Method and apparatus for optimizing controlled positive airway pressure using the detection of cardiogenic oscillations

• US 6,739,335 B1
• Filed: 09/07/2000
• Issued: 05/25/2004
• Est. Priority Date: 09/08/1999
• Status: Active Grant

• Current Assignee: New York University School of Medicine (New York University)
• Original Assignee: New York University School of Medicine (New York University)
• Inventors: Norman, Robert G., Rapport, David M.
• Primary Examiner(s): Lewis, Aaron J.
• Assistant Examiner(s): MITCHELL, TEENA KAY
• Application Number:
  US09/656,746
• Time in Patent Office: 1,356 Days
• Field of Search: 128/200.24, 128/204.18, 128/204.21, 128/204.23, 128/204.24, 128/203.12, 128/671, 128/672, 128/716, 128/204.26, 600/481, 600/484, 600/501, 600/508, 600/509, 600/529, 600/533, 600/538
• US Class Current: 128/204.18
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2230/40 Respiratory characteristics

Abstract

A method and apparatus for optimizing the controlled positive pressure in treating sleep disordered breathing by using the appearance or disappearance of cardiogenic oscillation in the airway signal as an additional parameter useful for classifying the level of resistance. Ambiguities in breath monitoring can be resolved to determine whether or not breathing is labored due to an obstruction by the presence or absence of cardiogenic oscillations.

Claims

1. In a method for optimizing the amount of positive airway pressure to be applied to a patient receiving continuous positive airway pressure, comprising monitoring to determine whether or not breathing is labored due to an obstruction, and modulating the positive airway pressure based on whether or not an obstruction has been detected;

the improvement comprising resolving any ambiguities observed in the monitored breathing by detecting the presence or absence of cardiogenic oscillations between expiratory periods and between breaths in the airflow of the patient and classifying the ambiguous breath as being labored due to an obstruction if cardiogenic oscillations are absent and classifying the ambiguous breath as not being labored due to an obstruction if cardiogenic oscillations are present, and, if cardiogenic oscillations are present, indicating the absence of an obstruction, changing the airflow to the patient to optimize the airflow to the patient, and, if cardiogenic oscillations are not present, indicating the presence of an obstruction, and adjusting the airflow to the patient to overcome the obstruction.

2. The method according to claim 1, wherein said monitoring to determine whether or not breathing is labored due to an obstruction is accomplished by detecting flow limitation by analyzing an inspiratory waveform.

3. In an apparatus for optimizing the positive airway pressure to be applied to a patient, said apparatus comprising a device which applies an initial level of positive airway pressure of a breathing gas to a patient, a device which monitors the breath of the patient during expiratory periods and between breaths to determine whether or nor breathing is labored due to an obstruction, and a device which modulates the positive airway pressure of breathing gas based upon whether or nor labored breathing due to an obstruction has been detected;

the improvement comprising a device which resolves any ambiguities detected in the breathing by detecting the presence or absence of cardiogenic oscillations in the airflow of the patient, and wherein said device classified any ambiguous breath detected as being labored due to an obstruction if cardiogenic oscillations are absent and classifies the ambiguous breath as not being labored due to an obstruction if cardiogenic oscillations are present.