Design and Development Of a Simple Hardware Setup for Sensing Blood Volume Pulse and a PIC Microcontroller Based Heart Rate Meter

This paper describes the design and development of a simple hardware setup for recording the blood volume pulse from the finger tip using transmission mode of photoplethysmography (PPG). PPG is known for its simple construction, ease of use and cost effectiveness and can provide information about the changes in the respiratory and cardiac activity and as well aid in earlier non-invasive diagnostics. The blood volume pulse has two components-one a systolic peak which mainly reflects the heart condition and activity, while the other which is called the diastolic peak determines the elasticity and other features of the vascular system. Since one blood volume pulse is generated for each heart beat, a PIC microcontroller is used to measure the heart rate. The wavelet denoising algorithm is used to suppress the noise component in the PPG signal. For heart rate estimate comparison, PPG signals are evaluated by comparing their beat-to-beat estimates with the corresponding R-R intervals from an electrocardiogram (ECG).