Current approaches to analogue instrumentation design in electrical impedance tomography
Authors:
- 1 November 1996
- journal article
- review article
- Published by IOP Publishing in Physiological Measurement
- Vol. 17 (4) , 229-247
Abstract
Electrical impedance tomography (EIT) is a novel medical imaging method, which allows reconstructed tomographic images of the internal impedance of a subject to be made with the use of a ring of electrodes. High precision impedance measurements are needed, because the image reconstruction process is ill-conditioned and small errors in measurement can lead to large errors in the final image. In practice, there are formidable instrumentation problems, due to the interaction of finite current drive output impedance, recording amplifier common mode rejection, and unequal skin-electrode impedances. A number of different EIT systems have been constructed or are under development. These employ differing strategies, such as additional electrodes, multiple electrode current injection, or recording at multiple frequencies, to improve image accuracy. This paper reviews the nature of the instrumentation problems and the designs employed by differing groups in attempting to overcome them.Keywords
This publication has 22 references indexed in Scilit:
- Development of a real-time adaptive current tomographPhysiological Measurement, 1994
- Electrode current determination from programmable voltage sourcesClinical Physics and Physiological Measurement, 1992
- Improved wideband, high CMRR instrumentation amplifierClinical Physics and Physiological Measurement, 1992
- Electrical impedance tomography systems based on voltage driveClinical Physics and Physiological Measurement, 1992
- Performance of a differential synchronous demodulator for electrical impedance tomographyClinical Physics and Physiological Measurement, 1992
- An improved design of voltmeter for semi-parallel data acquisitionClinical Physics and Physiological Measurement, 1992
- Novel current-mode instrumentation amplifierElectronics Letters, 1989
- An electric current tomographIEEE Transactions on Biomedical Engineering, 1988
- The Sheffield data collection systemClinical Physics and Physiological Measurement, 1987
- Some physical results from an impedance cameraClinical Physics and Physiological Measurement, 1987