Multielectrode Multiplexing for Bioimpedance Surface Topography Mapping

Traditional bioimpedance point scanning for tissue identification successively measures tissue electrical properties at discrete locations; this process is not optimised for developing a bioimpedance map with sufficient spatial resolution in a short time frame to reflect the underlying tissue topography. We build on previous work implementing a tetrapolar bioimpedance measuring system, with a novel combination of computational bioimpedance multiplexing and a multi-electrode architecture. Experimental results were obtained from porcine tissue, using a 12-electrode probe with 14.3 seconds of recorded data sampled at 1MSPS. The reconstructed bioimpedance image resembles the tissue sample RGB image and can provide mesoscopic tissue structural information, surpassing the spatial resolution previously limited by electrode pitch size. The spatial resolution obtained with our approach scales exponentially with the number of electrodes, with an adaptable electrode geometry to achieve optimal reconstructed bioimpedance maps for real-time tissue identification.