Design of A Biopotential Amplifier for ECG

This article presents the design and development of a wideband biopotential amplifier circuit for acquiring Electrocardiogram (ECG) signals. Amplification is crucial for enhancing the very small signals from electrodes, allowing them to serve as input for subsequent stages. The circuit design includes an active filter to reduce noise and provide final signal amplification. The amplifier is built using the INA128 IC, a type of instrumentation amplifier, and is assembled onto a Printed Circuit Board (PCB). Testing and analysis indicate that the biopotential amplifier functions effectively, meeting specified requirements with a circuit gain of 2080 V/V, a CMRR of 90.18 dB, and a bandwidth ranging from 0.58 to 40.6 Hz, successfully displaying clear ECG signals.