OT: Artificial heart that seems to work

[boB]

On Mon, 02 Sep 2019 21:39:39 -0400, krw@notreal.com wrote:

On Mon, 2 Sep 2019 19:34:23 +0100, Mike Coon <gravity@mjcoon.plus.com
wrote:

In article <prvomedk1or32a3b8q3jlnte0m4o78umvr@4ax.com>, krw@notreal.com
says...

Primarily the lack of magnetic materials in the device and lead(s) and
a means to disable feedback (shuts off sensing and enters an open-loop
mode with default operation). The device is signaled to go into this
"safe mode" by placing a rare earth magnet over the device (opens a
reed switch).

Interestingly (to me, at any rate!) the model name of my pacemaker
includes "MRI" suggesting they are proud of its compatibilty. On the
other hand, no-one suggested not putting a magnet over it...

That's malpractice by your hospital/cardiologist/electrophysiologist
and staff. I can't count the number of times I was warned, and that
was _before_ I left the hospital. It does take a strong magnet,
placed very close to the device but the magnets in high-end headphones
are enough to do it. They're not likely to cause a problem, in use,
because of the distance from your ear to chest but hanging them around
your neck can cause problems. I also was warned to not put my cell
phone in my shirt pocket. In addition to the transmitter being very
close to the device, the magnet in the speaker is pretty strong (to
make it small). Or, as one of the tech suggested, a spouse listening
to music while resting their head on my chest may be enough. Well,
that's not likely to happen for a few reasons. ;-)

Magnetic fields in general are badness but not only because it might
trigger the safe mode. Large AC magnetic fields can confuse sensing
causing abnormal and unpredictable device operation (really not
goodness).

Girlfriend's (fiance's) pacemaker was moved down near her stomack and
probe wires "tunneled" underneath the skin so that radiation after
radiation for breast cancer would not affect the device. That
tunneling was more painful than moving the pacemaker itself.

Someone from Medtronics usually comes in to do the work to disable and
re-enable the pacemaker for surgery.

Her pacemaker paces around 25% of the time.

My late wife had a neuro-stimiulator implant in her lower back (Boston
Scientific) that had 16 probes and stearable stimulation that was very
cool. That particular implant worked great but was before MRI safe
electronic implants. That was around 2007 but it worked very well.