Real-time monitoring of the hydration level by multi-frequency bioimpedance spectroscopy

This paper presents a system designed to monitor at real-time the hydration index of patients suffering from renal diseases and that are forced to undergo regular dialysis sessions. The system comprises the smart electrode (SE)-skin interface and the SE stimulation and readout electronics. This medical system combines the tetra polar multi-frequency bioimpedance analysis with the four-electrode focused impedance measurement (FIM). When compared to the Keysight E4980A, the SE is able to measure impedances with 3% of maximal relative error. Measurements obtained by monitoring patients during dialysis sessions show the close correlation between the removed fluid and the hydration index H.