Abstract
A multichannel biopotential amplifier for simultaneous use with biomagnetic measurements in a magnetically shielded room is designed and evaluated. Particular care is taken to make the amplifier electromagnetically compatible with the biomagnetic instruments over the whole frequency spectrum, from DC to RF. The electromagnetically quiet environment allows the use of high electrode impedances: the preamplifier has been designed accordingly. Special care is taken to analyse the coupling mechanisms of mains interference to the amplifier. Over 170 simultaneous electric and magnetic recordings have been performed using the system in a hospital environment.
Similar content being viewed by others
References
Ahonen, A. I., Hämäläinen, M. S., Kajola, M. J., Knuutila, J. E., Laine, P. P., Lounasmaa, O. V., Parkkonen, L. T., Simola, J. T., andTesche, C. D. (1993): ‘122-channel SQUID instrument for investigating the magnetic signals from the human brain’,Pysica Scripta,T49, pp. 198–205
Cooper, R., Osselton, J. W., andShaw, J. C. (1969): ‘EEG technology’ (Butterworth, London) pp. 25–28.
Hämäläinen, M., Hari, R., Ilmoniemi, R. J., Knuutila, J., andLounasmaa, O. (1993): ‘Magnetoencephalography—theory, instrumentation, and applications to non-invasive studies of the working human brain’,Rev. Mod. Phys.,65, pp. 413–497
Huhta, J. C., andWebster, J. G. (1973): ‘60-Hz interference in electro-cardiography’,IEEE Trans.,BME-20, pp. 91–101
Metting van Rijn A. C., Peper, A., andGrimbergen, C. A. (1990): ‘High-quality recording of bioelectric events. Part 1 Interference reduction, theory and practice’,Med. Biol. Eng. Comput.,28, pp. 389–397
Metting van Rijn, A. C., Peper, A., andGrimbergen, C. A. (1991): ‘The isolation mode rejection in bioelectric amplifiers’,IEEE Trans.,BME-38, pp. 1154–1157
Mäkijärvi, M., Montonen, J., Toivonen, L., Siltanen, P., Nieminen, M., Leiniö, M., andKatila, T. (1993): ‘Identification of patients with ventricular tachycardia after myocardial infaction by high-resolution magnetocardiography and electrocardiography’,J. Electrocardiol.,26, pp. 117–124.
Näätänen, R.M., Ilmoniemi, R. J., andAlho, K. (1994): ‘Magnetoencephalography in studies of human cognitive brain function’,Trends Neurosci.,17, pp. 389–395
Olson, W. H. (1978): ‘Electrical safety’ inWebster, J. G. (Ed.): ‘Medical instrumentation: application and design’ (Houghton Mifflin Co., Boston) pp. 667–706
Pallás-Areny, R. (1988): ‘Interference-rejection characteristics of biopotential amplifiers: a comparative analysis’,IEEE Trans.,BME-35, pp. 953–959
Teder, W. (1994): ‘An analog optical link in surface mount technology for multichannel biomedical data acquisition’,Behav. Res. Methods Instrum. Comput.,26, pp. 416–420
Wikswo, J. P., Gevins, A., andWilliamson, S. J. (1993): ‘The future of the MEG and EEG’,Electroenceph. Clin. Neurophysiol.,87, pp. 1–9
Winter, B. B., andWebster, J. G. (1983): ‘Driven-right-leg circuit design’,IEEE Trans.,BME-30, pp. 62–66
Wood, D. E., Ewins, D. J., andBelachandran, W. (1995): ‘Comparative analysis of power-line interference between two- and three-electrode biopotential amplifiers’,Med. Biol. Eng. Comput.,33, pp. 63–68
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Virtanen, J., Parkkonen, L., Ilmoniemi, R.J. et al. Biopotential amplifier for simultaneous operation with biomagnetic instruments. Med. Biol. Eng. Comput. 35, 402–408 (1997). https://doi.org/10.1007/BF02534098
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02534098