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Modeling electrodes in coductive tissue

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Hi everyone,

I´m trying to model a "communication channel" inside human tissue. A silicon cylinder with a copper electrode on the top and bottom is set up as a transmitter. At a different position, the same setup is used as a receiver. Both transmitter and receiver are inside a big cylinder, with heart tissue properties. The electrodes have fixed potential, since a stationary solution is enough for me.

Now, I want to simulate the potential distribution within the tissue-cylinder. The model should take in account the material properties of the transmitter and receiver.

I tried to move along the default example, like the pacemaker or capacitance example, but I cant really use their approach, because my surrounding domain consists not only of tissue, but a receiver with different material properties as well.

Once I click on study, I can take some probes and get values, but I doubt the physical reliability of these values, since I can´t use the floating potential node on the receiver electrode boundaries, because my license doesnt include that feature.

Another problem are the graphs. I´m not able to get a "solid xy-cut plane", where I can plot the potential distribution of the surrounding tissue. It only gives me the potential distribution for within the transmitter electrode.

Feel free to take a look at my model.

Thank you very much

Best regards

Jonas



2 Replies Last Post 2018年5月7日 GMT-4 04:54
Edgar J. Kaiser Certified Consultant

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Posted: 7 years ago 2018年5月4日 GMT-4 17:18

Hi Jonas,

I think you could use boundary probes to measure the potential on the receiver electrodes.

The reason why you don't see the field in the tissue domain is that you have hidden this domain in the View settings.

I would recommend to plot a logarithmic quantity like log10(abs(V)). This might give you more insight than the linear quantity.

However, I doubt that the Electric Currents application mode will provide realistic results in tissue. You probably have to take some electrochemical double layers at the electrode surface and ionic currents into account. The Electrochemistry module might achieve that, but I can't tell for sure because we do not have it.

If you are up for a real adventure add your own equations ;-).

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Hi Jonas, I think you could use boundary probes to measure the potential on the receiver electrodes. The reason why you don't see the field in the tissue domain is that you have hidden this domain in the View settings. I would recommend to plot a logarithmic quantity like log10(abs(V)). This might give you more insight than the linear quantity. However, I doubt that the Electric Currents application mode will provide realistic results in tissue. You probably have to take some electrochemical double layers at the electrode surface and ionic currents into account. The Electrochemistry module might achieve that, but I can't tell for sure because we do not have it. If you are up for a real adventure add your own equations ;-). Cheers Edgar

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Posted: 7 years ago 2018年5月7日 GMT-4 04:54

Hello Mr. Kaiser,

thanks for the quick reply. After performing a parametric sweep of the distance of the electrodes, I now want to get the ratio between the differetial potentials of the surface probes. Similiar to your approach, I defined a variable like 20log(diff_potential-recv)-20log(diff_potential-trans). Ufortunately I cant quite figure out how to derive the results for these Variables and eventually plot the ratio.

Uploaded model in the attachements.

Kind regards

Jonas

Hello Mr. Kaiser, thanks for the quick reply. After performing a parametric sweep of the distance of the electrodes, I now want to get the ratio between the differetial potentials of the surface probes. Similiar to your approach, I defined a variable like 20*log(diff_potential-recv)-20*log(diff_potential-trans). Ufortunately I cant quite figure out how to derive the results for these Variables and eventually plot the ratio. Uploaded model in the attachements. Kind regards Jonas

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