Reducing of Bioimpedance Influence on ECG by Correction Filter in Mobile Heart Monitoring System

The paper considers the problem of distortion of the ECG curve caused by bioimpedance of a patient's skin. The authors compare traditional analytical methods of bioimpedance estimation based on equivalent circuits (RLC and others) and “black box” method. Advantage of “black box” method is shown in the task of estimation of parameters of parasitic filter of the skin in comparison with traditional methods. The paper describes the theoretical base and the measurement experiment directed to estimation of real transition parameters of the correction filter. Obtained digital correction filter was experimentally investigated. The results of the computational experiment with ECG records from PhysioNET base shows the impact of bioimpedance changes to ECG signal form. The proposed solution is intended to implementation in portable heart monitoring systems.