Impedance measurements that involve the human body are affected by the capacitance between the body and earth ground. This paper describes a low-cost method to estimate that capacitance that can be applied to impedance analyzers intended to measure ungrounded impedances and also to inexpensive handheld LCR meters. The method does not require any external component other than two common capacitors and two electrodes in contact with the body.
Aliau-Bonet, C.; Pallas, R. Low-cost method to estimate body capacitance to ground at mid frequencies. A: International Conference on Electrical Engineering. "Actas VII International Conference on Electrical Engineering FIE 2014". Santiaco de Cuba: 2014, p. Bio04-1-Bio04-4.