Calibration and Electrical Validation of a BIS Portable System
Alves, J.é; Sousa, F.; Correia, M.V.
Studies in Health Technology and Informatics 249: 122-129
2018
ISSN/ISBN: 1879-8365 PMID: 29866967 Document Number: 695216
Heart failure (HF) affects at least 26 million people worldwide and is considered a global pandemic. Almost 1 out of 4 hospitalised patients are re-hospitalised for HF within the 30-day post-discharge period. This can be avoided if changes to the hemodynamics of the HF patient's body are early detected. Bioimpedance Spectroscopy (BIS) is a method that allows the measurement and analysis of multi-frequency body complex impedance and can be used to detect changes to the HF patient's hemodynamics. This paper presents the calibration and validation process of a low-cost portable BIS system, as well as, the study of the best Cole parameter estimation methods. The BIS system was calibrated using a three reference circuit method and a Resistance-Capacitance-Inductance (RCL) meter as calibration system. After calibration, BIS impedance measurements of validation circuits presented an average phase error of 0.76 degrees and an average magnitude relative error of 0.6% when compared with standard values. Regarding Cole parameters estimation, using the Impedance model and the Non-Linear Least Squares method for curve fitting, the relative errors were below 4% when compared with the expected values.