Design And Implementation Of Automatic Biochemical Analyzer’s Filling System

With the gradual popularization of ACA(Automatic biochemical analyzer), more and more clinicians depend on ACA’s test results for diagnosis. Therefore, all levels of hospital, blood station, the CDC(Centers for Disease Control) and other units have higher request for ACA’s test accuracy. At present, foreign ACA’s test result is more accurate. They are so expensive that the genera medical institutions could not bear. Due to the inaccurate problem of liquid level detection and the unstable problem of motor process, the test accuracy of domestic ACA is not high. Thus, to develop an ACA’s filling system with the accurate liquid level detection and the stable motor process. is necessary.On the basis of analyzing the functional requirements of the ACA’s filling system, this paper designs an ACA’s filling system which has four core components——water control, filling needle control, liquid level detection, filling pump control. Among them, to solve the inaccurate problem of liquid level detection, we select an liquid level detection method which uses the improved capacitive sensor to detect the liquid level, and joins the median average filtering method and memory height method to improve its ability to resist interference. According to the unstable problem of motor process, the ladder-type motor speed control method is introduced.After the test, the system achieves the expected goal and realizes three functions, namely the accurate filling, the effective cleaning of the filling needle, waste recycling timely. In addition, in the process of system operation, filling needle can accurately detect the liquid level, and the motor can smoothly process. That suggests the filling system effectively solves the inaccurate problem of liquid level detection and the unstable problem of motor process.