direct current stimulation

[mihov123]

I do not know much about eletronics, but I get around
Could you please help me with this

direct current stimulation
I need a battery powered constant current output of 1-2 mA,I have an Idea how to make this,
but I do not know how to cope with the skin resistance

It is important that the device is current controlled. What this means is that the device will adjust
the voltage up and down as the resistance changes so that the current never changes. For instance, if the
resistance of the skin is 10,000 ohms, then 10 volts will be needed to “push” 1 ma through the body. If for
some reason, the connection becomes poor and jumps to 20,000 ohms, then the device should
automatically increase the voltage to 20 volts in order to push the 1 ma current through the body.

Could could you tell me what I need to do, or give me a circuit similar to what I need.

Thank you

 

[crutschow]

Try Googling op amp constant current source. If you have further questions after that, let us know.

 

[Sceadwian]

Direct DC stimulation of human nerves is a very bad idea it will over time destroy the nerves (polarized them) and it's not exceptionally practical to create a DC source that can be current controlled in the manner you suggest, it also will not properly stimulate muscles. AC signals are used for muscle or nerve stimulation, controlling the current is as simple as selecting an appropriate transformer. In both cases you'll want to use a conductive gel on the skin as if you increase the voltage enough to force 1ma of current at a high resistance you'll get electrical arcing and damage the tissue, the overall energy needs to be kept low as well as the current. If you look around on the net you might find some studies on haptics that go into it in a little more detail, even the exact frequency used can be quiet important, especially for triggering sensation in skin nerves.

 

[mihov123]

I was thinking of using this for tdcs transcranial direct current stimulation, my friend participated in an experiment and they used device with this characteristics **broken link removed**

I do not know how they power the device with
# Power: 2 batteries type AA/LR6 – 1.5V – KAA
# Secondary battery: Renata batteries CR2325. Nominal capacity: 190mAh – current intensity in standard conditions: 0.3 mA – maximum intensity: 3m

 

[Sceadwian]

My first response is to simply say, stop what you're trying to do, if you don't have detailed medical and electrical knowledge then you can't guess what effect your device will have. The site of the device you've linked so far have reported no scientific or medical backing for their product or results of any kind. You are plain straight up not qualified to try to make such a device.