Method and apparatus for controlling sleep disorder breathing
First Claim
1. A method of controlling sleep disorder breathing in a person, the method comprising the steps of:
- connecting an interface from a source of compressed air to a person'"'"'s breathing passages;
supplying compressed air from the source of compressed air through the interface to the person'"'"'s breathing passages;
measuring flow related variables and pressure variables of the compressed air in the interface;
detecting from the measured flow related variables and the measured pressure variables indications of sleep disorder breathing by;
computing a standard deviation value for the measured flow related variables over an interval;
periodically determining if the computed standard deviation value exceeds a standard deviation threshold; and
comparing the computed standard deviation value with the standard deviation threshold over a certain time interval to establish occurrence of pharyngeal wall vibration;
responsive to the detection of indications of sleep disorder breathing, adjusting pressure of the compressed air while continuing to monitor the measured flow related variables and the measured pressure variables for sleep disorder breathing; and
responsive to passage of a period without detection of indications of sleep disorder breathing, adjusting pressure of the compressed air.
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Accused Products
Abstract
A method and device for controlling sleep disorder breathing utilizes variable multiple level pressures. A pressure source supplies compressed breathable gas at a relatively low pressure to the user'"'"'s airway. Pressure transducers monitor pressures and convert them into electrical signals. The electrical signals are filtered and processed to extract specific features such as duration and energy levels. If these features exceed selected threshold values for duration and energy level over a minimum period of time, then the microprocessor declares the presence of sleep disorder breathing. If a selected number of these events occur within a selected time period, then the microprocessor adjusts the pressure delivered by the pressure source. If sleep disorder breathing is not detected within a certain time period, then the microprocessor lowers the pressure level gradually. The device and method disclosed in this patent is capable of detecting apnea, hypopnea, and pharyngeal wall vibration. Further, it is able to distinguish between obstructive, central and mixed apnea and hypopnea.
321 Citations
43 Claims
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1. A method of controlling sleep disorder breathing in a person, the method comprising the steps of:
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connecting an interface from a source of compressed air to a person'"'"'s breathing passages; supplying compressed air from the source of compressed air through the interface to the person'"'"'s breathing passages; measuring flow related variables and pressure variables of the compressed air in the interface; detecting from the measured flow related variables and the measured pressure variables indications of sleep disorder breathing by; computing a standard deviation value for the measured flow related variables over an interval; periodically determining if the computed standard deviation value exceeds a standard deviation threshold; and comparing the computed standard deviation value with the standard deviation threshold over a certain time interval to establish occurrence of pharyngeal wall vibration; responsive to the detection of indications of sleep disorder breathing, adjusting pressure of the compressed air while continuing to monitor the measured flow related variables and the measured pressure variables for sleep disorder breathing; and responsive to passage of a period without detection of indications of sleep disorder breathing, adjusting pressure of the compressed air. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for sleep disorder breathing therapy of a person, comprising the steps of:
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connecting a face mask from an air compressor to a person'"'"'s breathing passages; supplying air from the air compressor through an interface to the face mask; periodically measuring a pressure difference along the interface and a pressure in the face mask; detecting from the measured pressure difference and the face mask pressure indications of sleep disorder breathing by; taking pressure difference measurements at each of a plurality of sample points during an interval; calculating a mean value for the sample points over each interval and a standard deviation for the sample of points over the interval; generating an initial base line from an accumulation of mean values for a sequence of intervals of sample point; thereafter adjusting the baseline for each subsequent pressure difference mean calculated; generating an area of respiration value from the area difference between the base line and calculated mean values; maintaining a first-in, first-out list of areas of respiration values for a plurality of respiration measurements; calculating a hypopnea threshold from the values in the first-in, first-out list; comparing each area of respiration value with the hypopnea threshold and indicating hypopnea if the area of respiration value fails to meet the threshold either as a single value or multiple values over a period of time; responsive to the detection of indications of sleep disorder breathing, adjusting pressure from the compressor while continuing to measure the pressure and the pressure difference for continued indication of sleep disorder breathing; and responsive to passage of a period without detection of indications of sleep disorder breathing, adjusting pressure of the compressed air. - View Dependent Claims (9, 10, 11, 12, 13)
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14. Apparatus for controlling sleep disorder breathing comprising:
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a source of compressed breathable gas; an interface having a first and a second end, the first end connected to the source of compressed breathable gas and the second end adapted to fit over a person'"'"'s breathing passages; means for measuring differential pressure from the first end to the second end of the interface; means for measuring pressure in the second end of the interface; means for detecting indications in the measurements of sleep disorder breathing from the measurement of pressure and differential pressure, including; means for calculating a mean over a set of sample points taken during an interval and for calculating a standard deviation for the set of sample points; means for accumulating mean values for a plurality of intervals; means for generating an initial base line from the accumulation of mean values for a sequence of intervals of sample points; means for adjusting the initial baseline for each subsequent pressure difference mean calculated; means for generating an area of respiration value from the area difference between the base line and each pressure difference mean calculated; means for maintaining a first-in, first-out list of areas of respiration values for a plurality of respiration measurements; means for calculating a hypopnea threshold from the measurements in the first-in, first-out list; means for comparing each area of respiration value against the hypopnea threshold and for indicating hypopnea if the area fails to meet the threshold either as a single value or multiple values over a period of time; means responsive to detection of indications of sleep disorder breathing for adjusting pressure of breathable gas from the source of breathable gas; and means responsive to passage of a period of time without detection of indication of sleep disorder breathing for adjusting pressure from the source of breathable gas. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A method of diagnosis of sleep disorder breathing, comprising the steps of:
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forcing air through a pressure line to a person'"'"'s breathing passages; periodically sampling a pressure rate variable related to pressure of air in the pressure line; accumulating samples of the pressure rate variable; generating a mean pressure rate for intervals of samples of the pressure rate variable; generating a variance measure for the intervals of samples of the pressure rate variable; comparing the variance measure with a threshold to detect pharyngeal wall vibration; maintaining a running average of mean pressure rates; comparing a generated mean pressure rate against the running average to detect hypopnea or apnea in the patient and signaling the results of the comparing steps where sleep disorder breathing is detected; calculating a hypopnea threshold from the running average of the mean pressure rates; following detection of hypopnea or apnea in the step of comparing the generated mean pressure rate against the running average, comparing the generated mean pressure rate to the hypopnea threshold; applying a secondary oscillating component to the forced air in the flow line; periodically sampling pressure at multiple points in the flow line; accumulating samples of pressure; utilizing the samples of pressure to detect full, partial, or no obstruction of the patient'"'"'s breathing passage; in the step of signaling sleep disorder breathing, where hypopnea but not apnea is detected and no obstruction of the patient'"'"'s nostril passages is detected, signaling central sleep hypopnea; in the step of signaling sleep disorder breathing, where apnea is detected in the hypopnea threshold comparison step and no obstruction of the patient'"'"'s breathing passages is detected, signaling central sleep apnea; in the step of signaling sleep disorder breathing, where hypopnea is detected, but not apnea, and an obstruction of the patient'"'"'s breathing passages is detected, signaling obstructive sleep hypopnea; and in the step of signaling sleep disorder breathing, where apnea is detected and an obstruction of the patient'"'"'s breathing passages is detected, signaling obstructive sleep apnea; responsive to detection of obstructive sleep hypopnea, adjusting pressure of forced air during inhalation by the patient and reducing pressure of forced air during exhalation if above a minimum; responsive to detection of obstructive sleep apnea, increasing pressure of forced air during inhalation and exhalation; and absent detection of sleep disorder breathing, adjusting pressure of forced air during inhalation and exhalation to the minimum. - View Dependent Claims (21)
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22. A method of controlling sleep disorder breathing in a person, the method comprising the steps of:
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connecting an interface from a source of compressed air to a person'"'"'s breathing passages; supplying compressed air from the source of compressed air through the interface to the person'"'"'s breathing passages; continuously measuring flow related variables and pressure variables of the compressed air in the interface by computing a standard deviation value for the measured flow related variables over an interval; continuously generating at least one standard deviation threshold value from the measured flow related variables and measured pressure variables, wherein the standard deviation threshold value is adapted to changing conditions occurring in at least the person'"'"'s breathing passages; comparing the measured flow related variables and measured pressure variables to the standard deviation threshold value to detect indications of sleep disorder breathing from the measured flow related variables and the measured pressure variables by periodically determining if the computed standard deviation value exceeds the standard deviation threshold value and comparing the computed standard deviation value with the standard deviation threshold value over a certain time interval to establish occurrence of pharyngeal wall vibration; responsive to the detection of indications of sleep disorder breathing, adjusting pressure of the compressed air while continuing to measure the measured flow related variables and the measured pressure variables for sleep disorder breathing; and responsive to passage of a period without detection of indications of sleep disorder breathing, adjusting pressure of the compressed air. - View Dependent Claims (23, 24, 25, 26)
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27. Apparatus for controlling sleep disorder breathing comprising:
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a source of compressed breathable gas; means for setting an initial command pressure to control pressure from the compressed breathable gas source at a minimum setting; an interface having a first end and a second end, the first end connected to the source of compressed breathable gas and the second end adapted to fit over a person'"'"'s breathing passages; means for measuring differential pressure from the first end to the second end of the interface; means for measuring pressure in the second end of the interface; means for detecting indications in the measurements of sleep disorder breathing from the measurement of pressure and differential pressure, including; means for setting a minimum standard deviation threshold as a function of the command pressure; means for computing the area and duration of the standard deviation curve above the minimum standard deviation threshold;
means for comparing the area and duration against their corresponding thresholds;means responsive to the area and duration exceeding their respective thresholds for signaling occurrence of pharyngeal wall vibration; means responsive to detection of indications of sleep disorder breathing for adjusting pressure of breathable gas from the source of breathable gas; and means responsive to passage of a period of time without detection of indication of sleep disorder breathing for adjusting pressure from the source of breathable gas. - View Dependent Claims (28, 29, 30, 31, 32)
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33. Apparatus for controlling sleep disorder breathing comprising:
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a source of compressed breathable gas; means for applying a secondary oscillating component to the breathable gas; an interface connected at a first end to the source of compressed breathable gas and adapted at a second end fit over a person'"'"'s breathing passages; means for measuring differential pressure from the first end to the second end of the interface; means for measuring pressure in the second end of the interface; means for detecting indications in the measurements of sleep disorder breathing from the measurement of pressure and differential pressure, including; means for accumulating a plurality of mean pressure difference measurements; means for accumulating a plurality of pressure measurements; means for calculating energy values for the accumulated measurements of pressure differences and pressure; means for determining a phase difference between the pressure measurements and the pressure difference measurements; means for comparing the energy values and the phase difference to thresholds to determine full or partial closure of a patient'"'"'s breathing passages; means responsive to detection of indications of sleep disorder breathing for adjusting pressure of breathable gas from the source of breathable gas; and means responsive to passage of a period of time without detection of indication of sleep disorder breathing for adjusting pressure from the source of breathable gas. - View Dependent Claims (34, 35, 36, 37, 38)
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39. A method of controlling sleep disorder breathing in a person, the method comprising the steps of:
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connecting an interface from a source of compressed air to a person'"'"'s breathing passages; supplying compressed air from the source of compressed air through the interface to the person'"'"'s breathing passages; measuring flow related variables and pressure variables of the compressed air in the interface; detecting from the measured flow related variables and the measured pressure variables indications of sleep disorder breathing by; applying a secondary oscillating component to the compressed air; accumulating a plurality of mean pressure difference measurements; accumulating a plurality of pressure measurements; calculating energy values for the accumulated measurements of pressure differences and pressure; determining a phase difference between the pressure measurements and the pressure difference measurements; comparing the energy values and the phase difference to thresholds to determine full or partial closure of a patient'"'"'s breathing passages; responsive to the detection of indications of sleep disorder breathing, adjusting pressure of the compressed air while continuing to monitor the measured flow related variables and the measured pressure variables for sleep disorder breathing; and responsive to passage of a period without detection of indications of sleep disorder breathing, adjusting pressure of the compressed air. - View Dependent Claims (40, 41, 42, 43)
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Specification