Heart Pacemakers and tube amps

[supro66]

At 62 years old a mans dream is a 46 foot Pacemaker boat with twin cat engines and a tuna tower

I just got a heart Pacemaker installed

Do I have to give up building and repairing tube amps because of the magnetic fields in the transformers and the speakers? 

Would a lead vest work?

Need some advice from you old guys

[rafe]

You might be able to get some unique feedback with it !!  Actually I don't have the answer for you, but I think it would be OK to be around magnets, of course I wouldn't get too close with them . Don't put them on your chest. I finally found a good schematic for the rectified thunderbolt. lol

[simonallaway]

This article mentions studies that found "intense magnetic fields" can in some cases cause issues. But I haven't read those studies to know whether transformers qualify as intense when compare to something like an MRI machine.

http://en.wikipedia.org/wiki/Artificial_pacemaker#Lifestyle_considerations

[RicharD]

>transformers qualify as intense when compare to something like an MRI machine

I've powered up MRI's before.  You can feel the magnetic pull on a screw driver 5 feet away.  You have to empty your pocket and remove jewelery before you even get near one. 

[Platefire]

Did you ask the doc if he had any tube pacemakers? I haven't got a pacemaker but got two stints and take plivax everyday plus a hand full of other pills. I took a MRI a couple of years ago and was wondering about my stints. That might have traveled up stream a few inches!! I'm 62 too. Platefire

[supro66]

I wouldn't get too close with them . Don't put them on your chest. I finally found a good schematic for the rectified thunderbolt. lol

I would like to see it the schematic


I think about 5 of us guys with the implants should start a band

we could call the band

THE PACEMAKER FIVE

[PRR]

http://content.onlinejacc.org/cgi/content/full/45/6/896

"No clinical study has reported specific and relevant information pertaining to magnetic fields near power lines or electrical appliances."
"A magnetic field pulsed at power frequency can cause a mode switch and pacing inhibition in patients with devices programmed in the unipolar sensing configuration. The risk of interference appears negligible in patients with bipolar sensing programming."
"400-kV outdoor power plant substations located along roads. Interference was observed in one of 15 patients"
"Our study shows a low incidence of interference by a high-density magnetic field"
"In patients with unipolar sensing programming, the interference can cause sustained asynchronous mode reversion and pacing inhibition. Therefore, the risk of interference by a 50-Hz/100-µT magnetic field appears negligible in patients with bipolar sensing programming. AutoCapture function, which may be sensitive to EMI, should be disabled in patients who work in such environments."
 
http://www-esh.fnal.gov/FESHM/5000/5062.2.pdf

http://enginova.com/should_wearers_of_heart_pacemake.htm

http://www3.interscience.wiley.com/journal/118913937/abstract?CRETRY=1&SRETRY=0

This is too much for me to digest; I think it may be too much for doctors or engineers to digest.

One tidbit: do you need the pacer ALL the time, or is it a safety net? If your heart does 999 of 1000 beats on its own, then a pacemaker momentarily stunned by magnetic field is a non-event _unless_ that's also the moment your heart skips more than a beat. OTOH, the stress and possible electric shock of working around electricity means this may BE the moment your heart skips and you want the pacemaker backup.

Obviously I aint' gonna say "Go ahead!"; I'd feel bad if you were found dead next to an amp.

As an empirical guide: the doc tells you not to do that, but do you listen? No! At least, a lot of liver, bile, and lung patients ignore instructions to change diet, stop drinking and smoking, and surely some pacer patients go back to electrical work. If pacemakered motor-mechanics were dropping dead the week after release, this would show up in studies, and some poor grad student would be assigned to collect some numbers. The fact there is very little hard evidence suggests you can hang around most electric machines at working distance and be OK. (What this really means is: if you die, you are not statistically significant.)

[PRR]

http://www.fac.org.ar/tcvc/llave/c365/dubner.PDF

Bipolar Sensing Polarity - The lead tip and the lead ring electrode are the poles of the sensing circuit. Because bipolar sensing is more localized, it reduces the likelihood of sensing myopotentials and electromagnetic interference. It may also permit sensitivity to be programmed to a more sensitive setting.

Unipolar Sensing Polarity - The lead tip (occasionally the lead ring) and the noninsulated stimulator case are the sensing electrodes. Unipolar sensing may allow sensing of smaller intrinsic signals than does bipolar sensing and therefore, can be selected when intrinsic cardiac signals are difficult to detect with bipolar sensing. Oversensing due to myopotentials is more common with unipolar sensing than with bipolar sensing.

Bipolar RV/LV Sensing Polarity - In the LV-1 lead, the electrical activity will be sensed between the lead tip and the right ventricular lead ring. The distance the stimulus travels between the lead tip and the right ventricular lead ring will be affected by the size of the heart. The greater the distance, the more prone the device is to sensing myopotentials.

Bipolar Sensing Polarity Confirmation
Before programming from unipolar to bipolar sensing, some of the programmer verifies the presence of a functioning bipolar lead by testing impedance for the lead. Testing is done under magnet operation for four seconds at an Amplitude of 5.0 V and a Pulse Width of 1.0 ms if the permanent settings are at or below this level.

Cardiac pacemakers step by step

[PRR]

Stingray might sell you a gaussmeter:

http://www.el34world.com/Forum/index.php?topic=8810.msg79235#msg79235

http://enginova.com/should_wearers_of_heart_pacemake.htm suggests "60-Hz magnetic flux- 1 G, Static magnetic fields- 5 G", which seem to be well within his meter's range.

> what the heck does a ham radio operator have use for a gaussmeter?

Maybe he got a pacemaker, had the same question, got the meter to find out what he was exposed to?

> was his dad's

Then we must wonder why Dad's stuff is a "was". Did the Gaussmeter imply "OK" and it wasn't? Or did the new leash on life suggest a new girlfriend, and girlfriend's other boyfriend objected?

[supro66]

http://content.onlinejacc.org/cgi/content/full/45/6/896


Obviously I aint' gonna say "Go ahead!"; I'd feel bad if you were found dead next to an amp.

No I will not blame anybody

I was just wondering if any of you old guys who do work on amps
stopped doing it if they had a pacemaker

By the book I should not use a Gas chain saw, power tools

I am going to test the waters on what I can do

I know I can't be an NDT inspector

checking for cracks with probs

I don't know why I am not dead, 3 times and the heart started it's self since July

[PRR]

> I just got a heart Pacemaker installed

supro66--

You have not posted in a while but I see you visited recently.

How is the metronome working?

I thought you and others might like to see how they did it in 1960.
(Popular Electronics, May 1960)

Bottom picture of old man with a box on his chest, of course!

Top picture has nothing to do with pacemakers but may warm your blood slightly. That type of propane IR patio heater is now widely sold. I don't see how it has ANYthing to do with electronics, but I guess the PE editors would grasp at any excuse to put a pretty woman on the page.

[PRR]

And in 1961:

[Ritchie200]

> I just got a heart Pacemaker installed

Bottom picture of old man with a box on his chest, of course!

Ya know, the older I get, that doesn't seem so old anymore!  However, there are days when I feel older than that!

Jim

[shooter]

I'm a little late finding this tread, I fixed the MRI's for 24 years n pacemakers were a Definite no for the reasons PRR already stated, Hi field + RF pulsing.  That said they were in clinical trials recently for a new pacemaker that would work in low field magnets, 1.5tesla n down.  The stints were also an issue but most new(90's n up) are designed MR safe.  In the 80's when I decided to get fixed, I told the surgeon to only use high grade titanium, otherwise I'd loose my job!!

[supro66]

> I just got a heart Pacemaker installed

supro66--

You have not posted in a while but I see you visited recently.

How is the metronome working?

I thought you and others might like to see how they did it in 1960.
(Popular Electronics, May 1960)

Bottom picture of old man with a box on his chest, of course!

Top picture has nothing to do with pacemakers but may warm your blood slightly. That type of propane IR patio heater is now widely sold. I don't see how it has ANYthing to do with electronics, but I guess the PE editors would grasp at any excuse to put a pretty woman on the page.

I am still kicking