Patent ID: 11857724
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A CPAP apparatus comprising:
a housing comprising an intake inlet and an exhaust outlet;
an air passage comprising a first end connected to the exhaust outlet;
a fan configured to expel air from a second end of the air passage, the air flowing into the CPAP apparatus at the intake inlet;
a fan driver configured to rotationally drive the fan according to a rotational parameter;
a processor configured to control the fan driver;
a flow rate sensor configured to measure an air flow rate between the fan and the second end of the air passage; and
a pressure sensor configured to measure a pressure of air between the fan and the second end of the air passage,
wherein the processor is configured to:
generate a command value corresponding to the rotational parameter of the fan at which a pressure of air expelled from the exhaust outlet is equal to a target pressure,
determine a change in a pressure of air delivered to the air passage based on a change in the measured air flow rate, and a respiration disturbance correction value based on the determined change in pressure,
determine a pressure difference between the measured pressure and the target pressure, and a rotation number correction value based on the determined pressure difference,
correct the command value based on a weighted combination of the command value, the respiration disturbance correction value, and the rotation number correction value, such that the pressure of air delivered to the air passage equals the target pressure.