A Study on the Development of a Device for Measuring Heart Rate Around the Ear Based on BLE

In this paper, a prototype heart rate measuring device that can be attached to the temporal bone was developed to measure the heart rate around the ear. The developed product consists of a photodiode and an ambient light photo sensor, and the signal is transmitted to the MCU through an analog filter implemented as an op-amplifier. In the MCU, the pulse was calculated based on the peak-to-peck interval and amplitude of the signal. The calculated result was transmitted once every 3 seconds by applying the UUID dedicated to UART communication provided by Nordic semiconductor. The receiving program that can review the transmitted data was written in Python, and the result was checked on the PC. heart rate accuracy was confirmed to be within 4 beat per minute.