- Amateur Radio (Ham Radio) Community

Call Search

New to Ham Radio?
My Profile

Friends Remembered
Survey Question

DX Cluster Spots

Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement

[Articles Home]  [Add Article]  

Antennas, Pacemakers & Defibrillators

Floyd Andrew Boggs (KB8PMD) on June 6, 2005
View comments about this article!

If You’ve Got an Implanted Pacemaker or Defibrillator,

Keep Your Distance From Transmitter Antennas!

By Andrew Boggs, B.A. / KB8PMD

A few years ago, I ended up in a hospital for Cellulitis -- I could soak a pair of socks within an hour. When I finally returned home, I had an implanted Defibrillator in my chest -- a doctor discovered I had a weak heart. And yes, it went off -- two episodes -- first time when in extended recovery in a nursing home it “buzzed” me seventy-two times according to an EMS technician -- the second time, at least a dozen before the hospital emergency room was able to bring it under control. I’ve got to tell you, I really am very spooked by the experience. My background is broadcast news, production and a touch of engineering. So, I have a passion for communications…and a great respect as to its use.

Awhile ago in the eHam blog section, a reader asked whether indoor transmitting antennas were safe? There were a lot of comments as to the pros and cons of such an installation. I had made the mistake as a beginning ham with a General ticket in installing a short vertical whip in my bedroom with my transceiver, a Yaesu 767GT while living in a brick-encased apartment building. When I pressed the mike button, I got one whopping RF shock that knocked me on my rear -- thankfully I didn’t have a heart Defibrillator in me at the time -- otherwise, I would have been a “Darwin Award” winner! Since then, I’ve had to make a lot of lifestyle changes in food I eat and keeping a distance from EMF-producing devices. My answer was from my pre-heart condition days. And while articles read that doctors and nurses inform the patient of the “do’s and don’ts” in living with such an implanted device -- they didn’t -- Medtronic’s in their recent newsletter says MRI’s are very dangerous, even with the device turned off. My answer back then to the ham was “don’t“ do it -- and my answer remains the same as of this writing.

According to the Medtronics website, it suggests such people to stay at least one foot away from cell phones and an HT that outputs three watts of power or greater, or ten feet from a transmitting antenna with a power of two hundred watts or better. Oh well, looks like I may stay with my Icom IC-765 or look into QRP operation on HF once again. The little devices have a metal casing in order to keep EMF interference to the circuit at a minumum -- however, they are not “bullet-proof” to every form of RF-producing equipment -- even a large magnet in a speaker can cause problems. Essentially the devices are adjusted via the use of an EMF-producing probe placed over the heart -- hence the need for precautions when dealing with EMF. It comes down to installing a well-designed antenna system that’s properly grounded and keeping in mind whether its yourself or a friend with a pacemaker or defibrillator to stay out of danger and away from devices producing potential harm. Please don’t read this as a reason to refrain from enjoying the hobby of Amateur Radio -- just carefully use your head in the design and placement and the transmit power utilized! For more information, check out

-Andrew Boggs-

Member Comments:
This article has expired. No more comments may be added.
Antennas, Pacemakers & Defibrillators  
by KG4RUL on June 6, 2005 Mail this to a friend!
I suppose you could add some Mix31, ferrite beads to the leads. Wait, that would make for some unsightly bulges.

Seriously, I have read, on several occasions, that the level of microwave energy present in tall buildings, in a dense urban environment, is often high enough to activate one of those microwave oven leakage detectors (side lobes and reflections from microwave links). You could be in danger by visiting your stockbroker!

With Field Day coming up, perhaps we need think about needing to post a warning regarding the potential for high energy RF fields at our sites. It would not do Ham Radio any good to injure or kill our visitors and even some of our fellow Hams.

The bottom line is to be conscious of and follow the FCC regulations for RF exposure.

Dennis KG4RUL
Antennas, Pacemakers & Defibrillators  
by G3RZP on June 6, 2005 Mail this to a friend!
This touches on my professional area of interest - one of my activities professionally is systems design of radios to go in pacemakers!

There was an interesting article in RF Design magazine back in the mid 1980's. Some guys at Georgia Tech tested a load of pacemakers, and found that anything made after about 1980 fell over in fields which were too intense for the human to be in. The international standards require that pacemakers operate in field strengths of 10volts/metre: the leads are filtered by some VERY expensive feedthroughs with low pass filters in them. So ten feet from an HF antenna doesn't seem too unreasonable, as it gives some extra protection.

To what extent fitting a 400 MHz radio (pacemaker radios operate in mainly the 402 to 405MHz band, with an ERP of less than 25 microwatts) will give overall EMC problems, I don't know - I don't work for a pacemaker manufacturer as such. But obviously, having an antenna connected will lead to more RF in the can. Getting an effective antenna ta 400MHz on a pacemaker is a real problem......

MRI scanners are pretty well known as being a bit nasty for should be standard practice to check on whether one is fitted before even recommending an MRI scan.

The effects of magnetic fields on communication will be reduced by going to radio rather than the present LF (under 300kHz) magnetic inductive systems. Incidentally, there are anecdotal stories about problems on Belgian railways where the traction current is 16-2/3Hz, with thyristor controlled locomotives producing an intense LF pulsed magnetic field, but I don't know how much truth there is in this.

I wouldn't recommend keeping your cellphone in your left hand shirt pocket anyway, but the Medtronics recommendations are certainly wise, if a bit conservative. Better that way, of course.........but there's no need to get too frightened. Incidentally, standard practice if RFI is detected is for the apcer to fall back to a steady 60 or so pulses per minute regime, rather than turn off all together.
Antennas, Pacemakers & Defibrillators  
by AP2WF on June 6, 2005 Mail this to a friend!
Floyd I am an old ham and hobbiest. I am very fond of reading ham and other electronics literature. Recently, and on also, I happened to see some of the material on or about use of indoor tansmitter antennas. Despite the fact the level of radiation and the distance from the antenna, I, some how or other, do not feel comfortable and have the same views for those who do not have Pacemakers & Defibrillators in them. This is where one can avoid exposure to RF energy. No doubt no level of the RF energy exposure is safe.

Wasay AP2WF
Antennas, Pacemakers & Defibrillators  
by WY3X on June 6, 2005 Mail this to a friend!
Thanks VERY much for the info! I never once really considered it! I guess we will be screening our Field Day visitors for these devices. We won't keep them away, we'll just advise them of the dangers.

Thanks! -KR4WM
RE: Antennas, Pacemakers & Defibrillators  
by K0BG on June 6, 2005 Mail this to a friend!
Every once in a while, an article appears to remind us of the fact that RF can kill. It doesn't have to do so directly, and that is the point. Unfortunately, far to many amateurs never think about such things, until they themselves are placed in harms way.

Thank you for re-reminding all of us.

Alan, KØBG
RE: Antennas, Pacemakers & Defibrillators  
by WB9JTK on June 6, 2005 Mail this to a friend!
Approximately how far is it from the probes to the surface of your skin? How far from the wiring from the probes (going to the encased pacemaker) to the surface of the skin ?

I am asking because these things are installed inside a body of very conductive saltwater.
Antennas, Pacemakers & Defibrillators  
by AA6E on June 6, 2005 Mail this to a friend!
The Medtronic info is too vague to be useful, in my opinion. They don't give any clue to frequency sensitivity, antenna gain, modulations, etc. What about a 2 kW xmtr? Extrapolating from their table, stay 30 ft away from the antenna? [I wouldn't be comfortable any closer, even without a pacemaker.] This assumes _no_ RF on feedlines.

The FCC maximum permitted exposure (MPE) guidelines should be much more useful for hams. See for example. You're legally required to do this analysis if you run more than 50 W PEP output on 10 meters. (You _are_ legal, right?)

If you are under the MPE limits, chances are you're in Medtronics comfort zone. But it would be nice if they would say so!

In my day, "EMF" meant "electromotive force" which is different from "electromagnetic field".

73, Martin
Antennas, Pacemakers & Defibrillators  
by VE5JCF on June 6, 2005 Mail this to a friend!
(You _are_ legal, right?)

I got bitten by this once, now I always ask for ID if I'm unsure. The judge never has any sympathy for "she said she was 18". Hi hi.

Antennas, Pacemakers & Defibrillators  
by W9OY on June 6, 2005 Mail this to a friend!
The best protection is a clear understanding of how a pace maker works. From the above article you can easily draw correct and incorrect conclusions. For example the comment:

"even a large magnet in a speaker can cause problems"

Has nothing to do with the EM nature of the pace maker. It has to do with the fact that the implanted device can be controlled with a magnet. That is to say if you place a magnet over the pacemaker you either turn it off in the case of a defibrillator, or you place it in a mode called vvi which turns off almost all the features of the pacemaker.

The heart has its own natural pace maker called the SA node. The SA node excites a transmission system in the atria that leads to the AV node, while at the same time it fires off the 2 upper chambers of the heart (the atria). The AV node located at the base of the atria, performs a delay on the signal and once the delay is accomplished the impulse is passed on to a high speed transmission system called the His-Purkinje system, which rapidly delivers the signal started by the SA node to the ventricles which are the lower 2 chambers of the heart.

It is by this method that normal coordinated heart contraction occurs. Lub Dub, Lub Dub, first the atria contract then the ventricles. In the diseased state or due to injury such as is occasionally caused by heart valve replacement surgery this system can become deranged and therefore an electrical device is substituted.

The pace maker works by sensing the hearts own physiologic rhythm if one is available. If one is not available, or the one that is available is not compatible with life, it will take over and provide a substitute rhythm. It can take over at any level of the above described points in the transmission system. That is it can provide the beat, it can provide the delay and it can be the transmission system in itself. It can have sensors that sense motion and can interpret exercise and it can increase the rate to improve cardiac output, or it can sense rest periods and reduce its output to some preset lower level. These devices are very smart and well engineered.

An Implantable Cardiac Defibrillator or ICD is an extension of pace maker technology that has the further ability to charge up a capacitor and deliver a number of joules to the heart. If the heart's ventricular rhythm degrades to a point where it can not effectively pump blood (called Vtach or Vfib). Vtach or Vfib are states of poorly coordinated or uncoordinated ventricular contraction. The brain and the heart itself rely on a regular pulsitile flow of blood for nutrition and oxygen. If this mechanical transport fails soon the organ begins to die. Uncoordinated conduction causes an interruption in this normal flow. The longer the interruption goes on the worse things become. Hence the advantage of the implantable device. Near immediate treatment.

The ICD will send a shock to the heart, the idea being to reset all the cardiac tissue to a zero state, by depolarizing the entire heart all at once, hopefully to start again in some kind of coordinated rhythm that effectively pumps blood.

So here are the points to be considered. The pace maker on one end acts like a receiver, it receives the heart's electrical signals and analyzes what it needs to do, based on that data. So here is one point of possible failure the introduction of a wrong signal due to RFI. The pace maker acts as a transmitter as well sending pulses to the cardiac muscle. So here is another possible point of failure. The leads are screwed directly into the heart muscle to accomplish this function. Fortunately the heart responds to at least tenths of a volt or volts of DC it does not respond to microvolts. As to the ICD, a patch is applied to the ventricle and it is through this patch the energy is provided to the heart. So again you have a couple of wires attached directly to the heart, and a device that is relying on some signal analysis to determine what action to take.

The device itself has some input into how all this takes place. The devices are not standardized in how they behave. A Medtronic’s device may not behave the same as a St Jude device to the same stimulus. This makes it hard to make a general recommendation. For example putting a magnet on some early ICD's would simply shut off the whole system and you could not turn it back on without a programmer. For other devices removing the magnet turns the system back on, but it may come back not in the same mode as it was turned off in, but it may be a more basic feature set, and require reprogramming.

Electro cautery is used in the operating room to gain control of bleeding. The electrocautery machine is basically a transmitter operating at several hundred watts in the HF spectrum (those industrial-medical bands). It provides a RF burn to bleeding tissue and "cauterizes" it to stop the bleeding. If you have ever gotten an RF burn and seen the cooked tissue you have first hand experience (pun intended) of what it is to get electro cautery. This device is commonly called a "Bovie" after its inventor.

In the operating room we use these devices all the time in patients who have pace makers (note this section is not relevant to ICD's but pace makers we will talk about ICD's in a second). There are 2 types of Bovie; one passes the current between 2 probes on a tweezers like device. This is called a "Bipolar". The other is a Unipolar device which passes the current from a single pencil point like electrode, and that passes through the body to a "ground" which is actually the return electrode. The return electrode is a big patch of conductive gel that spreads the current density out so much that no cautery action occurs. It's like a really good radial system, not much current at any one point but all together a lot of current is collected. In the O.R. for belt and suspenders safety and liability reasons we tend to use the Bipolar device as opposed to the Unipolar device. In 20 years in the OR I have never seen the bovie, which is a 250 to 500 W RF generator, which is directly connected to the body cause a pacemaker malfunction. I always have a magnet ready to turn off the pace maker, but in 20 years of practice and over 20,000 operations, I have never used it. This is not to say a malfunction due to the Bovie has never occurred but it is extremely rare. So these devices are very effectively shielded from stray RF. This is not to say there could never be a problem, but it is to put into perspective the kind of risk we are talking about.

The ICD is a different kettle of fish. The present recommendation of the heart doctors is that the ICD be turned off during periods where electrocautery will be in use. This is a pretty hard recommendation and one I would not violate in my practice without a good reason, such as the patient is bleeding to death and there is no time to get a rep to come in and turn the dang thing off. An ICD is pretty useless if it is protecting a dead heart, and as we say all bleeding eventually stops one way or the other. To my knowledge the present devices all can be turned off with a magnet. Earlier devices had variable response to a magnet and would sometimes reprogram themselves, but it is likely most if not all of those devices have gone the way of the dodo.

So with that as a background you can do your own risk analysis. I don't have either of these devices implanted, but if I did I would not hesitate to enjoy my hobby. Neither would I be very aggressive about loading my KW into the bedsprings and then laying down on the bed for a night of ragchewing on 75M. I would use good engineering practice to keep RF out of the shack and inside the coax. I might have pause at using the latest 50W handie talkie especially if I had an ICD. I might consider whether field day was for me.

I can't and won't tell you how to proceed. The point of this is to give those of you who have these devices, or those of you who entertain people in your shack who have these devices some idea of the level of risk involved. The risk is small and remote as best I can tell, but it is finite and not vanishing.

I hope this is of some use to the general community regarding this issue.

73 W9OY
Antennas, Pacemakers & Defibrillators  
by WI2Q on June 6, 2005 Mail this to a friend!
I hope all is well with you for a long time.... I just wanted to mention that QRP is not the end of the world.... in fact, you may like it better. There's a real kick when you work someone far away with pea power... I worked DXCC with an FT-817 a couple years ago and wasn't that excited since my novice licence in 1970!

PS... you are in our prayers for a long happy life!
RE: Antennas, Pacemakers & Defibrillators  
by KB1ELK on June 6, 2005 Mail this to a friend!
If you have a pacemaker/defibrillator installed and are taking advice from well meaning friends and neighbors or anything on the internet you are an idiot!! Call the manufacturer today. You should have the phone number. If you don't have the number, call the guy that stuffed it into your shoulder.
Antennas, Pacemakers & Defibrillators  
by N0AH on June 6, 2005 Mail this to a friend!
So that explains the high mortality rate at field day-
Antennas, Pacemakers & Defibrillators  
by G3RZP on June 6, 2005 Mail this to a friend!
For an implanted radio integrated circuit, see:

That's one of the activities that's kept me occupied at work for the last three years.

At HF, the body losses are pretty small, but a field of 10v/m (which is the MINIMUM level the implanted device has to operate in, according to various standards from the International Electrotechnical Committee) is pretty high. At 10m from an HF antenna, you are likely to still be in the near field, so simple calculations don't apply. The maximum field allowed from ICNIRP if there's any ungrounded metal around is 30v/m.
Antennas, Pacemakers & Defibrillators  
by KC2MMI on June 6, 2005 Mail this to a friend!
Considering all the RF producing devices hidden around us...It might pay to build a tiny RF detector and use a piezo beeper instead of a meter on it. Something literally small enough to slip in a shirt pocket (closer to the pacemaker) that would squeal in the presence of an RF field at, say, 1/2 the intensity that can affect the packemaker.
Too many RF gizmos out there today, and the FCC certainly isn't able to control them.
Pacemakers, Defibrillators & Deep Fried Chicke  
by WA6BFH on June 6, 2005 Mail this to a friend!
Good grief! All of these heart felt (no pun intended) sympathetic concerns and drivel make me want to up-chuck!

Andrew must make any such decisions of safety and concern for himself! That is all that any of us can do. For the one commenter who alluded to the litigious nature of our society, isn’t that just what we need to worry about? With such thinking I will never operate mobile again, either in my car, or with a handheld. Heaven knows I may go past someone with a pace-maker! It will probably be someone jogging on a hiking trail wearing Birkenstocks, or taking a trailside break for a little Tofu!

If we as a society are going to worry and fret about any and every aspect of our environment, technical or otherwise, we will simply cease living anyway! If you value the quality of your life -- don’t sweat the little things! I would never condone or suggest indoor-antennas to anyone anyway. There is a technical term that describes such installations -- they suck! I have many friends who have worked at Broadcast transmitters their entire professional lives, and have retired in very good health. I have worked amongst very high power transmitters at many varieties of wavelength and Joule energy levels, and I’m still in pretty good shape!

If Andrew wants to be very very cautious, that is the decision he makes in living his life. For myself, I want to have my fatal heart attack while taking a rest half way up the 800 foot tower, waiting for someone to bring me my deep fried chicken lunch!
RE: Antennas, Pacemakers & Defibrillators  
by AB5XZ on June 6, 2005 Mail this to a friend!
Thanks for the extended discussion - I think you filled in a lot of blanks for many of us.

73Tom (A-fib patient)
RE: Antennas, Pacemakers & Defibrillators  
by K6AER on June 6, 2005 Mail this to a friend!
I am unclear on what you called a RF shock. Did you mean the Implanted Cardiac Defibrillator gave you a shock when you pressed the microphone PTT? These devices are very immune to RF and most warnings are at best the legal department having the last say. Look around at your environment. Broadcast radio stations both FM and AM with many kilowatts of EIRP. High power mobile two-way radio, WiFi nodes, etc. Cell phones are the least of your worry. They are very low power, digital and start above .9 GHz. Most RF concerns regarding pacemakers are based in junk science. W9OY is correct in how immune pacemakers are to RF. Don’t forget your body is a large bag of water and has significant absorptive properties when it come to RF. That equates to shielding.

Now when it comes to putting an antenna indoors with a 100 watt transceiver I would be far more concerned with your corneas absorbing RF from heating. Having said that, the AMA, OSHA, FCC and others is still out on hard empirical science on the effects of low power RF on the human body. Remember to hub-bub about cell phone usage and head cancer..well no proof after dozens of agencies studying the subject. High RF power causes heating and believe me it gets you’re attention. To heat or burn your body you need kilowatts of energy at microwave frequencies just like you microwave oven. By the way can anyone show me a real instance on a Defibrillator being activated by someone using a microwave oven? I did a search and nothing came up.

The only limitation is when large magnetic devices are in the area such as CT scanners. For more info go to:
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W4SK on June 6, 2005 Mail this to a friend!
WA6BFH: "For myself, I want to have my fatal heart attack while taking a rest half way up the 800 foot tower, waiting for someone to bring me my deep fried chicken lunch! "

And I, for one, support you in that, 100%


RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WA6BFH on June 6, 2005 Mail this to a friend!
Better yet, deep fried squirrel, and Beeeerrr!
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W5AOX on June 6, 2005 Mail this to a friend!
Can't believe it. I actually agree with WA6BFH on this one.
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by N2WEC on June 6, 2005 Mail this to a friend!
Good Day,
I have to ask what the actual profession of W9OY is. He comes off as if he is a cardiac surgeon. I have been a cardiac nurse for many years and would never do some of the things he has said he has done. He also needs to go back and re-read some of the material on cardiac conduction, it is flawed in some areas even though he has tried to over-simplify the actual happenings. There is no delay, only a simple smooth transition at the SA/AV junction and the Perkinje network is two seperate items...The Bundle of His and the fiber network. As one writer said taking advice in this venue for a condition / problem such as this is asking for trouble....PLEASE consult the surgeon who did your surgery, your cardiologist and the company who produced your pacemaker or AICD (Automatic Internal Cardiac Defibrillator).
Best of luck and avoid high RF and microwaves.
William Chapman RN
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by K3AN on June 6, 2005 Mail this to a friend!
Internet: The most complete source of misinformation, half truths, urban legends and propaganda ever developed.

Talk to your doc and the pacemaker manufacturer.
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W9OY on June 6, 2005 Mail this to a friend!

just for your information that's how W2OY went out. He was up on the tower fixin his antenna 'cause some school bus rider smoked him on 75M the night before. He had the big one still belted in. He had to be hoiseted down the tower.

Good ol Mike No lids No KIds No space cadets No phonetic phonatics, only class A operators need apply

73 from W9OY
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W9OY on June 6, 2005 Mail this to a friend!

I am a fellowship trained cardiac anesthesiologist

In other words I pass gas for a living

73 W9OY
Antennas, Pacemakers & Defibrillators  
by N0AH on June 6, 2005 Mail this to a friend!
W9OY, did you stay at a Holiday Inn Express last night?
Antennas, Pacemakers & Defibrillators  
by WA4CCH on June 7, 2005 Mail this to a friend!

RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WB9AUJ on June 7, 2005 Mail this to a friend!
I'm from the government, and I'm here to help you. Out here in Delano, CA, I have 7- 250 kW and 2- 50 kW transmitters. The FIRST question I ALWAYS ask of a tour
group....does anyone have a pacemaker of defib unit? If yes, you get to stay inside the building and not see the antenna farm. VOA policy and just good judgement will not allow me to take anyone into the antenna field, due to the RF levels there, and inherant dangers of touching something HOT. RF burns from this stuff will KILL you. Our ERP with all the rigs up, is in the gigawatt range.

I'm not a doctor or anything more than a RF tech, but I
would not want to be around this stuff if I had a defib or pacemaker. At home, my Drake "C" line just kinda makes power anymore, so that isn't a problem.

Here at Delano, we have and USE personal RF detectors which are very expensive, when in the antenna field, or are working with open transmitter doors. We can be exposed to levels many times the permissable limit when the PA cabinet door is open.

I have been around high power RF since 1967 and haven't experienced any problems (yet).

I am out here because one of our former supervisors had to take a medical because of a defib unit he had implanted. So, there is some reality to the story of RF and medical devices.

73, John WB9AUJ / N6VOA
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W9OY on June 7, 2005 Mail this to a friend!
lemme see the voltage difference... 20*log(250/0.1)....

So all you hams who run 250kw AM transmitters beware!! All you guys who run 100W to a nice defined non whacky antenna 50ft or 100ft from the transmitter, out in the yard without a bunch of RF floating around the shack, you know antennas like a nice little beam or a nice little vertical or dipole have some radio fun.

You will note the gentleman said pacer/defib patients would not be allowed to go out to the antenna itself, nor would they be allowed to dismantle the transmitter, but they could stay in the building. That should give you some idea of the common sense we are talking about.

73 W9OY
RE: Antennas, Pacemakers & Defibrillators  
by W9OY on June 7, 2005 Mail this to a friend!

Yea and my back is friggin killin me
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by K1CJS on June 7, 2005 Mail this to a friend!
"I'm from the government, and I'm here to help you."

RE: Pacemakers, Defibrillators & Deep Fried Ch  
by K1CJS on June 7, 2005 Mail this to a friend!
"I'm from the government, and I'm here to help you."

RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WA6BFH on June 7, 2005 Mail this to a friend!
John, what is the dBd gain of your various curtain and Rhombic antennas?
Antennas, Pacemakers & Defibrillators  
by KG4TEZ on June 7, 2005 Mail this to a friend!
I guess shooting yourself with a Taser is totally out of the question!!
RE: Antennas, Pacemakers & Defibrillators  
by WA6BFH on June 7, 2005 Mail this to a friend!
Whatever turns you on?
RE: Antennas, Pacemakers & Defibrillators  
by W6SZG on June 7, 2005 Mail this to a friend!
In the real world where I live and work (with 10 other board certified cardiologist partners)we have not ever encountered an untoward event related to RF in any of our pacemaker or AICD patients. The actual and real risk faced by these folks (and the rest of us without devices) is related to the nature and severity of any underlying cardiac disease...not some very remote "possible" risk related to RF causing the device to malfunction - and in a LETHAL way. There has been a lot of misinformation posted here about this topic. And the product liability lawyeres just love it, just what they look for in a prospective juror. We all pay the increased costs associated with nonsence. If someone with a device dies = it must have been a device malfunction. We all know that otherwise we would all live forever. By the way, the blood pressure and cholesterol pills do work, we take them ourselves. Best 73, W6SZG.
RE: Antennas, Pacemakers & Defibrillators  
by KC8VWM on June 7, 2005 Mail this to a friend!
As a professional previously practicing in the medical field, I was made aware that certain (EMI) microwave signals presented a potential for electromagnetic interfere with cardiac pacemakers.

Unfortunatly, this information is often confused or with (RFI) interference that is generally associated with two way radio equipment that often interfere with computer like cardiac heart monitoring equipment located in hospitals.

A good source for information on the subject is not amateur radio operators, but rather the documented clinical studies actually conducted by the medical community.

73 Charles - KC8VWM
RE: Antennas, Pacemakers & Defibrillators  
by WA6BFH on June 7, 2005 Mail this to a friend!
Hmmmmmm, so what is your opinion on deep fried chicken?
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WB9AUJ on June 8, 2005 Mail this to a friend!
The rhombics are about 17-18 dB. Our curtains run between
18 and 30 dB, depending on the number of elements we have
active. One set of curtains can be "rotated" and the take off angle changed.
These get some real high gain..30dB.

BTW......the rhombics work GREAT on 20 meters.

73, John WB9AUJ / N6VOA
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by KF4VGX on June 8, 2005 Mail this to a friend!
Quote ,WA6BFH on June 7, 2005
Hmmmmmm, so what is your opinion on deep fried chicken?

Deep fried Chicken can kill your ticker.
** TO **
Krispy Kreme Donuts  
by KA4KOE on June 8, 2005 Mail this to a friend!
How about Krispy Kreme glazed donuts!???
RE: Krispy Kreme Donuts  
by KA4KOE on June 8, 2005 Mail this to a friend!
"WA6BFH: "For myself, I want to have my fatal heart attack while taking a rest half way up the 800 foot tower, waiting for someone to bring me my deep fried chicken lunch! "

And I, for one, support you in that, 100%


I'd much rather be doing something else than be on a tower when the woodbine twineth for me.

Think about it.
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WA6BFH on June 8, 2005 Mail this to a friend!
VGX, aren't you the chap who was asking me about Dr. House?
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by K4JSR on June 8, 2005 Mail this to a friend!
Pass me a chicken fried Twinkie and a Crisco sandwhich, please.
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WA6BFH on June 9, 2005 Mail this to a friend!
And Beer, Mmmmmmmm Beeeeerrrrr!
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W4SK on June 9, 2005 Mail this to a friend!
I've been away for a few days. Did BFH have his heart attack yet?

RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WA6BFH on June 9, 2005 Mail this to a friend!
After some responses to a post I got on another 'reflector', I'm thinking I may just shoot myself first!
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W9WHE-II on June 10, 2005 Mail this to a friend!
The practicle solutions are simple:

1) have a good, RF (not DC) ground with a short lead (#2 copper from radio to earth) to 20-50 feet of #6 solid copper burried SHALLOW (2-3 inches below the surface for stray RF;

2) Use double shielded cable, like LMR-400;

3) Make sure the antenna is far away;

4) when keying up, do not touch the radio or anything connected to it;

5) Put a torroid (#43 for HF) on the mic cable with lots of turns; and

6) do not operate with a high SWR.

RE: Pacemakers, Defibrillators & Deep Fried Ch  
by N2WEC on June 10, 2005 Mail this to a friend!
I will buy W9OY a beer. Seriously. Anybody with the smarts to do anesthia......OK with me. I will stick to chest trauma and and max inmates. A drink from one medical professional to another.

William Chapman RN
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WA6BFH on June 11, 2005 Mail this to a friend!
Yea W9OY, not to cast aspersions on your friend but, that expression you used almost sounds too close to the old "No kids, no K's, no WA's"!
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by K8LEA on June 11, 2005 Mail this to a friend!
Always wondered what happened to W2OY....

Some years back, Joe WD8PRG (now an SK) turned up at our repeater group lunch just after getting a pair of pacemakers installed.

We always seemed to have a dozen HT's on the table.

I told Joe to please shut off his pacemaker's 'cause they were bothering our receivers....

He lasted another 8 years or so. The HT's weren't a problem.

'Course, he didn't carry one. Joe had some serious HF gear at home, but had been warned, and apparently had no problems there either.

Great guy.... His oldest boy is a close friend.

A while before that, we were sitting at lunch deciding what to give Joe as a "retirement gift". It was customary for the group to buy a piece of ham gear when one of the guys retired. (A teenager of about 36 summers was our youngest member.) Since Joe's health conditions were known, one of or members sugbbested that we wait a bit, and if he croaked, we could save a few bucks.... He was given the check for that Saturday's lunch.... Along with a "sh...."

RE: Pacemakers, Defibrillators & Deep Fried Ch  
by W9EJB on June 11, 2005 Mail this to a friend!
I have gotten into this discussion a bit late. The issue of RF interference to implanted medical devices (particularly pacemakers and defibrillators) has been of some interest to the industry for some time. Ever since the days of the microwave ovens (has not been a FDA concern for over 25 years). More recently the cell phone issues have been of concern. The EMI center at the University of Oklahoma looked very specifially at this issue ( ). They looked at the issues of both analog (FM) and digital modulation schemes with the technology about 10 years ago. The industry standard, based on these studies, is to use feedthrough capacitors at the lead header of the devices.

However these are relatively low level RF fields and the issue of high field strength was not studied. I suspect that even if you are running a kilowatt the field strength in the shack is not something to be too concerned. The companies have excellent people who can give the best guidance.

By the way the rule of thumb for the cell phones is to use "prudent avoidance" , i.e. use the ear on the other side of your body from the device implant.

Also, the dicussion of cardiac conduction given by W9OY was reasonably accurate. The "delay" in the AV node is actually the result of very slow and continuous conduction (~.05 M/sec).

RE: Antennas, Pacemakers & Defibrillators  
by K9EKG on June 11, 2005 Mail this to a friend!
No, thats the food...
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by KD5VFD on June 11, 2005 Mail this to a friend!
Ummm K4JSR, we are running a special on Drug Eluding Stents this month in Waco, Texas. It sounds like you might need 5 or 6 with that kind of diet. Good Luck!
Mike H.
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by AD7DB on June 12, 2005 Mail this to a friend!
Rent the 1980 movie "Used Cars."

In one scene, two electronics gurus are explaining to Kurt Russell and his friends how they can hack into the White House satellite feed during a presidential address and slip their used car lot commercial on all the networks at once.

One of them shows his handiwork that he did on the other guy: "If I can build and install a pacemaker in this man's chest, I **** know how to jam a satellite!"

He also implies that he built the pacemaker using inexpensive parts from Radio Shack.

The actual commercial is one of the funniest scenes in the whole movie.

By the way, their relatively simple method of satellite hacking was nothing close to how "Captain Midnight" got onto HBO a few years ago.
RE: Pacemakers, Defibrillators & Deep Fried Ch  
by WA2JJH on June 12, 2005 Mail this to a friend!
This engineer at one of the stations I worked at, did
something unwise and lived to tell about it.

Mike V. just got a pace maker This dude was old school!

He stood directly in front of a 2gig antenna. He made a popeye the sailer pose. He laughs I am not afraid of 12 watts.

He was a few feet from the dual "GOLDEN ROD" antenna

I then told him that twin 4 foot "GOLDEN RODS" HAVE 23 DB of gain. So he was not facing 12W, but an ERP of
2400W concentrated and RHCP polorisation.

I can tell you that his pacemaker was not affected
by a RF gradiant. He did say sorry, and bolted away from being 2 feet of thatype of RF source.

Still DO NOT TRY THAT ONE AT HOME....KIDS of all ages!

Antennas, Pacemakers & Defibrillators  
by KC0NND on June 12, 2005 Mail this to a friend!
6/12/05. First I Thank my life long friend W0MSJ for alerting me to this ICD article and to the e-Ham site.
Thanks also to KB8PMD for the article and to W90X for his expert analysis. I have had ICD's implanted in my chest since 1995. The first one in Dec.1995, and the last one in May 1999. The battery in the first one got weak, hence the installation of the second unit. Recently my Heart rhythm doctor, while checking the ICD's status, testing battery life, and if I had any Episodes, had trouble downloading the past events. He indicated that my ICD log was showing "Noise". He inquired if I had changed any of my medication, or if I introduced any blood thinners into my medication (which I did not).
Another possibility, he explained, was that the insulation on my 'Leads' may be breaking down.

I have fun with my 2 meter ICOM V8000, but usually operate on low or mid-low wattage. My antenna is about 12 ft. above my Shack, and my rig has a good ground. I did use my friends 5 watt hand held unit several months ago for a short duration. I did contact Medtronic and inquired about the insulation on the leads, but received no satisfactory explanation.
It did not occur to me that the 'Noise' the ICD recorded might be from my hobby.

If anyone has any information beyond what has already been covered, I would appreciate your input.
Antennas, Pacemakers & Defibrillators  
by KE4ZHN on June 15, 2005 Mail this to a friend!
I guess this would rule out operating QRO on an indoor antenna on 1.2ghz. :-)
RE: Antennas, Pacemakers & Defibrillators  
by W6DWF on June 17, 2005 Mail this to a friend!
The advice to contact the manufacturer or the "installer" of an ICD for information as to RF safety sounds good. I suggest that those giving the advice actually try it. The responses range from a statement that one should stay "x" feet from the antenna - with no discussion of power, frequency, etc. - to no reponse at all. Their considerations seem to relate much more to attorneys than to patients. At one company the reponse seemed to be by a secretary reading from a script who had *no* additional information of any kind. When I asked the staff of an M.D. who did implants about their knowledge of RF considerations, they had little and asked me to let them know if I found anything.
Since my wife's ICD implant, I've often wondered about the fact that one can drive past all sorts of AM and FM broadcast towers with no warnings, no indication of field strength, and - fortunately - no problem.
Thanks & 73 to all who joined this discussion.
Email Subscription
You are not subscribed to discussions on this article.

My Subscriptions
Subscriptions Help

Other Operating Articles
Bring Ham Radio into DMR
I'm On FT8! Now What?