DESIGN AND IMPLEMENTATION OF PHOTOPLETHYSMOGRAPHY SIGNAL PROCESSING FOR HEART RATE ESTIMATION AND THRESHOLD-BASED ALERT SYSTEM

• Main Author: Rahma Guswir, Ahya
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/74747
• Institution: Institut Teknologi Bandung

Physical activity is a bodily movement performed by individuals to support their health and fitness. There are various types of physical activities, one of them is cycling. Instead of improving health, there are cases where cyclists experience sudden collapse (loss of consciousness) or even sudden death while cycling. Generally, these cases are related to heart conditions. The high heart rate is often unnoticed or even ignored by cyclists. However, heart rate is an important indicator to determine the body's health condition. Therefore, in this final project, a wearable device is designed to monitor the heart rate of cyclists, which can be worn while cycling and equipped with an alert system. This alert system detects excessively high heart rate values of cyclists, which fall into the danger zone. The alert system will be active when the heart rate value exceeds the predetermined threshold, which is set at 86% of the maximum heart rate value. When this alert feature is active, a red LED indicator will be on and a buzzer will be activated. This aims to make cyclists aware that the alert is active, prompting them to immediately reduce the intensity of their physical activity or take a rest. This wearable device utilizes a sensor based on photoplethysmography (PPG). The PPG signal, along with the acceleration values from the accelerometer, is processed directly in the device's microcontroller. The estimated heart rate value obtained is displayed directly on the device's display and transmitted to an Android application via Wi-Fi. The Android application is responsible for storing cycling history and receiving input data from the user. This device has been successfully implemented, meets the product characteristics, and can solve the problem faced by cyclists who need a heart rate monitoring device equipped with a threshold-based alert system.