Real-Time Signal Processing for Degree of Hand Grasping and Rotation Based on Electrical Impedance Measurements

Bioimpedance measurements provide more valuable information on contractions compared to EMG. In a typical hand EMG system, the dual-channel electrode system is placed between the lateral and medial side of the limb. Detailed studies on dual channel bioimpedance systems signal processing for gesture classification and muscle contraction degree still do not exist. In this study we propose a signal processing algorithm for bioimpedance measurements to determine the degree of muscle contraction during grasping and rotation. The developed algorithm includes preliminary filtering, transition definition, classification of two types of movement - grasping and rotation, and determination of the degree of movement performed. This method can be applied in prosthetics as well as in various muscle-machine and muscle-computer interfaces.