Methods and apparatus for providing ventilation to a patient

• US 9,597,468 B2
• Filed: 11/07/2012
• Issued: 03/21/2017
• Est. Priority Date: 11/07/2011
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated), University Of Essen
• Original Assignee: Redmed Limited
• Inventors: Schindhelm, Klaus Henry, Malouf, Gordon Joseph, Farrugia, Steven Paul, Dennis, Clancy John, Berthon-Jones, Michael, Bassin, David John, Teschler, Helmut
• Primary Examiner(s): Dixon, Annette
• Application Number:
  US14/356,471
• Publication Number:
  US 20140290658A1
• Time in Patent Office: 1,595 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23, 128/204.26, 128/205.25, 128/848, 600/529, 600/538
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/085 Measuring impedance of respiratory organs or lung elasticity
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/4866 Evaluating metabolism A61B5/083 takes precedence
• CPC Class Codes: A61M 16/0006 with means for creating vibrations in patients' airways
• CPC Class Codes: A61M 16/0051 with alarm devices
• 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 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/1075 by influencing the temperature A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 2016/0018 electrical
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0033 electrical
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/0039 : in the inspiratory circuit
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2230/205 : partial oxygen pressure (P-O2)

Abstract

The present technology relates to methods and apparatus to provide ventilation to patients. In particular, the present technology relates to changing ventilator parameters to match changing patient metabolic demand.

Claims

1. A controller for a ventilator, the ventilator being configured to deliver a pressure support waveform to a patient, said pressure support waveform having an inspiratory phase and a subsequent expiratory phase, and the controller being configured to adjust an expiratory pressure during the expiratory phase in response to an indication of a change in metabolic demand of the patient, wherein the controller is configured so that in response to an increase in a level of metabolic demand up to a predetermined limit of metabolic demand, the controller increases a level of the expiratory pressure to a level no higher than a maximum expiratory pressure value, and wherein the controller is further configured so that in response to an increase in the level of metabolic demand above the predetermined limit of metabolic demand, the controller increases a level of inspiratory positive pressure while a level of expiratory positive air pressure will remain substantially constant at the maximum expiratory pressure value.

2. The controller of claim 1, wherein the controller is further configured to accept a signal from a metabolic demand responsive transducer, and to determine a state of metabolic demand from said metabolic demand responsive transducer.

3. The controller of claim 2, wherein said metabolic demand responsive transducer is an oximeter.

4. The controller of claim 2, wherein said metabolic demand responsive transducer is a flow sensor.

5. The controller of claim 2, wherein said metabolic demand responsive transducer is a diaphragm electromyograph.

6. The controller of claim 2, wherein said metabolic demand responsive transducer is a combination of a flow sensor and an electromyograph.

7. The controller of claim 1, configured to increase an inspiratory pressure at a first rate in response to an increase in metabolic demand up to a given point.

8. The controller of claim 7, configured to increase an inspiratory pressure at a second rate in response to an increase in metabolic demand above the given point.

9. The controller of claim 8 wherein the second rate is lower than the first rate.

10. The controller of claim 1 wherein a maximum expiratory pressure value at the given point is about 10 cmH₂0.

11. The controller of claim 1 configured to follow a predetermined pressure support pathway.

12. The controller of claim 1, wherein at least for a range of metabolic demand values, the controller is configured to linearly adjust the at least one parameter of the ventilator in response to a change in metabolic demand values in the range.

13. The controller of claim 1, wherein at least for a range of metabolic demand values, the controller is configured to discretely adjust between metabolic demand values in the range.

14. The controller of claim 1, wherein the indication of change in metabolic demand is input manually.

15. The controller of claim 1, wherein the indication of change in of metabolic demand is determined automatically.

16. A ventilator for providing ventilatory support to a patient, the ventilator comprising:

a power supply;

a controller as claimed in claim 1; and

a pressure device under the control of the controller.

17. Apparatus for providing ventilatory assistance to a patient to assist in exercising comprising a ventilator as claimed in claim 16, and a metabolic demand responsive transducer.

18. A controller for a ventilator, the ventilator being configured to deliver a pressure support waveform to a patient, said pressure support waveform having an inspiratory phase and a subsequent expiratory phase, and the controller being configured to adjust an expiratory pressure during the expiratory phase in response to an indication of a change in metabolic demand of the patient, wherein the controller is configured so that in response to an increase in a level of metabolic demand up to a first metabolic demand threshold, the controller increases a level of the expiratory pressure to a level no higher than a maximum expiratory pressure value, and wherein the controller is further configured so that in response to an increase in the level of metabolic demand above the first metabolic demand threshold, the controller increases a level of inspiratory positive pressure while a level of expiratory positive air pressure will remain substantially at the maximum expiratory pressure value.

19. A method of control of a ventilator, the ventilator being configured to deliver a pressure support waveform to a patient, said pressure support waveform having an inspiratory phase and a subsequent expiratory phase, the method comprising:

adjusting with a processor an expiratory pressure during the expiratory phase in response to an indication of a change in metabolic demand of the patient, so that in response to an increase in a level of metabolic demand up to a predetermined limit of metabolic demand, a level of the expiratory pressure increases to a level no higher than a maximum expiratory pressure value, and so that in response to an increase in the level of metabolic demand above the predetermined limit of metabolic demand, a level of inspiratory positive pressure increases while a level of expiratory positive air pressure will remain substantially constant at the maximum expiratory pressure value.

20. The method of claim 19, further comprising with the processor, accepting a signal from a metabolic demand responsive transducer and determining a state of metabolic demand from said metabolic demand responsive transducer.

21. The method of claim 20, wherein said metabolic demand responsive transducer is an oximeter.

22. The method of claim 20, wherein said metabolic demand responsive transducer is a flow sensor.

23. The method of claim 20, wherein said metabolic demand responsive transducer is a diaphragm electromyograph.

24. The method of claim 20, wherein said metabolic demand responsive transducer is a combination of a flow sensor and an electromyograph.

25. The method of claim 19, further comprising with the processor increasing an inspiratory pressure at a first rate in response to an increase in metabolic demand up to a given point.

26. The method of claim 25, further comprising with the processor increasing an inspiratory pressure at a second rate in response to an increase in metabolic demand above the given point.

27. The method of claim 26 wherein the second rate is lower than the first rate.

28. The method of claim 19 wherein a maximum expiratory pressure value at the given point is about 10 cmH₂0.

29. The method of claim 19 further comprising with the processor following a predetermined pressure support pathway.

30. The method of claim 19, wherein at least for a range of metabolic demand values, linearly adjusting with the processor the at least one parameter of the ventilator in response to a change in metabolic demand values in the range.

31. The method of claim 19, wherein at least for a range of metabolic demand values, discretely adjusting with the processor between metabolic demand values in the range.

32. The method of claim 19, wherein the indication of change in metabolic demand is input manually to the processor.

33. The method of claim 19, wherein the indication of change in metabolic demand is determined automatically by the processor.