Simulating Electrical Stimulation w/ Comsol

Comsol is a finite element solver and applications in various engineering problems. I investigate its use in basic electrode design and analysis.

Effects of Various Electrode Configurations on Activation Functions

In the following writeup I investigate the effects of various stimulation on activation functions for nearby axons.

1. I create a spherical electrode centered inside a much larger cylinder. Grounding all surfaces of the cylinder, I show the voltage on axons traveling down the length of the cylinder that are 0,5mm, 1.0mm and 2mm away from the center of the electrode. I also show scaled version of the 1st and 2nd spatial derivatives on the same plots as the voltage.
2. I repeat the procedure using bipolar stimulation, varying the distance between the two electrodes.
3. I repeat the procedure using tripolar stimulation, again experimenting with electrode locations to find a good combination for a strong activation function.
4. Lastly I provide commentary on the differences between unipolar, bipolar and triplor stimulation, concluding that multi-polar stimulation setups can provide much more efficient activating functions.

Basic electrode design and analysis