31 is positioned within each opening 27. are not necessarily to scale and certain features of the One way valve 31 often takes the form of a so-called invention may be shown exaggerated in scale or in some- 55 "mushroom valve" which operates so as to keep gases what schematic form in the interest of clarity and con- traveling in one direction only. One way valve 31 is biased ciseness. In the description, relative terms such as "hor- so as tobe normally in an open,free air flow configuration. izontal," "vertical," "up," "down," "top" and "bottom" as [0015] It should be understood that some or all of top

3 5 EP 2 601 863 A2 6 panel 4, internal barrier panel 5, bottom panel 6, top pe- temperature of a human (37 degrees C.; 98.6 degrees rimeter band 8, bottom perimeter band 10, and plurality F.) and is present in the resin blend at a concentration of baffle-panels 11 are most often, but not always formed sufficient to constitute the continuous phase of the blend, from a sheet of fabric, e.g., nylon scrim or the like, and with the polyvinyl alcohol constituting a discontinuous may be coated on at least its outer surface with a water 5 phase of the blend. The aliphatic renders the proof coating. The water proof coating may be any of the resin blend, and the partially hydrolyzed polyvinyl alcohol well known polymeric or elastomeric compounds that are in the blend is, cold water insoluble and determines the known to be impervious to semi-solids and liquids, such temperature at which articles formed from the blend will as, blood, urine, feces, hospital strength disinfecting be subject to dissolution in an aqueous bath and subse- compounds, alcohol, or the like. For example, a nylon 10 quent disposal. A practical benefit associated with the twill fabric that is coated on one side with a heat sealable, use of the foregoing material is that double chambered polyurethane coating (e.g., an inner side) and the outer transfer mattress 2 not only retains a stained and dis- side coated with a Durable Water Repellant (Patient colored appearance for longer periods of time after use, side). A practical benefit associated with the use of the thereby alerting hospital staff or other care givers that a foregoing preferred materials is that double chambered 15 particular double chambered transfer mattress 2 has transfer mattress 2 retains a better appearance for longer completed its useful life, and must be discarded, but also periodsof time during use.A double coateddouble cham- if an attempt is made to launder the mattress after a single bered transfer mattress 2 can be easily wiped down, and use it disintegrates during the washing process. can be put back into use more quickly. [0018] Bottom panel 6 comprises a head portion 22, a [0016] Alternatively, in those instances where a single 20 foot portion 24, and a peripheral edge 26. Bottom panel use, single patient mattress is provided, i.e., where pa- 6 includes a plurality of tiny holes 30 that are defined tient use lasting less than twenty four hours is desired, through its thickness to allow air, that is supplied by a some or all of top panel 4, internal barrier panel 5, bottom high-pressure air supply to double chambered transfer panel 6, top perimeter band 8, bottom perimeter band mattress 2, via an air supply hose 34, to escape in a 10, and plurality of baffle-panels 11 may be formed from 25 controlled manner. The air supplied to double chambered for forming fabrics suitable for single use top panel transfer mattress 2 escapes through plurality of holes 30, 4 may be made of materials, such as, acetate, acrylic, providing a weight-bearing cushion of air that facilitates , aramid, azlon, , elastoester, fluorocarbon, thesliding ofdouble chambered transfermattress 2 along fur, glass, lyocell, melamine, metallic, modacrylic, modal, a surface, as well as, from one surface to another. mosacrylic, novoloid, nylon, nytril, olefin, PAN, PBI,30 [0019] Top perimeter band 8 and a bottom perimeter PEEK, Pelco, PEN, PLA, PTT, polyester, polyester-pol- band10 often take theform of elongate,rectangular strips yarylate, , saran, , sulfar, triacetate, vinal, of any of the foregoing materials. Top perimeter band 8 vinyon, and . A common characteristic of the fore- is sealingly fastened between peripheral edge 16 of top going and like materials is their propensity to stain or panel 4 and peripheral edge 20 of barrier panel 5, e.g., discolor as a result of contact with blood, urine, feces, 35 by heat sealing, gluing or sewing, so as to form a first hospital strength disinfecting compounds, alcohol, or the chamber 35. Bottom perimeter band 10 is sealingly fas- like. Additionally, a variety of films may be used to form tened between peripheral edge 20 of barrier panel 5 and a single patient, single use double chambered transfer peripheral edge 26 of bottom panel 6, so as to form a mattress 2, for example, copolyester, copolyether, eth- second chamber 37. ylene vinyl acetate, fluorocarbon, polyamide, olefins,40 [0020] Plurality of baffle-panels 11 each comprise sub- polybutylene, polycarbonate, polyester, polystyrene, stantially rectangular sheets of nylon scrim or the like, polyurethane, polyvinyl, alcohol, polyvinyl chloride, pol- and include a top edge 40 and a bottom edge 42. Baf- yvinyl fluoride, and polyvinylidene chloride. A practical fle-panels 11 may have differing widths, depending upon benefit associated with the use of the foregoing preferred their position within double chambered transfer mattress materials is that double chambered transfer mattress 2 45 2. Two sets of baffle panels 11 are installed within double retains a stained and discolored appearance for longer chambered transfer mattress 2, a first set of baffle panels periods of time after use thereby alerting hospital staff or 11 is located in first chamber 35 and a second set of other care givers that a particular double chambered baffle panels 11 is located in a second chamber 37. For transfer mattress 2 has completed its useful life, and must the first set on baffle panels 11, each top edge 40 is fas- be discarded. 50 tened transversely to a portion of inner surface 19 of top [0017] In one embodiment, some or all of top panel 4, panel4 and each bottomedge 42 is fastened transversely internal barrier panel 5, bottom panel 6, top perimeter to a portion of inner surface 20 of barrier panel 5. For the band 8, bottom perimeter band 10, and plurality of baf- second set of baffle panels 11, each top edge 40 is fas- fle-panels 11 may comprise a cold water soluble partially tened transversely to a portion of inner surface 21 of bar- hydrolyzed polyvinyl alcohol, cold water insoluble hot wa- 55 rier panel 5 and each bottom edge 42 is fastened trans- ter disintegrable aliphatic polyester, and minor propor- versely to a portion of inner surface 29 of bottom panel 6. tions of processing and performance aids. The aliphatic [0021] An inlet/outlet opening 50 is formed in perimeter polyester has a melt temperature above the normal body band 8 that sealingly accepts an air supply hose 34. Inlet

4 7 EP 2 601 863 A2 8 opening 50 is sized and shaped so that air supply hose ber 35 and second chamber 37 are fully inflated, with air 34 may be inserted, with the inlet being thereafter flowing through holes 30 so as to effect the cushion of snapped shut or otherwise closed to hold air supply hose air necessary for transfer of the patient, double chamber 34 in place while double chamber transfer mattress 2 is transfer mattress 2 is shifted laterally from a gurney or being inflated. Inlet openings 50may also include a valve 5 table onto the table in the X-ray theater. Once in this (not shown) that is biased to be normally closed to pre- position, the source of high pressure air connected to vent air from exiting through the inlet, and opened when opening 50 in top perimeter band 8 is shut- off, and inlet/ air supply hose 34 is inserted into inlet opening 50. Other outlet opening 50 is closed so that pressurized air con- arrangements known to those skilled in the art may be tinues to escape only through holes 30 in bottom panel used to inflate double chambered transfer mattress 2. 10 6. As the air escapes second chamber 37, one- way valve [0022] A double chambered transfer mattress 2 is as- 31 is biased closed as barrier panel 5 moves toward bot- sembled according to the present invention in the follow- tom panel 6. In this way, air escaping from first chamber ing manner. Bottom panel 6 is laid out on a suitable sup- 35 is stopped by one-way valve 31. As a consequence, port surface so that second set of baffle-panels 11 may the patient is comfortably positioned on top panel 4 while be transversely arranged in the center section of inner 15 the X-ray is taken. Once the X- ray procedure is complet- surface 29. Once in this position, bottom edge 42 of each ed air is reintroduced into double chamber transfer mat- baffle-panel 11 is fixedly fastened to inner surface 29 of tress 2 so as to reinflate second chamber 37 and reopen bottom panel 6. Baffle-panels 11 are advantageously one-way valve 31. Once second chamber 37 has been heat sealed along the interface between bottom edge 42 inflated with air flowing through holes 30, double chamber and inner surface 29 of bottom panel 6. This heat sealing 20 transfer mattress 2 and the patient may be shifted from may be done with the application of heat or ultra sonic the X-ray table onto the gurney for removal from the X- energy at the edge interface. In this way, a re-solidified ray theater. interface structure is formed so as to improve the bond [0026] It is to be understood that the present invention and its resistance to rupture under normal loading. is by no means limited only to the particular constructions [0023] Once second set of baffle-panels 11 are fas- 25 herein disclosed and shown in the drawings, but also tened to inner surface 29 of bottom panel 6, barrier panel comprises any modifications or equivalents within the 5 is arranged in overlying confronting relation with bottom scope of the claims. panel 6 so that head portion 17 of barrier panel 5 is con- frontinghead portion 22 ofbottom panel 6 and foot portion 19 of barrier panel 5 is confronting foot portion 24 of bot- 30 Claims tom panel 6. Once in this position, each top edge 40 of each baffle-panel 11 is fixedly fastened to inner surface 1. A transfer mattress comprising: 21 of barrier panel 5. [0024] At this point in the assembly, top panel 4 is ar- a top inflatable mattress having a selectable in- ranged in overlying confronting relation with barrier panel 35 let/outlet valve arranged for airflow communica- 5 so that head portion 12 of top panel 4 is confronting tion between an interior chamber of said top in- head portion 17 of barrier panel 5 and foot portion 14 of flatablemattress and a source ofpressurized air; top panel 4 is confronting foot portion 19 of barrier panel a bottom inflatable mattress separated by a 5. Once in this position, second set of baffle panels 11 common wall from said top inflatable mattress may be assembled by fixedly fastening each top edge 40 and including a plurality of holes; and 40 of each baffle- panel 11 to inner surface 29 of top panel a one-way valve positioned through said com- 4 and each bottom edge 42 of each baffle-panel 11 is mon wall so as to provide selective air flow com- fixedly fastened to inner surface 20 of barrier panel 5. munication between said top inflatable mattress Top and bottom perimeter bands 8 and 10 are then seal- and said bottom inflatable mattress so that when ingly fastened to peripheral edge 16 of top panel 4, pe- 45 said inlet/outlet valve is closed-off from said ripheral edge 20 of barrier panel 5 and peripheral edge source of pressurized air, said bottom inflatable 26 of bottom panel 6 so as to complete construction of mattress deflates by air escaping through said double chambered transfer mattress 2. plurality of holes whereby said one- way valve is [0025] Double chambered transfer mattress 2 is used actuated so as to prevent deflation of said top when positioning a patient for X-ray photography in the 50 inflatable mattress. following manner. The patient (not shown) is positioned atop outer surface 18 so that the patient’s head is resting 2. A transfer mattress according to claim 1 wherein said adjacent to head portion 12 atop panel 4. Double cham- common wall has at least one opening defined there- bered transfer mattress 2 is inflated by passing high pres- through and having said one-way valve disposed sure air through opening 50 in top perimeter band 8. As 55 within said opening that operates so as to keep air the high pressure air enters first chamber 35 it passes traveling in one direction only. through one-way valve 31 disposed in opening 27 so as to also pressurize second chamber 37. Once first cham- 3. A transfer mattress according to claim 1 wherein said

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one way valve is biased so as to be normally in an ble mattress and a source of pressurized air; open, free air flow configuration. a bottom inflatable mattress defined by a bottom sheet having a plurality of holes and a perimeter 4. A transfer mattress according to claim 1 wherein a band wherein said top inflatable mattress and top surface of said top inflatable mattress is coated 5 said bottom inflatable mattress are separated on at least its outer surface with a water proof coat- by a common sheet; and ing. a one-way valve positioned through said com- mon sheet so as to provide selective air flow 5. A transfer mattress according to claim 1 wherein at communication between said top inflatable mat- least one of said top inflatable mattress and said bot- 10 tress and said bottom inflatable mattress so that tom inflatable mattress is formed from one or more when said inlet/outlet valve is closed-off from fabrics selected from the group consisting of acetate, said source of pressurized air, said bottom in- acrylic, anidex, aramid, azlon, cotton, elastoester, flatable mattress deflates by air escaping fluorocarbon, fur, glass, lyocell, melamine, metallic, through said plurality of holes whereby said one- modacrylic, modal, mosacrylic, novoloid, nylon,15 way valve is actuated so as to prevent deflation nytril, olefin, PAN, PBI, PEEK, Pelco, PEN, PLA, of said top inflatable mattress. PTT, polyester, polyester-polyarylate, rayon, saran, spandex, sulfar, triacetate, vinal, vinyon, and wool. 10. A transfer mattress comprising:

6. A transfer mattress according to claim 1 wherein at 20 a top sheet having a width, a length, and periph- least one of said top inflatable mattress and said bot- eral edges, an intermediate, barrier sheet hav- tom inflatable mattress is formed from one or more ing said width, said length, and peripheral edg- films selected from the group consisting of copoly- es; ester, copolyether, ethylene vinyl acetate, fluorocar- a bottom sheet having said width, said length, bon, polyamide, olefins, polybutylene, polycar-25 peripheral edges and a plurality of perforations; bonate, polyester, polystyrene, polyurethane, poly- a first perimeter band sealingly fastened be- vinyl, alcohol, polyvinyl chloride, polyvinyl fluoride, tween said peripheral edges of said top and and polyvinylidene chloride. barrier sheets and a second perimeter band sealingly fastened between said peripheral edg- 7. A transfer mattress according to claim 1 wherein at 30 es of said barrier and bottom sheets; least one of said top inflatable mattress and said bot- a plurality of baffles, each having a width and a tom inflatable mattress is formed from one or more length, attached to an inner surface of said top fabrics which comprise a cold water soluble partially sheet and said barrier sheet; hydrolyzed polyvinyl alcohol, cold water insoluble a second plurality of baffles, each having a width hot water disintegrable aliphatic polyester. 35 and a length, attached to an inner surface of said barrier sheet and an inner surface of said bottom 8. A transfer mattress according to claim 1 wherein at sheet; least one of said top inflatable mattress and said bot- one or more inlet/outlet openings located within tom inflatable mattress is formed from an aliphatic at least one of said perimeter bands; and polyester that has a melt temperature above a nor- 40 one or more one-way valves located through mal human body temperature and is present in a said barrier sheet so as to provide selective air resin blend at a concentration sufficient to constitute flow communication between a first chamber the continuous phase of the blend, with a polyvinyl formed between said top sheet, said barrier alcohol constituting a discontinuous phase of the sheet, and said first perimeter band and a sec- blend, wherein said aliphatic polyester renders said 45 ond chamber formed between said barrier resin blend, and a partially hydrolyzed polyvinyl al- sheet, said bottom sheet, and said second pe- cohol in the blend cold water insoluble and deter- rimeter band so that when said inlet/ outlet valve mines a temperature at which said at least one of is closed-off from said source of pressurized air, said top inflatable mattress and said bottom inflata- said bottom inflatable mattress deflates by air ble mattress formed from said blend will be subject 50 escaping through said plurality of perforations to dissolution in an aqueous bath. whereby said one-way valve is actuated so as to prevent deflation of said top inflatable mat- 9. A transfer mattress comprising: tress.

a top inflatable mattress defined by a top sheet 55 and a perimeter band having a selectable inlet/ outlet valve arranged for airflow communication between an interior chamber of said top inflata-

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REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• US 19167405 A [0001] • US 5561873 A [0005] • US 60592251 B [0001] • US 6073291 A, Davis [0006] • US 4517690 A [0004]

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