Design and Implementation of a Bio-Impedance Analyzer Based on the Kramers-Kronig Transform

The increasing interest in bio-impedance analysis in various fields has increased the demand for portable and low-cost impedance analyzers that can be used in the field. Simplifying the hardware is important to maintain low-cost and portability, but this is not an easy task due to the need for accurate phase and magnitude measurements. In this paper, a magnitude only hardware design is proposed and tested. The need to measure the phase is replaced by using a modified Kramers-Kronig transform to extract the phase from the magnitude information. Testing using on-shelf components, and comparisons using apple bio-impedance measurements from a professional impedance analyzer are also reported.