Resmed Limited

Gregory Alan Colla

Barton John Kenyon

Steven Paul Farrugia

Chinmayee Somaiya

Gregory Newton Brewer

Shane Darren Finn

Barton Kenyon

Hary Soesanto Surjadi

John William Ernest Brydon

John William Brydon

CPAP treatment apparatus (), as one form of positive pressure ventilatory assistance, is disclosed. A turbine/blower (), operated by a mechanically coupled electrical motor (), receives air or breathable gas at an inlet () thereof, and supplies the breathable gas at a delivery pressure to a delivery tube/hose () having connection at the other end thereof with a nose mask (). A microcontroller () has an operational 'Mask-Fit' mode. An initial constant pressure level is applied by the blower () to the mask (). If the functional mode is a Manual mode, then the mask-fit test pressure is the current 'set' pressure. If the functional mode is the Automatic Titration mode, the mask-fit test pressure is the 95th percentile pressure of the previous session, otherwise it is the base treatment pressure, e.g. 10-12 cm HO. This constant pressure is applied for a period of time, typically 1-3 minutes. The microcontroller () continuously determines mask leak as the value, f, from a flow sensor (), comparing this to a threshold, and providing the patient with a visual indication of degree of leak. In this way the patient can manipulate the mask to ensure correct fitting as indicated by the appropriate message or indication.

Determination of mask fitting pressure and correct mask fit

A ventilation device for non-invasive positive pressure ventilation (NIPPV) or continuous positive airway pressure (CPAP) treatment of a patient has a gas flow generator, a gas delivery circuit optionally including a humidifier, a controller and sensors monitoring values of operational parameters of the device. The device further includes one or more relationships stored in data storage of the controller relating combinations of parameter values as being indicative of fault conditions of the device operation, the sensors and/or the fault detection process.

Fault diagnosis in CPAP and NIPPV devices

A method for determining a mask-fit test pressure to be applied to a wearer's mask by ventilatory assistance apparatus includes adaptively determining the mask-fit pressure from prior use.

A flow generator having use in the provision of CPAP or assisted ventilation treatment is disclosed The flow generator has a turbine for the supply of breathable gas which is driven by an electric motor and an associated motor power supply. The power supply in turn is controlled by a controller. A pressure sensing port measures delivery pressure that is passed to a pressure transducer, the output signal of which is passed to the motor controller. The zero offset of the pressure transducer is automatically calibrated on occurrence of the conditions where the turbine is not operating and no pressure activity is sensed by the transducer. The turbine not operating condition can be determined from Hall-effect sensors integral to the motor.

Auto-calibration of pressure transducer offset

A CPAP treatment apparatus, as one form of positive pressure ventilatory assistance, includes a turbine/blower, operated by a mechanically coupled electrical motor that receives air or breathable gas at an inlet thereof, and supplies the breathable gas at a delivery pressure to a delivery tube/hose having a connection at the other end thereof with a nose mask. A microcontroller has an operational &ldquo;Mask-Fit&rdquo; mode. An initial constant pressure level is applied by the blower to the mask. If the functional mode is a manual mode, then the mask-fit test pressure is the current 'set' pressure. If the functional mode is the automatic titration mode, the mask-fit test pressure is the 95 percentile pressure of the previous session, otherwise it is the base treatment pressure, e.g. 10-12 cm H O. This constant pressure is applied for a period of time, typically 1-3 minutes. The microcontroller continuously determines mask leak as the value, f , from a flow sensor, comparing this to a threshold, and providing the patent with a visual indication of degree of leak. In this way the patient can manipulate the mask to ensure correct fitting as indicated by the appropriate message or indication.

The occurrence of an arousal in a patient associated with an apneic or hypopneic episode car be determined. Sensors are placed on a patient to obtain signals representative of at least two physiological variables, for example skin conductance, heart rate and blood oxygen concentration. The signals are conditioned by conditioning circuitry, then processed by a processor to correlate at least two thereof. A coincident change in at least two of the processed signals is indicative of the occurrence of an arousal, that in turn indicates an apneic or hypopneic episode has occurred. A patient thus can be diagnosed as suffering conditions such as obstructive sleep apnea.

Monitoring the occurrence of apneic and hypopneic arousals

A flow generator for the supply of breathable gas, which includes an electric motor driving a turbine, control circuitry, a pressure transducer to sense delivery pressure at or remote from said flow generator and whose electrical output is connected to the control circuitry, and sensing means connected to the control circuitry, and wherein the control circuitry is operable to determine from the sensing means whether the electric motor or the turbine are operating and from the pressure transducer whether there is no pressure activity, and if both determinations are satisfied, to accept the output of the transducer as a calibrated pressure offset value representative of atmospheric pressure.

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North Sydney, Australia

Gregory Alan Colla