Simple two-electrode biosignal amplifier.
A simple, cost effective circuit for a two-electrode non-differential biopotential amplifier is proposed. It uses a 'virtual ground' transimpedance amplifier and a parallel RC network for input common mode current equalisation, while the signal input impedance preserves its high value. With this innovative interface circuit, a simple non-inverting amplifier fully emulates high CMRR differential. The amplifier equivalent CMRR (typical range from 70-100 dB) is equal to the open loop gain of the operational amplifier used in the transimpedance interface stage. The circuit has very simple structure and utilises a small number of popular components. The amplifier is intended for use in various two-electrode applications, such as Holter-type monitors, defibrillators, ECG monitors, biotelemetry devices etc.
Dobrev
D
D
Centre of Biomedical Engineering Ivan Daskalov, Bulgarian Academy of Sciences, Sofia. dobri@clbme.bas.bg
Neycheva
T
T
Mudrov
N
N
D000669:Amplifiers, Electronic; D004562:Electrocardiography / Q000295:instrumentation; D004566:Electrodes; D004568:Electrodiagnosis / Q000295:instrumentation*; D004582:Electronics, Medical; D004867:Equipment Design; D006801:Humans; D008954:Models, Biological