According to Ohm’s Law, I feel like I should have smoke coming out of my ears now that the RNS device has been switched into active mode.
The equation above signifies Volts = Amps x Ohms. And no, I don’t know why amps = current = I. (Physics and I didn’t have a great relationship back in school.)
In this case, the equation uses milliamps and ohms. They’re starting out with a very low amperage: the strip of electrodes on the surface is set to 0.5 milliamps and the lead that goes deeper into the brain is 1.0 milliamps. The resistance (ohms) in the strip varies from 1126-1557; the lead is 640-855.
So assuming I’m doing all of the math correctly (using the lowest resistance), the strip is 0.0005 x 1126 = 0.563 volts. The lead is 0.001 x 640 = 0.640 volts. Those don’t seem like large numbers, right?
Flash back to SEEG testing and they were measuring the testing in microvolts. Thus, the highest level they reached was 0.000008 volts. So again, assuming I’m doing all of the math correctly, the lowest voltage of the strip is currently 70,375 times stronger than what I experienced in the hospital.
That said, when we switched the RNS device to active mode this morning, we sent some test jolts to the strip and the lead to make sure my eyes wouldn’t roll into the back of my head or my hair lit on fire. The result: I didn’t notice anything happening. Dr. White gave me a medical information sheet to read and I had no problems as we were doing the tests. (I even noticed that one of the sentences was missing an “as”.)
So everything seems to be working so far and no problems with language comprehension. I’ll be going back again in three months so we can recheck the data—we’re starting at a really low amperage, so the RNS device may not be doing a very good job of preventing seizures at this point and we’ll need to turn it up. At that point, I don’t think I’ll try to figure out the math anymore. It seems easier (and less scary) to measure things by doing the burning hair test instead.