A High-sensitivity Four-layer Capacitively Coupled Electrical Impedance Tomography Sensor for Brain Stroke Monitoring

This paper aims at the development of a novel capacitively coupled electrical impedance tomography (CCEIT) sensor for brain stroke monitoring. The proposed CCEIT sensor employs the capacitive coupling principle for contactless measurement and a focusing sensing approach to reduce the adverse effects of the scalp and skull on impedance measurement. The proposed CCEIT sensor is characterized by a distinctive four-layer configuration, including a focusing electrode layer (4 large electrodes) to direct the signal deeper into the region of interest and a detection electrode layer (24 small electrodes) to capture the directive intracranial impedance signal. Compared with the traditional EIT sensor, the proposed CCEIT sensor does not rely on electrode-skin contact. And compared with the traditional CCEIT sensor, the proposed CCEIT sensor is more sensitive to the indepth stroke, and has significantly better imaging quality, reducing the maximum relative image error and the maximum location error by 45.7% and 31.2%, respectively. The results indicate the potential of the proposed CCEIT sensor in stroke imaging, offering a totally contactless, portable, and feasibly high-quality imaging device for early diagnosis and monitoring of cerebrovascular events.