Validation of a Simulink Model for Simulating the Two Typical Controlled Ventilation Modes of Intensive Care Units Mechanical Ventilators

Abstract

Mechanical ventilators are vital components of critical care services for patients with severe acute respiratory failure. In particular, pressure- and volume-controlled mechanical ventilation systems are the typical modes used in intensive care units (ICUs) to ventilate patients who cannot breathe adequately on their own. In this paper, a Simulink model is proposed to simulate these two typical modes employed in intensive care lung ventilators. Firstly, these two modes of ventilation are described in detail in the present paper. Secondly, the suggested Simulink model is analysed: it consists of using well-established subroutines already present in Simulink through the Simscape Fluids (gas) library, to simulate all the pneumatic components employed in some commercial ICU ventilators, such as pressure reducing valves, pressure relief valves, check valves, tanks, ON\OFF and proportional directional valves, etc. Finally, the simulation results of both modes in terms of pressure, tidal volume, and inspired/expired flow are compared with the real-life quantitative trends taken from previously recorded real-life experiments in order to validate the Simulink model. The accuracy of the model is high, as the numerical predictions are in good agreement with the real-life data, the percentage error being less than 10% in most comparisons. In this way, the model can easily be used by manufacturers and start-ups in order to produce new mechanical ventilators in the shortest time possible. Moreover, it can also be used by doctors and trainees to evaluate how the mechanical ventilator responds to different patients.