Architecture and Calibration of a Multi-channel Electrical Impedance Myographer

Electrical impedance myography (EIM) is a non-invasive measurement technique capable of determining physiological and morphological changes in skeletal muscle tissue. The method consists of applying an alternating current on the skin through two electrodes to determine the bioimpedance of the medium. EIM has contributed to the study of degenerative diseases that changes the electrical properties of muscle tissue during its evolution of the disease. The objective of this work is to develop a portable and low-cost impedance measurement instrument to assist in activities related to the study and diagnosis of muscle diseases. We present a modular hardware architecture that allows the impedance measurement of multiple muscles at the same time, but in the present work we test the performance of the prototype with a single impedance measurement channel implemented. The tests were performed with known theoretical impedance calculated to evaluate the accuracy of the impedance meter, as well as other performance tests of the system.