Fuzzy Control for Regulating Level of Pressure Support Ventilation

This paper proposes a fuzzy control for regulating level of pressure support ventilation (PSV). The control uses the expert knowledge of the qualitative relationship of the physiological parameters and the patientpsilas state. The physiological parameters include heart rate (HR), tidal volume (VT), respiratory rate (RR), arterial partial pressure of carbon dioxide (PaCO₂) and arterial oxygen saturation (SaO₂). A physical state controller, a tendency controller and a decision controller are designed to regulate the pressure support (PS) level on-line according to changing the adjustment experience of clinicians for the parameters of the ventilator into expert knowledge database by using fuzzy sets, and expressing physiological parameter values by using membership functions. Comparative results of the simulation and clinical cure show that the on-line regulation reduces the doctorspsila work and ensures that the PS level adapts to patientspsila physiological requirement accurately and fast, so as to make the process of weaning from ventilator smooth and comfortable.