Auto CPAP system profile information

• US 6,920,877 B2
• Filed: 03/12/2003
• Issued: 07/26/2005
• Est. Priority Date: 11/14/1991
• Status: Expired due to Fees

• Current Assignee: University Technologies International, Inc.
• Original Assignee: University Technologies International, Inc.
• Inventors: Feroah, Thomas Richard, Remmers, John Edward
• Primary Examiner(s): Lewis, Aaron J.
• Application Number:
  US10/386,109
• Publication Number:
  US 20030213488A1
• Time in Patent Office: 867 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23
• US Class Current: 128/204.18
• 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 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2205/3553 remote, e.g. between patient's home and doctor's office
• CPC Class Codes: A61M 2205/3561 local, e.g. within room or hospital

Abstract

The present invention relates to systems and methods for automatically and continuously regulating the level of nasal pressure to an optimal value during OSA treatment. OSA therapy is implemented by a device which automatically re-evaluates an applied pressure and continually searches for a minimum pressure required to adequately distend a patient'"'"'s pharyngeal airway. For example, this optimal level varies with body position and stage of sleep throughout the night. In addition, this level varies depending upon the patient'"'"'s body weight and whether or not alcohol or sleeping medicine has been ingested.

Claims

1. A pressure support system comprising:

a pressure generating system adapted to generate a flow of gas at a selectable pressure level;

a patient circuit having a first end adapted to be coupled to the pressure generating system and a second end adapted to be coupled to an airway of a patient;

a monitoring system associated with the patient circuit or the pressure generating system and adapted to determine a parameter indicative of a pressure at a patient'"'"'s airway, a flow of gas in such a patient'"'"'s airway, or both; and

a controller coupled to the monitoring system and the pressure generating system, wherein the controller is programmed to search for a critical pressure (P_crit) at which obstruction of such a patient'"'"'s airway occurs by (a) causing the pressure generating system to lower a pressure of the flow of gas delivered to such a patient by a first amount and (b) monitoring the parameter, and wherein, after P_crit is determined, the controller is programmed to search for an optimum pressure (P_opt) sufficient to treat the obstruction by causing the pressure generating system to increase the pressure of the flow of gas delivered to such a patient.

2. The system of claim 1, wherein the controller initiates the search for P_crit based on an increment between P_crit searches.

3. The system of claim 1, wherein the controller determines whether such a patient is experiencing a breathing instability based on the parameter and, wherein the controller deays the search for P_crit or the search for P_opt responsive to detection of the breathing instability.

4. The system of claim 1, wherein the controller determines whether such a patient is experiencing a breathing instability based on the parameter and, wherein the controller terminates the search for P_crit or the search for P_opt responsive to detection of the breathing instability.

5. The system of claim 1, wherein the controller performs a scan test before the search for P_crit, wherein the scan test includes (a) causing the pressure generating system to lower the pressure of the flow of gas delivered to such a patient by a second amount that is greater than the first amount, and (b) monitoring the parameter.

6. The system of claim 1, wherein monitoring the parameter includes monitoring a roundness, a flatness, or both of the parameter.

7. The system of claim 1, wherein searching for P_opt includes (a) monitoring the parameter at a first airway pressure and at a second pressure that is greater than the first pressure, and (b) comparing the parameter at the first airway pressure and the parameter at the second pressure.

8. The system of claim 1, wherein the controller conducts a post-test following a pressure change to determine whether the pressure change reduced airway instability, increased a flow of leakage gas, or both.

9. A method of providing pressure support to an airway of a patient comprising:

delivering a flow of gas to an airway of a patient;

determining a parameter indicative of a pressure at a patient'"'"'s airway, a flow of gas in such a patient'"'"'s airway, or both;

searching for a critical pressure (P_crit) at which obstruction of such a patient'"'"'s airway occurs by (a) lowering a pressure of the flow of gas delivered to a patient by a first amount and (b) monitoring the parameter; and

searching for an optimum pressure (P_opt) sufficient to treat the obstruction, after P_crit is determined, by increasing the pressure of the flow of gas delivered to a patient.

10. The method of claim 9, further comprising monitoring an increment between P_crit searches and initiating the search for P_crit based on the monitored increment.

11. The method of claim 9, further comprising:

determining whether such a patient is experiencing a breathing instability based on the parameter; and

delaying searching for P_crit or searching for P_opt responsive to detection of a breathing instability.

12. The method of claim 9, further comprising:

determining whether such a patient is experiencing a breathing instability based on the parameter and

terminating searching the search for P_crit or searching for P_opt responsive to detection of a breathing instability.

13. The method of claim 9, further comprising performing a scan test before searching for P_crit, wherein the scan test includes (a) lowering the pressure of the flow of gas delivered to such a patient a second amount that is greater than the first amount and (b) monitoring the parameter.

14. The method of claim 9, wherein monitoring the parameter for an indication of breathing instability includes monitoring a roundness, a flatness, or both of the parameter.

15. The method of claim 9, wherein searching for P_opt includes (b) monitoring the parameter at a first airway pressure and the parameter at a second pressure that is greater than the first pressure and (b) comparing the parameter at the first airway pressure and the parameter at the second pressure.

16. The method of claim 9, further comprising conducting a post-test following a pressure change to determine whether the pressure change reduced airway instability, increased a flow of leakage gas, or both.

17. A pressure support system comprising:

pressure generating means for delivering a flow of gas to an airway of a patient;

monitoring means for determining a parameter indicative of a pressure at a patient'"'"'s airway, a flow of gas in such a patient'"'"'s airway, or both;

controlling means for (1) searching for a critical pressure (P_crit) at which obstruction of such a patient'"'"'s airway occurs by (a) causing the pressure generating means to lower a pressure of the flow of gas delivered to a patient by a first amount and (b) monitoring the parameter, and (2) searching for an optimum pressure (P_opt) sufficient to treat the obstruction after P_crit is determined by causing the pressure generating means to increase the pressure of the flow of gas delivered to a patient.

18. The system of claim 17, wherein the controlling means monitors an increment between P_crit searches and initiates the search for P_crit based on the monitored increment.

19. The system of claim 17, wherein the controlling means determines whether such a patient is experience a breathing instability based on the parameter, and delays searching for P_crit or delays searching for P_opt responsive to detection of the breathing instability.

20. The system of claim 17, wherein the controlling means determines whether such a patient is experience a breathing instability based on the parameter, and terminates the search the search for P_crit or the search for P_opt responsive to detection of the breathing instability.

21. The system of claim 17, wherein the controlling means performs a scan test before searching for P_crit wherein the scan test includes (a) lowering the pressure of the flow of gas delivered to such a patient a second amount that is greater than the first amount and (b) monitoring the parameter.

22. The method of claim 17, wherein the controlling means monitors the parameter for an indication of breathing instability by monitoring a roundness, a flatness, or both of the parameter.

23. The method of claim 17, wherein searching for P_opt includes monitoring the parameter at a first airway pressure and at a second pressure that is greater than the first pressure and comparing the parameter at the first airway pressure and the parameter at the second pressure.

24. The method of claim 17, wherein the controlling means conducts a post-test following a pressure change to determine whether the pressure change reduced airway instability, increased a flow of leakage gas, or both.