Performance measures on blood pressure and heart rate measurement from PPG signal for biomedical applications

A photoplethysmogram (PPG) is a plethysmogram which is optically obtained, a volumetric measurement of an organ. Two PPG signals are used here to estimate the blood pressure and heart rate. Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels. Nowadays the standard blood pressure is measured by using cuff based digital devices. In cuff based method, there will be an uncomfortable to the patient and cannot measure the blood pressure in a continuous manner. Blood pressure is in terms of the systolic (maximum) pressure over diastolic (minimum) pressure and is measured in millimeters of mercury. Pulse Transit Time (PTT) is playing the main role here. PTT is the time between peaks of the two PPG signal. Heart rate can be measured by counting the number of peaks for sixty seconds. Blood pressure will be vary based on situation, activity, and disease states. Heart rate is the speed of the heartbeat measured by the number of contractions of the beat per minute (bpm). Threshold method is used to find the total number of peaks. The signals are need to be filtered to remove any noises. A low pass filter is used here to remove the noises from the PPG signals. Then the Pulse Transit Time (PTT) is determined by detecting the peak location, peak time and peak time difference using LabVIEW. Using linear regression analysis in MATLAB the blood pressure is obtained. GSM is used here to send the averaged PTT values.