How to simulate frequency-dependent conductivity of biological tissue using EM LF Electro Ohmic Quasi-Static solver?

[gotou]

Hello,
I’m currently working on a simulation involving electrical stimulation of biological tissue. I am using the EM LF Electro Ohmic Quasi-Static solver and varying the frequency to compare current flow in the tissue.

Since biological tissue conductivity is frequency-dependent, I would like to reflect this property in my simulation. Therefore, I have selected the IT'IS Database, rather than the IT'IS LF Database, to account for frequency-dependent changes in conductivity.

However, when I use the IT'IS Database, I receive a warning message recommending that I switch to the LF (low-frequency) version of the database.

How can I run a simulation where the tissue conductivity remains frequency-dependent, while still using the EM LF Electro Ohmic Quasi-Static solver?
If changing the solver is necessary to achieve this, I would appreciate any suggestions on which solver to use and how to proceed.

Any advice or insights would be greatly appreciated.
Thank you!

[bryn]

You can run an LF simulation with the normal (non-LF) database: just ignore the warning.

However, please note that the Gabriel Cole-Cole model (which is used in the standard IT'IS database) was primarily fitted using measurements above 1 MHz. For example, the conductivity of the skin is about 2 orders of magnitude smaller than the well-accepted value (see LF database).
I believe that at lower frequencies, there are currently not enough measurements in the literature to justify fitting a frequency-dependent model.

[gotou]

Thank you very much for your response.
I understand now that it's okay to ignore the warning, and that the Cole-Cole model in the standard IT'IS database is primarily fitted to measurements above 1 MHz.

I have a follow-up question:
Is there a recommended way to perform simulations with low-frequency currents (e.g., around 100 kHz)?

I couldn’t find a clear explanation in the manual regarding how to handle this frequency range, so I would really appreciate any guidance or suggestions you could provide.

Thanks again for your help!