Low cost computer based heart rate monitoring system using fingertip and microphone port

Heart rate of a human body can be measured considering the change of blood volume in fingertip using microcontroller based methods. In this paper, a low cost and portable method is proposed and implemented to measure heart rate from fingertip using the microphone port of a computer. The method detects the volume change of blood by an optical sensor based on infrared technology. The noisy output signal from the sensor is stripped out of unwanted components with the help of a hardware level active low pass filter. After interfacing through the microphone port, this signal is processed at software level to measure and monitor real time heart rate. The accuracy, noise suppression, and cost effectiveness of this method make it a suitable candidate for a low cost computer based heart monitoring system which can study and detect heart diseases like sleep arrhythmia.