| Title |
Bioimpedance Measurement Circuit for Large Input Range |
| DOI |
https://doi.org/10.5573/ieie.2022.59.4.39 |
| Keywords |
Neural; Impedance; Measurement; Circuit; Large input |
| Abstract |
A new type of integrated circuit for measuring bioimpedance was designed and verified through simulation. As a characteristic of bioimpedance, an impedance change has less than 1% of the nominal impedance level. This has a characteristic that the voltage signal induced by the applied current is very large compared to the voltage change due to the impedance change to be measured. For this reason, in order to avoid saturation when amplifying the measurement signal in the measurement circuit, the high amplification gain cannot be applied. In general, when using a 1.8 V operating voltage, the maximum amplification gain is 60 V/V for a 30 mV input signal. In this paper, a signal folding method is proposed to overcome the saturation problem at high amplification gain, and it is shown that 300 times amplification is possible without saturation. |