Research On Optical Fiber Sensing Technology For Rapid Hemolysis Detection

Blood circulation in the heart and blood vessels of human body is a necessary condition to maintain human health.The red blood cells in the blood will break down due to physical diseases or other reasons,resulting in hemoglobin overflow,that is,hemolysis.Hemolysis test can judge the occurrence of disease in time and accurately.But the current hemolysis detection method is complicated and has some problems such as external pollutants.So how to complete hemolysis test quickly,accurately and without pollution is of great significance and has great exploration value.For hemolysis detection,the key lies in the effective separation of red blood cells and free hemoglobin and accurate measurement of free hemoglobin concentration.This paper designs a new hemolysis detection scheme based on Fabry Perot cavity refractive index measurement.Fabry Perot cavity refractive index biosensor has many advantages,such as label free,high sensitivity,good real-time performance,anti electromagnetic interference and so on.In this paper,the filter of red blood cells is completed by using the microfiltration chip prepared by deep silicon etching and coating.The spectral information is collected by the non intrinsic Faber cavity composed of single-mode fiber end face and microfiltration chip.The refractive index information is calculated by using the processing circuit based on FPGA.The specific research work is as follows:Firstly,based on analysis of the disadvantages of centrifugal method,and according to the demand of red blood cell filtration,a micro nanofiltration structure is designed.A micro filter chip with 5μm holes was manufactured by etching and coating.The micro structure and peristaltic pump can replace centrifugal,thus reducing the probability of secondary hemolysis.Secondly,the current measurement method of free hemoglobin concentration is compared,and the scheme of measuring concentration by refractive index is determined.According to the requirement of high precision measuring liquid refractive index,the scheme of adopting non intrinsic fiber Fabry Perot fiber sensor is determined.Finally,according to the demand of refractive index calculation,the spectral information processing circuit based on FPGA and high-precision cross-correlation algorithm are designed to calculate the refractive index value and concentration value quickly and accurately.The optical fiber micro flow rapid hemolysis detection system was constructed with hemolysis detection sensor.Based on the above research content,the measurement accuracy of refractive index can reach 0.0001,and the measurement accuracy of hemoglobin concentration can reach 10mg/L.Due to the problem of ratio error in the dilution process,there is a deviation between the dilution degree of the prepared solution and the theoretical dilution degree.Compared with the actual concentration,the maximum measurement error is 8.13%,and the minimum measurement error is 1.04%.