Measurement Of Human Breath Based On Ordinary Camera

The measurement of respiration is an important method to evaluate person health,and it is also an important part of hospital monitoring alert system. But the traditionalway to measure the respiration is almost through the sensor, it makes the patient feeluncomfortable and the device is also very expensive. So this paper presents a newmethod to measure the respiration with the ordinary camera. It uses a non-contactmeasurement and the device is cheap and practical.In this paper, we use the ordinary camera as the measuring device, combine withimage processing technology and signal processing technology to achieve measuringrespiration. The main work of this paper is as follows:1) Propose a program of respiratory measurement based on the imageprocessing technology, and use the ordinary camera to recognize the changeof gray image which is caused by the breath. And then do signal processingand spectral analysis with the gray signal to get the frequency of therespiration.2) Propose a method of get the standard area to acquire the respiratory signal.Segment the image with the skin color, extract the face region, do thegray-level projection to determine the width and the length of the face, andthen we can determine the acquisition area with the priori knowledge of bodygeometry.3) Shoot video with the acquisition area, extract the gray signal from thecapture video, do the signal processing and signal normalization with thegray signal, filter the noise of human jog and other interfering factors, andthen we can do the FFT to analysis the frequency spectrum, finally we canget the frequency of the respiration.4) Use the SFFT to analysis the frequency change of the respiration in1minute.Analysis the spectrum of the SFFT to get the intuitional frequency change,and then calculate the average frequency within the time of SFFT window.At last draw the curve of average frequency.5) Select the hardware devices and use the C#programming the interactiveinterface. Complete the design of the respiratory measurement device. With this work, we can get the frequency of respiration with an ordinary camera,analysis the frequency change of the respiration in1minute, and get the curve ofaverage frequency.