DOCSLIB.ORG

Optimising Human Performance by Reducing Motion Sickness and Enhancing Situation Awareness with an Intuitive Artificial 3D Earth-Fixed Visual Reference

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

OPTIMISING HUMAN PERFORMANCE BY REDUCING MOTION SICKNESS AND ENHANCING SITUATION AWARENESS WITH AN INTUITIVE ARTIFICIAL 3D EARTH-FIXED VISUAL REFERENCE. Jelte E. Bos1,2, Mark M.J. Houben1, Jasper Lindenberg1 1 TNO Human Factors, Soesterberg, Netherlands, [email protected] 2 Research Institute MOVE, faculty of Human Movement Sciences, VU University Amsterdam. ABSTRACT Human performance has been shown to be negatively correlated with seasickness. By reducing crew, ship size, and hence redundancy, sickness induced risks increase exponentially. Although medication is effective, it also causes drowsiness. Non-pharmacological countermeasures are scarce, the most popular one being to look at the horizon. We exploited the latter by creating an artificial Earth-fixed matrix of 3D crosses, that can be used wherever outside views are scarce and visual displays are available. To test such a display we performed two experiments. In Experiment 1, 14 subjects completed a number of 20-minute trials in TNO’s Desdemona motion simulator reproducing a ship motion. The crosses were presented on a computer screen in the background of a demanding task, and on a projection screen in front of the participant. Sickness severity was rated at fixed intervals. In Experiment 2, 11 subjects completed a number of 20-minute trials in the same simulator, now reproducing an aircraft motion. No task was used in Experiment 2, but the display was extended by including a roller-coaster like track showing the trajectory to be followed ahead. Results of Experiment 1 showed that the anti-seasickness display did not interfere with the computer task per se, while it did reduce sickness due to ship motion, whether presented on the computer monitor or on the projection screen. In Experiment 2, sickness was further reduced from somewhat less than a factor of 2 when only showing the crosses (with respect to a control condition without any display), by over a factor of 4 when adding an anticipatory trajectory. These results allow for optimising operator performance and situation awareness at sea, as well as in the air and on land, as well as the performance of, e.g., troops having to perform right after a sickening transport. Keywords: human performance, operator performance, seasickness, airsickness, motion sickness, artificial horizon, visual display. 1. INTRODUCTION Human performance has been shown to suffer from motion sickness. McCauley et al. (2006), for example, estimated 90% of unadapted Utah Marine Reservists aboard HSV-2 Swift during African Lion in April 2005 to suffer from seasickness. Considering that these troops would yet have to perform after their transport, their capabilities to do so can seriously be doubted. Colwell (2000) and Bos (2004) showed that also in adapted crew, i.e., having been at sea already for two weeks, the number of failing tasks increased with their feelings of sickness as shown in Figure 2. In yet another study with the Canadian research vessel Quest (Colwell et al., 2008), crew cognitive and visual performance even showed to suffer more from seasickness than from the motions causing the sickness per se (Bos et al., 2008). Hence, counteracting seasickness, and likewise any form of motion sickness, pays. Bos JE, Houben MMJ, Lindenberg J (2012). Optimising human performance by reducing motion sickness and enhancing situation awareness with an artificial 3D Earth-fixed visual reference. MAST Europe, Malmö, Sweden, 11-13 September 1/10 Figure 1. Percentage of tasks failing due to seasickness (0 = no problems at all ... 100 = vomiting) in adapted naval crew (Bos, 2004). The most popular countermeasure against motion sickness seems to be the use of medication. Medication, however, needs to be taken well in advance to be effective and is associated with a decreased appetite, increased respiration, hyperthermia, euphoria, irritability, insomnia, confusion, tremors, convulsions, anxiety, paranoia, aggressiveness, loss of self-criticism, hot flashes, dry mouth, tachycardia, chest pain, hypertension, reduced mood, blurred vision, reduced (muscle) coordination, and/or a lack of memory. Most importantly, the majority of all medication are sedative, which is probably the most undesirable side-effect opposing their use by professionals performing critical tasks, such as flying an aircraft and operating a ship. Moreover, they require a certain time to wash out, why these side effects may still persist after cessation of the motion exposure when troops/marines typically have to do their job. More sophisticated instruments to counter motion sickness consist of reducing vehicle motion by, e.g., optimising (ship) hull form and (the location of) crew habitats, and adding appropriate ride control systems and/or anti-roll devices. Selection of unsusceptible crew or habituation training are yet another category of countermeasures. Incited by the general assumed positive effect of looking at the horizon when suffering from seasickness, we here report on the positive effect of providing an artificial Earth-fixed frame of reference when on a moving platform deprived from a natural view on the outside world, such as below deck on a ship (Experiment 1) or in an enclosed aircraft cabin (Experiment 2). Both experiments were performed in a laboratory setting using a motion platform to simulate the ship (Experiment 1) and aircraft (Experiment 2) motion, with the advantage of being able to reproduce exactly the same motion using different visual conditions. Although both experiments have been described separately before by Houben et al. (2010, Experiment 1) and Feenstra et al. (2011, Experiment 2), the current paper combines the two experiments, drawing additional conclusions based on the combined results. 2. EXPERIMENT 1 To study the effect of an Earth fixed frame of reference on seasickness, subjects were exposed to 20 minutes of simulated ship motion in several conditions with and without the artificial display. Subjects were in addition required to perform a task, so also the effect of sickness and the effect of the display thereupon could be studied in addition. More details are given by Houben et al. (2010). 2.1 Methods 2.1.1 Artificial display It was considered essential to visualise six degrees of freedom, i.e., not restricting to an artificial horizon. If a horizon would be presented in the frontal plane, only two degrees of freedom are visible: heave and roll, heave being confounded by pitch. To avoid such ambiguities we created layers of 3D crosses of equal size, suggesting water and air surfaces as shown in Figure 2. The tips of the crosses in the horizontal plane were given different colours allowing an increased situation awareness. The size of the objects and zoom factor was chosen such that a natural imagery with smoothly moving Bos JE, Houben MMJ, Lindenberg J (2012). Optimising human performance by reducing motion sickness and enhancing situation awareness with an artificial 3D Earth-fixed visual reference. MAST Europe, Malmö, Sweden, 11-13 September 2/10 objects was the result. Although roll, pitch and yaw could be inferred in an absolute sense (i.e. in degrees), surge, sway and heave could only be inferred relatively. Figure 2. Artificial image with 3D objects moving opposite the ship. This imagery was always moving opposite the ship/simulator motion (see below) such that it effectively suggested an Earth-fixed frame of reference. It was either shown on a computer monitor or projected on a screen using a beamer as further explicated below as well. 2.1.2 Simulated ship motion Motions were calculated of a recently acquired ship of the Royal Netherlands Navy, a 108 m Holland Class Patrol Vessel (see Figure 3 left). Hydrodynamic code was available to calculate ship motion depending on wave and wind conditions. For the present study a significant wave height Hs of 2.5 m, an average period T1 of 6.8 s was chosen, typical for sea state 4. The ship sailed with 12 kts 120o relative to the waves. The resulting six degrees of motion freedom were next slightly adapted to fit within the motion envelope of TNO’s Desdemona motion platform in Soesterberg, the Netherlands, used in this experiment. The main adaptation concerned filtering out the constant part of the forward velocity. The Desdemona motion platform as shown in Figure 3 consists of a cabin with a diameter of approximately 2 m, equipped with a safety chair, a modular instrument console and a three channel 120 x 40o visual of which only the centre screen was used in the current experiment. This cabin is fully gimballed allowing for unlimited angular motion about its yaw, pitch and roll axes. These gimbals can next move up and down with a stroke of 2 m, which device can bodily move over a horizontal sled of 8 m long. This sled, lastly can be rotated about a central Earth vertical axis so as to induce a sixth degree of freedom also allowing for centrifugation when the cabin is positioned off-axis. All degrees of freedom can be controlled dynamically and simultaneously. More information on this platform can be found at www.desdemona.eu. Figure 3. TNO’s Desdemona motion platform (centre), capable of simulating ship (Holland Patrol Vessel left) and aircraft (right) motion. Note that the anti-seasickness display was driven by the simulated motion, rather than the actual calculated ship motion, so as to realise a true Earth-fixed frame of reference. The current experiment can therefore be considered to be a veridical anti motion sickness experiment, and not one dealing with simulator sickness. Here, simulator sickness may be defined as sickness occurring in a simulator Bos JE, Houben MMJ, Lindenberg J (2012). Optimising human performance by reducing motion sickness and enhancing situation awareness with an artificial 3D Earth-fixed visual reference. MAST Europe, Malmö, Sweden, 11-13 September 3/10 when it does not occur in the condition that is simulated.
Recommended publications
  • Motion Sickness: Definition

    Motion Sickness: Definition

    Clinical and physiological characteristics of cybersickness Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy (Human Physiology) School of Biomedical Sciences and Pharmacy Faculty of Health and Medicine University of Newcastle, Australia This research was supported by an Australian Government Research Training Program (RTP) Scholarship. 1 STATEMENT OF ORIGINALITY I hereby certify that the work embodied in the thesis is my own work, conducted under normal supervision. The thesis contains no material which has been accepted, or is being examined, for the award of any other degree or diploma in any university or other tertiary institution and, to the best of my knowledge and belief, contains no material previously published or written by another person, except where due reference has been made. I give consent to the final version of my thesis being made available worldwide when deposited in the University’s Digital Repository, subject to the provisions of the Copyright Act 1968 and any approved embargo. Alireza Mazloumi Gavgani 2 ACKNOWLEDGMENT OF AUTHORSHIP I hereby certify that the work embodied in this thesis contains published paper/s/scholarly work of which I am a joint author. I have included as part of the thesis a written declaration endorsed in writing by my supervisor, attesting to my contribution to the joint publication/s/scholarly work. Alireza Mazloumi Gavgani 3 STATEMENT OF COLLABORATION I hereby certify that some parts of the work embodied in this thesis have been done in collaboration with other researchers. I have included as part of the thesis a statement clearly outlining the extent of collaboration, with whom and under what auspices.
  • Chapter 23 ENVIRONMENTAL EXTREMES: ALTERNOBARIC

    Chapter 23 ENVIRONMENTAL EXTREMES: ALTERNOBARIC

    Environmental Extremes: Alternobaric Chapter 23 ENVIRONMENTAL EXTREMES: ALTERNOBARIC RICHARD A. SCHEURING, DO, MS*; WILLIAM RAINEY JOHNSON, MD†; GEOFFREY E. CIARLONE, PhD‡; DAVID KEYSER, PhD§; NAILI CHEN, DO, MPH, MASc¥; and FRANCIS G. O’CONNOR, MD, MPH¶ INTRODUCTION DEFINITIONS MILITARY HISTORY AND EPIDEMIOLOGY Altitude Aviation Undersea Operations MILITARY APPLIED PHYSIOLOGY Altitude Aviation Undersea Operations HUMAN PERFORMANCE OPTIMIZATION STRATEGIES FOR EXTREME ENVIRONMENTS Altitude Aviation Undersea Operations ONLINE RESOURCES FOR ALTERNOBARIC ENVIRONMENTS SUMMARY *Colonel, Medical Corps, US Army Reserve; Associate Professor, Military and Emergency Medicine, Uniformed Services University of the Health Sci- ences, Bethesda, Maryland †Lieutenant, Medical Corps, US Navy; Undersea Medical Officer, Undersea Medicine Department, Naval Medical Research Center, Silver Spring, Maryland ‡Lieutenant, Medical Service Corps, US Navy; Research Physiologist, Undersea Medicine Department, Naval Medical Research Center, Silver Spring, Maryland §Program Director, Traumatic Injury Research Program; Assistant Professor, Military and Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland ¥Colonel, Medical Corps, US Air Force; Assistant Professor, Military and Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland ¶Colonel (Retired), Medical Corps, US Army; Professor and former Department Chair, Military and Emergency Medicine, Uniformed Services University of the Health Sciences,
  • Impact of Oral Vitamin C on Histamine Levels and Seasickness

    Impact of Oral Vitamin C on Histamine Levels and Seasickness

    Journal of Vestibular Research 24 (2014) 281–288 281 DOI 10.3233/VES-140509 IOS Press Impact of oral vitamin C on histamine levels and seasickness R. Jarischa,∗,D.Weyerb,E.Ehlertb,C.H.Kochc,E.Pinkowskid, P. Junga,W.Kählerb, R. Girgensohne, J. Kowalskib, B. Weisserf and A. Kochb aFAZ Floridsdorf Allergy Center, Vienna, Austria bGerman Naval Medical Institute, Kronshagen, Germany cHavariekommando (Central Command for Maritime Emergencies), Cuxhaven, Germany dShip’s doctor, anesthesist in a private practice, Pohlheim, Germany eSanitätsamt der Bundeswehr (Medical Office of the German Armed Forces), Munich, Germany f Institute of Sports Science, Christian-Albrechts University, Kiel, Germany Received 3 July 2013 Accepted 17 December 2013 Abstract. BACKGROUND: Seasickness is a risk aboard a ship. Histamine is postulated as a causative agent, inversely related to the intake of vitamin C. Persons with mastocytosis experienced improvement of nausea after the intake of vitamin C. OBJECTIVE: To determine whether vitamin C suppresses nausea in 70 volunteers who spent 20 minutes in a life raft, exposed to one-meter-high waves in an indoor pool. METHOD: Double-blind placebo-controlled crossover study. Two grams of vitamin C or placebo was taken one hour before exposure. Blood samples were taken one hour before and after exposure to determine histamine, diamine oxidase, tryptase, and vitamin C levels. Symptom scores were noted on a visual analog scale. On the second day the test persons were asked which day they had felt better. RESULTS: Seven persons without symptoms were excluded from the analysis. Test persons had less severe symptoms after the intake of vitamin C (p<0.01).
  • CIA's Prisoners," Washington Post, 15 July 2004; "CJ.A

    CIA's Prisoners," Washington Post, 15 July 2004; "CJ.A

    C06541727 Approved for Release: 2018/08/14 C06541727 Summary and Reflections of Chief of Medical Services on OMS Participation in the RDI Program 1 Approved for Release: 2018/08/14 C06541727 C06541727 Approved for Release: 2018/08/14 C06541727 . (b)(1)------ 'f'SF ~EleR~'i'/ C(b)(3) NatSecAct l/MO!'Oitlil I ' AL QA'IDA DETAINEES: the OMS Role Press attention to the Agency's interrogation and detention p~ogram began with'the 2002 capture ofAbu Zubayda~~;;lf.a~d again with the 2003 capture ofKhalid Shaykh Muhammed, accelerated in 2004 in the wake ofAbu Ghraib, and then exploded in 2(/f/lkllg,wing a number ofsignificant leaks. By 2007 hundreds-perhaps~ousan~s~f articles and editorials had been published on what ar,~ably.,has become the most controversial program in Agency history. Jji.f.;;,~dfrom withi~ resulti~g public pictur~ re~ains as ~~~a.1°fg_:.icature as fact. If tlie ~~~ i~­ any guzde, however, this dzstorted pzcture~w.z!l beco.me.the accepted P.,u'b1zc history ofan important chapter in Agency kis/o_ry,:·-;:Wiih\both present'?!ind fature implications for those within the Office.o/M~dical Services. These implications warrant a more lJiy"d internal aC,;QW..t ofhow OMS understood and experienced this 'P ogr,qm at the time.~iY"· · \. ~ J• ~(. ·.~:-· /; Introduction and Contents~ [J?.:--1 J ,:.,......\.!· J.-->,,. ..... The Context {p. 2J pioo J-2@~!1J . Saving the life ofqdlfg~.[alue: Ta.rget (HVT) 'fl!. 6} {2002} Embracing SERE (Sul-viral, EvtiSion,_Resistanc~scape) [p. JO] [2002] Initiation of.',;~n_bgnced i~i!?rrogatiori.
  • MEDICAL GUIDELINES for AIRLINE TRAVEL 2Nd Edition

    MEDICAL GUIDELINES for AIRLINE TRAVEL 2Nd Edition

    MEDICAL GUIDELINES FOR AIRLINE TRAVEL 2nd Edition Aerospace Medical Association Medical Guidelines Task Force Alexandria, VA VOLUME 74 NUMBER 5 Section II, Supplement MAY 2003 Medical Guidelines for Airline Travel, 2nd Edition A1 Introduction A1 Stresses of Flight A2 Medical Evaluation and Airline Special Services A2 Medical Evaluation A2 Airline Special Services A3 Inflight Medical Care A4 Reported Inflight Illness and Death A4 Immunization and Malaria Prophylaxis A5 Basic Immunizations A5 Supplemental Immunizations A5 Malaria Prophylaxis A6 Cardiovascular Disease A7 Deep Venous Thrombosis A8 Pulmonary Disease A10 Pregnancy and Air Travel A10 Maternal and Fetal Considerations A11 Travel and Children A11 Ear, Nose, and Throat A11 Ear A11 Nose and sinuses A12 Throat A12 Surgical Conditions A13 Neuropsychiatry A13 Neurological A13 Psychiatric A14 Miscellaneous Conditions B14 Air Sickness B14 Anemia A14 Decompression Illness A15 Diabetes A16 Jet Lag A17 Diarrhea A17 Fractures A18 Ophthalmological Conditions A18 Radiation A18 References Copyright 2003 by the Aerospace Medical Association, 320 S. Henry St., Alexandria, VA 22314-3579 The paper used in this publication meets the minimum requirements of American National Standard for Information Sciences—Permanence of Paper for Printed Library Materials. ANSI Z39.48-1984. Medical Guidelines for Airline Travel, 2nd ed. Aerospace Medical Association, Medical Guidelines Task Force, Alexandria, VA Introduction smoke, uncomfortable temperatures and low humidity, jet lag, and cramped seating (64). Nevertheless, healthy Each year approximately 1 billion people travel by air passengers endure these stresses which, for the most on the many domestic and international airlines. It has part, are quickly forgotten once the destination is been predicted that in the coming two decades, the reached.
  • Thermoregulatory Correlates of Nausea in Rats and Musk Shrews

    Thermoregulatory Correlates of Nausea in Rats and Musk Shrews

    www.impactjournals.com/oncotarget/ Oncotarget, Vol. 5, No. 6 Thermoregulatory correlates of nausea in rats and musk shrews Sukonthar Ngampramuan1, Matteo Cerri2, Flavia Del Vecchio2, Joshua J. Corrigan3, Amornrat Kamphee1, Alexander S. Dragic3, John A. Rudd4, Andrej A. Romanovsky3, and Eugene Nalivaiko5 1 Research Center for Neuroscience and Institute of Molecular Bioscience, Mahidol University, Bangkok, Thailand; 2 Department of Biomedical and Motor Sciences, University of Bologna, Bologna, Italy; 3 FeverLab, Trauma Research, St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA; 4 School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, China; 5 School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia. Correspondence to: Eugene Nalivaiko, email: [email protected] Correspondence to: Andrej A. Romanovsky, email: [email protected] Keywords: nausea, chemotherapy, temperature, hypothermia. Received: December 21, 2013 Accepted: February 21, 2014 Published: February 22 2014 This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT: Nausea is a prominent symptom and major cause of complaint for patients receiving anticancer chemo- or radiation therapy. The arsenal of anti-nausea drugs is limited, and their efficacy is questionable. Currently, the development of new compounds with anti-nausea activity is hampered by the lack of physiological correlates of nausea. Physiological correlates are needed because common laboratory rodents lack the vomiting reflex. Furthermore, nausea does not always lead to vomiting. Here, we report the results of studies conducted in four research centers to investigate whether nausea is associated with any specific thermoregulatory symptoms.
  • Medical Aspects of Harsh Environments, Volume 2, Chapter

    Medical Aspects of Harsh Environments, Volume 2, Chapter

    Medical Aspects of Harsh Environments, Volume 2 Chapter 32 PRESSURE CHANGES AND HYPOXIA IN AVIATION R. M. HARDING, BSC, MB BS, PHD* INTRODUCTION THE ATMOSPHERE Structure Composition THE PHYSIOLOGICAL CONSEQUENCES OF RAPID ASCENT TO ALTITUDE Hypoxia Hyperventilation Barotrauma: The Direct Effects of Pressure Change Altitude Decompression Sickness LIFE-SUPPORT SYSTEMS FOR FLIGHT AT HIGH ALTITUDE Cabin Pressurization Systems Loss of Cabin Pressurization Personal Oxygen Equipment SUMMARY *Principal Consultant, Biodynamic Research Corporation, 9901 IH-10 West, Suite 1000, San Antonio, Texas 78230; formerly, Royal Air Force Consultant in Aviation Medicine and Head of Aircrew Systems Division, Department of Aeromedicine and Neuroscience of the UK Centre for Human Science, Farnborough, Hampshire, United Kingdom 984 Pressure Changes and Hypoxia in Aviation INTRODUCTION The physiological consequences of rapid ascent and life-support engineers has established reliable to high altitude are a core problem in the field of techniques for safe flight at high altitudes, as demon- aerospace medicine. Those who live and work in strated by current atmospheric flight in all its forms, mountain terrain experience a limited range of al- military and civilian, from balloon flights to sail planes titudes and have time to adapt to the hypoxia ex- to supersonic aircraft and spacecraft. Although reli- perienced at high terrestrial elevations. In contrast, able cabin pressurization and oxygen delivery systems flyers may be exposed to abrupt changes in baro- have greatly reduced incidents and accidents due to metric pressure and to acute, life-threatening hy- hypoxia in flight, constant vigilance is required for poxia (see also Chapter 28, Introduction to Special their prevention.
  • Bluemagazine Caribbeanexplor

    Bluemagazine Caribbeanexplor

    38 SABA KITTS /ST. LUXURY LIVEABOARD Caribbean Explorer II The liveaboard experience is luxurious and focused on one thing—maximum diving pleasure. Hard-core divers who don’t mind interacting with a small group out at sea for a week, would love this excursion. By SOLOMON BAKSH Tent Reef is probably the most striking reef in Saba with vibrant sponges, enormous gorgonians and teeming with fish life 39 THE Boat at. Dive. Sleep…well, sleeping my shoes into. That was the last I saw of crew members on board: Tim Heaton, is optional. It’s a liveaboard them until seven days later. Captain, USA; Chris Johnson, Engineer, lifestyle—getting up from your I was the first guest to arrive on board USA; Nichol Schilling, Purser, Germany; Ebed every day for a week with a the boat and was given the best location to Instructors Claire Keany, Scotland; Brett view of a breathtaking sunrise from your set up my gear—right next to the exit. Lockhoff, USA; Joe Lamontage, Canada. window, the ocean always in sight, a hot The person responsible for keeping all of us breakfast and another day of great diving. Amenities well fed was chef, Sarah Dauphinee, USA. It’s the nature of these trips that make The Caribbean Explorer II was well laid Every day was an epicurean delight with them so attractive. Plying the open ocean out. The upper deck housed the galley, air- Sarah serving up Mexican, Mediterranean, to different dive sites every day and over conditioned dining area and sun deck. Italian, Caribbean and BBQ dishes.
  • Medical Guidelines for Airline Transport

    Medical Guidelines for Airline Transport

    Federal Aviation Administration Aeromedical Safety Considerations for Transportation of Patients by Airline Presented at: Brasilia By: Melchor J. Antuñano, M.D., M.S. Director, Civil Aerospace Medical Institute Date: 2011 INDIVIDUAL : OPERATIONAL : Physical Fitness Chemical/Biological Hazards Psychological Fitness Automation Issues Alcohol Consumption Workload & Performance Medication Use Decision-Making & Judgement Illicit Drug Use Crew Resource Management Diseases & Illnesses Spatial Disorientation Fatigue Life Support Systems Circadian Rhythms Personal Protective Equipment Nutrition & Hydration Acceleration Forces Emotional Stress Human-Machine Interface Human-Human Interface ENVIRONMENT : Noise & Vibration Barometric Pressure Airsickness Solar & Cosmic Radiation Transmeridian Flights Temperature and Humidity Cabin Air Medical Guidelines for Airline Travel Federal Aviation Administration • Cabin altitude during flight is between 5,000 and 8,000 ft (1,524 m and 2,438 m) • This results in reduced barometric pressure with a decrease in partial pressure of oxygen (PO2) • Barometric pressure is 760 mmHg at sea level with a PaO2 (arterial O2 pressure) of 98 mmHg • Barometric pressure at 8000 ft will be 565 mmHg with PaO2 of about 55 mmHg • This corresponds to a blood oxygen saturation of 90% Cabin Operation 3,048 m (8,000 ft MAX) Airplane Operation 12,192 m Typical Cruise Cabin Pressure Schedule Resulting Cabin Altitude at Cruise Depends on Airplane altitude Cruise Cabin Pressure Schedule Constant Diff Pressure Health-Related Symptoms as
  • Hyperthermia & Heat Stroke: Heat-Related Conditions

    Hyperthermia & Heat Stroke: Heat-Related Conditions

    Hyperthermia & Heat Stroke: Heat-Related Conditions Joseph Rampulla, MS, APRN,BC eat-related conditions occur when excess heat taxes or overwhelms the body’s thermoregulatory mechanisms. Heat illness is preventable and occurs more Hcommonly than most clinicians realize. Heat illness most seriously affects the poor, urban-dwellers, young children, those with chronic physical and mental illnesses, substance abusers, the elderly, and people who engage in excessive physical The exposure to activity under harsh conditions. While considerable overlap occurs, the important the heat and the concrete during the syndromes are: heat stroke, heat exhaustion, and heat cramps. Heat stroke is a life- hot summer months places many rough threatening emergency and occurs when the loss of thermoregulatory control results sleepers at great risk in hyperpyrexia (very high fever) and severe damage to many internal organs. for heat stroke and hyperthermia. Photo by Epidemiology Sharon Morrison RN Heat illness is generally underreported, and the deaths than all other natural disasters combined in true incidence is unknown. Death rates from other the USA. The elderly, the very poor, and socially causes (e.g. cardiovascular, respiratory) increase isolated individuals are disproportionately affected during heat waves but are generally not reflected in by heat waves. For example, death records during the morbidity and mortality statistics related to heat heat waves invariably include many elders who died illness. Nonetheless, heat waves account for more alone in hot apartments. Age 65 years, chronic The Health Care of Homeless Persons - Part II - Hyperthermia and Heat Stroke 199 illness, and residence in a poor neighborhood are greater than 65.
  • Hypothermia Hyperthermia Normothemic

    Hypothermia Hyperthermia Normothemic

    Means normal body temperature. Normal body core temperature ranges from 99.7ºF to 99.5ºF. A fever is a Normothemic body temperature of 99.5 to 100.9ºF and above. Humans are warm-blooded mammals who maintain a constant body temperature (euthermia). Temperature regulation is controlled by the hypothalamus in the base of the brain. The hypothalamus functions as a thermostat for the body. Temperature receptors (thermoreceptors) are located in the skin, certain mucous membranes, and in the deeper tissues of the body. When an increase in body temperature is detected, the hypothalamus shuts off body mechanisms that generate heat (for example, shivering). When a decrease in body temperature is detected, the hypothalamus shuts off body mechanisms designed to cool the body (for example, sweating). The body continuously adjusts the metabolic rate in order to maintain a constant CORE Hypothermia Core body temperatures of 95ºF and lower is considered hypothermic can cause the heart and nervous system to begin to malfunction and can, in many instances, lead to severe heart, respiratory and other problems that can result in organ damage and death.Hannibal lost nearly half of his troops while crossing the Pyrenees Alps in 218 B.C. from hypothermia; and only 4,000 of Napoleon Bonaparte’s 100,000 men survived the march back from Russia in the winter of 1812 - most dying of starvation and hypothermia. During the sinking of the Titanic most people who entered the 28°F water died within 15–30 minutes. Symptoms: First Aid : Mild hypothermia: As the body temperature drops below 97°F there is Call 911 or emergency medical assistance.
  • Carbon Monoxide Poisoning

    Carbon Monoxide Poisoning

    Carbon Monoxide Department of Boating and Waterways www.BoatResponsibly.com Exposure to CO in large amounts or for a long duration results in death. Carbon monoxide (CO) is an odorless, colorless gas in the exhaust produced in gasoline engines. Boats release CO through the exhaust ports of vessels that are either idling or underway. When inhaled, CO replaces oxygen in tissues. What are the symptoms of carbon monoxide poisoning? Symptoms of CO poisoning may include nausea, dizziness, confusion, headache and fainting; however, people often mistakenly attribute these symptoms to too much alcohol, sun, and noise, or to motion sickness from the water or exhaustion. How are people exposed to carbon monoxide in a marine environment? Traditionally, CO poisonings have occurred on houseboats, vessels with overhead canopies or other vessels that have poor ventilation. CO also accumulates onboard a vessel through a process known as the ‘station wagon effect.’ This occurs as air moves around a boat and forms a low pressure area immediately behind the broad, flat transom. CO from the exhaust system enters the low-pressure area and is fed back into the cockpit and into the cabin. Many cases of carbon monoxide inhalation have involved a recreational activity known as ‘teak surfing’. ‘Teak surfing’ involves holding onto the swim platform or transom of an underway vessel to bodysurf on the wake of the vessel. As of January 1, 2005, ‘teak surfing’ and other similar recreational activities are against the law in California. How common is carbon monoxide poisoning in a marine environment? Nationwide, between 1990 and 2004, there were 571 reported boating-related CO poisonings, including 113 deaths; 43 in California alone.