Estimation of anomaly location and size using electrical impedance tomography

• Published in: IEEE transactions on biomedical engineering Vol. 50; no. 1; pp. 89 - 96
• Main Authors: KWON, Ohin, JEONG ROCK YOON, JIN KEUN SEO, EUNG JE WOO, YOUNG GU CHO
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.01.2003; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Biological and medical sciences; Biomedical monitoring; Conductivity; Electric Conductivity; Electric Impedance; Event detection; Feasibility Studies; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Image reconstruction; Imaging phantoms; Imaging, Three-Dimensional - methods; Impedance; Measurement errors; Medical sciences; Minimization methods; Multiphase flow; Nondestructive testing; Pattern Recognition, Automated; Phantoms, Imaging; Quality Control; Reproducibility of Results; Sensitivity and Specificity; Studies; Tomography; Tomography - methods; Voltage measurement; electrical impedance tomography (EIT); conductivity; location and size estimation; Anomaly detection
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2002.805474

We developed a new algorithm that estimates locations and sizes of anomalies in electrically conducting medium based on electrical impedance tomography (EIT) technique. When only the boundary current and voltage measurements are available, it is not practically feasible to reconstruct accurate high-resolution cross-sectional conductivity or resistivity images of a subject. In this paper, we focus our attention on the estimation of locations and sizes of anomalies with different conductivity values compared with the background tissues. We showed the performance of the algorithm from experimental results using a 32-channel EIT system and saline phantom. With about 1.73% measurement error in boundary current-voltage data, we found that the minimal size (area) of the detectable anomaly is about 0.72% of the size (area) of the phantom. Potential applications include the monitoring of impedance related physiological events and bubble detection in two-phase flow. Since this new algorithm requires neither any forward solver nor time-consuming minimization process, it is fast enough for various real-time applications in medicine and nondestructive testing.