A Novel Pneumatic Proportional Control Unit for Medical Engineering

The medical device industry currently strongly demands pneumatic proportional components. Medical devices such as ventilators, anesthesia machines, and oxygen therapy equipment require accurate proportional control of compressed air and oxygen to achieve treatment goals. However, the pneumatic proportional components used in existing medical devices are primarily industrial products with complex structures, large volumes, and high costs, which cannot meet the requirements of small, lightweight, modular, and low-prime-cost medical devices. This paper proposed a novel pneumatic proportional control unit for medical engineering to meet the application requirements of miniaturization, integration, low pressure, high flow, and high precision of medical equipment. The active disturbance rejection control (ADRC) method is developed to achieve high-precision control of output pressure and flow. Finally, the pneumatic proportional control unit and ADRC control algorithm proposed in this paper has been validated through the experiments. The pressure and flow control range can reach 0-5kPa and 0-100L/min, respectively. The response time, overshoot, and accuracy are within 150ms, 5%, and 5%, respectively.