The Design And Implementation Of Automatic Platelet Aggregation Analyzer Based On Transmission Turbidimetry

The platelet aggregation is one of the important physiological characteristics of platelets what plays a great role in process of hemostasis and thrombosis.The platelet aggregation can well reflect the activation of platelets and plays an important role in the formation and development of atherosclerotic thrombosis.At present,the clinical treatment of atherosclerotic thrombosis is based on the drug-test method which can be used to determine the efficacy of drugs and adjust the drug regimen according to the laboratory analysis results of the blood samples at the end of the course of treatment.But the disadvantages of the drug-test method are higher cost of reagent and low efficiency,what is more,studies found that the patients with drug resistance accounted for 5%-20%of the population,which poses significant risk for clinical medicine plan.The automatic platelet aggregation analyzer based on transmission turbidimetry put forward to solve these problems to some extent.The analyzer can automatically load and stir the sample and reagent,control the temperature,detect the photoelectric signal,clean the whole reaction system.On the other hand,it allows that four channels detect multiple samples,reagents and indexes at the same time with high efficiency and reliability.This article first introduces the development history and present situation of platelet aggregation analysis instrument;then expounds several common methods of platelet aggregation detection as well as the advantages and disadvantages,to determine and demonstrate transmission turbidimetry as the method of platelet aggregation analysis;then design an program about automatic platelet aggregation analyzer based on transmission turbidimetry;finally,every functional modules of the analyzer is tested,especially the signal stability,repeatability and consistency of the photoelectric detection module.The accuracy of platelet aggregation analyzer is verified by comparison with common clinical instruments at the end.One of the STM32F103 series chip is choosed as the master controller of the hardware platform of the analyzer,on this foundation,carry out the modular design program which contains photoelectric detection module,constant temperature control module,automation module and signal progressing module.Photoelectric detection module mainly contains light source controlling circuit,signal collection and conversion circuit and test bench,to realize the conversion of optical signals into electrical signals.Constant temperature control module kept the constant temperature during the measurement processing through the heating and temperature detection circuit.The automation control module realizes to load,stir the samples and reagents,and clean the needle and reaction cups.The design of software for the analyzer includes the upper computer application and the controlling program of each module of the bottom computer.The former was designed based on the Qt Creator environment and C++ language,mainly realizes the interaction of command and data between upper machine and bottom machine,real-time display of the aggregation curve.The latter mainly includes automatic controlling program,constant temperature controlling program and A/D conversion program,etc.Finally,the article introduces problems and the solutions encountered in the process of debugging,and pointed out the place where need to be improved.