Study On Measurement System Of Cys-C Based On Photoelectric Turbidimetry

Renal disease is a common disease which seriously endangers human health.The clinical evaluation of the severity of renal disease is generally based on glomerular filtration rate.Cystatin C is an ideal endogenous marker to reflect the change of glomerular filtration rate.At present,the detection of renal function needs to go to the laboratory of the hospital to use a large biochemical analyzer for detection,which takes a lot of time and effort,and for patients with renal disease,it is necessary to monitor changes in renal function at all times.The domestic Cystatin C tester currently suitable for self-testing of patients with kidney disease is still a blank.Based on the above requirements,a cystatin C analyzer based on photoelectric turbidimetry was developed.Firstly,the principle of photoelectric turbidimetry,a common biochemical analysis method,is analyzed.The scattering turbidimetry is selected as the detection method after light passes through the suspension and the scattering model is established.Then,the 520 nm semiconductor laser and silicon photocell are selected as the light source and receiver of the photoelectric detection system.In order to obtain stable laser output,a semiconductor laser drivering power supply is designed and manufactured.Then,based on the scattering model,LightTools software is used to design the optical path.In the positive lens center,the obstruction is added to solve the problem that the silicon photocell can still receive the optical signal when the analyzer is in no-load operation,and then the external light source may affect the system to perform stray light.on the system to improve the accuracy of the photoelectric detection system.Finally,the experimental data of cystatin C analyzer were fitted to obtain the corresponding mathematical relationship and verified,and the stability and repeatability of the analyzer were tested.The experimental results show that the cystatin C analyzer developed in this paper has good stability and repeatability in the detection of cystatin C concentration,with the detection concentration range of 0 mg/L to 9.65 mg/L,which basically includes the serum cystatin C concentration in normal and diseased populations.Relative deviation ? 8%,intra-batch variation CV ? 5%,all parameters meet the requirements of project technical indicators,and can be used for practical detection.The development of this instrument fills the absense of domestic cystatin C analyzer in the market,which has very important practical significance.