一种新的ECT敏感场计算方法

New calculation method of sensitivity distribution for ECT

分析了电容成像传感器的敏感场电位分布与极板电容关系的理论模型,提出一种基于电位分布的灵敏度有限元计算方法。通常使用的敏感场计算的方法是根据灵敏度计算公式,改变场内每个单元介电常数,由正问题求解极板电容变化而计算得到,该法计算非常耗时。提出一种新方法,通过求解源极板和测量极板单独激励下电位分布,结合有限元单元的能量系数来计算整个敏感场分布。相比之下,新方法的计算时间大大缩短,可达2个数量级,并且重建结果与用常用计算方法的结果相一致。

The model of the potential distribution as a function of the inter-electrode capacitance has been discussed, and a calculation method of sensitivity distribution for electrical capacitance tomography is presented. Conventional method calculates the sensitivity distribution according to the sensitivity formula; the sensitivity distribution is obtained from solving a forward problem of electrode capacitance change by changing the dielectric constant of each cell in the field. Conventional method is very time consuming. The proposed new method calculates the potential distribution by exciting both the source electrode and detect electrode and can be used to calculate the potential distribution of all the cells in the field. The results indicate that the calculation time is shortened by 2 orders and the results of image reconstruction for both the proposed new method and conventional one are similar.