Chapter 2PPG Extraction and Heart Rate CalculationThe block diagram of camera-based PPG shows the system configuration.Hardware UsedCamera:The camera is the main focus of the project . AVT Stingray F-046B cameras are used with different filters. The AVT Stingray F-046B is a progressive scan CCD monochrome camera. This is an IEEE 1394b standard camera with resolutions of 780x580. The frame rate can reach 61 fps. Monochrome Optical Filters: Monochrome optical filters are used to filter out all wavelengths except the desired one. Since we are interested in green, red, and near-infrared wavelengths, the following filters are used. • Green (559 nm) • Red (675 nm) • Near infrared (842 nm) NI DAQ: The National Instrumentation Data Acquisition System is used to control the cameras. NI DAQ controls cameras via Fire Wire. And it serves as an intermediary between the software used in the computer to process the video, extract the PPG and calculate the heart rate. Philips Pulse Oximetry The Philips pulse oximetry probe and device are used for a reference heart rate. The National Instruments LabVIEW software is used for this purpose. LabVIEW stands for Virtual Instrument Engineering Laboratory. LabVIEW supports data acquisition, instrument control, signal processing, and more. LabVIEW files are saved in the .vi extension where vi stands for virtual instrument. The algorithm Currently, PPG extraction and heart rate calculation are done using pre-recorded videos. This is offline processing. The pre-recorded video of the subject (measurement data) is saved in the NI - TDMS file format. TDMS - Technical Data Management Streaming is a National Instruments file format for saving well-documented measurement data. Data from the TDMS is read frame by frame into the Read Frame VI. The TDM...... middle of paper ......ves error Median.viInput OutputX (data table) Median error Step vii: Calculate the average AC valueThe average AC value is calculated simply by adding the median values ​​of the peak and median valley amplitudes.Step viii: Calculate heart rateHeart rate, main objective of the work:The time taken by the total number of PPG cycles (rate) multiplied by 60;The number of cycles = no. of peaks – 1; Time = (location of last peak – location of first peak) / frame rate; So HR = total number of cycles / time * 60; Step ix: Calculate mNP mNP = AC / DC * 1000; Step x: Display PPG, heart rate and mNPThe process block or filter.vi produces the signal PPG, HR and mNPFilter SubVI.viInput OutputArray in(signal)Filter typeSampling rateHigh cutoff frequencyLow cutoff frequencyOrderTruncation lengthSize of the windowHeart rateAc valueDC mNP PPG value