Compatibility of TIG and MIG with implanted defibrillator

I'm visiting here from RCM.

I've been encouraged to have a defibrillator implanted in my chest. The "school solution" regarding any form of arc welding is "not recommended". However I've seen limited data from a credible source (Journal of the American College of Cardiologists) suggesting that it's not a problem at the light current I use, usually under 200A. (The JACC measurements were done at 900 amps without incident)

I asked the doc today what the downside might be if I were to not heed the "not recommended" advice. He said the defib wouldn't harm or kill me if it fired but I'd feel like I'd been hit by lightning.

He had no trouble persuading me that having one would be a good idea even if I must curtail my welding activities. He asked if welding was a passion with me or something. I said I wouldn't call it a passion, but I certainly would miss being able to do it after spending three decades working on my skills. It'd be a non-trivial loss and kind of a bummer. I'll skip shielding ideas like chainmail, foil shirts, lame, etc., but do feel free to have fun with this. My wife has already suggested cutting the bottom out of a garbage can and putting leather shoulder straps on it. I think she just wants the photos.

I do understand that arrangement of current-carrying cables strongly affects the fields they produce. I'm a retired electrical engineer.

My question for this group: are there any readers here who have ICD's (implanted cardiac devices) and do occasional or routine TIG, MIG or other arc welding, or does anyone here know of people like that?

Respectfully

Don Foreman

By the way, Martin Eastburn, the guy said no problem with rifles; he just asked me which shoulder I use so he'd know where to put it.

Reply to
Don Foreman
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I know of a couple folks who have them. I'll have to ask the one if he does any any hot glue work. I know the other doesn't. The doc did explain what that unit actually does right? The comment that it wouldn't harm or kill me kind of sets wrong. A defib is a simple unit in reality. It basically hits you with enough juice to stop your heart, then hopefully it restarts on the proper pattern. ICDs use less juice because they are directly connected but they still do the same thing. When they fire they kill you.

Consider that an external unit pumps out 200-300 joules per hit, they pack a punch.

Reply to
Steve W.

From Wikipedia:

"There are cases where the patient's ICD may fire constantly or inappropriately This is considered a medical emergency, as it depletes the device's battery life, causes significant discomfort and anxiety to the patient, and in some cases may actually trigger life threatening arrhythmias. Some emergency medical services personnel are now equipped with a ring magnet to place over the device, which effectively disables the shock function of the device while still allowing the pacemaker to function (if the device is so equipped). If the device is shocking frequently, but appropriately, EMS personnel may administer sedation."

External units use up to 1000 volts but the objective is 3 to 5 volts per centimeter -- so an internal unit will use considerably less voltage and energy because it need not overcome thoracic impedance. It's still bound to be a whack best skipped if avoidable!

Reply to
Don Foreman

Don't need an explanation, I used both an AED and a manual Defib unit on a weekly basis.

A pacemaker is a different type of unit that looks at the hearts A/V and S/A nodes for the firing signals and compares that to a table of "normal rhythms" if the timing is incorrect it fires a very low pulse to contract the area of the heart which it controls. You can do this with a defib unit as well IF it has the capability of pacing.

And ICD has a similar table, however it actually senses the firing of the nodes and when it sees an improper rhythm it hits the heart with a jolt that stops that rhythm. The ONLY way to actually stop it is to shut down all the electrical activity that is causing the problem. The nodes hopefully start back up on a good rhythm.

An external unit will give you a VERY nasty jolt if you are in the current path. I know of at least one case where an EMT was working on a patient, his assistant got the defib connected up and in the confusion forgot to check to verify that the EMT was clear. He hit the button to shock and the EMT was too close. He got hit with enough of a jolt that it stopped his heart as well as the patients. He recovered but it was interesting because they suddenly had two patients without a pulse!

Reply to
Steve W.

Well, there you go, mount a ring magnet in an appropriate location in your welding jacket to disable the ICD while you're welding. With it in the jacket, it will be automatic so you won't have to remember or fuss with it.

Reply to
Pete C.

I've about decided that I really would rather skip that experience unless a cardiac event makes it necessary. I'm going to nose around Medtronic next week, see what I can learn. It does seem like it'd be easy and advisable to include a reed switch that could be activated by an extrnal magnet.

Reply to
Don Foreman

Most have the ability to be disabled externally. However the catch is that when they are disabled many need a programmer unit to turn them back on. Not a problem if you were headed to the ER in the first place. Could be dicey if you didn't have access to the programmer.

Reply to
Steve W.

I seem to remember some type of unit that could be controlled over the telephone- the patient held a special unit over the implant, and this unit took its input from the cardiologists over the phone lines. Kinda like a data modem or fax machine, it could upload data to the docs, and download new parameters for activation.

Perhaps this is only in the trial stages somewhere.... Would be really good in places far removed from hospitals.

Reply to
TinLizziedl

I clearly need to know more than I do now. I'm working on that. As of right now I am discouraged and bummed but perhaps not out quite yet.

Dr Lin the electrician was somewhat incredulous when I told him I was doing 3 miles in an hour every day. Dr. B the Paki keeps raising the bar.

Today, after doing my 3 miles I repaired to the kitchen, still sweating, for a sandwich. Mar asked "did you hear the phone ring?"

I'm a vet, deaf as most of my age. I said I hadn't heard a ring.

She said it was Dr B. "Oh, what did he have to say?"

"He said if you can do one hour then you should be doing two."

My response was unprintable until I tumbled. I do enjoy her humor.

Reply to
Don Foreman

Worked in this field for about 20 years. For the ICD to detect the "interference" will be a few seconds, about 5-14 seconds to charge the capacitor and then it fires. Thus you have about 7 - 16 seconds to weld before you get a shock. Unfortunately you dont know whether its 7 or 16 seconds!.What I would do is get your bloke who adjusts the Defib to enable the audio charging alarm. The ICD will beep if it starts to charge. Soon as you hear it , stop welding. One problem is that once a "tachy" or "inteference" is detected the device maybe programmed to interpret a tachy a little more loosely and will be even more sensitive. Modern leads are intrinsically more "noise rejecting" than older types as well. I had people welding when I was working with them, but discuss it with your tech people like at Medtronics and Guidant . John

Reply to
John

I have a pacemaker, and have had no problems, but my welding is very infrequent. I seem to remember reading somewhere that the failure mode for the pacemaker is to not fire with the interference. This would not be an issue for me, perhaps, because mine rarely needs to fire anyway.

Reply to
Bob F

If the pacer does pick up signals that are out of the normal biological range it will pace ( noise response) . If it interprets those signals as heart rate it will stop pacing (inhibit). New style pacing/sensing leads make noise rejection much better , if it was me and welding was my hobby I,d certainly be chasing it up. Not with a medico but one of the technical reps who looks after your device. John

Reply to
John

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