3/22 Session 3:
Current: Not measured, previous estimate likely incorrect
Time: 20 minutes total, switching polarity halfway
The Sugru’d valley and Vaseline on the back of my hands made this much more pleasant, but I think the real problem is I use too much water.
This thing will find nicks on your hands you didn’t even know you had.
So… apparently I don’t know what resolution is, in terms of the multimeter, and I read my skin resistance wrong. I have no idea what my skin resistance is – it’s 6-7 somethings when wet with the range at 20 megaoohms – and consequently, I have no idea what the actual current is through my skin, from hand to hand.
Before next session, I’ll test the current through the water from pan to pan tomorrow, using my multimeter. During the session, I’ll only use enough water to get my palms wet and not fully submerged.
3/21 Session 2:
Current: Not measured, estimated at 0.2mA over skin, unknown through water
Time: 20 minutes total, switching polarity halfway
I cut out valleys in the pan walls nearest me, so that I didn’t have to raise my arms awkwardly to fully submerge my palms. I also covered the edge in Sugru so now I can lean into the pans without shocking my arms.
Although the setup was the same, the stinging, itchy sensation while submerged was worse. It was borderline unbearable, and I was squirming the whole time. If you’ve ever had to sit in a salon chair with relaxer on your head until it “starts burning”, and the stylist tells you to give it 10 more minutes, that’s what it felt like, but only at the water line. It didn’t leave a red line this time.
Next session, I’m going to brush a thin layer of Vaseline at the line where the thick skin of the palms ends. The Vaseline prevents water from touching the sensative thin skin, thus blocking the stinging current.
So, something I’ve dealt with since I was a kid is hyperhidrosis. I can’t really hide it, so I might as well write about it. Others have posted videos about it:
Things I can’t or have to do because of how sweaty my hands and feet are:
- Can’t wear sandals, high heels, flats or dress shoes without socks
- Socks must be 100% cotton
- Can’t wear Crocs or Vibram FiveFingers as their creators intended
- Can’t go barefoot
- Sharing game controllers is embarrassing
- Holding hands is embarrassing
- Giving handshakes and highfives is embarrassing and probably cost me some jobs (way to start my school day everyday, by having a mini panic attack shaking 90 judgmental kids’ hands. This would have been a nightmare when I was a shy, anxious student)
- Steering wheel must have suede cover
- Paper falls apart sometimes when I write or draw
- or the ink/graphite doesn’t transfer
- Have to wear cotton gloves or carry a towel while lifting weights, riding bikes, playing video games, working inside computers or with electronics, drawing, writing or sometimes even typing, but I don’t do that in front of other people because it’s embarrassing
- I’ve locked myself out of my phone because it doesn’t recognize my fingerprints
- I’ve locked myself out of my phone because it thinks my finger is still on the sensor because of the sweat imprint
- Getting fingerprints taken for background checks takes longer than it should, if it happens at all
- When my hands and feet sweat, everything sweats and it just cascades from there
- Now that I think about it, I must be dehydrated all the time
On the plus side, I never have to wear moisturizer and my hands and feet are super soft, like a baby’s.
It’s not always that bad. I’m usually dry at work, for some reason, and usually I’m dry when I go to bed. It’s worse when I’m stressed or excited, or when I’m in contact with synthetic fabrics. It’s gotten to the point where I want to do something about it.
And that something is an iontophoresis machine. Professional medical iontophoresis devices can cost upwards of around $1000. Mine cost about $20-$30. It uses 2 6V lantern batteries for a total of 12V (I have a 3rd 6V battery in case the 12V wasn’t enough), 4 aluminum pans for hands and feet, a role of grip liner so I can rest my hands without touching the pans, 2 wires at about a meter each to connect the hand pans to the foot pans, 2 foot-long wires to connect the hand pans to the opposite terminals (+/-) on the batteries, 1 small wire to connect the other pair of opposite terminals between the two batteries, and 10 alligator clips to attach the wires to. I got the instructions from this video and this video (don’t touch the pans together!).
Everything but the wires were easy to find at Walmart. I was actually surprised at how difficult it was to find wired alligator clips or test leads, especially in the lengths I needed. I got the wires and clips from AutoZone. The wires are 18 AWG, but a thinner AWG would’ve been easier to thread through the alligator clips. I also regret not getting insulated boots for the clips. I’m pretty sure I won’t shock myself if I’m touching one clip at a time, but I used insulated pliers to put the clips on and take them off anyway. Traditionally, black wires are used for ground and the battery’s negative electrode, and red wires are used for hot and positive electrode. AutoZone didn’t have black wires in the same AWG, so I got yellow (traditionally used for signal, I think). The colors don’t matter here, as long as I connect the batteries to the opposite electrode of another battery.
I didn’t test the current from lead to lead, but the voltage was between 12V-13V, so I assume the current was, at least, not too high because of my shabby wiring. Before I wired anything, I tested my skin’s resistance while submerged in water. That came out to about… uh… either 6,000,000 ohms or 60,000 ohms. 60,000 ohms if I was reading my multimeter right (tested up to 20 megaohms with a resolution of 10 kiloohms. Screen showed about 6, so, 6 x 10 kiloohms is 60,000 ohms?). From what I read, dry skin can be between 1,000 and 100,000 ohms, so I was a little surprised that my submerged skin from hand to hand had a resistance in that range. My guess is that, since the rest of my body between my hands was dry, that increased the overall resistance. Don’t quote me on that, I’m just a hobbyist. Although, I did find a questionable source that put submerged hands at 200-500 ohms. That’s 60 mA at 12 volts, minimum, which is very dangerous, even for DC current. We’ve all stuck a 9V battery on our tongues and lived to tell the tale, so, that can’t be right. I tested a single 6V battery with this setup first (not my tongue, the actual iontophoresis setup), just in case. And felt absolutely nothing.
With those numbers in mind, I used Ohm’s Law to figure out the current in milliAmps. 12 volts / 60,000 ohms = 0.2 mA, which is ridiculously low and safe. According to the chart on this page, 0.6-1.0 mA DC produces a slight sensation or tingling in the hands. If my hands truly had a resistance of 200-500 ohms, that would be 60 mA minimum, which is very dangerous.
So, what did I feel?
- tingling when I first put my hands in, but I got used to it quickly. It’s nowhere near the tingling you get with a TENS unit. The itching was worse…
- itchiness where the water met the top of my hands
- a red splotchy line appeared at the waterline as well, but it went away after an hour or so, as did the itching
- slight stinging at one my cuticles which had been mashed somehow
- shoulder, head and neck pain, probably because I was tense. The table I was sitting at was too high to comfortably relax my arms on the pan without my skin squeezing through the grip liner, touching the pan, and giving me an annoying little shock – like being continuously poked with the corner of a paper. It stung! A little. I think?
- I punctured my finger with one of the wires while I was threading it through a clip. It didn’t hurt at all while submerged, like I thought it would.
At 12 volts, 0.2 mA, I was a little itchy. The itching (or stinging that felt like itching) was the most annoying part of this experience. It wasn’t painful, just annoying or kind of uncomfortable. And boring, at 20 minutes total without moving my hands.
What can be improved?
- wires with a thinner gauge OR solder wires to clip
- insulating boots for the clips
- shallower pans
- arm rests at the front of the pans to reduce shoulder tension
- conductive plates in plastic pans instead of entirely conductive pans, to avoid accidental shocks and shorts
- I could use an AC -> DC transformer and skip the batteries, but I don’t trust it. 120V AC is nothing to mess with.
Hopefully I start seeing results after a few sessions. I can’t wait to give nice, firm, dry handshakes and wear cute shoes! If nothing else, I learned a lot about Ohm’s Law and how DC current affects the body.