A Low-Power Autonomous Sensor Module for Biomedical Applications

The paper presents the construction of an energy-efficient, stand-alone measurement module, designed for use in biomedical applications. The paper discusses the use of an algorithm implementing the acquisition and processing of data, whose main objective was to minimize energy consumption. For the construction of the measuring module, there are used a microcontroller with Cortex-M4F core and two external digital sensor systems: (1) analog-front-end circuit, designed to measure the ECG signal, and (2) a 3-axis system of an integrated accelerometer, gyroscope and magnetometer, made in MEMS technology. In order to minimize the energy consumption, the solutions proposed include dynamic frequency management, the introduction of sleep modes, and the use of selected hardware features of the microcontroller. The proposed techniques and algorithms are implemented to measure the ECG signal at a sampling rate of 250 Hz. Experimental studies of the sensor module constructed were carried out. As a result of the energy saving techniques used, the working time of the device was extended by more than 6 times.