Electronics Brings Magic (Oct, 1944)
Electronics Brings Magic
OF ALL the miraculous aids to better living that are pouring from electronics laboratories to brighten the postwar era, those which promise to be of the most intimate, personal value to every man and woman are new tools to combat disease and promote health. These tools come as close to pure magic as anything man has dreamed of. They are divided into several classes: Some are magic yardsticks of infinite accuracy that measure the faltering course of human organs â€” even the brain itself â€” long before any external symptoms can be noticed. Others are instruments for the immediate treatment of injuries and infirmities… for the prevention of illness… for the longe-range study of disease… for the development of the much-discussed new approach to health known as “physical medicine.” Carl Dreher describes all these in this, the fourth and last article of his series on electronics in the postwar world.
PART IV OF A SERIES ON ELECTRONICS AFTER THE WAR
By CARL DREHER
THE one major use of electronics which has received the least publicity, and about which the public is consequently least informed, is in public health. Probably the reason for this is that the achievements of electronics in communications, entertainment, and industry have grown to such overpowering stature that they have elbowed everything else out of the picture. Whatever the cause, however, it would not be surprising if, in the long run, it was in the field of public health that electronics proved to be of the greatest importance to mankind.
An inkling of this may have been in Bernard M. Baruch’s mind when, earlier this year, he donated $1,100,000 for research and instruction in physical medicine, meaning external medicine of all kinds as distinct from internal medicine or the administration of drugs. That takes in a great deal of ground, but it is safe to predict that a considerable part of it will be occupied by electronic techniques and appliances. We already know enough about what electronics can do for healthful living to warrant the conclusion that it will do much more in the postwar years.
Before the physician can hope to cure a patient he must know what is wrong with him: diagnosis must precede therapy. Instruments are of paramount importance in scientific diagnosis. They range from the simplest to the most complex. The stethoscope is one of the simpler instruments. In its conventional form, consisting of a small pickup bell and flexible ear tubes, it is familiar to every layman. The physician uses it to listen to a patient’s heart, breathing, and other bodily sounds. It is simply a hearing aid. The fundamental design has changed little in the past 100 years. It will transmit sounds in the band between 200 and 1,500 cycles per second, or three octaves, and it is not “flat,” or free from distortion, even within that narrow range. In other words, it is not a particularly good hearing aidâ€”more like an ear trumpet than a product of modern acoustics.
Last year the RCA Laboratories announced an improved stethoscope, flat from 40 to 4,000 cycles, which about spans the fundamental tones of the full piano keyboard. For some purposes this range is excessive. Consequently, a filter controlled by a knob is built into the instrument to select any desired band of frequencies. Although, through long practice, physicians acquire great skill in interpreting the sounds transmitted by the ordinary stethoscope, it stands to reason that better results can be secured with the new wide- * range, high-fidelity type.
The high-fidelity stethoscope, like its venerable predecessor, is purely an acoustic instrument, and it may seem out of place in a discussion of medical electronics. The fact is, however, that practically all progress in acoustics since the First World War has been due to the work of electronic engineers, and to all intents and purposes applied acoustics has become another of the many branches of the field of electronics. Like the old-style stethoscope, the 1920 acoustic phonograph transmitted a relatively narrow and distorted band of frequencies. People accepted it because there was nothing better. Around 1924 J. P. Maxfield, of the Bell Telephone Laboratories, designed the orthophonic phonograph, which was a greatly improved acoustic type of reproducer. This was shortly supplanted by the electronic phonograph in use today. Corresponding to the latter, there are electronic stethoscopes incorporating a microphone, vacuum tubes, and a loudspeaker, which may be used for special work where simplicity and lightness are not primary considerations. The RCA device that has been mentioned is essentially an orthophonic stethoscope, the product of electronic principles applied to an acoustic instrument. This is a typical example of the germinal influence of electronics in other technological fields, of which we may be sure we have seen only the beginnings so far.
Such cross-fertilizations are sometimes deliberate and sometimes they just happen, although even then they are scarcely accidental. They are, rather, the logical results of the convergence of knowledge in adjoining technological areas. The May, 1943 issue of the Bell Laboratories Record describes a typical caseâ€”a novel use of the Western Electric RA-281 sound-frequency analyzer. This electronic-acoustic instrument was designed to sweep over the band from 10 to 10,000 cycles per second in two minutes and to give a complete analysis of sounds picked up in that range. The purpose was the prosaic one of helping to decrease noise and vibration in automobiles, refrigerators, and other machines.
After our entrance into the war, an explosives manufacturer found that employees in one department of his plant were fainting at their work. Fainting in an explosives factory is not only disturbing, but dangerous, since the person who faints may drop a chemical that will blow up the plant. The physicians who were called in found that the fainting was caused by heart-muscle fatigue, which in turn was the result of inhaling a certain vapor to which the workers were unavoidably exposed. The problem was to detect the condition before fainting occurred.
Examination of the workers’ hearts with the ordinary stethoscope gave no results. A more refined method of diagnosis was needed. It then occurred to someone that the RA-281 analyzer could be used on people just as well as on machines. The heart sounds of the employees who had fainted were analyzed and characteristic records were obtained. The rest was merely a matter of periodic examination of all employees with the analyzer. Those who were being affected by the fumes were screened out and transferred to other departments before the critical point was reached. Thus the problem was solved by what was in effect a superior kind of electronic stethoscope, although its use as such could scarcely have occurred to the original designers. This problem might have been solved, but probably with considerably more expense and trouble, by the use of an electrocardiograph. This complex medical instrument resembles the stethoscope in that it started without benefit of electronics and now leans heavily on the vacuum tube. It was discovered before the Civil War that the heart generates small potentials while beating. Later it was found that “injury potentials” are associated with heart disease. A vast clinical literature arose in connection with the measurement and interpretation of these potentials. Some of it was contradictory and erroneous. Part of the difficulty lay in the limitations of the pre-electronic cardiograph, which was merely a sensitive string galvanometer whose terminals were connected to the patient’s arms, or the left leg and one arm. Like the telephone engineers and the designers of motor-control equipment, the doctors needed an amplifier to get intelligible records of potentials whose peaks did not exceed a thousandth of a volt. Like the others, they seized on the vacuum-tube ampliner. The modern electrocardiograph utilizes several stages of amplification feeding into a mirrortype galvanometer. It is really a vacuum-tube voltmeter, or rather microvoltmeter, such as was mentioned in last month’s article, with the addition of amplification and means for recording the readings.
The electrophysiology of an organ like the heart is extremely complex, and progress is largely dependent on the development of sensitive and reliable recording equipment. This requires close collaboration between physicians and engineers who are specialists in their own branches and at the same time know a great deal about each other’s work. Many problems remain in this field which electronics will no doubt help to solve. This is true of all phases of what has become known as bio-electricityâ€”the study of electrical effects in living tissue.
The electroencephalograph, which does for the brain what the electrocardiograph does for the heart, has an equally promising future. This brain-potential measuring instrument deals with even lower voltages, down to 10 microvolts, and with frequencies as low as one cycle per second. Special low-frequency amplifiers with a minimum of internal noise are needed to record these potentials. The cathode-ray oscillograph, mentioned in the previous articles in connection with television and industrial measurements, is also a clinical tool for the brain surgeon and neurologist. Where a lesser degree of refinement is sufficient, ink-writing oscillographs may prove more practical. Whatever recording means are employed, certain types of slow waves indicate the presence of brain tumors, epilepsy, and other pathological conditions.
The electron microscope is about equally important in industry and medicine. In this instrument electronics has improved on optics. The best optical microscope is capable of magnifying about 2,000 diameters; the electron microscope has already attained a resolving power a hundred times better. What a radical improvement like this means in bacteriology can readily be imagined. The electron microanalyzer, an accessory to the electron microscope which makes possible high-speed chemical analysis of ultramicroscopic bits of matter, such as bacteria, is another clinical tool which is just starting its career in the conquest of disease.
Another instrument at the disposal of the modern physician is the Berman-Moorhead metal locator, or electronic probe, employed by Army surgeons preparatory to removing shrapnel fragments and bullets from the body.
The exploratory and diagnostic uses of the X ray are too well known to require more than passing mention, but X-ray technique is undergoing high-pressure wartime development, the results of which may eventually compensate for some of the losses of the war. For example, chest X-rays are now established on a mass-production basis, with a lower unit cost than ever before. The time is not far off when children and adults will have chest X-rays made at regular intervals, just as they now go to a dentist periodically. A few thousand such pictures always uncover a considerable percentage of unsuspected tuberculosis cases, which in the good old days would perhaps have progressed beyond the point where the disease could easily be arrested.
All these instruments mark the transition from crude empirical diagnostic methods to highly scientific techniques, many of which incorporate electronic devices. The full exploitation of these new tools of science will impose new demands on medical education and organization. One way or another, these demands will have to be met, for if rule-of-thumb and hit-and-miss methods are no longer good enough for the factory, they are certainly not good enough for the hospital.
Prophylaxis is concerned with the prevention, therapeutics with the cure, of the diseases that afflict mankind. Electronic methods are not as far advanced in these branches as in diagnosis. One promising field involves the physiological effects of radiation. We already possess considerable knowledge of the effects of radiation of various wave lengths on living tissues, but there is probably a great deal more that we do not know. Ultraviolet light in the region of 2,537 Angstrom units, for example, is known to kill many harmful species of bacteria. Light of this wave length does not reach the earth in any appreciable quantities from the sun; it is filtered out by the atmosphere. For prophylactic purposes it is generated by mercury-vapor lamps designed for the purpose with glass envelopes which will pass the desired wave length. Such lamps are used for sterilizing the air and exposed surfaces in hospital operating rooms and laboratories. Very likely other wave lengths will be found to have useful properties. In the immense range from infra-red radiation down through the solar rays, ultraviolet rays, X rays, gamma rays, and cosmic rays there may be many electronic frontiers awaiting the onward march of medical research toward new discoveries. Like the X ray, diathermy, or electronic heating, was a recognized medical technique before industry began to exploit its possibilities. The body is not a particularly good conductor, and when heat is applied externally up to a bearable temperature, not much of it reaches the internal organs. It is, however, often desirable to use deep-heat therapy to increase the supply of blood to inflamed or injured tissues. In such cases, as in the parallel industrial situations, the obvious answer is to generate heat within the body rather than to try to make it flow in from the surface. This is readily accomplished by radio-frequency induction heating, either electromagnetic or electrostatic.
Induction heating may be applied therapeutically to specific muscles or organs, or to the entire body. In the latter case it is called fever therapy, since in effect an artificial fever is produced. Therapeutic fevers may also be induced by infecting the patient with a fever-producing disease like malaria; this was tried a number of years ago as a cure for syphilis. Even when it works, the disadvantages of such a procedure are obvious. A far better method is to place the patient in a cabinet surrounded by a coil carrying a radio-frequency current produced by a vacuum-tube oscillator with an output of 200-300 watts at a frequency of 25-50 megacycles, or about the same frequency range as is used in industrial dielectric heating. The artificial fever is thus kept completely under control. The patient’s temperature may be raised to the desired level without harmful side effects, and as soon as he is removed from the radio-frequency field his temperature returns to normal.
Instead of diffuse application of electronic heat, surgical diathermy utilizes extremely concentrated application of high-frequency currents through a small electrode which functions as an electronic cutting tool and cautery. The electrode produces coagulation as it cuts, so that bleeding is greatly reduced and there is less necessity for tying off blood vessels.
Electric-shock therapy appears to be beneficial in certain psychotic conditions. Electrical anesthesia is another possibility. The amounts of power involved in such applications are relatively large: electric-shock therapy employs temple-to-temple currents of almost half an ampere. The duration of the shocks must be controlled to a fraction of a second, and here again electronic methods are the obvious solution.
It is not to be expected that electronics will revolutionize the practice of medicine; it is, after all, only one physical tool among many. But we can be confident that electronics will play a role of rapidly increasing importance. We may even hope to see, after the present conflict is over, such developments as the great work of G. W. Crile on surgical shock, which followed the last war â€”work which, like electronic medical methods, was based on the scientific application of physics to physiology.
The conditions under which people work, eat, sleep, and amuse themselves influence their well-being as much as inherited or acquired factors. Consequently, in discussing electronics in relation to public health, we are interested not only in specific medical applications, but in anything that promises to make daily living more hygienic, efficient, and comfortable. We want to know what electronics can do for us in the office, the factory, and particularly the home.
To get the right perspective, we must distinguish at the outset between gadgets or technological toys, and things which have a serious function. Electronic experts who write, as distinguished from electronic engineers who have to make electronics work and electronic businessmen who have to sell it, delight in getting up long lists of what electronics will do after the war. They usually compile these lists by itemizing everything that electronics can do. But that is a different thing from what electronics will do. The latter depends on the answers to such questions as: How much do we need and want these things? Who wants and needs them, and how many people are included under the who? Will they be able and willing to pay for them? A burglar-proofing device for country homes, for instance, may be needed by movie stars and millionaires, but it certainly is not a mass-production article even if all other possible outlets, such as industrial plants, safe-deposit vaults, and museums are included.
Or take electronic cooking. An electronic range, applying the technique of industrial induction heating to chops and steaks, would be a nice thing to have in the kitchen. Such a device would cook the steak quickly and evenly, and it would not be necessary to make an incision to see how well it was done on the inside. The steak would be cooked and not the housewife, for practically all the heat would be concentrated where it was needed. Yet we are not likely to have electronic ranges in our kitchen in the decade following the war, because of some obvious and obstinate facts which have to be considered.
For one thing, it just won’t be economic to put the equivalent of a fair-sized radio transmitter in Joe Doakes’ kitchen. Joe won’t have the money, and if he had it he would be well advised to spend it on something more urgent. As we saw in last month’s article, electronic heating is inherently expensive. Electric power isn’t too cheap to begin with; then you must convert it to high frequency, losing a considerable part of it. By that time it can’t compete with fuel on a cost basis. That seems to knock out the electronic kitchen for the time being, even without taking into consideration the dangers of high-voltage shock and radio interference which it would necessarily entail.
There is a better chance for electronically dehydrated foods for some special purposes, as when it is desirable to take practically all the moisture out of vegetables so that they will keep a year or two in a tropical climate. A process already in use drives out 80 percent of the moisture with hot air. Then the vegetables are compressed into bricks, electronically heated so that only one percent of the original moisture remains, and wrapped. One kwh. will remove about one pound of water. For use, the dried vegetables are soaked in water and cooked in the usual way. The reason this might work out economically after the war is that only a part of the process is electronic, and that part is carried out after compression and under factory conditions. That makes quite a difference.
A precipitron or electronic air cleaner for every home and office would be a fine thing. This device is in use and perfectly practical; it removes dust, dirt, ashes, and pollen grains from the air by electrostatic attraction. It would probably improve everybody’s health to some extent, and would certainly be a boon to hay-fever sufferers and others sensitive to airborne particles. It also makes sense from an efficiency standpoint: why let in dirt and then sweep it around or suck it up in a vacuum cleaner? The thing to do is to keep it out in the first place.
But note that windows would have to be kept closed and be more nearly airtight than most existing windows. Then the air would necessarily be sucked in with a pump and distributed around the house through ducts. In short, you end up with more or less the equivalent of an air-conditioning system. It is idle to talk of mass air-conditioning when many of our existing homes don’t even have electricity or inside toilets. So there is not going to be a little precipitron in every American household right after the war.
Fluorescent lighting is an example of an electronic device which, without revolutionary economic advances, will continue to find an expanding market. Basically, gaseous-discharge lighting is old: the names of Faraday, Crookes, and Geissler occur in connection with it as well as the more recent Cooper-Hewitt, Moore, Claude, and others. A high-voltage discharge through gas will produce light at various frequencies, and the amount of useful light may be increased, in any desired color, by incorporating a hot cathode and chemical compounds known as phosphors which are capable of reradiating ultraviolet light as visible light. Fluorescent lighting is practical, decorative,-efficient, cool, and easy on the eyes. In this field, electronics will make a substantial contribution to health and comfort; the process is already well under way.
Generally speaking, however, the impact of electronics on daily living, aside from its indirect contributions through audio and video broadcasting, is not going to be very great in the postwar period. Later? Well, given enough time and an unbridled imagination, one can conceive of an electronic house, almost perfectly insulated and electronically heated or cooled to the desired temperature. Although there are no windows, the occupants can see in every direction by means of suitable television pickup devices in the walls, while no one can look in except over a television telephone line or radio circuit that can be switched on or off at will. Radio brings every form of entertainment and instruction from near and far. The electronic house offers the combination of perfect privacy and perfect communication. About the only tangible contacts with the outside world it will need are an intake for electronically purified air, a door or hatch for the delivery of electronically cooked food, and, if the occupants are socially inclined, for the entrance and exit of Electronically sterilized visitors. But, since the visitors can be heard and seen, and perhaps even smelled and touched through future electronic inventions, they might just as well stay home and use electronic channels for social intercourse.
Personally I am too reactionary to envisage this way of life with any pleasure. But there is no need to be alarmed; it will scarcely come before the 21st century. Before that time, electronics may give us the large-scale transformation of mass into energy, so that a battleship will be driven across the ocean with a few ounces of fuel. Or, as Dr. Irving Langmuir has suggested, airplanes may plunge at speeds of 2,000 to 5,000 miles an hour through vacuum tubes extending from New York to San Francisco. These highly speculative possibilities are beyond the scope of these articles, which have dealt only with short-term probabilities. We can be sure that electronics will make possible better communications, safer travel, entertainment limited only by our creative abilities and tastes, all sorts of useful industrial devices, and medical techniques capable of prolonging and enhancing life. If the really revolutionary electronic inventions are delayed until we have learned to use these immediate gifts wisely, it may be just as well.