Abstract: A method and a CPAP apparatus for characterizing mask systems provided. The CPAP apparatus can be calibrated by including sensors configured to measure flow and pressure. When the flow generator is fitted to a new or changed mask system, a method for calibrating the flow generator for the new or changed mask system. The method includes determining air flow characteristics using flow measurements made during a first test period when the flow through the mask system is open, measuring or estimating pressure in the mask system during a second test period when the flow through the mask system is blocked and determining air flow characteristics of the diffuser of the mask system using the air flow characteristics of the air delivery hose determined during the first test period and the pressure measurements made during the second test period.

Abstract: A method and a CPAP apparatus for characterizing different mask systems, e.g., masks and hoses, are provided. The apparatus can be calibrated for different mask systems and hoses by including sensors for measuring flow and pressure at a flow generator of the apparatus. When the flow generator is fitted to a new system, or changes are made to an existing system, mask or patient interface, and/or hose, a method of calibrating the flow generator is provided. The method includes determining air flow characteristics of the hose using flow measurements made during a first test period when flow through the system is open, measuring or estimating pressure in the system during a second test period when flow through the system is blocked, and determining air flow characteristics of the diffuser using the air first test period flow characteristics of the air delivery hose and the second test period pressure measurements.

Abstract: A method and a CPAP apparatus for characterizing a plurality of different mask systems, e.g., masks and hoses, are provided. The CPAP apparatus can be calibrated for different mask systems and hoses by including sensors configured to measure flow and pressure at a flow generator of the CPAP apparatus. When the flow generator is fitted to a new mask system, or any changes are made to an existing mask system, mask or patient interface and/or hose, a method for calibrating the flow generator for the new mask system, mask and/or hose is provided.

Abstract: A sub-housing received within a housing of an apparatus for supplying breathable gas, includes a gas flow path between a gas inlet and a gas outlet and an impeller in fluid communication between the gas inlet and the gas outlet. The impeller is structured and configured to be releasably engaged with a shaft associated with an electric motor that is disposed exterior to the housing, whereby rotation of the shaft causes rotation of the impeller.

Abstract: In a respiratory apparatus for treatment of sleep apnea and other disorders associated with an obstruction of a patient's airway and which uses an airflow signal, an obstruction index is generated which detects the flattening of the inspiratory portion of the airflow. The obstruction index is used to differentiate normal and obstructed breathing. The obstruction index is based upon different weighting factors applied to sections of the airflow signal thereby improving sensitivity to various types of respiration obstructions.