I have been an operator at an electric railway museum for a dozen years. My doctor wants me to insert an electric pacemaker to help an irregular heart beat. I am wondering if the 600 volt electric motors, circuits, etc. of a trolley will effect the pacemaker in a serious way. A lot of senior citizens volunteer at trolley museums. Have there been any issues or concerns?

Electromagnetic fields are an issue with implantable devices. I recommend that you have your doc put you in touch with his/her rep at the device manufacturer and that you have the rep put you in touch with a technical specialist at the manufacturer. You should be prepared for this conversation with as much data as is reasonably possible to obtain on the operating current and voltage specs of the motors and larger gauge wiring, the field strength of any permanent magnets in the motors, your proximity to the devices, and the duration of exposure. The link below discusses general recommendations for a range of common and industrial exposures. Good luck!

https://www.heart.org/en/health-topics/arrhythmia/prevention--treatment-of-arrhythmia/devices-that-may-interfere-with-icds-and-pacemakers

If electric railways were any particular risk, that would be well known. Passengers ride electric railways all the time, and no where on that document is any warning about such. I think 99% of the perceived risks are very over rated-when is the last time you've seen a "microwave oven in use" sticker?

You're going to be exposed to similar energy just walking down the street, crossing over underground utilities, or walking under high tension lines. Going to the fair, and walking over the cables snaked everywhere powering the rides.

That document suggests 2 feet spacing between welding and your pacemaker. Welding will create far more erratic and nasty waveforms and energy then a electric railway.

The major issue with pacemakers is induction in the leads, which is primarily an AC thing.

The risk for DC operations, particularly traction, is going to be close exposure to rapidly-changing current, the 'best' example bending over something like a traction motor turning at high rpm with the commutator switching the fields in sequential windings on and off. Or inrush current when a contactor closes.

I have an implanted ICD with a number of 'issues' and much of the common impulse-noise or AC-frequency artifacts in induced signal are 'compensated for' by the processing built into the device. There, the issue is that the device might detect some transient electrical signal on the leads that it interprets, say, as developing v-fib, and starts whacking out pulses every couple of seconds. That's just no fun at all, let alone when it happens five or six times in close succession and there's no indication that it will stop there.

Just bought a Harbor Freight electric Pressure Washer.

In the Instructions it has a caution about Pacemakers.

STOP!!!

A pacemaker is far too sensitive a subject for this forum.

You need to sak the Dr. that will install the pacemaker the question.

Be prepared to tell the Dr. all the devices you will be working with, the voltages, amps, frequencies, duration and distance of exposure.

Ask your specific expert.

Phil Mulligan

I am seeking antidotal info because the doctors are not familiar with this specialized situation. There must be several senior operators with pacemaker experience

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I can understand your Dr. being unfamiliar with 1880's technology but unwilling to find out? I'd hate to be his insurer.

If you're planning only to be the car operator you would be several feet from the motors and brushes. A K-controller would be much closer to your chest and wouls carry the full traction power. Will you be dealing with no more than 600 VDC?

Have you thought of asking the device manufacturer?

Here's an American Heart Ass'n page on the subject:
https://www.heart.org/en/health-topics/ ... pacemakers

Phil Mulligan

As a specialist in electromagnetic and Radio frequency field effects and environmental electromagnetic radiation hazards. I would think a doctor would say no, you could have a health safety EM field study done, under load abd various conditions. It would be pricey and you may still find it risky and the manufacturer of the device could take those results and approve or disapprove of the activity.

Wood bodied cars of yesteryear make poor shielding from EM waves

For God's sake, I have one of these devices (although it only paces in bradycardia), I understand how it works in detail, I have talked with a range of physicians, and I understand the difference between AC and DC induction effects.

It is a technical concern, not 'too delicate for this forum' or some other crap. If anything we should be as careful as possible to expose what the actual potential risks are, and precisely what activities would put a pacemaker user at risk. Does anyone here actually thing a correct answer is "see your doctor who knows nothing technical about 600V DC traction"?

Naturally he should discuss it with his cardiologist and device team. And they will be able to recommend what he should and should not expose himself to -- learning if necessary about the types of induced field that might be involved. But he should then share what he learns with others, and I almost think this is valuable enough to start a 'sticky' or part of the best-practices manual about.

Since you are an expert, you should explain where and how DC power is generating EM waves., why the magnitude of the fields is substantial enough to produce coupling effects in typical pacemaker-lead arrangements, and perhaps why a modern device would be susceptible to the particular effects of exposure to DC traction equipment.

First of all, using voltage to characterize the risk is completely wrong. There is no correlation between voltage and the intensity of the electromagnetic field. It would make much more sense to use wattage, which would much more reliably predict the electromagnetic field.

Trying to ask your cardiologist to calculate the effect of a 1899 trolley car would be pointless. He's a medical doctor, not an electrical engineer! He's just going to hand you the device's brochure and/or put you in touch with the manufacturer. Or, he'll just take the easy route and tell you to stay far, far away.

The ??? are everywhere. Just walking over the trolley line between the car and the power house would expose you to some very intense energy. The current has to get to and from the car somehow!

Notable, is that the manufacturers undoubtedly spend a LOT of time making these devices resistant to interference, but I'm sure they are hesitant to come flat out and say some of these situations are 100% risk free. SOMEONE is going to find a way to take things too far....

It's hard to be sure, and always that "we're talking about someone's life!", but the evidence that people have been injured by these kind of effects is lacking.

There used to be an era when restaurants that had microwave ovens plastered warnings on the entrance doors, purportedly to address this issue.

Now that the microwave is ubiquitous just about everywhere but Colonial Williamsburg, when was the last time you saw one of these signs?

Well, not really. Some instances of electromagnetic field interference are measured in Volts/Meter. Think of the Science Museum demo of the DC charged globe that makes your hair stand out on end (to separate the insulated hairs that are changed by the induced DC voltage).

And the frequency of the source of electromagnetic energy makes quite a difference. A 60 Hz field is actually quite ineffective at transferring energy over large distances. A 60 Hz Motor with circuit elements (field and armature windings) within inches of each can transfer well over 90% of the energy over the mechanical gap. However if you are 10 feet away the magnetic field has almost no strength to move anything.

At the same time an RF generator (100's of KiloHertz) can transfer enough of an RF voltage field to illuminate an old fashioned fluorescent light bulb with no magnetic field present.

I would believe that most modern pacemakers have been designed to function properly when exposed to the whole spectrum of DC, 60 Hz and RF field strengths expected in "typical" exposures.

Would of course check with the device manufacturer's technical team to see if a 600 Volt DC Motor winding 5 feet away from their device would cause concern.

Would standing directly over a trolley controller be an issue? I have been carrying a Hamilton watch and it has yet be magnetized.