Reverse Polarity Scanning Method on 64-Channel Capacitive Sensor to Improve the Performance of ECVT System

This research proposes a scanning method on tomography namely electrical capacitance volume tomography (ECVT). This study discusses the new scanning method of reverse polarity scanning that is applied to 64-channel capacitive sensors. In tomography process, the data acquisition system measures the capacitance from capacitive sensors using scanning process by activating the electrode pairs. Generally, scanning process in ECVT uses conventional scanning by activating an electrode pair and measure the capacitance signal for the pair. This study proposes a new scanning process, by reversing the polarity of electrode in scanning method. The method is applied by changing the polarity of excitation electrode into detection electrode, and vice versa. Then, both of methods are compared to evaluate the performance of the acquisition system. Simulation and experiment are performed using 64-channel capacitive sensors with cylinder rods phantom filled with water. To evaluate the performance of the ECVT system, static objects were used to measure parameters such as Mean Absolute Error (MAE), Coefficient-Correlation (R), and image qualitative observation. From the simulation and experiment, the Coefficient-Correlation (R) value as 0.6 and Mean Absolute Error (MAE) value as 0.2, so that the proposed method can improve image quality of 3.2%.