Re: Pacmakers and Tesla coils = bad??

Hi Stan,

	WOW!!!  When I was reading about pacemakers, it was implied that they
could be accidently triggered by a number of things.  I was not really
"sure" a TC could do it but the things they described seemed like it would
be very possible.  However, this is proof that a 15/60 coil can trigger the
defibrillator types at 25 feet.  The people that have these are warned by
their doctors what the jolt they give is like so they will be somewhat
prepared.  This is especially important if they are driving or something
(Mark mentioned that they would normally be unconscious, but perhaps that
can be programmed).  Pacemakers can also be stunned into safe and default
modes if their logic detects something is wrong.  This may go unnoticed but
they may not be able to operate as needed in such a fail safe state.  The
equipment that "talks" to these pacemakers may be able to detect and count
the number of times they are affected.

	There apparently are no official levels or standards of EM interference
for these things.  Different brands appear to be affected more or less.
They are somewhat "hardened" against normal EMI but a Tesla coil is
obviously quite abnormal in most EMI respects.  CERN calls out 0.5mT but I
am not sure that is well based.


	It would be nice if we could come up with a "safe" distance or some
maximum EM level but there appears to be no such data that would apply to
all manufacturers of pacemakers.  It looks like the only thing we can go by
now is "Keep pacemakers FAR away from any TC!"

Many thank for this very important post on this subject!



At 09:15 PM 02/13/2000 -0500, you wrote:
>I witnessed first-hand what a TC can do to a modern pacemaker.  A fellow
>was about 20-25ft from a running 15/60 coil.  It ran for maybe 30
>seconds then suddenly he shook violently and dropped down on to his
>knees.  Apparently, the gap misfired or whatever and for a second the
>frequency of the output was abnormal and triggered his pacemaker.  If I
>remember right his delivered 5J.  Whatever it delivered, it scared the
>holy heck out of me and was very painful for him.  Fortunately, the
>shock had no ill effects on his rhythm.
>Obviously this situation could have been disastrous.  The TC could have
>triggered his pacemaker and sent his heart into an irregular beat, or
>perhaps worse could have quietly destroyed his pacemaker and would have
>never been noticed until it failed to shock when it was really needed.  
>IMHO it's just not worth it.  Keep pacemakers FAR away for any TC!
>Tesla List wrote:
>> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
>> Hi Mark,
>> I just want to thank you for adding this sort of expert addition to all
>> this.  I got onto this pacemaker thing by accident, but the stuff I saw
>> really worried me!!
>> Having a pacemaker zap someone would be sort of unpleasant.  However,
>> having it do ANYTHING it is not supposed to be doing is a real concern.
>> Tesla coils would be almost a worst case situation to find these ultra high
>> tech gizmos dealing with.
>> When they were just simply bipolar devices they were probably pretty immune
>> to a lot of things.  However, the are now really sophisticated and they
>> could do a lot of harm if they were to get "confused".  I think we need to
>> be extra careful of these things now!
>> Cheers,
>>         Terry