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, the apparatus comprising:
- a gas flow generator;
a patient interface adapted to couple the gas flow generator to an airway of a patient;
a sensor adapted to detect a fluid characteristic associated with a flow of breathing gas within the patient interface and to transmit a signal corresponding to the characteristic;
a pressure controller associated with at least one of the gas flow generator and the patient interface to control a pressure of the flow of breathing gas provided by the gas flow generator;
control means, receiving the signal from the sensor, for controlling the pressure controller so as to cause the flow of breathing gas to be delivered to the patient at a minimally sufficient pressure during at least a portion of a breathing cycle to prevent airway collapse, wherein the minimally sufficient pressure is a summation of a pressure needed to overcome mechanical airway collapsing forces and a pressure needed to overcome airway collapse due to respiratory effort; and
a first selector unit operatively connected to the control means to selectively establish a first gain, the control means controlling the pressure controller so as to deliver the flow of breathing gas at the minimally sufficient pressure during at least a portion of a breathing cycle based on the first gain and the signal from the 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 a gain to flow rate of pressurized gas delivered to a patient during inspiratory and/or expiratory phases of a respiratory cycle to deliver the pressurized gas in proportion to the respective gains during inspiration and/or 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 treatments, such as CPAP or bi-level positive airway pressure equipment to effect various beneficial treatment applications.
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Citations
39 Claims
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1. An apparatus for delivering pressurized breathing gas to an airway of a patient, the apparatus comprising:
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a gas flow generator;
a patient interface adapted to couple the gas flow generator to an airway of a patient;
a sensor adapted to detect a fluid characteristic associated with a flow of breathing gas within the patient interface and to transmit a signal corresponding to the characteristic;
a pressure controller associated with at least one of the gas flow generator and the patient interface to control a pressure of the flow of breathing gas provided by the gas flow generator;
control means, receiving the signal from the sensor, for controlling the pressure controller so as to cause the flow of breathing gas to be delivered to the patient at a minimally sufficient pressure during at least a portion of a breathing cycle to prevent airway collapse, wherein the minimally sufficient pressure is a summation of a pressure needed to overcome mechanical airway collapsing forces and a pressure needed to overcome airway collapse due to respiratory effort; and
a first selector unit operatively connected to the control means to selectively establish a first gain, the control means controlling the pressure controller so as to deliver the flow of breathing gas at the minimally sufficient pressure during at least a portion of a breathing cycle based on the first gain and the signal from the sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of providing pressured breathing gas to an airway of a patient, the method comprising the steps of:
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supplying a flow of breathing gas to an airway of a patient from a source of gas via a patient interface;
determining a fluid characteristic associated with the flow of breathing gas within the patient interface and outputting a fluid characteristic signal indicative thereof, establishing a first gain to be applied to the flow rate signal; and
controlling the flow of breathing gas to the patient during at least a portion of a breathing cycle based on the fluid characteristic signal and the first gain so as to deliver the flow of breathing gas to a patient at a minimally sufficient pressure to prevent airway collapse, wherein the minimally sufficient pressure is a summation of a pressure needed to overcome mechanical airway collapsing forces and a pressure needed to overcome airway collapse due to respiratory effort. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. An apparatus for delivering pressurized breathing gas to an airway of a patient, comprising:
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a gas flow generator;
a patient interface coupled to the gas flow generator to communicate a flow of breathing gas from the gas flow generator with an airway of a patient;
a sensor associated with the gas flow generator or the patient interface that detects a fluid characteristic associated with the flow of breathing gas within the patient interface and outputs a signal corresponding to the fluid characteristic;
a pressure controller associated with the gas flow generator or the patient interface to control a pressure of the flow of breathing gas delivered to a patient;
an input device; and
processing means, adapted to receive the signal output from the sensor, a continuous positive airway pressure (CPAP), and an expiratory gain GainExp from the input device, for determining a pressure to be delivered to a patient during inhalation (Pinhalation) as; Pinhalation=CPAP,
and for determining a pressure to be delivered to such a patient during exhalation (Pexhalation) as;Pexhalation=CPAP+GainExp*(Flow−
FlowOffset),
where “
Flow”
is the current patient flow measured by the sensor, where “
FlowOffset”
corresponds to a final value of patient flow during inspiration responsive to the final value being positive, otherwise FlowOffest is set to zero, and wherein the processing means controls the pressure controller so as to deliver a pressure corresponding to Pinhalation during an inspiratory phase of a breathing cycle and corresponding to Pexhalation during an expiatory phase of a breathing cycle. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A method of delivering pressurized breathing gas to an airway of a patient, comprising:
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generating a flow of breathing gas;
sensing a current flow (Flow) of the breathing gas and outputting a signal corresponding thereto;
selecting an expiratory gain (GainExp);
setting a continuous positive airway pressure (CPAP) level;
controlling a pressure of the flow of breathing gas delivered to a patient during inhalation (Pinhalation) as; Pinhalation=CPAP; and controlling the pressure of the flow of breathing gas to be delivered to such a patient during exhalation (Pexhalation) as; Pexhalation=CPAP+GainExp*(Flow−
FlowOffset),
where “
FlowOffset”
corresponds to a final value of patient flow during inspiration responsive to the final value being positive, otherwise FlowOffest is set to zero. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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Specification