Study On The Multi-wavelength And High Signal-to-noise Ratio Methods Of The CD-like Biochemical Analysis

Biochemical analyzer has been widely used since its birth in 1957,providing a basis for clinical diagnosis by measuring the content of biochemical components in body fluids.The current biochemical detection is mainly based on large biochemical analyzer,which has poor applicability for sudden,small and portable detection needs.In primary medical institutions,there is a general lack of biochemical analysis equipment.China is a vast country with a large population.With the improvement of residents’ living standards and the increasing medical demand,the development of miniature and cheap biochemical analyzer will have great commercial and social value.CD-Like centrifugal biochip system has great potential in the miniaturization of biochemical analyzer.The existing CD-Like biochemical analysis system has the common problem of low accuracy,and the detection cost has no obvious advantage compared to the traditional large biochemical detection equipment.By building the CD-Like biochemical analysis prototype,the performance of the prototype was tested and the error source was analyzed.Aiming at the main error sources,a multi-wavelength absorbance detection method is developed based on scalar scattering theory.According to the characteristic that the intensity of pulse light source is zero at the non-scintillation time,the correlation detection method of pulse light is designed.The multi-wavelength absorbance detection method and pulse-light correlation detection method can effectively reduce the cost of chip manufacturing,improve the accuracy of measurement results,and accelerate the application and promotion of CD-Like biochemical analyzer.The main work of the thesis includes:1)The development status of biochemical analysis equipment,biochemical detection methods,microfluidics technology and CD-Like chip system were reviewed,and the existing problems in the application and promotion of CD-Like centrifugal analysis system were analyzed.2)The detection principle of CD-Like biochemical analysis system and the functional requirements of the system were analyzed.The software and hardware of the system were designed,and the prototype of the analyzer was developed.3)Main performance parameters and common biochemical indexes of the system were tested and system errors were analyzed.Combined with the measurement results,the main source of error was identified.4)The effects of the actual surface roughness on the absorbance measurement were analyzed,and a multi-wavelength linear regression model including the effect of the surface roughness was given according to the scalar scattering theory.Multi-wavelength detection method can eliminate the influence of surface roughness,improve the measurement accuracy,and reduce the difficulty and cost of chip manufacturing.5)Aiming at the problems of weak signal intensity,low SNR,wide spectrum of pulse light source waveform,inability of filtering to effectively improve SNR in the CD-Like biochemical analysis system,and difficulty in ensuring measurement accuracy,according to the characteristics that the non-flicker time point intensity of the pulse light source is zero,the pulse light correlation detection method was designed based on the detailed analysis of the photoelectric signal amplification circuit,and the feasibility and effect of the method were verified by simulation.This method can greatly improve the signal to noise ratio and the accuracy of measurement results.Finally,the research work is summarized and the future research is prospected.