Control for pressure of a patient interface

A control method in a processor for determining a pressure adjustment in a patient interface that delivers a supply of air or breathable gas to entrance of a patient's airways, the control method comprising:

• in a presence of a selective blocking of fluid communication between a blower and a patient interface, determining an expiratory characteristic;
• and
• determining an adjustment for a first pressure in the patient interface based on the expiratory characteristic.

An apparatus for controlling a supply of breathable gas at a positive pressure for treatment of a respiratory disorder, the apparatus comprising:

• a controller, including at least one processor, adapted to control setting of a blower of a therapy apparatus for controlling a supply of breathable gas at a controlled pressure above ambient in a patient interface, the controller coupled with at least one sensor for the therapy apparatus, the at least one sensor to measure pressure through a conduit from the therapy apparatus to the patient interface, the conduit in fluid communication with the patient interface, the patient interface configured to deliver the supply of breathable gas to an airway of a patient,
• the controller being further configured to determine gas pressure in the patient interface in presence of cyclical blocking and unblocking of the conduit to the sensor, the determination of the gas pressure in the patient interface including a first unblocked-conduit process and a second blocked-conduit process.

A method of a processor to control setting of a blower of a therapy apparatus for providing a supply of breathable gas to a patient interface at a controlled pressure, the method comprising:

• with a sensor of the therapy apparatus, measuring a pressure through a conduit from the therapy apparatus to the patient interface, the conduit in fluid communication with the patient interface,
• determining in a first unblocked-conduit process and a second blocked-conduit process a patient interface gas pressure for control of the blower in presence of blocking and unblocking of the conduit to the sensor.