What You Should Know About DIATHERMY (Jul, 1957)

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What You Should Know About DIATHERMY

New rigid controls enforced by FCC prevent communication snag EARLY IN 1954, a Chicago housewife innocently became responsible for the murder of a bank guard and the subsequent escape of the criminal with over $10,000 in unmarked Federal bills. Her rented diathermy machine had jammed radio police calls emanating from a local police transmitter, preventing the prowl cars from receiving the robbery tip-off in time.

In the same year, the FCC published warnings that illegal diathermy machines had been known to interfere with instrument landing signals, causing the crash of at least one large airliner, and had blocked a nearby radar screen used by airports to prevent midair collisions. Another terrifying story was told of a doctor’s ultra-short-wave machine which had thrown a guided missile—the new Army NIKE—off its course and started it homing toward the doctor’s office itself. Only at the last moment was the tragedy averted by emergency control from the ground.

These machines that bedevil radio communications are strange crossbreeds between the dissimilar sciences of electronics and medicine. Their history and present use are filled with hopeful promise for the art of healing, yet clouded by so many false notions that it seems timely to sift fact from fancy and tell plainly what these machines can and cannot do.

“Live” Test Rig. The idea of beaming a concentrated field of radio waves into the human body may seem odd at first. But we must remember that the science of electricity has from its beginnings been allied with biology. The twitching frog leg was the first indicator of electric current, long before the electroscope or other indicating instruments were invented. The effect of electricity on living organisms has ever since been a subject of research.

Convulsion—the sickening cramp most of us have experienced as an “electric shock”—was the only known human reaction to electricity. This occurred with direct current or with alternating current of low frequency, such as ordinary, 60-cycle house current. Toward the end of the last century, fast-turning generators made it possible to step up the alternating current to several thousand cycles per second. It was then discovered that such currents did not cause the familiar and often lethal convulsion.

The French scientist d’Arsonval (remembered chiefly for his invention of the modern meter movement) experimented courageously along these lines, with himself as chief guinea pig. In 1891, using a ¦ newly invented spark-gap generator, he revved up his a.c. to a million cycles. Then he did something seemingly suicidal. He hooked himself into the circuit, holding a light bulb to see if he was “drawing juice.” Everyone was shocked except d’Arsonval. When the bulb lit up, all he felt was a pleasant, relaxing warmth deep inside his body. D’Arsonval didn’t know it, but he had just given himself the world’s first diathermy treatment.

Brief Hope. Radio, the new wonder of the 1920′s, provided the next big push.

Vacuum-tube oscillators made it possible to control the frequency used for medical treatment within narrow limits, rather than spray out a broad band as did the old spark generator. Particularly, the newly developed short-wave circuits suggested the possibility of aiming focused radio beams at diseased parts of the body.

In 1924, Dr. Schereschewsky succeeded in killing a malignant tumor with 150-megacycle waves. This announcement created a sensation. It was front-page news to the public. Even medical journals dreamed of bloodless surgery, in which the short-wave electrode would replace the knife. To doctors and the public alike, this seemed like the millenium of medicine. For the surgeon’s knife, though it can halt decay and sometimes repair damage, can never accomplish positive good. Surgeons themselves, though confident and practiced in their art, often share their patients’ sense of mystic dread—for cutting of the living body brings to mind that all flesh is mortal and that the realm of medicine is ultimately powerless against the greater domain of death.

Yet medical hope fell as quickly as it rose. It was simply impossible to focus radio waves sharply enough to localize their effect to knife-edge exactness. Instead of becoming a substitute for surgery, short-wave therapy or diathermy simply remained a means of internal heat treatment.

The Healing Wave. In effect, shortwave diathermy is like a heating pad wrapped around a distressed organ or muscle inside the body. Doctors use the expression “point heating in depth” to describe the action. Such diathermy is now widely used to reduce inflammations of the internal organs, ease the pain of neuritis, neuralgia and bursitis. It has also been applied successfully in cases of pneumonia, tuberculosis and heart disease.

Just how it works, nobody knows. The patient is placed between antenna-type electrodes—but what happens within the body is still a mystery. We know that heat is generated by the motion of molecules, and apparently the molecules of the body are stirred into a fast jig by the fluctuations of the high-frequency field. But aside from mere heat, there seems to be some unique organic effect having to do with still unknown forms of physiological energy transformation.

Only within recent years has the science of physical chemistry begun to investigate the action of complex organic molecules when placed within fields of electric energy. Much remains to be learned. Meanwhile, diathermy is prescribed by countless doctors as a welcome pain-reliever and accelerator of natural healing.

Pain in the Neck. The new pain-soothers, however, created a new pain—right in the neck of the FCC. Every day, thousands of these machines burst into the radio spectrum—into practically every part of it. From all over the country came a flood of complaints from the radio services that diathermy machines were jamming the communications frequencies.

The FCC took quick action. After consultation with medical authorities, the commission in 1947 assigned two specific frequencies to which the machines were to be confined: 27.12 mc. and 13.56 mc. At the same time, owners of existing machines were given until June 30, 1953, to get back their original investment. On that date, the old machines were to have been discarded. Yet in flagrant violation of these regulations, the onset of 1957 saw over 10,000 of these illegal machines still in operation. Such machines were evidently responsible for the incidents reported at the outset.

FCC-approved machines must be fully shielded and metal-enclosed, must stay on frequency and not radiate spurious or harmonic frequencies. Notice that the permissible frequencies—27.12 and 13.56 mc.— are already harmonically related so that a diathermy operating on the lower frequency can produce a second harmonic only on the other diathermy frequency, thus limiting the chances of interference.

Safety Circuits. Modern diathermy machines employ special filters consisting of heavy choke coils and capacitors to prevent any radiation other than the approved 27.12 mc. to pass as interference through the over-all shield. The signal itself is usually generated by a push-pull oscillator of the grounded plate “TNT” type (tuned plate/untuned grid). The frequency of oscillation is preset at the factory by means of a shunt bar sliding along the center-tap rods of the plate tank circuit.

Unusual circuit features protect the patient. Most high-power oscillators are operated with their cathodes grounded; in this case, the plates of the oscillator tubes are grounded to the shielding enclosure, chassis, and all other metal structures, while the cathodes (filaments in this circuit) are made highly negative with respect to ground. Thus, should the pickup coils of the output circuit somehow become shorted to the tuning coils, the electrodes will still be at ground potential and the patient will not be in danger of possible electrocution!

After placing the patient between two suitable electrodes, the machine is tuned until a milliammeter in the plate circuit swings to maximum. This shows that the entire load circuit, including the patient himself, is in resonance with the oscillator. In effect, the patient acts as a dielectric between the electrodes.

Although the FCC has approved several different models of self-excited oscillator diathermies, some manufacturers claim that such equipment can never be relied upon to remain on the legal frequency. These manufacturers swear by crystal-controlled units which provide pin-point frequency stability and remove all the guesswork during the life of the machine regardless of tube changes or dislocation of wiring or components. As for output power, about 400 watts is considered by the medical profession as just about right to produce deep-seated heating in bone and cartilage tissue.

The erstwhile “miracle of medicine” that sprang directly from radio experimentation is now shorn of false claims and unreasonable expectation. Yet its very real merits have earned for it a firm and respected place in the doctor’s office for specific, limited application. In the home, diathermy equipment should be used only on a doctor’s advice. In either case, increasing public dependence on radio-operated devices demands that every diathermy user know the necessary precautions to safeguard radio service from interference.

15 comments
  1. Stannous says: November 22, 200710:56 am

    Just learned more about this subject than I’d ever have guessed:
    Medical diathermy devices were used to disrupt German radio signals during the Blitz.

    Here’s a medical description of the technique:
    Heat speeds up healing by increasing blood flow to the injury. It may be used after cold treatments when inflammation and swelling are gone. Diathermy is a deep tissue heat treatment. The temperature of the injured tissues is raised by high frequency current, ultrasonic waves, or microwave radiation. Like surface heating, deep heat is used to:
    * reduce pain,
    * relieve muscle spasm,
    * decrease soft-tissue contractures,
    * resolve inflammation, and
    * promote healing.

    Deep heat may be used to treat chronic arthritis, bursitis, fractures, gynecologic diseases, and other problems. Electromagnetic heat (shortwave and microwave) sends heat up to two inches into the tissues and muscles. It works best for injuries in joints, muscles, and tendons. These are sprains, tendinitis, bursitis, and osteoarthritis.

    Electromagnetic heat should not be used over any areas that are wet or filled with fluid or metal objects. The risk for burning is too great. These include:
    * eyes,
    * a pregnant uterus,
    * blisters,
    * moist skin or clothing,
    * perspiration,
    * wound dressings,
    * intrauterine device, or
    * a pacemaker.

    Treatments with electromagnetic heat last about 15 minutes and are given 2 to 3 times per day for 3 to 14 days. Safety eye goggles should be worn by both the patient and therapist.

  2. Bendarr says: February 10, 20106:52 pm

    “Another terrifying story was told of a doctor’s ultra-short-wave machine which had thrown a guided missile ”the new Army NIKE”off its course and started it homing toward the doctor’s office itself. Only at the last moment was the tragedy averted by emergency control from the ground.”

    Being a former computer operator for the Nike Hercules Missile system (MOS 16C10), I found this to be of particular interest.

    I suspect that it was an earlier version of the Nike Missile system and not the later versions (Nike Hercules) because of what is required for targeting the missile. Upon searching the date, it would have been the Nike Ajax missile system. The Nike Hercules (what I was trained on) didn’t come about until 1958. So we can pinpoint the type of Nike that the incident occurred. Nike Ajax.

    The only way that I could see it happening is for the HIPAR (Hi power Acquisition Radar) or the LOWPAR (Low Power Acquisition Radar) to somehow lock on the signal from the Ultra Shortwave radio from their originally designated target. Assuming no operator intervention, the MTR (Missile tracking Radar) would continue to send signals to the missile telling it to go to the radio. For the emergency detonation all the Acquisition Radar operator would have to do is press the “Burst” button. For safety reason there is always an officer in the control van during any sort of life fire exercise or testing for just such an emergency.

    This is written from my experience as a Nike Hercules Fire Control Crewmember. Like I mentioned earlier the Nike in the story must have been a Nike Ajax, since the Hercules hadn’t come out yet.

  3. jayessell says: February 11, 20101:14 pm

    Bendarr:
    I have a collection of annecdotes titled
    “A Funny Thing Happened on the Way to the Moon”.

    A missile test at Cape Canaveral went awry when the
    Range Safety Officer’s radar controlled X-Y Plotter
    showed the missile heading inland.
    He hit the big button.

    However…
    The test was going well until then. It was heading over the ocean.

    Oops… wires backwards on the plotter.

  4. Firebrand38 says: February 11, 20101:41 pm

    jayessell: Unfortunately this is how urban legends are created and propagated. Do you have any kind of source for this anecdote? When did it happen? Who reported it? What missile was it?

  5. Jari says: February 11, 20109:07 pm

    Bendarr: I can’t imagine how that’s even possible. I mean, shouldn’t MTR operator notice, if there were excess interference or required missile elevation suddenly became 0 degree or something like that? Of course, I don’t know Nike system that intimately than SA-1, which I was trained as an radar engineer in Finland at eighties.

  6. Bendarr says: February 11, 201010:03 pm

    Jari, While I was a computer operator for the Nike system, I am somewhat familiar with the other stations. In my scenario that I proposed, I mentioned “Assuming no operator intervention, the MTR (Missile tracking Radar) would continue to send signals to the missile telling it to go to the radio.” I’m sure that the MTR operator would notice something. The displays for those radars were rather crude (MTR, TTR, and TRR). Essentially what you’d be looking at is a Oscilloscope wave pattern. The TTR (Target Tracking Radar) and TRR (Target Ranging Radar) would move rotational dials until the “Locked in” on the strongest signal and then lock it in thus making it self running and needing no further input until your time to intercept. Boy have I some stories to tell about that old computer that I ran.

    The number one person who would notice anything would be 3 people in one of the control vans. The acquisitions radar operator, the officer in charge, and the computer operator.

    The acquisitions radar operator would see it on his scope and it’s his hand that designates a target for the other radars to track.

    The officer in charge, well, it’s his job really. Both he and the radar operator monitor the scope and the plotting boards for real time info on both the missile and the target.

    The computer operator (me). Among other things I would monitor would the the readouts from the computer showing time to intercept. A brief word on the computer. Analog, vacuum tube and relays and you get your time to intercept through mechanical gear pots. Very primitive but it did it’s job beautifully even when I was in (80 – 83). One of my daily checks would be a simulated launch. In fact the only difference would be flipping of one switch. So a experienced operator would be able to see something that wasn’t right in the speed of the time to intercept.

    By the way the display for the MTR operator was pretty much the same as the TTR, TRR displays. All your seeing is a waveform. So I figure that if this story mentioned in the article is accurate it was likely that the Lopar operator noticed something and brought it to the officer’s attention who then pressed the “Burst” button.

    I hope that this is of help.

  7. Bendarr says: February 11, 201010:32 pm

    urgh, post vanished! ah well once more into the breach.

    Jari,
    The way I figure it (if what is reported in the article is accurate) is that once the Dr. Fired up his radio it may have been just the right frequency to show up on either the HIPAR or LOPAR radars. If so then it possible that the LOPAR operator designated the blip. The MTR, TTR and TRR operators wouldn’t have noticed anything odd since their displays resemble an oscilloscope and they only see a wave pattern. The TTR and TRR operators would then lock in on the strongest part of the signal. The MTR operator would of course lock in on the signal from the missile’s transponder. After the launch there would be only 3 people who might have an inkling something was wrong.

    1: The LOPAR operator.

    2: The officer next to him.

    Both of them monitor the radar screen (in the LOPAR and HIPAR case) use the radar screen that most people are familiar with. Along with plotting boards that show real time graphics of the target and missile.

    3: The computer operator. My job. The computer operator would be monitoring the time to intercept and making a countdown. One test we did on a daily basis consisted of a simulated launch which was accurate to all details. An experienced operator could tell something was off by the time to intercept being screwy. FYI, the computer was a analog, vacuum tubed based system that correlated all the info from the radars and showed your time to intercept through mechanical gear pots.

    At any time (other than the first 10 seconds of launch) all the officer has to do is press the “Burst” button and the missile goes up in flames. During the first 10 seconds by the way, the missile is autonomous and only after 10 seconds go by does the warhead rotate and take commands.

    I hope this is of help.

  8. Bendarr says: February 11, 201010:35 pm

    urgh. Now both posts appear. ah well.

  9. Firebrand38 says: February 11, 201010:54 pm

    Bendarr: If you make a post that doesn’t appear either e-mail Charlie or wait for him and his minions to catch it.

  10. Bendarr says: February 11, 201011:05 pm

    Got it Firebrand38. You’ll need to forgive me, I’m pretty new to this site.

    Ah well, each post has some info the other didn’t so it kinda works out.

  11. Firebrand38 says: February 12, 201012:07 am

    Bendarr: They have a certain symmetry, if you will. Fascinating stuff on the Nike missiles in any case. Thanks for your posts.

  12. Jari says: February 12, 20105:02 pm

    Bendarr: Thanks for the info, very fashinating. I must have been tired while typing last night, mixing up designations. SA-3 is the NATO designation for “my” system. Myself being specialized to service and repair P-15 TA radar. The sytems themselves doesn’t appea too different. Analog computer with tubes, syncros and everything. Instead of the mechanical plotter, SA-3 had 2 CRT:s showing horizontal and vertical views of the intercept. The missile(s) blip(s) ought to follow a pre-drawn curve to the target blip, if everything goes normal. Unless I mix it up with other Russian firecontrol system in my memory. Multiples, because 2 missiles could be launched simultaneously against one target. As the good doctors diathermy machine emits continuously, it ought to show in TA radar as a cone-like blob emanating from the center of the screen to all the way to the edge. Or multiple cones, if the antenna has “bad” sidebeam attenuation. Something that can’t be missed to anything else. The live launch was fun to watch. Things coming alive one by one. First the vertical radar, then the fire control radar, launchpad rotated and then there were this mighty “WHOOOOOSHH!” when the missile fired. First stage dropped and then just watching the smoke trail to go on and on over a half a minute or so. Then it ended in visible puff, the sound of the explosion didn’t carry to our position. One target drone down. In that day two other drones dropped by themselves, so we had only one live launch instead of three….

  13. Alan B. Barley says: October 29, 20109:33 pm

    I wish that Modern Melchanix web site had better cross reference links between related articles. See “Fever Machine Treats Rheumatism by Short Wave Radio” I often come accross related articles which are not x-referenced. [Maybe web visitors could suggest relevent cross links]. Articles and advertisments on the mirical of the teeter-totter bed appear on your site across several decades — Interestingly, each claims to be the newest health discovery of the ages.. I hope you setup some sort of “user found crosslinks” area on your site.

    Thank you
    Alan B.

    http://blog.modernmecha…

  14. Charlie says: November 2, 20105:01 pm

    Alan: I agree, I’ve been wanting to do something like that for some time. Basically I’d have user generated tags for each post. I’ll look into it again and see if there are any new plugins to make it easier.

  15. arun says: August 16, 20115:01 am

    sir, can you please send the circuit of diathermy.

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