Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

electrode for spinal cord stimulation

Please login with a confirmed email address before reporting spam

Hi,
i'm using Comsol 5.0. and i am new.
I need to make a model of two electrodes (cathode and anode) resting on a series of biological tissue (dura mater, cerebrospinal fluid and white matter, of which I know the parameters). I have to stimulate the electrode with a rectangular voltage pulse and I would see how it propagates the electric field, temperatures and current density in biological tissues.
1) Which type of "study" should I use? (Stationary .. .... transitional ...frequency ...?)
2) What "physical" should I use? (I tried it with electric currents and heat transfer in solids but using these I did not understand what kind of "study" should I use)
3) how can I apply the rectangular pulse function to the electrode voltage?

thank you!!!

4 Replies Last Post 27.07.2016, 11:22 GMT-4

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 24.07.2016, 17:20 GMT-4
How short is your pulse?
How short is your pulse?

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 24.07.2016, 17:50 GMT-4
It is 500 micro seconds
It is 500 micro seconds

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 25.07.2016, 10:44 GMT-4
You used the word "propagate". Electromagnetics waves "propagate" at the speed of light. If your pulse is a very, very slow 500 us, the electic and magnetic fields will "propagate" very fast (even in tissue) and you could simply use a stationary study to see the steady state value of the fields when the pulse is on. Just use the on value of the pulse as your voltage.

On the other hand, if you really do want to investigate step-function wave propagation through tissue, indeed you'd want the time dependant study. Again, there's no need to simulate over the forever length of a 500 us pluse. You'd probably want to look at the first few hundred picoseconds.
You used the word "propagate". Electromagnetics waves "propagate" at the speed of light. If your pulse is a very, very slow 500 us, the electic and magnetic fields will "propagate" very fast (even in tissue) and you could simply use a stationary study to see the steady state value of the fields when the pulse is on. Just use the on value of the pulse as your voltage. On the other hand, if you really do want to investigate step-function wave propagation through tissue, indeed you'd want the time dependant study. Again, there's no need to simulate over the forever length of a 500 us pluse. You'd probably want to look at the first few hundred picoseconds.

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 27.07.2016, 11:22 GMT-4
ok, thank you!!
anyway...if i apply a voltage of 10 volt (typical of scs in commerce).. I've noticed that the temperature at the interface electrode-first biological tissue is too high! I think all the parameters are correct...do you think that i have to add some particular condition (like a boundary condition......?)
ok, thank you!! anyway...if i apply a voltage of 10 volt (typical of scs in commerce).. I've noticed that the temperature at the interface electrode-first biological tissue is too high! I think all the parameters are correct...do you think that i have to add some particular condition (like a boundary condition......?)

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.