Recently, I wanted to build a replica of a bio-impedance circuit that I found in one of the NIH.gov papers. As obvious, bio-impedance circuits are usually used to measure body composition. They are using two electrodes in the design instead of four which is commonly used, meaning, the current will be inserted through the same electrodes as well as the voltage readings. I am still an undergrad student, so I had some questions regarding the inputs voltages and frequencies usually used to generate current or to be specific in this circuit. .
I am trying to generate signals with a function generator for Vin- and Vin+ but the paper hasn't discussed what inputs are needed, for example, the voltage amplitude, frequency, and Vin+(-) phase difference. Also, they say they are doing a no-load current test in which they measure the current with a DMM. But where should I measure the current in a no-load case?
- Input signal characteristics?
- Where is the no-load current measured?
Link to the paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3777733/#R7