Experimental Validation of a Method for Removing the Capacitive Leakage Artifact from Electrical Bioimpedance Spectroscopy Measurements
Journal article, 2010

Often when performing electrical bioimpedance (EBI) spectroscopy measurements, the obtained EBI data present a hook-like deviation, which is most noticeable at high frequencies in the impedance plane. The deviation is due to a capacitive leakage effect caused by the presence of stray capacitances. In addition to the data deviation being remarkably noticeable at high frequencies in the phase and the reactance spectra, the measured EBI is also altered in the resistance and the modulus. If this EBI data deviation is not properly removed, it interferes with subsequent data analysis processes, especially with Cole model-based analyses. In other words, to perform any accurate analysis of the EBI spectroscopy data, the hook deviation must be properly removed. Td compensation is a method used to compensate the hook deviation present in EBI data; it consists of multiplying the obtained spectrum, Zmeas(ω), by a complex exponential in the form of exp(–jωTd). Although the method is well known and accepted, Td compensation cannot entirely correct the hook-like deviation; moreover, it lacks solid scientific grounds. In this work, the Td compensation method is revisited, and it is shown that it should not be used to correct the effect of a capacitive leakage; furthermore, a more developed approach for correcting the hook deviation caused by the capacitive leakage is proposed. The method includes a novel correcting expression and a process for selecting the proper values of expressions that are complex and frequency dependent. The correctness of the novel method is validated with the experimental data obtained from measurements from three different EBI applications. The obtained results confirm the sufficiency and feasibility of the correcting method.

capacitive leakage

electrical bioimpedance spectroscopy

artifact removal

Author

Ruben Buendia

University of Alcalá

University of Borås

Fernando Seoane Martinez

Chalmers, Signals and Systems, Signalbehandling och medicinsk teknik, Biomedical Signals and Systems

Roberto gil-pita

University of Alcalá

Measurement Science and Technology

0957-0233 (ISSN) 1361-6501 (eISSN)

Vol. 21 11 115802-

Areas of Advance

Information and Communication Technology

Subject Categories

Medical Laboratory and Measurements Technologies

Control Engineering

DOI

10.1088/0957-0233/21/11/115802

More information

Latest update

5/30/2018