A single supply biopotential amplifier.
A biopotential amplifier for single supply operation is presented. It uses a Driven Right Leg Circuit (DRL) to drive the patient's body to a DC common mode voltage, centering biopotential signals with respect to the amplifier's input voltage range. This scheme ensures proper range operation when a single power supply is used. The circuit described is especially suited for low consumption, battery-powered applications, requiring a single battery and avoiding switching voltage inverters to achieve dual supplies. The generic circuit is described and, as an example, a biopotential amplifier with a gain of 60 dB and a DC input range of +/-200 mV was implemented using low power operational amplifiers. A Common Mode Rejection Ratio (CMRR) of 126 dB at 50 Hz was achieved without trimming.
Spinelli
E M
EM
Departamento de Electrotecnia, Universidad Nacional de La Plata (UNLP), and Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CICPBA), CC 91, (1900), La Plata, Argentina. spinelli@venus.fisica.unlp.edu.ar
Martinez
N H
NH
Mayosky
M A
MA
D000669:Amplifiers, Electronic; D017097:Electric Impedance; D011211:Electric Power Supplies; D004562:Electrocardiography; D004867:Equipment Design; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*