Portable photoplethysmogram acquisition and analysis instrument

On-site measurement of physiological information can provide a quick assessment of patients' health condition. The paper illustrates a simple PPG acquisition and preliminary level analysis instrument using a laptop. A portable data acquisition system based on ATmega16 microcontroller was developed to collect 30 sec PPG data at 250 Hz sampling using USB interface. Based on the data, all the fiducial points were detected using first and second difference PPG. The software computes the heart rate, peak to peak time, stiffness index and crest time averaged over all cardiac cycles and displays them on the front panel of the laptop.