Imaging Algorithm and Optimal Measurement Protocol for 3-D Impedance Tomography on 2-D High-Density Microelectrode Array

Abstract

Electrical impedance imaging using high-density microelectrode arrays (HD-MEAs) is an emerging noninvasive technology to monitor cell cultures. This study aims to develop a practical electrical impedance tomography (EIT) strategy for 3-D imaging of cells cultured on 2-D HD-MEAs. Addressing for computational and memory constraints, we leverage for the utilization of the limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) method for HD-MEA-based EIT. Alongside the reconstruction algorithm, the efficacy of EIT is significantly influenced by measurement protocols. Tailored to the geometrical attributes of 2-D HD-MEAs, we present an algorithm rooted in sensitivity parallelotope to formulate a measurement protocol, ensuring both heightened spatial resolution and noise tolerance. Numerical experiments, reflective of our on-chip HD-MEA prototype, are conducted to validate the proposed EIT strategy. Findings demonstrate that the following hold: 1) the L-BFGS method exhibits approximately twice the speed of the widely utilized Gauss-Newton (GN) method for a given spatial resolution, while necessitating only a fraction of the memory consumption and 2) our algorithmically derived measurement protocol surpasses the Sheffield protocol, a prevalent choice in EIT applications, in noise tolerance.