Apnea and hypopnea detection
First Claim
1. A method for identifying obstructed breathing by a patient undergoing continuous positive airway pressure therapy, including at least one of an apnea condition and a hypopnea condition, the method comprising:
- receiving a signal representative of a flow rate of therapeutic gas being delivered to the patient for a predetermined time window over a plurality of respiration cycles;
deriving a peak flow value of each of the respiration cycles within the predetermined time window;
deriving a minimum flow value of each of the respiration cycles within the predetermined time window;
generating a polynomial difference function from the peak flow values of a plurality of the respiration cycles in the predetermined window and the minimum flow values of a plurality of the respiration cycles in the predetermined window;
deriving a respiration index from a minimum of the polynomial difference function;
indicating the at least one of the apnea condition and the hypopnea condition based upon a comparison of the respiration index to a predefined obstruction threshold over a predefined obstruction time period; and
actuating a ventilation source of the therapeutic gas in accordance with the indicated at least one of the apnea condition and the hypopnea condition.
11 Assignments
0 Petitions
Accused Products
Abstract
The identification of obstructed breathing, including an apnea condition and a hypopnea condition, is disclosed. A signal representative of a flow rate of therapeutic gas being delivered to the patient is received. A peak flow value and a minimum flow value over a predetermined time window encompassing a plurality of respiration cycles is derived. A polynomial difference equation from the peak flow values and the minimum flow values is generated, and a respiration index from a minimum of the polynomial difference equation is derived. The apnea and/or hypopnea condition is indicated based upon a comparison of the respiration index to a predefined obstruction threshold over a predefined obstruction time period.
7 Citations
24 Claims
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1. A method for identifying obstructed breathing by a patient undergoing continuous positive airway pressure therapy, including at least one of an apnea condition and a hypopnea condition, the method comprising:
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receiving a signal representative of a flow rate of therapeutic gas being delivered to the patient for a predetermined time window over a plurality of respiration cycles; deriving a peak flow value of each of the respiration cycles within the predetermined time window; deriving a minimum flow value of each of the respiration cycles within the predetermined time window; generating a polynomial difference function from the peak flow values of a plurality of the respiration cycles in the predetermined window and the minimum flow values of a plurality of the respiration cycles in the predetermined window; deriving a respiration index from a minimum of the polynomial difference function; indicating the at least one of the apnea condition and the hypopnea condition based upon a comparison of the respiration index to a predefined obstruction threshold over a predefined obstruction time period; and actuating a ventilation source of the therapeutic gas in accordance with the indicated at least one of the apnea condition and the hypopnea condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for identifying obstructed breathing by a patient undergoing continuous positive airway pressure therapy, the method comprising:
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receiving a signal representative of a flow rate of therapeutic gas being delivered to the patient for a predetermined time window over a plurality of respiration cycles; deriving a peak flow value of each respiration cycle within the predetermined time window; deriving a minimum flow value of each respiration cycle within the predetermined time window; generating a polynomial difference function from the peak flow values of a plurality of the respiration cycles in the predetermined window and the minimum flow values of a plurality of the respiration cycles in the predetermined window; deriving an apnea index from a minimum of the polynomial difference function; if the apnea index is less than a predefined apnea threshold over a predefined time period, indicating an apnea condition; and actuating a ventilation source of the therapeutic gas in accordance with the indicated apnea condition. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. An article of manufacture comprising a program storage medium readable by a data processing apparatus, the medium tangibly embodying one or more programs of instructions executable by the data processing apparatus to perform a method for identifying obstructed breathing by a patient undergoing continuous positive airway pressure therapy, including at least one of an apnea condition and a hypopnea condition, the method comprising:
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receiving from a signal representative of a flow rate of therapeutic gas being delivered to the patient for a predetermined time window over a plurality of respiration cycles; deriving a peak flow value of each respiration cycle within the predetermined time window; deriving a minimum flow value of each respiration cycle within the predetermined time window; generating a polynomial difference function from the peak flow values of a plurality of the respiration cycles in the predetermined window and the minimum flow values of a plurality of the respiration cycles in the predetermined window; deriving a respiration index from a minimum of the polynomial difference function; indicating the at least one of the apnea condition and the hypopnea condition based upon a comparison of the respiration index to a predefined obstruction threshold over a predefined obstruction time period; and actuating a ventilation source of the therapeutic gas in accordance with the indicated at least one of the apnea condition and the hypopnea condition. - View Dependent Claims (20, 21, 22, 23, 24)
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Specification