HIGH-ALTITUDE RESEARCH

Press, Volume C, Issue 29436, 11 February 1961, Page 10

HIGH-ALTITUDE RESEARCH

[Bs/ CAPTAIN THOMAS O. NKVISON, V.S. Air Force] 14IGH altitude medical research, one of the ** objectives of the Himalayan Scientific and Mountaineering Expedition, was a major reason which prompted the United States Air Force early in 1960 to accept the invitation of Sir Edmund Hillary to participate in the venture. In addition to its snowman search and glaciological studies, the Hillary expedition is conducting one of the most extensive programmes of high altitude medical research ever to be undertaken by any expedition.

The medical research is under the direction of Dr. Griffith Pugh of the Medical Research Council Laboratories of London, England. With Dr. Pugh are four other doctors and one medical student representing England, America and New Zealand. All are working on various problems of high altitude physiology and medicine.

Ever since man first ventured upward in balloons he has experienced difficulties from such factors as cold and lack of oxygen. Aviators and their doctors, flight surgeons, have been concerned with the effects of high altitude and have struggled to protect pilots from the adverse environment of flight. At 18.000 feet, for example, there is only one half the amount of oxygen normally found at sea level. Breathing While a pilot flying at 18,000 feet must either remain inside a pressurised cabin or breathe oxygen by mask, a mountaineer can exist quite happily at this altitude. The difference is that during the climber’s gradual exposure to altitude certain physiological adaptations occur which permit him to live and function at much higher altitudes. This adaptation is

While a pilot flying at 18,000 feet must either remain inside a pressurised cabin or breathe oxygen by mask, a mountaineer can exist quite happily at this altitude. The difference is that during the climber’s gradual exposure to altitude certain physiological adaptations occur which permit him to live and function at much higher altitudes. This adaptation is termed acclimatisation and full acclimatisation requires weeks, even months, to take place. In the past, mountaineers have climbed as high as 28.000 feet—on Mount Everest —without using oxygen. On the other hand, a pilot whose oxygen supply failed at 28.000 feet would become unconscious within a few minutes.

One object of the expedition is to make a detailed study of the process of acclimatisation to high altitude. The information obtained will enlarge our knowledge of high altitude physiology and some day may help to protect our fliers, particularly in an emergency situation involving the failure of ordinary protective equipment.

Today, space travel is in the minds of us all. The problems of putting a man into space are tremendous.

High-Altitude Hut

One of the medical difficulties stems from the fact that for engineering reasons the earliest space vehicles may require the occupant to live in a partial vacuum equivalent. for example, to an. altitude of 18.000 feet. Very little is known about the prolonged exposure to altitudes above 18,000 feet, which is .the height of the highestknown habitation in the Andes. During the Hillary expedition at least six scientists and mountaineers will spend upward of three months in a hut which has been constructed at 19.200 feet. The hut is extremely well insulated and complete with six, 12 and 24-volt electrical systems powered by a wind generator. One section has been equipped for physiological research and the long-term response of the respiratory, circulatory and nervous systems of the six subjects will be studied in detail. Electronic Devices Of course, such a programme could be carried out in a chamber at sea level and a number of shorter studies have been undertaken in altitude chambers and space cabin simulators. One difficulty in a long chamber experiment is to get volunteers who will live for months in a cramped steel

chamber merely for the sake of experimentation. Another difficulty is the tremendous expense involved and the problem of maintaining 24-hour medical surveillance and round-the-clock control by trained chamber operators. The expedition, then, will investigate the effects of prolonged exposure to altitudes above 18.000 feet The knowledge obtained may well benefit the early astronauts, although later space travellers will undoubtedly enjoy fully pressurised cabins just as the present ar traveller sits in near sea-level comfort. A part of the research programme which is of direct interest to an astronaut is the development and testing of electronic devices for monitoring the medical'condition of the test subject. In the earlier vehicles it will be vitally important to follow the occupant’s reactions to the various stresses of launching and of space flight. Since it will not be possible for a doctor to accompany the astronaut, various devices must be developed to monitor the subject's heartbeat, respiration, brain function and the environment about him Many instruments are available to do this.

The problem is to develop a battery of devices which will be lightweight, simple and fool-proof and still yield a maximum of physiological data which can either be stored or telemetered to observers on the ground. A major objective of the Hillary expedition is to test a number of such devices under adverse conditions of cold and high altitude and to assemble a system to gather data from active mountaineers. Equipment Many of the components have already been used by the United States Air Force School of Aviation Medicine to monitor animals in space, such as the monkeys Sam and Miss Sam. Other equipment has been developed by Dr. M. Wright and others at the National Institute of Medical Research in London, England. The combined apparatus will weigh from 20 to 30 pounds and will supply a permanent record of some 10 different functions such as brain waves, electrocardiogram, respiration, body temperature and so forth. One mountaineer will have electrodes, tiny amplifiers, and miniature sensors attached to his body while a second climber will carry a lightweight photographic recorder and batteries. The two units are joined by an electric cable although the data could equally well be transmitted by radio telemetry. Objectives The record, after development. will consist of a series of wavy lines on a long strip of photographic paper. When set up the apparatus may be switched on at any time, either during rest or on an actual climb.

This will be the first time such a system has been used in high mountains. Although the primary objective is testing and development of the equipmnt itself, the data obtained should constitute an important addition to our knowledge of high altitude physiology. Some of the devices tested may even find their way into the space cabins of our early astronauts.

Copyright 1961—by World Book Encyclopedia. Chicago. Distributed by Opera Mundi. Paris.