Bioastronautical contributions to medicin

Mc Farland, R. A.

English

NASA Technical Reports Server

30343
INTRODUCTION TO
LIVING IN SPACE
Ross A. MCFARLAND
Guggenheim Professor
of Aerospace Health and Safety
Harvard School of Public Health
In the preceding sessions of this conference many
of the leaders in the space program have discussed the
problems of placing men in space, as well as machines
in space. Considerable attention is also being devoted
to the practical uses of satellites, and related areas.
Dr. Werner M. von Braun gave a very inspiring
presentation on the future of space. He emphasized
the contributions being made to many aspects of
modern life, and he clearly portrayed the nature of
things to come and the possible impact of the space
program in absorbing the energies of men in the
future. One might interpret Dr. von Braun's views
to imply that space activities eventually may be substi-
tuted for the material and psychological needs which
in the past have led to war. Thus, the exploration of
space eventually may prove to be "The Moral Equiv-
alent of War," as reminiscent of William James'
famous essay on this subject. The objective of our
program in this session is to discuss some of the accom-
plishments and problems relating to Living In Space.
First of all, it is important to note that the Na-
tional Aeronautics and Space Act of 1958 requires
that " . . the aeronautical and space activities of
the United States shall be conducted so as to con-
tribute materially . . . to peaceful and scientific pur-
poses .... " In other words, those responsible for
the space effort must also be concerned with the social,
economic, and scientific ramifications of the national
space program for our society. In this conference on
the peaceful uses of outer space, we are sharing in
these objectives. Accordingly, it is appropriate to
examine some of the implications of the national
space program for medicine and related biological
sciences.
It may be too early to appraise accurately the im-
pact of the space effort on medicine. It is possible,
however, to examine the role of medicine in areas
relating to living in space. The basic objective is to
develop principles relating to the avoidance of disease
and the prevention of injury. The real goal, how-
ever, is not simply marginal survival. An attempt
must be made to predict and maintain optimum
human performance.
In order to achieve these objectives relating to
human performance in space, it is necessary to con-
sider the interaction between the engineering and
medical sciences, or, as commonly expressed, the
trade.o#s or compromises required in the design of
equipment. Coordinating the efforts of design engi-
neers and biological scientists has resulted in more
efficient and safer aircraft to fly within the Earth's
atmosphere, and this objective can also be accom-
plished for vehicles to operate in space.
It should be emphasized that aerospace medicine
involves a team approach including the disciplines
of psychology, physiology, biology, medicine, and
engineering. Often there is a problem of communica-
tion and understanding between the physical and
biological scientists. In practice, the engineer and
physician, finding themselves as joint participants in
a project, are forced to find a common mode of ex-
pression--obliged to make their ideas and solutions
useful to each other. Thus, there develops an integra-
tion between medicine and engineering. Understand-
ing has increased with time, and significant contribu-
tions have resulted from a joint effort.
The medical sciences of today, as is equally true of
the aerospace sciences, would be very limited if the
physician's experience did not include knowledge of
the manner in which man responds to his total
environment. Indeed, the sciences of molecular biol-
ogy and the art of medicine constitutes only a small
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174
I[
PEACEFUL USES OF SPACE
fraction of the knowledge required for the care of
individual patients and the practice of public health.
With the increasing control of communicable diseases,
the patient is not as great a threat to the community
as the community and its byproducts are a threat to
the patient. Likewise, in the exploration of space,
it is the hostile environment which must be conquered,
whether natural or man made.
One professor of medicine, Dr. John Parks of
George Washington University, has made the follow-
ing points about environmental health, in answer to
the question, "What is the nature of that threat in
an effluent society ?"
It is air pollution and its effects on the cardiopulmonary
system; it is water pollution and its relationship to hepa-
titis; it is the effect of urban noise and auto traffic on the
nervous system; it is the body-burden of radiation and its
widespread effects: it is the chemicals of the work space;
it is the great unknown of pesticides. Surely physicians,
who for centuries have fought and conquered the great
unknowns of disease, will join in the common attack on
these environmental problems.
These statements are directly relevant to space
medicine with only slight rephrasing.
We ordinarily think of the relationships between
aerospace medicine, preventive medicine, and public
health as four general areas.
ENVIRONMENTAL INFLUENCE ON
HUMAN HEALTH AND PERFORMANCE
The physician working in the field of bioastro-
nautics is vitally concerned with the effects of the
environment on human health and performance. In
most cases, physical or chemical hazards are involved.
His ultimate task is to establish scales which relate
duration and intensity of exposure to human tolerance
and performance. These must be stated in terms
which are useful to design engineers. There is direct
applicability of most of these design criteria to pre-
ventive medicine here on Earth. Thus, there is a
direct interrelationship between the environmental
health sciences and space medicine. Radiation, heat
and cold, toxic chemicals and barometric pressure are
but a few of the areas common to both fields.
Obviously, means of protection against these hazards
in space flight should contribute significantly to the
control of hazardous situations in industry.
There are many other examples of this interchange
of knowledge and techniques. Studies of weightless-
ness on various biological organisms show the effect
of gravity on cellular growth and differentiation, and
other physiological effects such as dccalcification. The
use of pressure-suit-type devices may aid in venous
return of blood to the heart in certain types of
patients. The mechanisms by which microbial spores
are transported by air are highly important to both
biology and medicine; there are direct implications
for reducing the spread of agricultural crop diseases
and for protecting persons suffering from allergies.
The use of hyperbaric oxygen in certain surgical
procedures is proving to be of interest in a variety of
clinical conditions.
THE DESCRIPTION AND
MEASUREMENT OF "NORMAL HEALTH"
A general principle in industrial medicine is the
effective matching of men and jobs. Implicit in this
procedure is knowledge of the characteristics of both
the man and the job. The selection of astronauts and
the design of their training program are based essen-
tially on this procedure. However, criteria for selec-
tion were essentially nonexistent at the outset.
Because of the need for this data in the selection
process, a great deal of information on healthy in-
dividuals, with and without the factor of stress, has
been developed within studies in aerospace medicine.
The immediate usefulness of this type of information
to clinical medicine is obvious.
THE ALTERATION OF BASIC
BIOLOGICAL MECHANISMS TO INCREASE
OR TO PROLONG USEFUL ADAPTATION
The specialist in aerospace medicine is vitally in-
terested in basic physiological mechanisms. His inter-
est is directed not only toward an understanding of
these bodily systems, but equally toward prediction of
behavior in times of anticipated stresses. Knowledge
of the mechanical characteristics of the vestibular ap-
paratus allows the aerospace physician to predict the
distortion of visual perception and disorientation
which would occur to a tumbling or spinning astro-
naut. The otolaryngologist uses this same knowledge
when he traces through a causative disease process.
Closed ecological systems, withdrawing of normal
sensory inputs, variations in oxygen pressure, and
the prolonged effects of certain gases and toxic agents
provide a few illustrations of other areas under
current study.
Means of altering the biological organism to in-
crease resistance to disease are of common interest to
LIVING IN SPACE
clinical and aerospace medicine. For example, findings
in the field of antiradiation drugs obtained from
research in one specialty are useful to the other.
THE REFINEMENT OF INSTRUMENTS
FOR OBSERVING, RECORDING, AND
ANALYZING DATA
The man-in-space program requires that a large
volume of information about the astronaut be remotely
collected and transmitted instantaneously to ground-
based observers. A large number of tools have been
perfected during the past few years to observe, record,
and analyze physiological data. These developments
are often referred to as an important contribution of
bioastronautics to clinical medicine. A wide variety
of sensors have been developed, as well as miniatur-
ized telemetry devices and computers. Many of these
have found immediate application in surgery, medicine,
and anesthesiology. The transmission of physiological
data via the communications satellite Relay I between
England and a major medical center in the United
States in order to make a diagnosis for an individual
patient provides a dramatic illustration.
STIMULUS OF SPACE RESEARCH
After this brief summary of the relationships be-
tween space and terrestrial medicine, one may ask the
question whether these contributions could have arisen
without the stimulus and challenge of the space
program. Analysis has suggested that while a few
developments might have appeared, most would not.
A Brookings Institute Report, "Implication of Peace-
ful Space Activities for Human Affairs," written in
1960, noted that: " . . major breakthroughs in
science and technology have always produced accelera-
tion in the rate of succeeding innovation, but space
activities appear to be pushing the pace of innovation
to unprecedented levels."
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The Mercury program found man not only an
effective link in a complex system, but on three of
seven missions, an indispensable element in terms of
their success. Many have asked, "Why send a man
on such a dangerous mission ? Wouldn't it be better
to use instruments ?" One space scientist has recently
pointed out that as we approach these more advanced
studies we need a skilled interpretation of the broad
situation from which alternative courses of action can
be weighed objectively. If we were to try to design
an instrument to exercise this broad comprehension,
it would look surprisingly like a man.
More specifically, a human operator in the space-
craft can: (1) report upon and cope with unexpected
events and phenomena; (2) make generalizations
from specific observations; (3) profit from experience
as the mission progresses by assimilating bits of
pertinent information into intelligible form, and re-
program as necessary; (4) improvise and use flexible
procedures which contribute to the success of a mis-
sion; and, finally, (5) exercise judgment. Because of
these abilities it can be seen that a well-trained astro-
naut is very essential when there is a need for flexibil-
ity and when there is an extreme range of alternative
conditions.
The experience obtained from the Mercury project
has provided a basis for judgment in planning later
man-in-space programs. The results demonstrate that
man can survive for short intervals in space. The
effects of missions of longer duration are unknown.
Prominent among these are the effects of weightless-
ness and the interaction of this variable with other
hazards. Man's function and behavior while breath-
ing an artificial atmosphere, altered as to pressure and
composition for long periods of time, are as yet
unknown.


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