High-quality recording of bioelectric events

A multichannel instrumentation amplifier, developed to be used in a miniature universal eight-channel amplifier module, is described. After discussing the specific properties of a bioelectric recording, the difficulties of meeting the demanded specifications with a design based on operational amplifiers are reviewed. Because it proved impossible to achieve the demanded combination of low noise and low power consumption using commercially available operational amplifiers, an amplifier equipped with an input stage with discrete transistors was developed. A new design concept was used to expand the design to a multichannel version with an equivalent input noise voltage of 0·35 μV RMS in a bandwidth of 0·1–100 Hz and a power consumption of 0·6 mW per channel. The results of this study are applied to miniature, universal, eight-channel amplifier modules, manufactured with thick-film production techniques. The modules can be coupled to satisfy the demand for a multiple of eight channels. The low power consumption enables the modules to be used in all kinds of portable and telemetry measurement systems and simplifies the power supply in stationary measurement systems.

[1]  F. Duffy,et al.  TOPOGRAPHIC DISPLAY OF EVOKED POTENTIALS: CLINICAL APPLICATIONS OF BRAIN ELECTRICAL ACTIVITY MAPPING (BEAM) * , 1980, Annals of the New York Academy of Sciences.

[2]  S. Grimnes.  Impedance measurement of individual skin surface electrodes , 1983, Medical and Biological Engineering and Computing.

[3]  C. A. Grimbergen,et al.  Low-power, low-noise instrumentation amplifier for physiological signals , 1984, Medical and Biological Engineering and Computing.

[4]  R. Pallas-Areny,et al.  Interference-rejection characteristics of biopotential amplifiers: a comparative analysis , 1988, IEEE Transactions on Biomedical Engineering.

[5]  I. C. Forster.  Measurement of patient body capacitance and a method of patient isolation in mains environments , 2006, Medical and biological engineering.

[6]  John H. Busser,et al.  Principles of Applied Biomedical Instrumentation , 1968 .

[7]  John G. Webster,et al.  Driven-right-leg circuit design , 1983, IEEE Transactions on Biomedical Engineering.

[8]  L. E. Baker,et al.  The relationship between input impedance and electrode area in recording the ECG , 2006, Medical and biological engineering.

[9]  C A Grimbergen,et al.  High-quality recording of bioelectric events , 1990, Medical and Biological Engineering and Computing.

[10]  C. A. Grimbergen,et al.  Recording of surface His-Purkinje potentials , 1985, Medical and Biological Engineering and Computing.

[11]  H. W. Smit,et al.  A Low-Cost Multichannel Preamplifier for Physiological Signals , 1987, IEEE Transactions on Biomedical Engineering.

[12]  Nitish V. Thakor,et al.  Ground-Free ECG Recording with Two Electrodes , 1980, IEEE Transactions on Biomedical Engineering.

[13]  A. D. McClellan,et al.  Extracellular amplifier with bootstrapped input stage results in high common-mode rejection , 1981, Medical & Biological Engineering & Computing.

[14]  F. C. Fitchen,et al.  Low-Noise Electronic Design , 1973 .

[15]  J G Webster,et al.  60-HZ interference in electrocardiography. , 1973, IEEE transactions on bio-medical engineering.

[16]  J. Rosell,et al.  Skin impedance from 1 Hz to 1 MHz , 1988, IEEE Transactions on Biomedical Engineering.

[17]  Lawrence P. Huelsman,et al.  Operational Amplifiers; Design and Applications , 1971 .

[18]  Franklin D. Johnston,et al.  Electrocardiograms that represent the potential variations of a single electrode , 1934 .

[19]  Geddes La,et al.  Chlorided silver electrodes. , 1967 .

[20]  Ralph Morrison,et al.  Grounding and Shielding Techniques in Instrumentation , 1986 .

[21]  T A Duff,et al.  Topography of scalp recorded potentials evoked by stimulation of the digits. , 1980, Electroencephalography and clinical neurophysiology.

[22]  S. Grimnes.  True r.m.s. volt/ammeters for surgical diathermy measurements during an operation , 2006, Medical and Biological Engineering and Computing.

[23]  A. J. Dunning,et al.  Body surface mapping during percutaneous transluminal coronary angioplasty. QRS changes indicating regional myocardial conduction delay. , 1990, Circulation.

[24]  Otto H. Schmitt,et al.  SYSTEMIC AND RANDOM VARIATIONS OF ECG ELECTRODE SYSTEM IMPEDANCE * , 1970 .