Compatibility of TIG and MIG with implanted defibrillator
Don Foreman
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.
Steve W.
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.
--
Steve W.
Don Foreman
wrote:
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!
Steve W.
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!
--
Steve W.
Pete C.
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.
Don Foreman
wrote:
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.
Steve W.
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.
--
Steve W.
TinLizziedl
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.
--
Tin Lizzie
"Elephant: A mouse built to government specifications."-Lazarus Long
Don Foreman
wrote:
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.
John
"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
Bob F
"Don Foreman" <dfor...@NOSPAMgoldengate.net> wrote in message
news:tabgm4p4tc1ur049d...@4ax.com...
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.
John
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