A Novel Capacitively Coupled Electrical Impedance Tomography Sensor for Stroke Detection

Early and rapid detection of stroke is crucial for patient prognosis. Electrical impedance tomography (EIT) is a promising technique for developing wearable stroke detection and monitoring devices. In this work, with a 4-layer hemisphere model of head, a capacitively coupled electrical impedance tomography (CCEIT) sensor is developed for contactless 3D brain imaging. The electrode arrangement of the sensor is determined by comparing the response characteristics and sensitivity matrix of different sensor configurations. Image reconstruction experiment was carried out on a data acquisition system developed with an impedance analyzer to evaluate the imaging and stroke detection capability of the sensor. Anomalies of conductive agar balls with the diameters of 4cm and 2cm were used to simulate the stroke. Experimental results show that the developed CCEIT sensor is feasible and effective in contactless 3D stroke imaging. The reconstructed images can tell the existence and approximate location of the stroke, indicating the potential of the sensor in further clinical applications. The location error of the stroke in the reconstructed images is 14.29%.