publication . Article . 2002

a comparison of techniques to optimize measurement of voltage changes in electrical impedance tomography by minimizing phase shift errors

Fitzgerald, A. J.; Holder, D. S.; Eadie, L.; Hare, C.; Bayford, R. H.;
Open Access
  • Published: 01 Jun 2002 Journal: IEEE Transactions on Medical Imaging, volume 21, pages 668-675 (issn: 0278-0062, Copyright policy)
  • Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Abstract
In electrical impedance tomography, errors due to stray capacitance may be reduced by optimization of the reference phase of the demodulator. Two possible methods, maximization of the demodulator output and minimization of reciprocity error have been assessed, applied to each electrode combination individually, or to all combinations as a whole. Using an EIT system with a single impedance measuring circuit and multiplexer to address the 16 electrodes, the methods were tested on resistor-capacitor networks, saline-filled tanks and humans during variation of the saline concentration of a constant fluid volume in the stomach. Optimization of each channel individual...
Subjects
free text keywords: Mathematical optimization, Observational error, Multiplexer, Demodulation, Capacitance, Electrical impedance tomography, Electrical capacitance tomography, Mathematics, Control theory, Electrical impedance, Parasitic capacitance, demodulator, EIT, reciprocity error, SYSTEM, EIT
17 references, page 1 of 2

[1] J. G. Webster, Electrical Impedance Tomography. Bristol, U.K.: IOP, 1990.

[2] K. Boone and D. Holder, “Current approaches to analogue instrumentation design in electrical impedance tomography,” Phys. Meas., vol. 17, no. 4, pp. 229-247, 1996.

[3] , “A model of the effect of variations in contact and skin impedance on electrical impedance tomography measurement artefacts,” Innov. Tech. Biol. Med., vol. 16, no. 2, pp. 62-70, 1995.

[4] D. Murphy and P. Rolfe, “Aspects of instrumentation design for impedance imaging,” Clin. Phys. Physiol. Meas., vol. 9A, pp. 5-14, 1988.

[5] J. Rosell, D. Murphy, R. Pallas, and P. Rolfe, “Analysis and assessment of errors in a parallel data acquisition system for electrical impedance tomography,” Clin. Phys. Physiol. Meas., vol. 9A, pp. 93-9, 1988.

[6] P. Riu, J. Rosell, A. Lozano, and R. Pallas-Areny, “Multi-frequency static imaging in electrical impedance tomography: Part 1. Instrumentation requirements,” Med. Biol. Eng. Comput., vol. 33, no. 6, pp. 784-792, 1995.

[7] R. Bragos, R. Povill, and P. Riu, “Applicability of the three coefficients calibration technique to EIT,” in Abstracts 6th Eur. Community Workshop Electrical Impedance Tomography, Ankara, Turkey, Sept. 16-21, 1994, pp. 49-50.

[8] H. Griffiths, “Modeling of systematic errors in dual-frequency EIT,” Innov. Tech. Biol. Med., vol. 15, no. 1, pp. 116-22, 1994.

[9] A. D. Seagar and B. H. Brown, “Limitations in hardware design,” Clin. Phys. Physiol. Meas., vol. 8A, pp. 85-90, 1987.

[10] D. B. Geselowitz, “An application of electrocardiographic lead theory to impedance plethysmography,” IEEE Trans. Biomed. Eng., vol. BME-18, pp. 38-41, 1971. [OpenAIRE]

[11] B. H. Brown and A. D. Seagar, “The Sheffield data collection system,” Clin. Phys. Physiol. Meas., vol. 8A, pp. 91-97, 1987. [OpenAIRE]

[12] H. Griffiths, “A Cole phantom for EIT,” Physiol. Meas., vol. 16, pp. 29-38, 1995.

[13] H. Griffiths and R. J. Williams, “The Cardiff Cole phantom - A comparison of its theoretical and practical characteristics,” Med. Biol. Eng. Comput., vol. 35, no. I, p. 328, 1997.

[14] G. Cusick, D. Holder, A. Birkett, and K. Boone, “A system for impedance imaging epilepsy in ambulatory human subjects,” Innov. Tech. Biol. Med., vol. 15, no. 1, pp. 33-39, 1994.

[15] D. S. Holder, C. A. Gonzalez-Correa, and T. Tidswell, “Assessment and calibration of a low-frequency system for electrical impedance tomography (EIT), optimized for use in imaging brain function in ambulant human subjects,” Ann. NY Acad. Sci., vol. 873, pp. 512-519, 1999.

17 references, page 1 of 2
Powered by OpenAIRE Open Research Graph
Any information missing or wrong?Report an Issue
publication . Article . 2002

a comparison of techniques to optimize measurement of voltage changes in electrical impedance tomography by minimizing phase shift errors

Fitzgerald, A. J.; Holder, D. S.; Eadie, L.; Hare, C.; Bayford, R. H.;