Use of a priori information in estimating tissue resistivities - a simulation study

Date

1998-12-01

Author

Baysal, U
Eyüboğlu, Behçet Murat

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Accurate estimation of tissue resistivities in vivo is needed to construct reliable human body volume conductor models in solving forward and inverse bioelectric field problems. The necessary data for the estimation can be obtained by using ht four-electrode impedance measurement technique, usually employed in electrical impedance tomography. In this study, a priori geometrical information with statistical properties of regional resistivities and linearization error as well as instrumentation noise has been incorporated into a new resistivity estimation algorithm which is called a statistically constrained minimum mean squares error estimator (MiMSEE) to improve estimation accuracy. MiMSEE intakes geometrical information from the image which is obtained by using a high-resolution imaging modality. This study is an extension of earlier work by Eyuboglu et al and obtains simulated measurements from two numerical models containing five and six regions on a background region. Also, estimations are repeated by suing up to eight multiple current electrode pairs, in order to observe the effect of estimation performance while increasing the number of measurements up to 96. The results are compared with a conventional least squares error estimator (LSEE) which is used in one-pass algorithms. It is shown that the MiMSEE estimation error is up to 27 times smaller than the LSEE error which is realized for a small, high-contrast region, for example the aorta. In estimating the regional resistivities, the MiMSEE algorithm requires 25.8 (for the five-region resistivity distribution) and 22.2 (for the six-region resistivity distribution) times more computational time than the LSEE. This gap between the computational times of the two algorithms decreases are the number of regions increases.

Subject Keywords

Radiological and Ultrasound Technology, Radiology Nuclear Medicine and imaging

URI

https://hdl.handle.net/11511/46979

Journal

PHYSICS IN MEDICINE AND BIOLOGY

DOI

https://doi.org/10.1088/0031-9155/43/12/015

Collections

Department of Electrical and Electronics Engineering, Article

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Citation Formats

U. Baysal and B. M. Eyüboğlu, “Use of a priori information in estimating tissue resistivities - a simulation study,” PHYSICS IN MEDICINE AND BIOLOGY, pp. 3589–3606, 1998, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46979.