JBM  Vol.1 No.2 , October 2013
Digital biomedical electrical impedance tomography based on FPGA
Abstract: A digital biomedical electrical impedance tomography (EIT) system is developed with the aid of FPGA. The key elements of EIT system are described specifically in the paper. The functions are realized to generate excitation source, switch electrode channels, deal collected signals, demodulate measured voltages etc. The system is tested by a circular tank with 16 stainless electrodes attached around the boundary. The adjacent incentive adjacent measurement mode is adapted to collect boundary voltages of the interesting field. By testing, the system works with 36 dB signal-to-noise ratio (SNR) when 1 mA 100 KHz current is applied into a homogenous tank.
Cite this paper: Wu, J. , Chen, X. and Ding, Z. (2013) Digital biomedical electrical impedance tomography based on FPGA. Journal of Biosciences and Medicines, 1, 14-18. doi: 10.4236/jbm.2013.12004.

[1]   Brown, B.H. and Seagar, A.D. (1987) The Sheffield data collection system. Clinical Physics and Physiological Measurement, 8, 91-97.

[2]   Smith, R.W.M. and Freeston, I.L. (1995) A real-time electrical impedance tomography system for clinical use-design and preliminary results. IEEE Transactions on Bio- medical Engineering, 42, 133-140.

[3]   Wilson, A.J., Milnes, P., Waterworth, A.R., Smallwood, R.H. and Brown, B.H. (2001) Mk3.5: A modular, multi-frequency successor to the Mk3a EIS/EIT system. Physiological Measurement, 22, 49-54.

[4]   Christopher William Lawrence Denyer (1996) Electronics for real-time and three-dimensional electrical impedance tomographs. Christopher William Lawrence Denyer, Oxford.

[5]   Cook, R.D., Saulnier, G.J., Gisser, D.G., Goble, J.C., Newell, J.C. and Isaacson, D. (1994) ACT3: A high-speed, high-precision electrical impedance tomography. IEEE Transactions on Biomedical Engineering, 41, 713-722.

[6]   Halter, R., Hartov, A. and Paulsen, K.D. (2004) Design and implementation of a high frequency electrical impedance tomography system. Physiological Measurement, 25, 379-390.

[7]   Cui, Z.Q., Wang, H.X., Tang, L., Zhang, L.F., Chen, X.Y. and Yan, Y. (2008) A specific data acquisition scheme for electrical tomography. IEEE Proceedings of Instrumentation and Measurement Technology Conference, IMTC 2008, Victoria, 12-15 May 2008, 726-729.

[8]   Zhao, L.P. and Chen, X.X. (2010) Design of electrical impedance tomography data acquisition system based on 128 electrodes. Transducer and Microsystem Technologies, 2010, 29, 83-88.

[9]   Shi, X.T., You, F.S., Ji, Z.Y., Fu, F., Liu, R.G. and Dong, X.Z. (2010) Digital demodulation in data acquisition system for multi-frequency electrical impedance tomography. 4th International Conference on Bioinformatics and Biomedical Engineering (iCBBE), Chengdu, 18-20 June 2010, 1-3.

[10]   Xilinx Inc. (2010) PicoBlaze 8-bit embedded microcon-troller user guide, UG129 (v2.0).

[11]   Rafiei-Naeini, M. and McCann, H. (2008) Low-noise current excitation sub-system for medical EIT. Physiological Measurement, 29, 173-184.

[12]   Zhang, X.-H. and Wang, H.-X. (2008) Phase sensitive demodulation in ECT system. Microcomputer Information, 24, 300-302.

[13]   Wen, X.N., Wang, H.X. and He, Y.B. (2006) Application of USB communication module in EIT data acquisition system. Electronic Measurement Technology, 29, 163- 165.

[14]   Seagar, A.D. and Brown, B.H. (1987) Limitations in hardware design in impedance imaging. Clinical Physics and Physiological Measurement, 8, 85-90.

[15]   Sha, H. and Wang, Y. (2008) A high precision data collection method in electrical impedance tomography. Chi- nese Journal of Biomedical Engineering, 27, 675-678.

[16]   Ren, C.-S. and Wang, Y. (2006) Simulation study for comparing line electrodes with compound electrodes in medical impedance tomography. Chinese Journal of Biomedical Engineering, 25, 637-640.