INSPIRATORY DURATION IN CPAP OR ASSISTED RESPIRATION TREATMENT

摘要

Apparatus for the supply of breathable gas cyclically at an inspiratory pressure and the lower expiratory pressure substantially in synchronism with a patient's (16) respiration is disclosed. A flow generator (10) is coupled to a gas delivery system (12) to deliver the breathable gas to the patient's airways. A motor controller (23) receives a signal (36) representing respiratory flow. A motor controller (23) outputs a control signal (24) has control over the electric motor (25) and thus the turbine (22) to generate the required inspiratory and expiratory pressures. The controller (23) detects transitions between inspiration and expiration from the flow signal (36) to discriminate between patient inspiration and expiration. A counter (58) counts a first time duration commenced from the last transition to inspiration, whereby if the first time duration elapses before a transition to expiration, the controller (23) causes the supply of the expiration pressure. Furthermore, another counter (62) counts a second time duration commenced from the last transition to inspiration that forces the turbine (22) to supply the inspiratory pressure until the second time duration elapses even if during the second time duration there is a transition to expiration by the patient.