Digital phase-sensitive demodulator for electrical impedance tomography

Author

Oh, Tong In ; Lee, Jeong Whan ; Kim, Kyu Sik ; Lee, Jae Sang ; Woo, Eung Je

Author_Institution

Coll. of Electron. & Inf., Kyung Hee Univ., Seoul, South Korea

Volume

2

fYear

2003

fDate

17-21 Sept. 2003

Firstpage

1070

Abstract

In electrical impedance tomography (EIT), we measure boundary voltages due to multiple injection currents using surface electrodes placed on a subject and try to reconstruct cross-sectional resistivity images. This requires a precision phase-sensitive demodulator. In this paper, we present a design and performance analysis of a digital phase-sensitive demodulator including both in-phase and quadrature detectors. The designed demodulator was implemented and tested to verify SNR of 143dB, phase error of 2.25 , and stability of 0.0135%.

Keywords

biomedical electrodes; demodulators; electric impedance imaging; image reconstruction; matched filters; phase detectors; 143 dB; digital phase-sensitive demodulator; electrical impedance tomography; multiple injection current; precision phase-sensitive demodulator; quadrature detector; reconstruct cross-sectional resistivity image; surface electrodes; Current measurement; Demodulation; Electric variables measurement; Electrodes; Image reconstruction; Impedance measurement; Surface impedance; Surface reconstruction; Tomography; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Engineering in Medicine and Biology Society, 2003. Proceedings of the 25th Annual International Conference of the IEEE

ISSN

1094-687X

Print_ISBN

0-7803-7789-3

Type

conf

DOI

10.1109/IEMBS.2003.1279430

Filename

1279430