Design Of Syringe Injection System Based On Motion Control

Blood coagulation detector(simply called blood coagulation instrument,BCI hereafter)used in the diagnosis of coagulation disease,preoperative coagulation mechanism detection etc,is instrument for medical test.The development of a BCI that can quickly obtain accurate test results and has a simple and friendly operating performance is of great scientific significance for the study of hemostasis and thrombosis.Therefore,the automatic BCI has been rapidly developed and widely used,and now it has become one of the essential diagnostic equipment in the major hospitals.According to the principle and detection method of BCI,the system with main control module,photoelectric detection module,injection module and auxiliary module was designed by using a modular design method in this paper.The main control module controls other modules by the CAN bus.The automatic sampling module accomplishes barcode reading and sample & reagent sampling.In this paper,the hardware design,software design and motion control algorithm based on artificial potential field method is introduced.The hardware circuit was composed of the control circuit,drive circuit,download circuit,communication circuit,power circuit,limit circuit etc.STM32 was used as the control chip,THB6128 was used to drive stepper motor for the movement of the mechanism,and UIS1200 was used to achieve liquid level detection.The software design mainly includes the communication between the sampling module and the main control module,program for motor driving,program for electro-magnetic valve control,self-test for and so on.The sampling system was operated by two arms(one for reagent and another for sample).The software design based on artificial potential field optimization method was carried out to make the arms choosing the optimal path without obstacle during the movement,to complete the sampling of the reagent and the blood sample,and to improve the efficiency of the sampling system.Through the combination of software and hardware design,the BCI can complete the injection work automatically,and the speed and practicability of the BCI is improved.Finally,the overall debugging for the improved sampling system of BCI,and testing the system from the aspects of accuracy and precision was carried out.