Design of Embedded Microcontroller for Controlling and Monitoring Blood Pump

The peristaltic pump has a vital role for transporting the blood in the extracorporeal circuit of hemodialysis machine. Such a pump consits of a stepper motor, gear box and rotor shaft with two roller attached on it. The transported volume of the pump depends on the tube segment pressed by roller. Therefore, the deviation in the amount of delivered fluid may occurs. It is a problem when it is used in the medical device with high accuracy requirements such as hemodialysis machine. To overcome such a problem, the transport of fluid need to be controlled.The aim of this work was to design and implement of an embedded microcontroller for controlling and monitoring fluid transport in the peristaltic pump. An electronic hardware which consists of STM32F4 development board, stepper motor driver circuit, current sensor, magnetic sensor and arterial presure sensor circuits was developed in parallel with embedded software development. The embedded sofware consists of routines for monitoring current sensor, pressure sensor, and magnetic sensor, as well as routines for pump speed controller. The STM32F4 board which consits of ARM Cortex M4F microcontroller was chosen because of the trade off between price, performance, and low power consumption.The peristaltic pump system was tested with the mixture of water and glycerin with certain composisition and having viscosity simular to human blood. The validation was also be performed by comparing the results with the measurement conducted using turbine flow meter. The results shows that the performance of the controller is working as expected.