Design and implementation of low power compact amplifier circuitry for wearable biosignal device

Biomedical signals are always present in few micro volts. Hence recording biomedical signals is a major challenge in clinical diagnostics. This work presents a design approach for building a signal acquisition system for capturing low amplitude signals, with focus on low power consumption, low cost of components and longer operating battery life. It consists of a compact amplifier design with data transmission over Bluetooth to a compatible recording device. The analog circuit uses INA333 as the instrumentation amplifier because of its lower power ratings and low quiescent current characteristics, with suitable gain adjustment. Suitable filters are used for selecting the signal in desired frequency range. The amplified signal is digitized which can be transmitted wirelessly to a portable device such as tablet or a smartphone via Bluetooth module (HC-05). Hence a low power, low noise compact amplifier is designed which can be used for biosignal acquisition. With added facility of wireless communication this compact system can be a part of any wearable system which can be operated anywhere anytime.