A Comparative Study of Controllers for Robust Disturbance Rejection in Hyperbaric Surgical Chambers

Hyperbaric Oxygen Therapy (HBOT) surgical chambers require precise pressure control to ensure patient safety and therapeutic efficacy. This paper presents a comparative analysis of three advanced control strategies for pressure regulation in HBOT chambers: a PID controller with a low-pass filter, a FOPI controller, and an IMC structure integrated with a PD controller. The performance of each controller is evaluated under setpoint tracking and disturbance rejection scenarios, with a focus on two distinct negative pressure disturbances to simulate real-world operational challenges. Simulation results demonstrate that the filtered PID and IMC-PD controllers outperform the FOPI controller in terms of transient response, steady-state accuracy, and robustness against disturbances. Quantitative metrics, including the steady-state error, Integral of Time-weighted Squared Error (ITSE) and settling time, are used to validate the superiority of the filtered PID and IMC-PD schemes. The findings highlight the potential of fractional-order and modelbased control frameworks in enhancing the dynamic response and reliability of HBOT systems, offering critical insights for medical device control engineering.