南京大学学报（自然科学版）2018，Vol.54Issue(3)：571-579,9.DOI:10.13232/j.cnki.jnju.2018.03.012
基于准静态场的新型灵敏度系数计算方法
A new calculation method of sensitivity coefficient based on quasi-static field
摘要
Abstract
Electrical Tomography(ET)is an advanced visualizing technique which is efficient,non-invasive and real-time,and has been widely used in industrial process detection and biomedicine diagnosis.As a priori information and an indispensable part,the sensitivity coefficient plays a significant role in the ET process.However,the existing calculation method of sensitivity coefficient has the drawbacks of ambiguity,lack of explanation capacity,poor adaptability and linear hypothesis,which results in an obstacle of improving the quality of reconstructed images and restricts the development of ET process.This paper starts from the physical significance of sensitivity coefficient in quasi-static field.In the Electrical Resistance Tomography(ERT)field,the relationship between each pair of excitation electrodes can be equivalent to a pair of dipoles.Furthermore,each corresponding measured point can be equivalent to a pair of dipoles.Then,corresponding to the distribution of physical field,a new method of calculating the sensitivity coefficient is proposed,which has the advantages of clear physical significance,strong interpretability and operability.Finally,in the COMSOL with MATLAB platform,a set of experiments was established to test the performance of the new method.During the simulation,the new sensitivity coefficient was compared with the original sensitivity coefficient in the numerical,projection area and calculation time.Besides,the two different sensi-tivity coefficients and the sensitivity coefficient back projection(BP)method were used to reconstruct the four typical models:three circles model,discrete vesicle model,double lung model and cross model.Through a series of simula-tion and analysis,the results show that the new method is feasible and consistent with the numerical distribution of the original calculating results.Moreover,the new sensitivity coefficient solution has better performances in noise immunity,computation time and image reconstruction.关键词
电学层析成像/灵敏度系数/准静态场/偶极子/物理意义Key words
Electrical Tomography(ET)/sensitivity coefficient/quasi-static field/dipole/physical significance分类
数理科学引用本文复制引用
刘笑远,王泽莹,岳士弘..基于准静态场的新型灵敏度系数计算方法[J].南京大学学报（自然科学版）,2018,54(3):571-579,9.基金项目
国家自然科学基金(61573251) （61573251）
