An apparatus for humidifying a flow of breathable gas includes a water reservoir and a water reservoir dock forming a cavity structured and arranged to receive the water reservoir in an operative position. The water reservoir comprises a reservoir base including a cavity structured to hold a volume of water, the reservoir base including a main body and a thermally conductive portion provided to the main body. The thermally conductive portion comprises a combined layered arrangement including a metal plate and a thin film, the thin film comprising a non-metallic material and including a wall thickness of less than about 1 mm. The thin film is adapted to form at least a bottom interior surface of the water reservoir exposed to the volume of water, and the metal plate is adapted to form a bottom exterior surface of the water reservoir.

A patient interface is configured to deliver a pressurized flow of respiratory gas to a patient's airways. The patient interface includes a cradle base configured to cradle the patients nose in use. Two protrusions extend from the cradle base and are configured to be inserted into the patients nares in use. Each of the protrusions have formed therein an opening configured to allow a continuous flow of air therethrough. In addition, a plenum base forms a plenum chamber together with the cradle base. The cradle base is configured so that movement of the cradle base is decoupled from the plenum base.

A breathing assistance apparatus and method of controlling a breathing assistance apparatus is disclosed. Particularly, the breathing assistance apparatus is controlled such that it has a drying cycle to enable drying of the tubing that supplies gases to a user and prevent the harbouring of pathogens within the tube. The drying cycle is preferably operated automatically by internal controllers in the apparatus. However, it may be manually activated by pressing a button on the apparatus. The drying cycle is preferably activated at the end of a user's treatment session.

Method and apparatus obtain information about a patient and/or a respiratory therapy system that is configured to deliver respiratory therapy to the patient. The respiratory therapy system may include a flow generator configured to generate a supply of pressurized air along an air circuit to a patient interface. A sound signal representing a sound in the air circuit may be processed to obtain cepstrum data. A time series of delay estimates based on acoustic signatures of the cepstrum data may be generated. Each acoustic signature may represent a reflection of sound from a patient interface along the air circuit. Variation in the time series of delay estimates may be analysed. One or more output indicators based on the variation may be generated. The one or more output indicators may concern patient and/or system status.

A PAP system for delivering breathable gas to a patient includes a flow generator to generate a supply of breathable gas to be delivered to the patient; a humidifier including a heating plate to vaporize water and deliver water vapor to humidify the supply of breathable gas; a heated tube configured to heat and deliver the humidified supply of breathable gas to the patient; a power supply configured to supply power to the heating plate and the heated tube; and a controller configured to control the power supply to prevent overheating of the heating plate and the heated tube.

A method of controlling a medical device is disclosed for delivering respiratory therapy to a user to treat sleep-disordered breathing, for instance obstructive sleep apnea, Cheyne-Stokes respiration etc. by estimating the user's CO2 percentage or concentration from a dynamic lung model driven by an observed respiration signal. The estimated user's CO2 percentage or concentration can be used to predict breathing events, such as hypopnea and apnea. The predictive capacity can be used for adjusting the respiratory therapy as required or for applying a ramp cycle therapy, in an attempt to reduce the prevalence and adverse effects of the breathing events. In other examples a variable ventilation therapy is provided in which pressure is supplied between first and second pressures, with the pressure being increased over more than one breath, and then dropped relatively rapidly, for example during expiration of a single breath.

Disclosed are methods, apparatus and systems for treating a respiratory disorder in a patient. The apparatus comprises a pressure generator configured to generate a flow of air so as to provide ventilatory support to the patient; a transducer configured to generate a flow signal representing a property of the flow of air; and a controller configured to analyse the flow signal to estimate the inspiratory volume and the expiratory volume of a breath of the patient and servo-control the degree of ventilatory support to adjust an estimated tidal volume toward a target tidal volume. A gain of the servo-control is dependent on a difference between the estimated inspiratory volume and the estimated expiratory volume. The method comprises operating an apparatus or system in a similar manner.

Novel tools and techniques for assessing, predicting and/or estimating effectiveness of hydration of a patient and/or an amount of fluid needed for effective hydration of the patient, in some cases, noninvasively.

A method of controlling a medical device is disclosed for delivering respiratory therapy to a user to treat sleep-disordered breathing, for instance obstructive sleep apnea, Cheyne-Stokes respiration etc. by estimating the user's CO2 percentage or concentration from a dynamic lung model driven by an observed respiration signal. The estimated user's CO2 percentage or concentration can be used to predict breathing events, such as hypopnea and apnea. The predictive capacity can be used for adjusting the respiratory therapy as required or for applying a ramp cycle therapy, in an attempt to reduce the prevalence and adverse effects of the breathing events. In other examples a variable ventilation therapy is provided in which pressure is supplied between first and second pressures, with the pressure being increased over more than one breath, and then dropped relatively rapidly, for example during expiration of a single breath.

A breathing assistance apparatus is disclosed, for use with delivery of respiratory gases to a patient. The breathing assistance apparatus includes a patient interface, having a body section adapted to cover the nose, or nose and mouth of a patient and a sealing interface. The sealing interface includes at least an outer sealing member. The outer sealing member is adapted to attach to the body section in a sealing manner and has a substantially thin section in at least its nasal bridge region. The thin section is substantially thinner than the rest of the outer sealing member. The patient interface comprises a mask body and a seal assembly. The seal assembly includes a flexible seal, and a rigid seal clip, the seal assembly being removably attached to the mask body via the rigid seal clip. The mask body and rigid seal clip are profiled to match the contours of a user's face so that the seal has a substantially constant wall depth.