Resmed Limited

Resmed Pty Ltd

Matthew Alder

Steven Paul Farrugia

Chinmayee Somaiya

Kristian Thomsen

Ron Richard

Andrew Mikael Price

Tracey Bullivant

Andrew Martin Price

CPAP treatment apparatus is disclosed having a controllable positive airway pressure device. A sensor generates a signal representative of patient respiratory flow that is provided to a controller. The controller is operable to determine the occurrence of an apnea from a reduction in respiratory airflow below a threshold determined from long term ventilation. When an apnea or hypopnea has occurred the calculation of the threshold is suspended until the end of that event.

Determination of apnea/hypopnea during CPAP treatment

A method and apparatus are disclosed for determining airflow through a PAP device while applying PAP therapy. The actual speed of a bloweris measured. The desired motor current I DES required for the actual speed to approach or maintain a desired speed is used, together with the actual speed RPM ACT, in a flow estimation algorithm to determine flow through the PAP device. The estimation algorithm consists of a two-dimensional look-up table, where the inputs are the desired motor current and actual motor speed, and the output is the flow through the PAP device.

Using motor speed in a PAP device to estimate flow

A CPAP apparatus is provided that determines the presence of a snore by the simplified method of using filtered expiratory noise as the measure of intrinsic device noise and comparing that to filtered inspiratory noise. The filtering time constants for inspiratory and expiratory noise are adjusted such that treatment pressure does not cause false snore detection.

Computer controlled CPAP system with snore detection

A low-cost CPAP apparatus in which, upon detection of the transition from inhalation to exhalation, the blower motor is de-energized to allow it to freewheel. When the pressure in the patient mask (or whatever interface is utilized) reaches a minimum pressure level during exhalation, the motor is re-energized and its speed is controlled so to maintain the pressure at a level suitable for exhalation. Upon detection of the transition from exhalation to inhalation, the motor speed is increased to provide higher pressures in the patient mask suitable for inhalation.

Method and apparatus for improving the comfort of CPAP

A method and apparatus are disclosed for determining airflow through a PAP device while applying PAP therapy. The actual speed of a bloweris measured. The desired motor current IDES required for the actual speed to approach or maintain a desired speed is used, together with the actual speed RPM ACT, in a flow estimation algorithm to determine flow through the PAP device. The estimation algorithm consists of a two-dimensional look-up table, where the inputs are the desired motor current and actual motor speed, and the output is the flow through the PAP device.

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Scarborough, Australia

Matthew Alder