Research On Photoelectric System Of Specific Protein Analyzer Based On LED Light Source

In recent years,with the rapid development of IVD(In vitro diagnosis)technology,the detection of specific proteins,enzymes,small molecules and other substances in the human body has become an important method for determining the health status of the body tissues.However,the study of specific protein analyzers used to detect the concentration of the abovementioned substances is lagging behind.At present,most of the current researches are focused on the field of instrument automation and intelligence,and there are few researches on the core detection module(the photoelectric system)of the instrument,while the performance of the photoelectric system directly affects the instrument’s detection accuracy and clinical diagnosis results.In addition,the halogen lamps commonly used in the analyzers are characterized by high power consumption,short life,obvious light decay and high temperature,which seriously affect the activity of above substances in the detection process,thereby affecting the detection results and easily causing energy loss.In order to solve the above problems,a new structure of combined LEDs light source is proposed based on LEDs emission spectrum in this paper.In this structure,the light,emitted from LEDs with different light-emitting bands,is converged to form a spot by the reflector and convex lens.The spot can cover the instrument operating band of 340-800 nm and the light intensity is concentrated.Based on the basic principle of holographic concave gratings,a new type of optical structure,which can be read directly by the photoelectric sensor,is proposed.The optical structure takes a Rowland grating as the monochromator,and uses double-lenses structure as the conversion module to get rid of the complex spectral flattening algorithm to transform the spherical spectrum that Rowland grating should present into the plane field.Moreover we design the aberration correction lenses.According to the principle of ray tracing,TracePro is used to simulate and optimize the light source structure.The results show that the ray emitted from LEDs can converge to form an ideal spot.The irradiance value of the spot center in the vertical direction is the same as that in the horizontal direction,and the light intensity is mainly concentrated at the spot center with a radius of only 1.0 mm.The optical structure is simulated and optimized by ZEMAX.The results show that the spectral flattening effect of optical structure is obvious.The resolution of monochromatic light reaches the spectral precision of 0.3-0.7 nm with the spectrum range of 340-800 nm,and the energy is relatively concentrated,which is close to the spectrometer standard.Besides,the circuit schematic diagrams are designed by EDA software,and the software system under Keil MDK5 environment is briefly introduced in combination with the circuit schematic diagrams.We conduct experiments and analysis on the photoelectric system with the whole instrument,and the experimental results are basically consistent with the simulation results.According to the industry standard,the performance of the instrument is tested.The testing results show that the stray light,the absorbance linear range,the absorbance accuracy,the absorbance stability,the absorbance repeatability and other indicators of the specific protein analyzer based on the photoelectric system we design are all up to the industry standard.In addition,many of the indicators are better than the same kind of instrument,so the instrument has a wide application prospect.