NBC 2009August2
Electrostim
More electrostim excitement ensued. Once again, driving signal generator output backwards through a transformer extracted from a wall-wart into 3M red dots on our valiant experimenters.
Skin resistance. We tested this after the other tests, and found that the resistance started low and climbed. These numbers are about when we got sick of waiting for it to stabilize. Mikolaj: 55 kOhms, Orion: 50 kOhms, Mike: 116 kOhms, Rachel: 300 kOhms
Results were recorded chronologically. MikeW and Mikolaj observed notable sweating on hands, Orion and Rachel not at all. Also belatedly noticed that symmetry was way skewed to one side until MikeW's second test of second round.
General conclusions: 1mA seems to be a sensible upper bound for current. Next step is to build an inductor-based current source based on standard dc-dc boost topology.
Videos: http://www.youtube.com/watch?v=YRH0xjcnHV4 http://www.youtube.com/watch?v=XSz21QeLd-U
Mikolaj Habryn 15:10, 2 August 2009 (PDT)Subject | V | mA | f | Perception |
---|---|---|---|---|
MikeW | 11 | 0.5 | 60 | initial sensation |
MikeW | 14 | 0.6 | 60 | Definitely feel tickle |
MikeW | 18 | 0.9 | 60 | muscle contractions (bordering on v. uncomfortable) |
MikeW | 22 | 1.2 | 60 | stops being fun |
Rachel | 6 | 0.15 | 60 | initial sensation |
Rachel | 12 | 0.5 | 60 | can distinguish brief pulses |
Rachel | 14 | 0.9 | 60 | distinct buzzing and less precise location sensation when tapping |
Rachel | 16 | 1.0 | 60 | muscle twitches in hand |
Rachel | 18 | 1.25 | 60 | distinctly uncomfortable |
Orion | 7 | 0.2 | 60 | initial sensation |
Orion | 10 | 0.5 | 60 | distinct sensation |
Orion | 15 | 1.0 | 60 | strong muscular influence |
Mikolaj | 7 | 0.2 | 60 | can feel it |
Mikolaj | 11 | 0.7 | 60 | sharp tingling sensation |
Mikolaj | 13.5 | 0.9 | 60 | pins & needles |
Mikolaj | 17 | 1.2 | 60 | can't straighten middle finger. done! |
Mikolaj | 11.5 | 0.9 | 80 | slightly more pronounced than at 60 Hz |
Mikolaj | 13 | 0.9 | 120 | not huge difference with 80 Hz |
Mikolaj | 9 | 0.6 | 5 | feels like 5 Hz tapping |
Mikolaj | 7 | 0.4 | 10 | starts to feel like tapping |
Mikolaj | 12.5 | 1.0 | 10 | uncomfortable |
Mikolaj | 11 | 1.1 | 7 | finger twitches at 7Hz |
MikeW | 14.6 | 0.62 | 60 | mild tickle |
MikeW | 13.4 | 0.53 | 60 | symmetry fixed initial sensation |
MikeW | 15.6 | 0.78 | 60 | distinct sensation |
MikeW | 16.4 | 0.92 | 60 | beginning discomfort |