Hi, I'm fairly new to electronics so I appreciate any help I can get.
I'm trying to design a circuit that can provide a constant current of about 50 microamperes (μA) at the load, using a 1.5V battery.
In the image, the load is represented by a resistor, which in reality will be a cathode and an anode. Between the anode and the cathode should be a poorly healing wound, such as a diabetic ulcer.
This is more of a thought experiment at the moment. Not even thinking about phase I trials yet. As far as I know, there is no such medical device commercially available. A 1.5V battery can't cause harm in its intended use in this design. TENS units work at far higher currents and are considered safe. Patients with epilepsy and pacemakers/arrhythmias would, of course, be excluded, as a precautionary measure.
I'm looking at a current pump design, as discussed here (https://www.allaboutcircuits.com/technical-articles/how-to-design-a-precision-current-pump-with-op-amps/). I read that the LM324 can work at lower supply voltages and the 1.5V battery shouldn't be a problem. But I'll change the op amp if necessary, of course.
Skin resistance is highly variable, that's why I'm looking at this type of configuration. The situation can be helped using conducting gels, but I was planning on using an ohm meter to test it out. The device is to be worn for longer periods of time (72h+), so it could be the case that a close enough average for the skin resistance could work. This will also include failsafes in the final design.
I'm a physician, not an electronics engineer, so I really appreciate the help.
