| Heart rate and blood oxygen saturation can be obtained based on light volume pulse wave,in which heart rate can reflect the speed of heart beating and heart health status,and blood oxygen saturation can reflect blood oxygen level.Heart rate and oxygen saturation are important indicators of cardiopulmonary function.Compared with traditional electronic sensors,optical fiber sensors have the advantages of small size,light weight,low cost,high sensitivity and electromagnetic interference resistance.The fiber is woven as "yarn" to form a fabric fiber sensor,which can be perfectly combined with clothing and clothing to achieve real-time monitoring of human physiological parameters with high comfort.In this paper,based on the principle of photovolume pulse wave graphy(PPG),a fabric fiber optic pulse oximetry sensor was designed and fabricated using plastic fiber as the material,and the experimental study on the sensor sample proved the feasibility of the sensor.The research results of this topic provide a new idea and scheme for the development of wearable human physiological parameter detection technology.The main work completed is as follows:1.The structure and mechanism of optical side luminescence/sensitization are studied.COMSOL software was used to build models of different side luminescence/photosensitive structures,and ray tracing method was used to simulate and calculate the efficiency of side luminescence or side photosensitive structures under different parameters.The optimum side luminescence/photosensitive structure is used to design fabric fiber optic pulse oximetry sensor.2.Fabric fiber optic pulse oximetry sensor is designed.The design method of fabric fiber pulse oximetry sensor based on side luminescence/photosensitive structure fiber is proposed,the detection principle of the sensor is analyzed,and the fabric fiber pulse oximetry sensor is prepared by weaving technology,which can detect the volume pulse of different parts of the human body.3.The signal processing algorithm of fabric fiber optic pulse oximetry sensor is studied.By analyzing the frequency characteristics of the original signal,a signal processing algorithm for the sensor is proposed,including signal denoising,feature point extraction,heart rate and oxygen saturation calculation algorithm modules.The design of each algorithm module is completed,and the Matlab software is used to program and verify each algorithm module.4.The measuring effect of fabric fiber optic pulse oximetry sensor is studied experimentally.The experimental platform of fabric fiber optic pulse oximetry sensor was built to test the frontal volume pulse wave of different wearers in the state of rest,head movement and sweating,and the heart rate and blood oxygen saturation were calculated by using the algorithm above.Compared with the measurement results of commercial monitor,the sensor can measure heart rate and oxygen saturation in the state of rest,head movement and sweating.The average error of heart rate measurement is less than 1bpm,and the error of oxygen saturation measurement is less than 2%. |
