Research On Photoelectric Detection System In Automatic Blood Coagulation Instrument Based On Absorbance Method

As the deepening research to the mechanism of hemostasis and thrombosis, it’s found that their related indicators are closely connected with many diseases and concerned test items gradually increased and that put forward higher requirements to the coagulation detection technology. Therefore, the study of coagulation detection technology not merely conforms to the medical inspection technology developing towards intelligence, automation and modularization but also benefits to the prevention and treatment of many diseases. This has important significance to the development of medical enterprise in China.This paper studied a kind of automatic and modularized blood coagulation detector based on STM32 processor. On the basis of the research on the existing blood coagulation testing method, this paper chose the Lambert Beer’s law as the detection principle and modularized the overall design which contains main control module, automatic sampling module, photoelectric detection module and auxiliary module. The main control module controls and harmonizes other modules by the CAN bus. The automatic sampling module accomplishs reading barcode and sampling the sample. The auxiliary module completes the data display,printing and other functions through some devices including Capacitive Touch Screen, thermal printer, SRAM, SD card and so on. The photoelectric detection module is the core part and used for detecting indicators related blood coagulation and it’s consist of LED lamps with fixed wavelength, silicon photodiode and amplifier, etc. And there is details of the photoelectric detection module.In the photoelectric detection circuit, there are background noise and noise interference of various electronic components. what’s more, the photoelectric signal is relatively weak and the amplifier in the circuit not only enlarge the photoelectric signal also magnifies the noise signal. One kind of digital filtering algorithm based on wavelet threshold method is studied in the paper and it is verified by the experiment to be effective in filtering the noise.The design of the automatic blood coagulation detector in the paper makes full use of the advantages of STM32 processor such as good performance, low cost, low power consumption and et al. to achieve the function of high-level automation, operation simple and good human-computer interaction.