Method and apparatus for improving the comfort of CPAP
AssigneeResMed Limited
InventorsSteven Paul Farrugia, Matthew Alder, Andrew Mikael Price, Ron Richard
Life of this patent
Estimating the term…
Abstract
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.
Claims18
An apparatus for delivering breathable air to a patient throughout the patient's respiratory cycle, the respiratory cycle including an inhalation phase and an exhalation phase, the apparatus comprising:
- a blower having an electric motor configured to rotate an impeller within a volute;
- a patient interface;
- an air delivery conduit arranged to deliver breathable air from the blower to the patient interface;
- at least one sensor adapted to sense a transition between the inhalation phase and the exhalation phase;
- and
- a controller configured to control a speed of the electric motor to cause a pressure of the breathable air delivered to the patient interface to vary between a comfort pressure during at least a portion of the exhalation phase and a therapeutic pressure during at least a portion of the inhalation phase
- wherein the controller is configured to:
- predict when the inhalation phase will occur based upon a transition sensed by the at least one sensor;
- and
- control an adjustment to the speed of the electric motor based on the prediction of when the inhalation phase will occur, and wherein the adjustment to the speed of the electric motor causes an increase in pressure from the comfort pressure to the therapeutic pressure to maintain synchrony between the blower and the patient's respiratory cycle,
- wherein the controller includes a timer to record the time since the start of the exhalation phase, te, and is configured to determine each of an average exhalation phase duration, td, and a time required for an increase in pressure from the comfort pressure to the therapeutic pressure, tp, such that the electric motor is accelerated to cause an increase in pressure from the comfort pressure to the therapeutic pressure when te=td−tp.
An apparatus for delivering breathable air to a patient throughout the patient's respiratory cycle, the respiratory cycle including an inhalation phase and an exhalation phase, the apparatus comprising:
- a blower having an electric motor configured to rotate an impeller within a volute;
- a patient interface;
- an air delivery conduit arranged to deliver breathable air from the blower to the patient interface;
- at least one sensor adapted to sense a transition between the inhalation phase and the exhalation phase;
- a controller to control a pressure of the breathable air delivered to the patient interface to vary between a comfort pressure during at least a portion of the exhalation phase and a therapeutic pressure during at least a portion of the inhalation phase;
- and
- a synchrony means to predict when the inhalation phase will occur based upon a transition sensed by the at least one sensor and to cause an adjustment in pressure between the comfort pressure and the therapeutic pressure based on the prediction of when the inhalation phase will occur, to maintain synchrony between the blower and the patient's respiratory cycle,
- wherein the synchrony means includes a timer to record the time since the start of the exhalation phase, te, and is configured to determine each of an average exhalation phase duration, td, and a time required for an increase in pressure from the comfort pressure to the therapeutic pressure, tp, such that the electric motor is accelerated to cause an increase in pressure from the comfort pressure to the therapeutic pressure when te=td−tp.
Dependencies are inferred from the claim text.