Design of automatic blood collection scale system and study on measurement method of blood collection velocity

Aiming at the problem that automatic blood collection scale cannot detect blood collection velocity in real time, an automatic blood collection scale is designed and implemented by using DC reduction motor, resistance strain type weighing sensor, serial touch screen and other devices with STM32F407 microcontroller as the core. In this paper, timing difference method, least square method, Kalman filter and moving average filter are used to detect the blood collection velocity based on the blood collection scale. Weighing accuracy test and comparison test were carried out respectively for four blood collection velocity detection methods. The test results show that the system is stable and reliable, reaching 0.2% static weighing accuracy. The least square method and difference method are more suitable for the situation requiring fast response speed of blood collection velocity, while the moving average filter is more suitable for the situation requiring high accuracy of the velocity.