Evaluation of Electrical Impedance Tomography Electrodes in the Measurement of Biceps Muscle Activity

Abstract Electrical impedance tomography (EIT) is a non-invasive imaging technique used to assess the electrical conductivity of biological tissues which in turn can be related to other physiological tissue properties such as hydration status, vascular inflow, tissue composition and pathological conditions. The ability of EIT to provide information in real time, has sparked interest in rehabilitation, sport science and clinical diagnostics applications. Thus, EIT emerges as a suitable measurement solution to detect muscle activation patterns from changes in the electrical conductivity due to muscle activity. EIT measurements rely on the use of a set of electrodes placed in contact with the skin around the muscle to be studied. Therefore, there is a compromise between electrode size, shape and material to yield the best quality of measurements while allowing placing sufficient electrodes for EIT imaging. In this paper, the authors evaluate the performance of different types of reusable electrodes in terms of measurement stability, noise, response to muscle contraction and root mean square error. The results suggest that the shape and material of the electrode significantly influence the quality of the bioimpedance measurements and the reconstructed images. Stainless steel resulted in the most suitable option for delivering consistent and reliable bioimpedance measurements for EIT image reconstruction. e image reconstruction.