Design of a Lung Simulator for Ventilator Trigger Testing Using Sliding Mode Control Based on Extended State Observer

Mechanical ventilation serves as a vital life-supporting intervention for patients with severe respiratory impairment. Artificial lung simulators represent a crucial technological platform for advancing mechanical ventilation development. This study presents an advanced artificial lung simulator featuring continuously adjustable respiratory mechanics parameters and more importantly - the unique ability to accurately simulate inspiratory triggering during pressure support ventilation, addressing a critical deficiency in existing systems where this core functionality is either absent or inadequately implemented. The developed system incorporates a stepper motor-based driving mechanism with sliding mode control for precise lung compliance regulation. It successfully replicates passive breathing under conscious conditions while achieving two key advancements: faithful reproduction of pressure support ventilation triggering scenarios and continuously adjustable compliance with measurement accuracy maintained within $\pm 5 \%$ of target values. These innovations provide researchers and clinicians with unprecedented testing capabilities for ventilator performance evaluation and respiratory research.