Apparatus and method of providing continuous positive airway pressure

• US 6,401,713 B1
• Filed: 03/31/2000
• Issued: 06/11/2002
• Est. Priority Date: 05/05/1999
• Status: Expired due to Term

• Current Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Original Assignee: Respironics Incorporated
• Inventors: Mechlenburg, Douglas M., Hill, Peter D., Estes, Mark C.
• Primary Examiner(s): Dawson, Glenn K.
• Application Number:
  US09/539,386
• Time in Patent Office: 802 Days
• Field of Search: 128/200.24, 128/204.18, 128/204.21, 128/205.23, 128/205.24, 128/205.25, 128/848
• US Class Current: 128/204.21
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/161 with means for measuring the humidity
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/3561 local, e.g. within room or hospital

Abstract

A pressure support system and method in which a gas flow generating system provides a continuous flow of breathing gas at selectable pressure levels. A patient circuit and interface communicate the continuous flow of breathing gas to the airway of a patient. A controller causes the gas flow generating system to provide the continuous flow of breathing gas to the patient at a first pressure level P₁ in an initial therapy session. Thereafter, the pressure level of the continuous flow of breathing gas is increased from the first pressure level P₁ to a final pressure level P₂ over a first predetermined number D of days. More specifically, in one embodiment, the pressure level is incrementally increased by a predetermined incremental amount Δp after n therapy sessions taking place on separate days over this first predetermined number D of days. As a result, the current therapy pressure in each therapy session that takes place on separate days following the initial therapy session is incrementally and automatically increased.

Claims

1. A pressure support system comprising:

a gas flow generating system adapted to generate a continuous flow of breathing gas at selectable pressures;

a patient circuit having a first end coupled to an output of said gas flow generating system to communicate said continuous flow of breathing gas to a patient;

a patient interface coupled to a second end of said patient circuit to communicate said continuous flow of breathing gas from said patient circuit to an airway of a patient;

usage tracking means for monitoring usage of the pressure support system by a patient;

a controller operatively coupled to said usage tracking means and said gas flow generating system, wherein said controller outputs a control signal to said gas flow generating system to control said gas flow generating system, wherein said controller determines whether such a patient has completed a therapy session based on an output of said usage tracking means, and wherein said controller causes said gas flow generating system to provide said continuous flow of breathing gas to such a patient at a first pressure P₁ in an initial therapy session and increases said pressure of said continuous flow of breathing gas from said first pressure P₁ to a final pressure P₂ over a first predetermined number D of therapy sessions, so that a current pressure P_current of said continuous flow of breathing gas provided to a patient in a current therapy session following said initial therapy session is greater than a pressure provided to such a patient in a previous therapy session.

2. A pressure support system according to claim 1, wherein said controller increases said pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating system to increase said pressure of said flow of breathing gas by a predetermined incremental amount Δ

p after every n therapy session(s) over said first predetermined number D of therapy sessions.

3. A pressure support system according to claim 2, wherein n is equal to one, so that an increase in said pressure of said continuous flow of breathing gas provided to a patient by said predetermined amount Δ

p from said first pressure to said final pressure occurs after such a patient completes each therapy session following said initial therapy session.

4. A pressure support system according to claim 2, wherein said controller causes said gas flow generating system to output said continuous flow of breathing gas at a constant pressure during a major portion of a therapy session.

5. A pressure support system according to claim 2, wherein said controller automatically determines said predetermined amount Δ

p by subtracting said first pressure P₁ from said final pressure P₂ and dividing a result by said first predetermined number D of therapy sessions.

6. A pressure support system according to claim 2, wherein said controller causes said gas flow generating system to output said continuous flow of breathing gas at (1) a pressure of a last therapy session or (2) a pressure of a last therapy session increased by said predetermined incremental amount Δ

p responsive to said controller determining that a therapy session was not completed on a preceding day.

7. A pressure support system according to claim 6, wherein said controller also increments said first predetermined number D of therapy sessions by one if a therapy session was not completed on a preceding day.

8. A pressure support system according to claim 6, wherein said controller recalculates said predetermined incremental amount Δ

p by subtracting a current pressure from said final pressure P₂ and dividing a result by a number of therapy sessions remaining until said first predetermined number D of therapy sessions is reached, if a therapy session was not completed on a preceding day.

9. A pressure support system according to claim 1, wherein said controller increases a pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating system to increase a pressure of said flow of breathing gas by a predetermined incremental amount Δ

p after n therapy sessions over a first predetermined number of days.

10. A pressure support system according to claim 1, wherein said controller increases a pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating system to increase said current pressure P_current of said flow of breathing gas on a continuous basis during operation of said pressure support system.

11. A pressure support system according to claim 1, wherein said controller determines a therapy start date of said initial therapy session and, at each subsequent therapy session, said controller determines a number of days that have elapsed since said therapy start date and sets a pressure at which said continuous flow of breathing gas is to be provided to said patient during a current therapy session based on said number of days elapsed since said therapy start date.

12. A pressure support system according to claim 1, wherein, in a therapy session, said controller causes said gas flow generating system to output said continuous flow of breathing gas at an initial low pressure and increases said pressure to said current pressure P_current over a period of time.

13. A pressure support system according to claim 1, wherein said gas flow generating system includes:

a flow generator that outputs a substantially constant predetermined flow of breathing gas; and

a breathing gas pressure controller operatively coupled to said flow generator and said controller, wherein said breathing gas pressure controller varies a pressure of the flow of breathing gas output from said flow generator based on an output from said controller to provide said flow of breathing gas at a selected pressure.

14. A pressure support device comprising:

gas flow generating means for providing a continuous flow of breathing gas at selectable pressure levels;

means for communicating said continuous flow of breathing gas to an airway of a patient;

usage tracking means for monitoring usage of the pressure support device by a patient;

control means for determining whether such a patient has completed a therapy session based on an output of said usage tracking means and for causing said gas flow generating means to provide said continuous flow of breathing gas to such a patient at a first pressure P₁ in an initial therapy session and to increase said pressure of said continuous flow of breathing gas from said first pressure P₁ to a final pressure P₂ over a first predetermined number D of therapy sessions so that a current pressure P_current of said continuous flow of breathing gas provided to a patient in a current therapy session following said initial therapy session is greater than a pressure provided to such a patient in a previous therapy session.

15. A pressure support device according to claim 14, wherein said control means increases a pressure of said continuous flow of breathing gas provided to said patient in subsequent therapy sessions until the final pressure level P₂ is reached or a number of days D elapse.

16. A pressure support device according to claim 14, wherein said control means increases a pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating means to increase a pressure of said flow of breathing gas by a predetermined incremental amount Δ

p after every n therapy sessions over said first predetermined number D of therapy sessions.

17. A pressure support device according to claim 16, further comprising input/output means for entering said first pressure P₁, said final pressure P₂, and said number D of therapy sessions, wherein said control means sets said predetermined amount Δ

p as follows;

Δ

p=(P₂−

P₁)/D.

18. A pressure support device according to claim 16, wherein said control means sets a current pressure P_current provided to a patient in a therapy session subsequent to said initial therapy session as follows:

P_current=Δ

p*N+P₁, where N is an integer corresponding to a number of therapy sessions that have been completed since said initial therapy session.

19. A pressure support device according to claim 16, wherein said control means causes said gas flow generating means to output said continuous flow of breathing gas at (1) a pressure level of a last therapy session or (2) a pressure level of a last therapy session increased by said predetermined incremental amount Δ

p responsive to said controller determining that a therapy session was not completed on a preceding day.

20. A pressure support device according to claim 14, wherein said control means increases said pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating system to increase said pressure of said flow of breathing gas by a predetermined incremental amount Δ

p after n therapy sessions over said first predetermined number D of therapy sessions.

21. A pressure support system according to claim 20, wherein n is equal to one so that an increase in said pressure of said continuous flow of breathing gas provided to a patient by said predetermined amount Δ

p from said first pressure to said final pressure occurs after such a patient completes each therapy session following said initial therapy session.

22. A pressure support device according to claim 14, wherein said control means increases a pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating system to increase a current pressure P_current of said flow of breathing gas on a continuous basis during operation of said pressure support device.

23. A pressure support device according to claim 14, wherein, in a therapy session, said control means causes said gas flow generating system to output said continuous flow of breathing gas at an initial low pressure and increases said pressure to a current pressure over a period of time, wherein said period of time is measured by one of a clock source and a respiratory count of a patient.

24. A method of providing pressure support to a patient, comprising:

(a) providing a continuous flow of breathing gas to a patient at a first pressure P₁ in an initial therapy session by means of a gas flow generating system that operates under control of a controller based on a control signal provided to said gas flow generating system by said controller;

(b) determining whether a patient has completed a therapy session in which such a patient receives said flow of breathing gas for a predetermined period of time;

(c) increasing said pressure of said continuous flow of breathing gas from said first pressure P₁ to a final pressure P₂ over a first predetermined number D of therapy sessions so that a current pressure P_current of said continuous flow of breathing gas provided to a patient in a current therapy session following said initial therapy session is greater than a pressure provided to such a patient in a previous therapy session responsive to such a patient having completed a therapy session; and

(d) repeating step (c) until the final pressure level P₂ is reached or a predetermined number D of therapy sessions elapse.

25. A pressure support system according to claim 24, wherein said increasing step includes increasing a pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating system to increase a pressure of said flow of breathing gas by a predetermined incremental amount Δ

p after every n therapy sessions over said first predetermined number D of therapy sessions.

26. A method according to claim 25, further comprising manually entering said first pressure level P₁, said final pressure level P₂, and said first predetermined number D of therapy sessions to said controller, and wherein said controller automatically calculates said predetermined amount Δ

p as follows;

Δ

p=(P₁−

P₁)/D.

27. A method according to claim 25, wherein said step (c) includes setting a current pressure P_current provided to a patient in a therapy session as follows:

P_current=Δ

p*N+P₁, where N is an integer corresponding to a number of therapy sessions since said initial therapy session.

28. A method according to claim 25, further comprising providing said continuous flow of breathing gas at (1) a pressure level of a last therapy session or (2) a pressure level of a last therapy session increased by said predetermined incremental amount Δ

p responsive to said controller determining that a therapy session was not completed on a preceding day.

29. A method according to claim 24, wherein said step (c) includes outputting said continuous flow of breathing gas at an initial low level and increasing said pressure to a current therapy level over a period of time, wherein said period of time is measured by one of a clock source and a respiratory count of a patient.

30. A method according to claim 24, wherein said increasing step includes increasing a pressure of said continuous flow of breathing gas from said first pressure P₁ to said final pressure P₂ over said first predetermined number D of therapy sessions by causing said gas flow generating system to increase a current pressure P_current of said flow of breathing gas on a continuous basis during operation of said pressure support system.