Integrated Pneumatic Servo Module for Mechanical Ventilation With ADRC and RLS-Based Feedforward Control

This article presents a miniaturized integrated pneumatic servo module with hybrid adaptive control for mechanical ventilation. Unlike conventional ventilators requiring three or more actuators, the proposed design achieves air-oxygen blending and pressure/flow regulation using only two proportional solenoid valves. The control architecture adopts dual closed-loop control, with parallel active disturbance rejection control for the inner flow loops and PI control for the outer pressure loop. Online recursive least squares identification of respiratory mechanics deployed for adaptive feedforward compensation. Fuzzy control was adopted for positive end-expiratory pressure (PEEP) regulation. Experimental results demonstrate a 300 ms rise time with zero overshoot in pressure tracking, FiO₂ control accuracy within 5% across the 30–90% oxygen concentration range, PEEP control accuracy within ±1.5%, and robust performance under varying respiratory mechanics. The integrated design reduces system complexity while maintaining clinical-grade performance, offering a cost-effective solution for resource-constrained healthcare settings.