Electrical impedance tomography: Induced-current imaging achieved with a multiple coil system

Date

1996-02-01

Author

Gençer, Nevzat Güneri
Williamson, SJ

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An experimental study of induced-current electrical impedance tomography verifies that image quality Is enhanced by employing six rather than three induction coils by increasing the number of independent measurements. However, with an increasing number of coils, the inverse problem becomes more sensitive to measurement noise, Using 16 electrodes to measure surface voltages, it Is possible to collect 6 x 15 = 90 independent measurements. For comparison purposes, images of two dimensional conductivity perturbations are reconstructed by using the data for three and six coils with the truncated pseudoinverse algorithm, By searching for the optimal truncation index that minimizes the noise error plus the resolution error, the signal-to-noise ratio of the data acquisition system was established as 58 db, Images obtained with this six-coil system reveal the sizes and locations of the conductivity perturbations, This system also provides images within the central region of the object space, a capability not achieved in previous experimental studies using only three circular coils, Nevertheless, the three-coil system can identify the conductivity perturbations near the periphery, However, it displays shifts in the locations and spread in the sizes of perturbations near the center of the object.

Subject Keywords

Tomography, Coils, Conductivity, Signal to noise ratio, Surface impedance, Image quality, Impedance measurement, Electric variables measurement, Inverse problems, Noise measurement

URI

https://hdl.handle.net/11511/46366

Journal

IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING

DOI

https://doi.org/10.1109/10.481983

Collections

Department of Electrical and Electronics Engineering, Article

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Citation Formats

N. G. Gençer and S. Williamson, “Electrical impedance tomography: Induced-current imaging achieved with a multiple coil system,” IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, pp. 139–149, 1996, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46366.