Auto-titration bi-level pressure support system and method of using same

• US 20060000475A1
• Filed: 09/01/2005
• Published: 01/05/2006
• Est. Priority Date: 10/12/2001
• Status: Active Grant

• Current Assignee: Philips RS North America LLC (Koninklijke Philips N.V.)
• Original Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Inventors: Martin, Daniel, Matthews, Greg, Duff, Winslow K., Ressler, Heater, Shankar, Uday S.
• Granted Patent: US 7,938,114 B2
• Time in Patent Office: Days
• US Class Current: 128/204.210
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0063 Compressors
• 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 16/204 used for inhalation control
• 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 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation

Abstract

A bi-level pressure support system and method of treating disordered breathing that optimizes the pressure delivered to the patient during inspiration and expiration to treat the disordered breathing while minimizing the delivered pressure for patient comfort. The pressure generating system generates a flow of breathing gas at an inspiratory positive airway pressure (IPAP) during inspiration and at an expiratory positive airway pressure (EPAP) during expirations. A controller monitor at least one of the following conditions: (1) snoring, (2) apneas, (3) hypopneas, or (4) a big leak in the pressure support system and adjusts the IPAP and the EPAP independently based on the occurrence of any one of these conditions.

Claims

1. A bi-level auto-titration pressure support system comprising:

(a) a pressure generating system adapted to generate a flow of breathing gas at an inspiratory positive airway pressure (IPAP) during inspiration and at an expiratory positive airway pressure (EPAP) during expiration;

(b) 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;

(c) a monitoring system associated with the patient circuit or the pressure generating system and adapted to measure a parameter indicative of a pressure at a patient'"'"'s airway, a flow of gas in such a patient'"'"'s airway, or both and to output a pressure signal, a flow signal indicative thereof, respectively, or both; and

(d) a controller coupled to the monitoring system and the pressure generating system, for controlling the pressure generating system based on the output of the monitoring system, wherein the controller is programmed to monitor at least one of the following conditions;

(1) snoring, (2) apneas, (3) hypopneas, or (4) a big leak in the pressure support system, wherein the big leak is a system leak that is substantially greater than any intentional system leaks, and wherein the controller adjusts the IPAP and the EPAP independently based on the occurrence of any one of conditions (1), (2), (3), or (4).

2. The system of claim 1, wherein the controller performs an auto-titration process in which the controller adjusts the IPAP and the EPAP independently to determine an optimal IPAP for the patient.

3. The system of claim 1, wherein the controller causes the pressure generating system to increase the EPAP without changing the IPAP, responsive to a determination that the patient is snoring, is experiencing only apneas, or is experiencing a combination of apneas and hypopneas.

4. The system of claim 1, wherein the controller causes the pressure generating system to decrease the IPAP without changing the EPAP, responsive to a detection of the big leak.

5. The system of claim 1, wherein the controller causes the pressure generating system to increase the IPAP without changing the EPAP, responsive to a determination that the patient is snoring or experiencing only hypopneas.

6. The system of claim 1, wherein the controller:

(a) controls one of the IPAP or the EPAP as a primary pressure control variable,

(b) compares a current pressure support (PS) level to a maximum pressure support (PS_max) level, a minimum pressure support level (PS_min), or both, and

(c) causes the pressure generating system to adjust a remaining other of the IPAP or the EPAP so that the current PS level does not exceed the PS_max or does not fall below PS_min.

7. The system of claim 1, wherein the controller causes the pressure generating system to provide the IPAP, the EPAP, or both at substantially constant levels during an inspiratory phase and an expiratory phase, respectively, of a patient'"'"'s respiratory cycle.

8. The system of claim 1, wherein the controller:

(a) causes the pressure generating system to reduce or modify the EPAP during at least a portion of the expiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the expiratory phase;

(b) causes the pressure generating system to reduce or modify the IPAP during at least a portion of the inspiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the inpiratory phase;

or

(c) causes the pressure generating system to reduce or modify the EPAP during at least a portion of the expiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the expiratory phase, and causes the pressure generating system to reduce or modify the IPAP during at least a portion of the inspiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the inpiratory phase.

9. The system of claim 1, wherein the controller chooses between adjusting either the EPAP, the IPAP, or a combination of IPAP and EPAP based on a monitored condition of the patient, a monitored condition of the pressure support system, an input provided to the pressure support system, or any combination thereof.

10. The system of claim 1, further comprising an input device for selecting activation of a ramp cycle, wherein the controller (a) decreases the IPAP and the EPAP responsive to activation of the pressure ramp, and (b) thereafter increases the IPAP and EPAP, and wherein the controller adjusts the IPAP and the EPAP independently during a pressure increase portion of the ramp cycle.

11. A method of providing a bi-level auto-titration pressure support therapy to a patient, comprising:

(a) generating a flow of gas at an inspiratory positive airway pressure (IPAP) during inspiration and at an expiratory positive airway pressure (EPAP) during expirations;

(b) coupling a first of a patient circuit to the pressure generating system and coupling a second end of the patient circuit an airway of a patient;

(c) monitor at least one of the following conditions;

(1) snoring, (2) apneas, (3) hypopneas, or (4) a big leak in the pressure support system, based on a pressure of a rate of the flow of gas, wherein the big leak is a leak that is substantially greater than any intentional system leaks; and

(d) adjusting the IPAP and the EPAP independently based on the occurrence of any one of conditions (1), (2), (3), or (4).

12. The method of claim 11, further comprising performing an auto-titration process in which the IPAP and the EPAP are adjusted independently to determine an optimal IPAP for the patient.

13. The method of claim 11, wherein adjusting the IPAP and the EPAP independently includes increasing the EPAP without changing the IPAP, responsive to a determination that the patient is snoring, is experiencing only apneas, or is experiencing a combination of apneas and hypopneas.

14. The method of claim 11, wherein adjusting the IPAP and the EPAP independently includes decreasing the IPAP without changing the EPAP, responsive to a detection of the big leak.

15. The method of claim 11, wherein adjusting the IPAP and the EPAP independently includes increasing the IPAP without changing the EPAP, responsive to a determination that the patient is snoring or experiencing only hypopneas.

16. The method of claim 11, further comprising:

(a) controlling one the IPAP or the EPAP as a primary pressure control variable,

(b) comparing a current pressure support (PS) level to a maximum pressure support (PS_max) level, a minimum pressure support level (PS_min), or both, and

(c) adjusting a remaining other of the IPAP or the EPAP so that the current PS level does not exceed the PS_max or does not fall below PS_min.

17. The method of claim 11, wherein the IPAP, the EPAP, or both are maintained at substantially constant levels during an inspiratory phase and an expiratory phase, respectively, of a patient'"'"'s respiratory cycle.

18. The method of claim 11, further comprising:

(a) reducing or modifying the EPAP during at least a portion of the expiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the expiratory phase;

(b) reducing or modifying the IPAP during at least a portion of the inspiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the inspiratory phase;

or

(c) reducing or modifying the EPAP during at least a portion of the expiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the expiratory phase, and reducing or modifying the IPAP during at least a portion of the inspiratory phase by some amount to provide a degree of pressure relief during the at least a portion of the inpiratory phase.

19. The method of claim 11, further comprising choosing between adjusting either the EPAP, the IPAP, or a combination of EPAP and IPAP based on a monitored condition of the patient, a monitored condition of a pressure support system that provides a flow of gas to such a patient, an input provided to the pressure support system, or any combination thereof.

20. The method of claim 11, executing a ramp cycle that includes:

(a) decreasing the IPAP and the EPAP responsive to activation of the ramp cycle, and

(b) thereafter increasing the IPAP and EPAP, wherein the IPAP and the EPAP are permitted to be adjusted independently during a pressure increase portion of the ramp cycle.

21. A bi-level auto-titration pressure support system comprising:

a pressure generating system adapted to generate a flow of breathing gas at an inspiratory positive airway pressure (IPAP) during inspiration and at an expiratory positive airway pressure (EPAP) during expiration;

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 measure a parameter indicative of a pressure at a patient'"'"'s airway, a flow of gas in such a patient'"'"'s airway, or both and to output a pressure signal indicative thereof, a flow signal indicative thereof, respectively, or both; and

a controller coupled to the monitoring system and the pressure generating system, and adapted to control the IPAP and the EPAP independently based on the output of the monitoring system, wherein the controller is programmed to operate according to one control layer in a set of prioritized control layers, wherein each control layer in the set of prioritized control layers competes for control of the pressure generating system with the other control layers, and wherein each control layer implements a unique pressure control process for controlling the IPAP, the EPAP, or both.

22. The system of claim 21, wherein each control layer in the set of prioritized control layer includes:

a detection module that receives the pressure signal, the flow signal, or both;

a monitoring module that monitors an output of the detection module to determine whether to request that the control layer take control of the pressure generating system; and

a control module that controls the operation of the pressure generating system responsive to the control layer being granted control thereof.

23. The system of claim 21, wherein the set of prioritized control layers include:

(a) flow limit control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a large leak indicative of the patient circuit not being connected to an airway of a patient, and causes the pressure generating system to lower the IPAP, the EPAP, or both responsive to detection of the large leak and maintains the pressure generating system at the lower pressure;

(b) snore control layer that monitors the flow signal, the pressure signal, or both for snoring, and causes the pressure generating system to increase the IPAP, the EPAP, or both responsive to detection of snore;

(c) a big leak control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a leak that is less than the large leak but great enough to cause the pressure support system to not operate reliably, and causes the pressure generating system to lower the IPAP, the EPAP, or both responsive to detection of the large leak for predetermined period of time;

(d) an apnea/hypopnea control layer that monitors the flow signal, the pressure signal, or both to determine whether the patient is experiencing an apnea, a hypopnea, or both, and causes the pressure generating system to adjust the IPAP, the EPAP, or both responsive to detection of apnea, hypopnea, or both;

(e) a variable breathing control layer that monitors the flow signal to determine whether the patient is experiencing erratic breathing, and causes the pressure generating system to adjust the IPAP, the EPAP, or both responsive to detection of erratic breathing; and

(f) an auto-titration control layer that controls the IPAP, the EPAP, or both responsive to proactively search for a pressure that optimizes the pressure provided to the patient to treat disordered breathing.

24. The system of claim 23, wherein:

(1) the flow limit control layer has a higher priority than the snore control layer, the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-titration control layer;

(2) the snore control layer has a higher priority than the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-titration control layer and has a lower priority than the flow limit control layer;

(3) the big leak control layer has a higher priority than the apnea/hypopnea control layer, the variable breathing control layer, and the auto-titration control layer and has a lower priority than the flow limit control layer and the snore control layer;

(4) the apnea/hypopnea control layer has a higher priority than the variable breathing control layer, and the auto-titration control layer and has a lower priority than the flow limit control layer, the snore control layer, and the big leak control layer; and

(5) the variable breathing control layer has a higher priority than the auto-titration control layer and has a lower priority than the flow limit control layer, the snore control layer, the big leak control layer, and the apnea/hypopnea control layer.

25. The system of claim 21, further comprising a manual input for controlling the operation of the pressure support system, and wherein the set of prioritized control layers include at least one first control layer that is initiated based on the manual input and at least one second control layer that is initiated based on the pressure signal, the flow signal or both, wherein the at least one first control layer has a higher priority than the at least one second control layer.

26. The system of claim 25, wherein the first control layer is a ramp control layer that causes the pressure generating system to gradually increase the IPAP, the EPAP, or both from a relatively low level to a target level responsive to receipt of a ramp activation signal as the manual input.

27. The system of claim 26, wherein the second control layer includes at least one of the following control layers:

(a) flow limit control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a large leak indicative of the patient circuit not being connected to an airway of a patient, and causes the pressure generating system to lower the IPAP, the EPAP, or both responsive to detection of the large leak and maintains the pressure generating system at the lower pressure;

(b) snore control layer that monitors the flow signal, the pressure signal, or both for snoring, and causes the pressure generating system to increase the IPAP, the EPAP, or both responsive to detection of snore;

(c) a big leak control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a leak that is less than the large leak but great enough to cause the pressure support system to not operate reliably, and causes the pressure generating system to lower the IPAP, the EPAP, or both responsive to detection of the large leak for predetermined period of time;

(d) an apnea/hypopnea control layer that monitors the flow signal, the pressure signal, or both to determine whether the patient is experiencing an apnea, a hypopnea, or both, and causes the pressure generating system to adjust the IPAP, the EPAP, or both responsive to detection of apnea, hypopnea, or both;

(e) a variable breathing control layer that monitors the flow signal to determine whether the patient is experiencing erratic breathing, and causes the pressure generating system to adjust the IPAP, the EPAP, or both responsive to detection of erratic breathing; and

(f) an auto-titration control layer that controls the pressure of the flow of breathing gas responsive to actively search for a pressure that optimizes the IPAP, the EPAP, or both provided to the patient to treat disordered breathing.

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

generate a flow of breathing gas at an inspiratory positive airway pressure (IPAP) during inspiration and at an expiratory positive airway pressure (EPAP) during expiration;

monitoring a pressure, a flow, or both of the flow of breathing gas and outputting a pressure signal, a flow signal indicative thereof, respectively, or both;

selecting a control layer from a set of prioritized control layers based on the pressure signal, the flow signal, or both; and

controlling the IPAP, the EPAP, or both according to a pressure control technique unique to the selected pressure control layer.

29. The method of claim 28, wherein the set of prioritized control layers include:

(a) flow limit control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a large leak indicative of the patient circuit not being connected to an airway of a patient, and causes the pressure generating system to lower the IPAP, the EPAP, or both responsive to detection of the large leak and maintains the pressure generating system at the lower pressure;

(b) snore control layer that monitors the flow signal, the pressure signal, or both for snoring, and causes the pressure generating system to increase the IPAP, the EPAP, or both responsive to detection of snore;

(c) a big leak control layer that monitors the flow signal to determine whether the pressure generating system is exhibiting a leak that is less than the large leak but great enough to cause the pressure support system to not operate reliably, and causes the pressure generating system to lower the IPAP, the EPAP, or both responsive to detection of the large leak for predetermined period of time;

(d) an apnea/hypopnea control layer that monitors the flow signal, the pressure signal, or both to determine whether the patient is experiencing an apnea, a hypopnea, or both, and causes the pressure generating system to adjust the IPAP, the EPAP, or both responsive to detection of apnea, hypopnea, or both;

(e) a variable breathing control layer that monitors the flow signal to determine whether the patient is experiencing erratic breathing, and causes the pressure generating system to adjust the IPAP, the EPAP, or both responsive to detection of erratic breathing; and

(f) an auto-titration control layer that controls the pressure of the flow of breathing gas responsive to actively search for a pressure that optimizes the IPAP, the EPAP, or both provided to the patient to treat disordered breathing.

30. The method of claim 29, wherein selecting a control layer includes:

(1) selecting the flow limit control layer over the snore control layer, the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-titration control layer;

(2) selecting the snore control layer over the big leak control layer, the apnea/hypopnea control layer, the variable breathing control layer, and the auto-titration control layer but not over the flow limit control layer;

(3) selecting the big leak control layer over the apnea/hypopnea control layer, the variable breathing control layer, and the auto-titration control layer but not over the flow limit control layer and the snore control layer;

(4) selecting the apnea/hypopnea control layer over the variable breathing control layer and the auto-titration control layer but not over the flow limit control layer, the snore control layer, and the big leak control layer; and

(5) selecting the variable breathing control layer over the auto-titration control layer but not over the flow limit control layer, the snore control layer, the big leak control layer, and the apnea/hypopnea control layer.

31. The method of claim 30, further comprising receiving a manual input for controlling the operation of a pressure support system adapted to implement the method of providing pressure support, wherein the set of prioritized control layers include at least one first control layer that is initiated based on the manual input and at least one second control layer that is initiated based on the pressure signal, the flow signal, or both, wherein the selecting step includes selecting the at least one first control layer over the at least one second control layer.