Heart Rate Measuring System using Accelerometer And Gyroscope Sensor in Android Smartphone

Heart rate is an important indicator of human health, reflecting physiological conditions and cardiovascular problems. Research and development in the field of heart rate measurement continues to grow, utilizing accelerometer and gyroscope sensors as well as techniques such as R peak detection, digital bandpass, and peak detection. However, previous research was hampered by the smartphone API’s 100 Hz measurement frequency limit, so the sensitivity and accuracy of measurements were limited. This research aims to develop a measurement method for a more accurate heart rate using an Android smartphone with a measurement frequency of up to 200 Hz. The method used is Seismocardiography (SCG) with Aortic Open (AO) peak detection on accelerometer and gyroscope sensors. Heart rate data was collected from 20 healthy subjects using a Samsung A50 smartphone and Sensor Logger software and then processed using MATLAB R2015a to extract heart rate information. The SCG signal was processed with a bandpass filter and Hilbert transforms to obtain the envelope of the heart rate signal. The Aortic Open (AO) peak detection determines the heartbeat time. The SCG signal is processed with Baseline Wander Removal, Savitzky-Golay Filter, and Hilbert Transform to obtain the envelope of the heartbeat signal. The Aortic Open (AO) peak detection determines the heartbeat time estimation. The results showed that the SCG signal extraction method and Aortic Open (AO) peak detection achieved an accuracy of 99.3% for placement in the Upper abdomen and 97.36% for placement in the Sternum. This research provides a solution for more accurate and accessible heart rate measurement by utilizing existing smartphone technology.