A 9.6-mW/Ch 10-MHz Wide-Bandwidth Electrical Impedance Tomography IC With Accurate Phase Compensation for Early Breast Cancer Detection

Abstract

An eight-channel 10-MHz wide-bandwidth electrical impedance tomography (EIT) IC is proposed for early breast cancer detection system. To increase the resolution of EIT images, the proposed IC has three key features: 1) wide-bandwidth instrumentation amplifier (WB-IA) to detect large impedance changes in cancer cells at a high frequency; 2) dual-mode driver (DM-driver) to obviate the complex switching network to reduce the noise and the system form factor; and 3) phase compensation loop (PCL) to efficiently correct the phase error for accurate images without artifacts. The proposed EIT IC occupies 16 mm2 in the 65-nm CMOS technology and consumes 9.6 mW for each channel. Thanks to the key features, the proposed breast cancer detection system with the dedicated EIT IC can operate up to 10 MHz with a small phase error of 4.32° and a state-of-the-art impedance resolution of 1.6 $\text{m}\Omega /\surd $ Hz eventually can detect a small-size target object of 0.5 cm and verify with the phantom experiments.