High-speed Electrical Impedance Tomography (EIT) System

Being designed for general purposes, the high-speed EIT system will be used for surgical margin assessment. Aside from being designed for high-speed application, this 32-channel tetrapolar-based system can be programmed to apply either voltages or currents. Expected specifications include a bandwidth of 500 kHz, SNR of ~100dB, frame rate of ~100 frames per second, continuously selectable frequencies, and recording of total-harmonic distortion (THD) and DC values to enhance the reconstruction algorithms. These algorithms have been retooled to incorporate THD as part of a data-weighting measurement, and DC value will be used to ensure data quality during clinical acquisitions.

High-speed EIT system: National Instruments (NI) Chassis with NI-based modules, power supply, and custom front-end analog hardware (PCB shown). This system is configured around a National Instruments Chassis (PXIe-1082) and a number of NI Modules (PXIe-8375, PXIe-6674t, PXI-5406, PXIe-6341, PXI-7952R). We designed and constructed a front-end analog printed circuit board (PCB) to provide voltage-to-current conversion and multiplexing to up to 32 channels.