Noninvasive Image Reconstruction of Flowing Thrombus With Electrical Capacitance Tomography

A method for noninvasive real-time measurement of blood cardiopulmonary bypass is proposed by electrical capacitance tomography (ECT). An eight-electrode sensor ECT data acquisition system is designed, including sensor design and data acquisition module design. The system has a real-time imaging speed of 40 frames per second (FPS) and an average signal-to-noise ratio (SNR) of 64.59 dB per channel, which has been experimentally verified. First, the system is able to detect 6.25%–42.25% of the target area ratio (AR) when the sensor inner diameter is 20 mm, the outer diameter is 25 mm, and the image correlation coefficient (ICC) is not less than 0.7, which obtained by static experiments. Second, the corresponding voltage sum curve is different when different sizes of targets flow through the electrode coverage area. Dynamic experiments have verified that the sum of voltage curve for each frame image is available to further determine the size of the thrombus generated during the circulation process. Finally, dynamic experiments were performed using fresh porcine blood clots to mimic thrombus, which verified the feasibility of using ECT for in vitro thrombus detection.