Science in Action: Aero Medicine (1956)

To another program in the award-winning television series Science in Action. Science in Action is produced by the West's oldest scientific institution, the California Academy of Sciences, now in its 100th year. I have a very interesting ticket that I received just recently. It is a ticket for space travel. A trip to the moon. And this first ticket is good for travel from the Earth to a space platform, which is scheduled to be about 1,200 miles out from the Earth. And then the second ticket is supposed to take me from this space platform by another rocket to the moon. At least that is what it says here. Actually, of course, there are a good number of things that we're going to have to know before either you or I will be able to make a trip to the moon. For example, can our bodies withstand the terrific effects of hurtling through space at, say, 25,000 miles per hour? Well, much valuable information has been gained in this field of aeromedicine through the studies which have been conducted on people living at high altitudes in the mountains. And so, as our first guest on Science in Action, we are privileged to have an authority in this field, Dr. John Lawrence, who comes to us from the University of California. Welcome to Science in Action, Dr. Lawrence. Very glad to be here, Dr. Harold. And I'm glad to uh know that you're going to start about talking about the effects of altitude on people on the ground. Because I think from what we can learn on the effects of altitude on people living on the Earth, much can be applied later to the problems of the aviator flying at altitude in the air. Yes, well, now it's not uncommon for a person to travel, say, in a pressurized cabin in a plane at about 14,000 ft, and he thinks nothing of it at all. But, there are people that live 14,000 ft and higher, and you've made some very important studies on them, and they are found in the highlands of Peru. Now, what can you tell us about that? Yes, so this area of Peru is the only area in the world where you can find large numbers of people living at high altitude. Actually, in the Altiplano of Peru, and uh uh there are about 165,000 people living between the altitudes of 14,000 and 16,000 ft. And to the medical man, uh these people, and also the animals, uh are very interesting. Uh the animals that are particularly interesting are the llama and the vicuña, the animal that produces that very fine fur. Well, suppose we examine some of the problems that are connected with this, and the first would be uh oxygen, and the second would be pressure. Now, suppose uh Dr. Lawrence, you give us an idea as to what would be involved in our as we start from sea level and go up to the top of a mountain in terms of pressure. Well, in terms of pressure, at sea level, as you know, the uh pressure on the body is about 14.6 lb per square inch. Whereas at uh 20,000 ft, it's about 7 lb, and at 40,000, about 3 lb per square inch. Now, let's see how this uh variation in pressure affects the human being. Well, I know from your work and the study of pressures that they are very, very important. Here at sea level, with 14 lb pressure against us at all points, then we exert 14 and 1/2 lb pressure outwards, so that we're sort of an equilibrium. But, as we go up into the air, or as we go down in the ocean, then this equilibrium changes, and that's where these problems come in. Exactly. Uh as you go from sea level to high altitude, the pressure falls off, and secondly, the uh oxygen pressure falls off. So, that the body is faced with being exposed through the air we breathe with a lack of oxygen, which we call anoxia. Yes, and it takes that pressure to force the oxygen into the lungs, and without that, then if you happen to be a lowlander, you're going to have trouble when you go into high altitudes. That's very true, and it might be a good idea to talk for a minute about how the body utilizes oxygen. Uh as you know, the oxygen in the air we breathe uh is exposed to the red cells in our lungs. Yes. And the red cells carry the oxygen to the tissues because the red cells contain hemoglobin. Now, let's look at that hemoglobin for just a moment. That is a word made up of two parts, hemo and globin, and the hemo means blood, and the globin comes from the word globulin, which means the protein materials in the blood. Well, I think this uh chart here will uh help us uh uh explain how hemoglobin carries oxygen. Here we have the lungs, which uh uh carry the oxygen to the uh red cells in the blood, and the red cells in turn circulate to the tissues and unload the oxygen, and then come back for another load, so you have a continuous circuit of oxygen-carrying hemoglobin in the red cells. Well, these principles, of course, apply to people who live at high altitudes. Yes, uh with less oxygen that the people at high altitude have, uh the way they compensate for it is by developing more red cells. And secondly, one of the most important compensatory adaptation mechanisms is the fact that they can do more work on the same amount of oxygen. How about the chest volume now? You were mentioning a little bit earlier that these uh high Peruvians have a tremendous chest volume. Well, yes, uh now this is a chest film of a young Peruvian, uh copper miner, actually living uh at about 16,000 ft. His chest circumference would be around uh 40 in. uh inches uh compared to a normal uh similar age and size sea well sea level dweller whose diam- I mean, circumference would be about 36 in. Let's go back once more. Again, and now this one, uh, how about the heart cavity here? That looks quite a bit larger. Well, now the the consistent finding in all people who live at, uh, altitude is this enlargement of the right side of the heart. Mhm. And we compare that with a normal lowland dweller and we find that the heart is much smaller. You can see the difference there quite clearly, I think. Yes. Well, now I'd like to ask you something else. What about the red blood cell count in, uh, people who live at high altitudes as compared to those at low altitudes? Well, uh, in this, uh, young, uh, Peruvian highlander, his count is about 7 million. And how about the normal for a lowland? one is about 4 and 1/2 to 5 million. And then how about, uh, blood volume? That is, the total amount of blood in the system. Well, there's quite a striking difference. Now, this, uh, man would have about, uh, oh, 8 quarts of blood. Uh-huh. As compared to as a normal of about what? About 5 quarts. About 5 quarts. Well, now suppose that I were to go to the highlands of Peru, how long would it take me to acclimate myself to the conditions there? Well, uh, in our experience and that of others, uh, uh, takes several days before you become acclimated, but, um, uh, in this picture here, in the movie picture, you'll see people in, uh, uh, the town that we first go to, La Oroya in Peru, about 12,500 ft. And the acclimatization, uh, gradually, uh, takes place so that it in the end of about 2 months, you're completely acclimatized. But it's, uh, also limited by the fact that, uh, you can't, uh, reach proper acclimatization above about 22,000 or 23,000 ft. You have two factors that, uh, here that, uh, are, uh, uh, difficult ones. First, acclimatization is slow. Second, acclimatization is limited to about 22,000 or Well, yes. Now, all of this, of course, does apply to flyers. Well, yes. Of course, in the case of flyers, uh, they ascend to 20,000 or 40,000 or more in a matter of minutes. Yes. So, you have very special problems here. Mhm. Well, now to tell us about flyers problems at altitude, we've invited as our second guest on Science in Action, Dr. William Orlob, who comes to us from Hamilton Airfield. Howdy, sir? I'm glad to join you, Dr. Harold. Well, there needs to be a great deal of debunking about this high altitude flying. The problems already considered by Dr. Lines, namely pressure and oxygen. In addition to these problems, the flyer has the problem of acceleration, heat, radiation, gravity, and noise. Of course, all of these various things fit into the general pattern, but the modern flying in jet planes that travel faster than sound and up to speeds of more than 1,000 miles an hour brings about these complex problems. There's vertical takeoff, the rate of climb, to mention only two. Of course, all of these problems did not start necessarily with the the airplane. We go back to 1875, there was a Frenchman by the name of Tissandier who went up in a balloon to the unheard of height of 28,000 ft. That was more than 5 miles. Yes, and this was indeed an unfortunate and tragic experience for two of Tissandier's companions died in this experiment. Uh-huh. They carried oxygen at all times, but by the time they knew they needed it, it was already too late. Now, Tissandier himself carried oxygen and used oxygen from the ground up. But even he became unconscious and would have died had not the balloon descended from altitude. That would be a case of anoxia. Yes, anoxia or the very early phases of anoxia, which includes a feeling of euphoria or false sense of well-being, which is poor judgment. They feel they're so much better off than they are that by the time they're aware of the danger they're in, it's already too late. Yes, well, I know divers when they go down sometimes run into this caisson's disease or decompression troubles or bends. Flyers have the same problems. Yes, indeed they do. In fact, uh any decrease in pressure, the flyer will experience pain in his joints. This is due to the fact that the nitrogen which is normally dissolved in the blood under pressure begins to bubble out and this creates bubbles in the tendons, muscles and other tissues of the body. This can cause a great deal of pain. Well, let's assume that this bottle of carbonated beverage contains nitrogen in solution. Now, let's just shake this up and watch now what happens the way this nitrogen is going to come out when I take the top off here. In other words, that would be the same sort of thing that the change in pressure would do to the blood and maybe to the tissues as a result of this pressure change. That is correct, Earl. In fact, a great deal of work has been done on the high altitude pressure chamber. That's a device which permits us to study the effects on the flyer pressure when it's under exact controlled conditions. Now, Dr. Lawrence has done a great deal of study on this high altitude pressure chamber during World War II. I wish we could show you the chamber that we've been working with Captain Orlove and Dr. Harold, but we have a movie here that shows the chamber in operation. Yes, well, oh oh what's this? I guess this isn't your chamber. No, this must be the first chamber that was ever made, 1878. Paul Bert wrote a book about the experiments that he did on himself. Now, for nearly 50 years everybody forgot about this man until 1900 aviation came into being and then of course his work became very, very important. Now, I guess we're over to more modern This is the one of those modern pressure chambers that you can put about 15 men in. Actually, these men are being studied at uh uh about 38,000 ft for the high altitude bends. And this work was done for the selection of men who could fly at extremely high altitude without pressure cabin aircraft. Actually, uh we found that if you could have crew members all 15 years of age are are under. You wouldn't need pressure cabin aircraft because 15 year olds never develop the bends. Of course this wasn't practical. Now what are they doing here? Well these men are breathing pure oxygen, 100% oxygen. They're learning to acclimatize themselves under these conditions. It's a rapid process. This is exercise tolerance. These men who are under the the decrease of pressure and at this time breathing 100% pure oxygen. This is a to an attempt to bring out this pain in the knees that flyers uh got during the war at high altitude. And the wrists too, you see. Is he having trouble with his wrist there? He's having pain in his wrist now. Now the nitrogen bubbles we spoke of are coming out into the joint. Uh the uh doctor in attendance there is marking out the points where the man is experiencing pain and uh which would be the location of these nitrogen bubbles we spoke of. And this was a real problem in World War II because uh pressure cabin bombers were not uh very numerous at that time. And of course now with pressure cabin aircraft, this is not so much of a problem with the bends. Now there's a man clearing his Eustachian tube to prevent this pressure increase in pressure in his eardrums. The man next to him is not quite so fortunate. He uh he cannot clear his. He's going to have to have help. And now the doctor in attendance is spraying is going to spray his nose with a vasoconstrictor drug which will open the Eustachian tube and permit equalization of pressure. This relieves the man of the pain he would normally experience in his ears. Again we see the men breathing 100% pure oxygen. This man has developed pain in his abdomen. Apparently he had pancakes for breakfast and a little gas. Gas? Yes, pancakes. They're not good for flyers. Flyers in Korea experienced these pains and found out they could not tolerate such things as pancakes for breakfast before a high flight. But pancakes on the ground are perfectly all right. Pancakes on the ground are all right. Now, he's being what? Taken out into another chamber. Well, that's the lock. He's going into the lock and taken down to sea level. So, he has to be recompressed, as it were. the test. Oh, he flunked the test. About half of the uh young men that we studied, uh these were Air Force men, they were very resistant to the bends, and about half were uh not resistant. A great deal depends on the youth of these men. If they are young men, they survive quite well. This is the operator, the man who's adjusting the amount of pressure which simulates high altitude in the chamber. He's literally carrying them up to a high altitude. These tests are done at about 35,000 ft. Now, what was that? Well, that's a rapid decompression. The man is uh ostensibly at an altitude of, say, 10,000 ft. The chamber next to him is at 35,000. The membrane between is suddenly ruptured, and the man precipitated into an uh atmosphere of uh decreased density. Now, this was an interesting instrument. Just what is What is this now? This is a Well, that's a human centrifuge in which we uh tend to produce the effects of extreme acceleration or high uh multiply the effect of gravity many, many times. This man is signaling on a stick to simulate firing of his machine guns to show that he's still conscious. He's He never becomes aware of the fact that he is unconscious. He believes that he continued to push that button. Although, if you watch closely, you'll see that he uh loses consciousness. Mhm. Now, this loss of consciousness is due to the blood flowing down into the lower limbs, and not enough gets up to the brain to keep him functioning. Now, this is a period of amnesia. He remembers nothing about this when the experiment is over. And he'll swear up and down that he didn't uh do that. He didn't do that. He was still punching away. Mhm. Well, it seems to me that the ear is very, very important in all of this. So, let's examine carefully this ear chamber, starting first with the outer lobe, and then passing into the canal, and here is where the ear membrane would be located. Let's just put it in here. On the other side of that ear membrane is the inner ear and then passing down from the inner ear is the Eustachian tube which goes down into the back of the mouth. Well, Dr. Harold, we have here a mechanical contrivance devised to simulate the effects of the eardrum. This is the outer canal which which you just pointed out. This communicates with outside atmospheric pressure. And this is normal as long as we stay on the ground. Yes. Now, the middle ear which is a closed space except for this bleeding valve for the Eustachian tube contains air and will under the conditions of descent, say under the water 20 or 30 ft below the surface or More pressure's coming in now. That's correct. From the outside. Pressure's increasing. Anyone can see that the tympanic membrane or eardrum as we commonly call it is depressed inward, compressed very violently. Now, if the Eustachian tube is operating as a safety valve as it should be this excursion of the eardrum is very modest and recovers Perfectly all right. normally. Well, now what is the other extreme the eardrum being pushed out from the inside? Well, Earl, if we uh increase the pressure within the middle ear or conversely decrease the pressure on the outside of the ear the eardrum then tends to bulge outward as you can see here in this model. But only if you hold the ear or stop off the Eustachian tube. Again, it's only if the Eustachian tube does not properly function. If the Eustachian tube properly functions, it bleeds off the air. Let's see, increase pressure out and everybody is comfortable. Seems to me the logical conclusion is that if you have a cold, you should never go up in an aircraft or go diving with diving equipment. That is correct because a flyer when his ears are not in good shape will automatically be grounded by a conscientious flight surgeon. Well, that pretty well takes care of this problem of pressure. how about uh such things as acceleration? Well, Earl, if you're going to use your ticket to the moon, you'll have to be able to travel a great deal faster than the uh present-day speed record, which is in excess of 1,600 mph. Uh in fact, uh speed of 25,000 mph is necessary just to overcome the effects of gravity. Now, when you arrive at the other end of your journey on the moon, the uh deceleration or braking action would be tremendous. Um out in space, say in 10 mi from the surface of the Earth, uh we really don't know the what problems we will encounter at that altitude. some of these problems have been anticipated by knowing the way in which a certain things uh affect the Earth, as for example, cosmic rays. And so, from that uh rocket ships have been designed with double hulls, so that uh the outer hull is um is very thin and will stop uh anything before it gets through it to the vital inner hull. Now, what about such things as uh oh, gravity? Well, Earl, now you're talking about 10 years into the future. There are a whale of lot of uh there's a whale of lot of research to be done, a great many problems yet to be solved. We have the uh pressure and the oxygen problems of high-altitude bailouts solved. At Randolph Field, they are presently working on the problems of uh whirling and frostbite. Now, what's happening here? Well, now here uh there's been a uh explosive decompression because the uh a blister blew out of one of the aircraft, and the man has been precip- itated suddenly into a rarefied atmosphere. Uh he will be suffering pain in his ears shortly, but the uh decrease in the amount of oxygen. Uh one thing I'd like to ask you, how high has man been able to go up into the atmosphere? Well, uh in excess of 80,000 ft, uh 83,275 ft published record to date. Well, by no odd coincidence, we have as our guest on the program Captain Charles Yeager, who has flown higher more than 20 mi and flown faster than the other man. And why don't we step over here and see some of this equipment that he uses. How are you there Major? How are you doing? I called you Captain, it's Major, excuse me. I'm very very sorry. That's all right. we're interested in this piece of equipment. What is it and how does it work and what does it do? Well, uh fortunate enough people like you all and uh are interested enough in aviation medicine to uh stay quite a bit ahead of the research pilots. Our needs are a little beyond uh production pilots. So, here we have a T-1 pressure suit which was developed back in 1945 and we were uh using in 1947 in the X-1 original X-1 flights when we had to fly above 50,000 ft. As you explained before, you need uh pure oxygen under pressure to uh fortify that your blood with oxygen to get it into the bloodstream rather. Once you get above say about 46,000 ft, the rib cage won't support the pressure required to get this oxygen into the bloodstream. So, this uh T-1 pressure suit was devised. Now, on the leg we carry a bailout bottle down here which is not on this particular suit. It makes the suit self-sustaining. You can bail out of the airplane even at 100,000 ft and it will uh take care of you till you get down to 40,000 ft where you don't need reinforcement for your lungs. It's automatically inflated by an aneroid cell. There are capson tubes here that which run up each arm, down the back and the legs uh inflate. That pulls these straps very tight and it reinforces the body all over to keep uh rupturing from rupturing from the real high breathing pressures that have to go into your lungs. On top as you see is a a crash helmet which is more or less for protection and reinforcement. Uh here in the visor we have small filament wires to keep the glass heated to keep it from frosting up since it's very cold on the outside and your hot breath on the inside would frost it up. And the face piece as you can see is removable for pilot comfort. It's snapped on and pressurized uh from the time you get in the airplane. And since you have quite a bit of pressure under your uh on your neck and on the head. This uh strap here and the cable that go on each side of the helmet keep from more or less stretching your neck when you inflate your suit. Now, this suit we use like a parachute. There's no no need to wear it around inflated if you have a pressurized cockpit, but if you should happen to lose a canopy, which we did in the one of our research airplanes that above 70,000 ft, then that's only thing can save your neck. And we're very fortunate in having out cover. This is the radio and we have the microphone. That's the microphone right there. Yes, he talks and also your headset is on the inside of the helmet. And everything else is more or less just like a normal flying suit. You have incorporated inside a G suit, which takes care of high accelerations. And there again, we're very fortunate in having people who look that far ahead of uh the requirements of pilots both in pressure suits and energy suits and they're doing a lot of study now on gravity free flight. So, it makes it uh very uh uh makes a man feel pretty good when you're doing research flying to know that they're looking that far ahead of you. One thing I'd like to ask you very quickly, our time is short. How fast have you been able to fly or how fast can you tell us? Well, we've been up to around 1,650 mph in the X-1A. That was last December. Oh, last December. Well, thanks very much for coming here to demonstrate this equipment Major Yeager and uh Bill. How are you? And where's Dr. Lawrence here? How are you, sir? And we want to thank you very much for bringing all these things into the laboratory to demonstrate for us. Thank you Major for coming. All right. And we'll be back in just a moment. Our animal of the week is the angelfish, sometimes called the scalar. Now, these are fairly old fish. They're about 3 years old at the present time. They are one of the more popular tropical fishes and we often get quite a number of inquiries as to what you should do to keep these alive and what you can do to keep them so that you will have some offspring. Well, now the scalaire likes to spawn perhaps on broadleaf plants such as this one we have here or some people say that you should use a piece of slate as this and there are some who swear by lamp glasses such as this. Now, whatever you do however, you will find that after the eggs are deposited on the spawning surface, the very quickly the youngsters hatch and over in this end tank down here we have some 10 day old scalaires. They're very very little fellows. For the first two days after they are hatched they remain with their heads attached to whatever they happen to be on and they wiggle their tails. Six weeks they're about this size, very cute little fellows and very very nice. They have to have quite small food. About 12 months they have reached this size. As you can see they're about half grown. And finally in a period of two or three years they achieve the giant size that we see here. Now, as to food you can feed them all sorts of things, dry food or perhaps you can feed them if you have it available such things as brine shrimp. Now, we'll see they may discover that those shrimp are there and suddenly come up after them. Uh to keep fish such as this you have to have the proper temperature. In other words, about 75° and if you want to spawn them, then you have to keep them at a little bit higher temperature and increase their food supply. Very very beautiful fish and this is the angelfish sometimes called a scalaire and we'll have to take these fellows back and put them in their regular tank at Steinhart Aquarium. Perhaps you're wondering about this. This is one of the friendly snakes. That is the type of snake that we'll talk about on our next program. One of our special guest we will have Dr. Robert Stebbins from the University of California. Friendly snakes and their value to mankind. Very, very important thing, and we hope that you will plan to be with us then. Thanks very much. You have just seen another in the fascinating television series, Science in Action. Science in Action is produced by the California Academy of Sciences under the supervision of Dr. Robert C. Miller.