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US 5,551,419 AGranted
Control for CPAP apparatus
AssigneeDeVilbiss Health Care, Inc.
InventorsJames P. Froehlich, Joseph N. Mitchell, Stephen M. Jones
Life of this patent
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AssigneeDeVilbiss Health Care, Inc.
InventorsJames P. Froehlich, Joseph N. Mitchell, Stephen M. Jones
Estimating the term…
The invention relates to continuous positive airway pressure (CPAP) respiratory therapy apparatus for treatment of apnea, hypopnea and other sleep disorders, and particularly to a control for the CPAP apparatus. A blower is connected through a hose and a mask, such as a nasal mask or a nasal cannula, to the patient's respiratory airway. An air flow sensor and an air pressure sensor are located at the blower end of the hose. Optionally, a vent valve also may be located at the blower end of the hose. The sensor outputs are used to estimate the air pressure at the mask and the air flow sensor output is used to determine the gross air flow to the hose, the patient air flow and the occurrence of patient snoring. The air flow sensor output also is used to generate a square wave breathing signal. The breathing signal may be used by a microprocessor to control the optional vent valve to establish different levels in the applied pressure during inspiration and expiration. The applied CPAP pressure may be increased in response to the detection of apnea and hypopnea events. The microprocessor detects and ignores mask leaks, open mouth breathing and exhale puff breathing.
An improved method for controlling CPAP apparatus adapted to apply a positive airway pressure to a patient, said apparatus including an air blower and means for applying a positive air pressure from said blower through a hose to a mask adapted to be secured to a patient in communications through the patient's nose with the patient's respiratory airway, said apparatus including means for detecting abnormal breathing events and for automatically increasing the positive airway pressure applied to the patient in response to the detection of at least one abnormal breathing event, said method comprising the steps of:
An improved method for controlling CPAP apparatus adapted to apply a positive airway pressure to a patient, said apparatus including an air blower and means for applying a positive air pressure from said blower through a hose to a mask adapted to be secured to a patient in communications through the patient's nose with the patient's respiratory airway, said apparatus including means for detecting abnormal breathing events and for automatically increasing the positive airway pressure applied to the patient in response to the detection of at least one abnormal breathing event, said method comprising the steps of:
A method for generating a square wave breathing signal indicative of patient inspiration and expiration into a mask comprising the steps of:
A method for generating a square wave breathing signal indicative of patient inspiration and expiration into a mask comprising the steps of:
A method for generating a square wave breathing signal indicative of patient inspiration and expiration into the mask comprising the steps of:
In CPAP apparatus adapted to apply a positive airway pressure to a patient, said apparatus including an air blower having a positive pressure output applied through a hose to a mask adapted to be secured to a patient in communications with the patient's respiratory airway, a method for detecting patient snoring comprising the steps of:
In CPAP apparatus which includes blower means for creating a positive air pressure, a mask adapted to be attached to a patient in communications with the patient's respirator system and a hose having a first end for receiving a flow of positive pressure air from said blower means and a second end for delivering such flow of positive pressure air to said mask, apparatus for detecting when a patient is snoring comprising means for generating a first electric signal indicative of the mass air flow at said first hose end, such mass air flow including a first component resulting from air flow from said blower means, a second component resulting from patient inspiration and expiration at said mask, a third component comprising noise resulting from patient snoring, and a fourth component comprising noise other than snoring noise, band pass filter means responsive to the first signal for establishing a second electric signal consisting of snoring and non snoring noise, means responsive to the fourth component of the first signal for establishing a snoring threshold level signal, and means for indicating the presence of snoring when the second signal exceed the snoring threshold level signal.
Dependencies are inferred from the claim text.