Method and apparatus for providing positive airway pressure to a patient
First Claim
1. An apparatus for delivering pressurized breathing gas to an airway of a patient, said apparatus comprising:
- a gas flow generator;
a patient interface adapted to couple said gas flow generator to an airway of such a patient;
a sensor adapted to detect a fluid characteristic associated with a flow of gas within said patient interface and to transmit a signal corresponding to said characteristic;
a pressure controller associated with at least one of said gas flow generator and said patient interface to control a pressure of breathing gas provided by said gas flow generator;
control means, receiving said signal from said sensor, for controlling said pressure controller so as to cause said breathing gas to be delivered to such a patient at a minimally sufficient pressure during, at least a portion of a breathing cycle to perform, at least one of the following functions at any given moment;
(1) reduce cardiac preload and afterload, wherein said minimally sufficient pressure is a summation of a pressure needed to reduce cardiac preload and afterload in an absence of respiratory loading and a pressure needed to overcome an impact of respiratory loading on cardiac preload and afterload; and
(2) prevent airway collapse, wherein said minimally sufficient pressure is a summation of a pressure needed to prevent airway collapse and a pressure needed to overcome respiratory effort; and
a first selector unit operatively connected to said control means to selectively establish a first gain, said control means controlling said pressure controller so as to deliver said breathing gas at said minimally sufficient pressure during at least a portion of said breathing cycle based on said first gain and said signal from said sensor.
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Accused Products
Abstract
A system including methods and apparatus for treatment of a medical disorder such as obstructive sleep apnea or congestive heart failure. The system involves applying separate and independent gains to flow rates of pressurized gas delivered to a patient during inspiratory and expiratory phases of a respiratory cycle to deliver the pressurized gas in proportion to the respective gains during inspiration and expiration. A base pressure may be applied in addition to the gain-modified pressures and an elevated pressure profile may be employed to assist or control inspiration. The system may be fully automated responsive to feedback provided by a flow sensor that determines the estimated patient flow rate. A leak computer can be included to instantaneously calculate gas leakage from the system. The system may be utilized in connection with conventional continuous positive airway pressure (bi-level PAP) equipment to effect various beneficial treatment applications.
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Citations
44 Claims
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1. An apparatus for delivering pressurized breathing gas to an airway of a patient, said apparatus comprising:
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a gas flow generator; a patient interface adapted to couple said gas flow generator to an airway of such a patient; a sensor adapted to detect a fluid characteristic associated with a flow of gas within said patient interface and to transmit a signal corresponding to said characteristic; a pressure controller associated with at least one of said gas flow generator and said patient interface to control a pressure of breathing gas provided by said gas flow generator; control means, receiving said signal from said sensor, for controlling said pressure controller so as to cause said breathing gas to be delivered to such a patient at a minimally sufficient pressure during, at least a portion of a breathing cycle to perform, at least one of the following functions at any given moment; (1) reduce cardiac preload and afterload, wherein said minimally sufficient pressure is a summation of a pressure needed to reduce cardiac preload and afterload in an absence of respiratory loading and a pressure needed to overcome an impact of respiratory loading on cardiac preload and afterload; and (2) prevent airway collapse, wherein said minimally sufficient pressure is a summation of a pressure needed to prevent airway collapse and a pressure needed to overcome respiratory effort; and a first selector unit operatively connected to said control means to selectively establish a first gain, said control means controlling said pressure controller so as to deliver said breathing gas at said minimally sufficient pressure during at least a portion of said breathing cycle based on said first gain and said signal from said sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A proportional positive airway pressure apparatus for delivering pressurized breathing gas to an airway of a patient, said apparatus comprising:
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a gas flow generator; a patient interface adapted to couple said gas flow generator to an airway of a patient; a sensor adapted to detect at least one physiological condition of such a patient, wherein said physiological condition is suitable for use to differentiate between an expiratory phase and an inspiratory phase of a breathing cycle of such a patient and to output a signal indicative thereof; a pressure controller associated with at least one of said gas flow generator and said patient interface to control a pressure of said breathing gas provided by said gas flow generator; control means for controlling said pressure controller so as to cause said breathing gas to be delivered to such a patient at a first pressure level during at least a portion of said inspiratory phase of said breathing cycle and in accordance with a predetermined pressure profile during said expiratory phase of said breathing cycle, wherein a shape of said predetermined pressure profile is set independent of any monitored respiratory characteristics of such a patient. - View Dependent Claims (22)
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23. A method of providing pressured breathing gas to an airway of a patient, said method comprising the steps of:
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supplying gas to an airway of such a patient from a source of gas via a patient interface; determining a fluid characteristic associated with a flow of gas within said patient interface and outputting a fluid characteristic signal indicative thereof; establishing a first gain to be applied to said fluid characteristic signal; and controlling said supply of gas to such a patient during at least a portion of a breathing cycle based on said fluid characteristic signal and said first gain so as to deliver said gas to such a patient at a minimally sufficient pressure to perform at least one of the following functions at any given moment during at least a portion of a breathing cycle; (1) reduce cardiac preload and afterload, wherein said minimally sufficient pressure is a summation of a pressure needed to reduce cardiac preload and afterload in an absence of respiratory loading and a pressure needed to overcome an impact of respiratory loading on cardiac preload and afterload; and (2) prevent airway collapse, wherein said minimally sufficient pressure is a summation of a pressure needed to prevent airway collapse and pressure needed to overcome respiratory effort. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42)
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43. A method of delivering pressurized breathing gas to an airway of a patient, said method comprising the steps of:
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providing a gas flow generator and a patient interface adapted to couple said gas flow generator to an airway of a patient; detecting at least one physiological condition of such a patient, wherein said physiological condition is suitable for use to differentiate between an expiratory phase and an inspiratory phase of a breathing cycle of such a patient and outputting signals indicative thereof; and controlling said gas flow to such a patient at a first pressure level during at least a portion of said inspiratory phase and in accordance with a predetermined pressure profile during said expiratory phase of said breathing cycle, wherein a shape of said predetermined pressure profile is set independent of any monitored respiratory characteristics of such a patient. - View Dependent Claims (44)
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Specification