Methods and apparatus for pressure therapy in the treatment of sleep disordered breathing

摘要

An apparatus to set a change in respiratory treatment for a patient interface that directs a flow of breathable gas to a patient is disclosed. The apparatus comprises: (a) a flow generator for coupling with the patient interface to generate a flow of the breathable gas through the patient interface; (b) a pressure transducer to provide a pressure signal indicative of pressure associated with the flow generator; (c) a tachometer to provide a velocity signal indicative of a speed of the flow generator; and (d) a processor to control the flow generator. The processor coupled with the pressure transducer processes the pressure signal and is coupled with the tachometer to process the velocity signal where the processor is configured to control generation of control signals to set a respiratory pressure treatment produced by the flow generator and derive an estimate of patient respiratory flow. Generation of control signals sets a respiratory pressure treatment produced by the flow generator where the respiratory pressure treatment comprises an inspiratory pressure and an expiratory pressure, and the expiratory pressure is a reduction of pressure from the inspiratory pressure. An estimate of patient respiratory flow is derived as a function of a difference of (a) a measure of pressure from the pressure signal and (b) and an expected pressure derived from a measure of a frequency from the velocity signal where the generated control signals set at least one of the inspiratory pressure and the expiratory pressure as a function of the estimate of patient respiratory flow.