Patent ID: RE39225

Claim:
A method for detecting disconnection and occlusion of a patient tubing system of a pneumatically driven, electronically controlled ventilator system for providing breathing gas to a patient during the exhalation phase of a breath cycle, said exhalation phase having a plurality of control intervals, comprising the steps of: delivering a flow of breathing gas to a patient during an inspiratory phase of a breath cycle; determining an onset of an exhalation phase of said breath cycle; suspending gas flow delivery to the patient tubing system during said exhalation phase of said breath cycle; monitoring exhalation flow and pressure in the patient tubing system during a plurality of control intervals of said exhalation phase of said breath cycle to determine whether a condition indicating occlusion of the patient tubing system has occurred; monitoring exhalation pressure in the patient tubing system during a plurality of control intervals of said exhalation phase of said breath cycle to determine whether a condition indicating occlusion of the patient tubing system has occurred; and generating a disconnection signal indicating disconnection of the patient tubing system responsive to said exhalation flow and said pressure in said patient tubing system if said condition indicating occlusion of the patient tubing system has not occurred, and if said condition indicating disconnection of the patient tubing system has occurred.