Non-Invasive Blood Flow Measurement Using Optical Sensor

Blood flow is the volume of blood that passes through a particular point in the circulatory system. Measuring the blood flow is of prime importance because it not just plays a very crucial role in understanding the functionality of heart but also other organs. It is a reflection of the cardiac activity and greatly helps in monitoring the same. The proposed methodology of blood flow measurement is based upon the acquisition of the photoplethysmography (PPG) signal from the body and by carrying out analysis on the signal the parameters related to heart like the stroke volume, heart rate and blood flow are calculated. The methodology involves design of a reflectance type of an optical sensor from which the photoplethysmography (PPG) signal is acquired. The transfer of the conditioned signal on the computer for further processing is accomplished by using a microcontroller. The signal is then analyzed and processed on MATLAB to determine the blood flow happening across the measurement site. Experimental analysis is then done by carrying out data collection on subjects of different age groups and gender and reliable conclusions are drawn. This method of measurement is advantageous when compared to other methods of blood flow measurement as it is a non-invasive technique and makes use of optical sensor which is rugged and simple in construction making the entire system easy to maintain. Keywordsphotoplethysmography; cardiac output; blood flow; stroke volume; heart rate