Design and Analysis of Low-Noise Instrumentation Amplifier for Biomedical Signal Acquisition Systems

Biomedical signals are essentially required to be monitored in the diagnosis and treatment of many human illnesses and health problems. Biomedical instrumentation, consisting of instrumentation amplifiers, various filters, digitizers, and data acquisition systems, is essential for building efficient physiological signal acquisition systems to sense, monitor, and acquire low-amplitude biomedical signals. This article describes a thorough simulation research work conducted to analyze the noise levels in several biomedical instrument amplifier circuits. The research aimed to develop an instrumentation amplifier (INA) with high gain and low noise while keeping the cost reasonable. Three distinct biopotential amplifier circuits have been designed and developed using NI-Multisim software, and a thorough examination of noise was conducted to determine the optimal biomedical measuring method. The simulation results demonstrate that the instrumentation amplifier, constructed using a combination of a voltage feedback instrumentation amplifier (VF-INA), exhibits the highest gain (98.22 dB), a high signal-to-noise ratio (SNR) of 70.93 dB, and a high common mode rejection ratio (CMRR) of 102 dB. These characteristics are achieved while maintaining a low noise level within the biomedical signal bandwidth of the voltage feedback amplifier. This study offers a comprehensive framework for developing biomedical signal acquisition system (BSAS) circuits that exhibit great amplification with lower noise interference. These circuits are specifically designed to capture the low-amplitude physiological signals for biomedical research.