Spinal Cord Stimulators & EM Pollution

Hi, I’ve got an odd one for you all today, but this is SDMB so I’m not too worried.

Spinal Cord Stimulators ( https://en.wikipedia.org/wiki/Spinal_cord_stimulator ) are medical devices implanted in the bodies of patients, which administer light electrical pulses to the spinal cord to treat back pain.

Some of them have internal batteries to power this, while others have a radio antenna to allow external power. These are the interesting ones, because an antenna can’t magically discern whether the source of some power is the intended or unintended transmitter, though I suppose they can be directional.

Does anyone know what frequency these operate on? The Murder Mystery writer in me is running wild with ideas of some kind of terrorist broadcasting a powerful signal at the right frequency, frying the spinal cords of thousands of geriatric Americans.

Does anyone know of any cases of radio noise (e.g. a malfunctioning microwave) or other errant or malicious radio signals interfering with these or other similar devices? I’d take pacemaker stories but I’m more interested in the weirder implantables to be honest.

Obviously, if the people who designed these systems are smart, they chose a frequency in one of the attenuation bands of the atmosphere to limit the possibility of such a thing, but still!

I have used one of these stimulators (medical grade) as part of a scientific research project. I don’t know the specifications by heart but I remember the following things:

These stimulators have two types of antenna: one to receive external power and one to communicate with a programmer.

I don’t have the frequency in mind, but the charger works by placing another antenna in very close proximity (about 1 cm away). The power of radio signals decreases with distance, so one would have to send a very powerful radio signal in order to load this antenna from a distance. In addition to this, this type of device is extensively over-engineered with safety in mind, and you can bet there are many safeties against power surges in the stimulator.

The stimulator has a computer chip that regulates the intensity, frequency, waveform (etc) of the stimulation. The patient and caretaker have a device that can pair (with a password protected protocol) to this computer chip and program it. You may imagine interfering with this but that would mean hacking this protocol.

These things are really designed to be safe and foolproof. You may encounter difficulties pairing your programmer (for instance because it has low batteries) but, short of a massive radio signal (comparable to a EMP), I don’t see anything interfering with them.

Huh. Wonder what the effect of a massive EMP would be on such devices…

Of course, if a location did experience such a thing there would be far greater worries than back pain for a lot of people.