Method and system for controlling breathing

• US 20070255160A1
• Filed: 04/17/2007
• Published: 11/01/2007
• Est. Priority Date: 04/17/2006
• Status: Active Grant

• Current Assignee: The Periodic Breathing Foundation, LLC
• Original Assignee: The Periodic Breathing Foundation, LLC
• Inventors: Daly, Robert
• Granted Patent: US 8,074,646 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61M 16/0003 Accessories therefor, e.g. sensors, vibrators, negative pressure
• CPC Class Codes: A61M 16/0045 Means for re-breathing exhaled gases, e.g. for hyperventilation treatment
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• 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 16/04 Tracheal tubes catheters in general A61M25/00
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0605 Means for improving the adaptation of the mask to the patient
• CPC Class Codes: A61M 16/0633 with forehead support
• CPC Class Codes: A61M 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 16/0683 Holding devices therefor
• CPC Class Codes: A61M 16/0694 Chin straps
• CPC Class Codes: A61M 16/08 Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/20 Valves specially adapted to medical respiratory devices
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 16/209 : Relief valves
• 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 2016/103 : the CO2 concentration
• CPC Class Codes: A61M 2230/005 : Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/202 : partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: A61M 2230/432 : partial CO2 pressure (P-CO2)
• CPC Class Codes: Y10S 128/911 : Unilimb inhalation-exhalation breathing tubes
• CPC Class Codes: Y10S 128/914 : Rebreathing apparatus for increasing carbon dioxide content in inhaled gas

Abstract

The present invention relates to a method and a system for controlling breathing of a patient. A system for controlling breathing of a patient includes a respiratory conduit. The respiratory conduit is configured to be coupled to a patient interface device and is further configured to be coupled to a pressurized air generating device. The respiratory conduit includes at least two air flow control devices, positioned between the patient interface device and the pressurized air generating device. The respiratory conduit includes at least two volumes, wherein one volume is positioned between a first air flow control device and a second air flow control device and another volume is positioned between a second air flow control device and a third air flow control device.

Claims

1. A system for controlling breathing of a patient, comprising

a respiratory conduit;

said respiratory conduit is configured to be coupled to a patient interface device;

said respiratory conduit is further configured to be coupled to a pressurized air generating device;

said respiratory conduit includes at least two air flow control devices, positioned between said patient interface device and said pressurized air generating device; and

said respiratory conduit includes at least two volumes, wherein one volume is positioned between a first air flow control device and a second air flow control device and another volume is positioned between a second air flow control device and a third air flow control device;

wherein said second airflow control device configured to control evacuation of air from an airflow control conduit that is further configured to include multiple openings.

2. The system according to claim 1, wherein said airflow control conduit is configured to be at least partially disposed within said other volume.

3. The system according to claim 1, wherein said airflow control conduit includes a control valve configured to adjust airflow through each one of said multiple openings.

4. A method for controlling flow of carbon dioxide to a patient, comprising

controlling a level of carbon dioxide in blood of the patient using the system of claim 1;

wherein said controlling includes;

measuring airflow through at least one of said airflow control devices;

detecting a content of carbon dioxide in the measured airflow;

adjusting airflow through at least one other one of said airflow control devices based on said detecting of said concentration of carbon dioxide; and

adjusting sizes of said volumes based on said detection of said concentration of carbon dioxide and said adjusting of said airflow through at least one of said air flow control devices.

5. The system according to claim 4, wherein said adjusting sizes step further comprises

adjusting sizes of said volumes and said airflow through at least one of said airflow control devices based on a relationship between _CO2 and _E, wherein _CO2 is a rate of excretion of carbon dioxide by the patient per minute;

_E is a total rate of ventilation per minute by the patient.

6. The system according to claim 5, wherein a curve representing said relationship between _CO2 and _E contains at least two discontinuities;

said discontinuities are determined using the lengths of

a hypoventilatory traverse segment caused by a placement of said first airflow control device in the system;

a first respiratory plateau segment caused by a placement of said volume in the system;

at least one eucapnic traverse segment caused by a placement of said multiple openings in said second airflow control device;

a second respiratory plateau segment caused by a placement of said another volume in the system; and

a hyperventilatory traverse segment caused by a placement of said third airflow control device in the system.

7. The system according to claim 6, wherein said hypoventilatory traverse segment has a slope defined by a relationship between volume of air breathed by the patient during a breathing interval and an amount of carbon dioxide exhaled by the patient in said breathing interval.

8. The system according to claim 6, wherein during said eucapnic traverse segment, an additional volume of carbon dioxide escapes from at least one of said multiple openings of said second airflow control device, wherein said additional volume is determined based on the volume of carbon dioxide that escaped from said first airflow control device.

9. The system according to claim 6, wherein during said hyperventilatory traverse segment, an additional volume of carbon dioxide escapes from said third airflow control device, wherein said additional volume is determined based on a volume of carbon dioxide that escaped from at least said first and second airflow control devices.

10. The system according to claim 5, wherein said controlling further includes

determining a target mean arterial concentration of carbon dioxide based on said adjusting sizes step.

11. The system according to claim 5, wherein said adjusting sizes step is automatic.

12. The system according to claim 5, wherein said adjusting sizes step is manual.

13. The system according to claim 1, wherein said volumes are partial dead space volumes configured to accumulate at least a portion of breath expired by the patient.

14. The system according to claim 1, wherein said patient interface device is selected from a group consisting of a nasal mask, an oral mask, an orofacial mask, a nasal prong device, an intra-oral device, and an endotracheal tube.

15. The system according to claim 14, wherein said patient interface device is configured to create a substantially sealed connection between said respiratory conduit and a breathing airway passage of the patient.

16. The system according to claim 1, wherein said respiratory conduit includes an auxiliary air flow control device located substantially adjacent to said patient interface device configured to control flow of air to the airway of the patient.

17. The system according to claim 16, wherein said auxiliary air flow control device is controlled by the patient.

18. The system according to claim 1, wherein said respiratory conduit includes an anti-asphyxiation valve configured to create an access to air and to bypass said respiratory conduit, if said pressurized air generating device fails, and located substantially adjacent to said patient interface device.

19. The system according to claim 1, wherein said air flow control devices are configured to adjust said rate of gas flow through said air flow control devices based on at least one physiological variable of the patient.

20. The system according to claim 1, wherein said air flow control devices and said volumes are configured to control

a rate of excretion of gas from said respiratory conduit;

and

a concentration of said gas in the blood of the patient.

21. The system according to claim 20, wherein said air flow control devices and said volumes are configured to allow a range of amounts of said gas readily excreted from said respiratory conduit to be equal to a range of production of said gas by the patient.

22. The system according to claim 1, wherein said gas is carbon dioxide.

23. The system according to claim 1, wherein said first air flow control device is configured to allow an escape of an amount of said gas that is lower than or equal to the amount of said gas produced by the patient at a time.

24. The system according to claim 23, wherein said second air flow control device is configured to allow an escape of an amount of said gas that is based on

said amount of gas allowed to escape from said first air flow control device, and

a maximum total amount of gas produced by the patient at a time.

25. The system according to claim 23, wherein said third air flow control device is configured to allow an escape of air that is based on said amount of air allowed to escape from said first and said second air flow control devices to prevent re-breathing of excess amount of said gas by the patient.

26. The system according to claim 1, wherein

said respiratory conduit is configured to be rotatably coupled to said patient interface device.

27. The system according to claim 1, wherein said respiratory conduit includes a protective cover configured to prevent damage to said respiratory conduit.

28. The system according to claim 1, further comprising a collector configured to be coupled to said respiratory conduit and further configured to collect condensation during breathing of the patient.

29. A system for controlling breathing of a patient, comprising:

a respiratory conduit configured to be coupled to a patient interface device of the patient;

said respiratory conduit is configured to be coupled to a pressurized air supply device, wherein said pressurized air supply device supplies air to the patient at the other end;

wherein said respiratory conduit includes

a first valve located adjacent said patient interface device and includes a first opening configured to control escape of said gas during the breathing process;

a second valve configured to withdraw air from at least one location within said respiratory conduit during the breathing process;

a first volume connector connecting said first valve and said second valve and configured to control supply of gas to the patient during the breathing process;

a third valve that includes a third opening configured to control escape of gas during the breathing process;

a second volume connector connecting said second valve and said third valve and configured to allow withdrawal of air from said at least one location within said second volume; and

a third connector connecting said second valve and said air supply device.

30. A method of controlling breathing of a patient, wherein air is supplied to the patient using a patient interface device coupled to an air supply device using a respiratory conduit that includes at least one valve configured to withdraw air from at least one openings disposed within at least one volume connector, wherein said valves and said volume connectors are positioned along the length of the respiratory conduit, comprising:

determining a rate of production of gas generated by the patient;

measuring a rate of flow and a concentration of gas at each of the controllable openings;

adjusting the flow rate through the multiple openings based on said measuring; and

adjusting sizes of said multiple volume connectors based on at least one of said determining and said measuring;

wherein air supplied to the patient includes a mixture of air supplied by the air supply device and a gas generated by the patient.

31. The method according to claim 30, further comprising:

determining an increase in a pressure of gas in the arterial blood of the patient, wherein said determining includes

measuring said pressure of gas contained in the arterial blood of the patient using time-based monitoring selected from the group consisting of;

end-tidal gas monitoring, transcutaneous gas monitoring, and arterial blood gas analysis; and

calculating a desired changes in pressure of said gas in the arterial blood of the patient based on said measuring.

32. The method according to claim 30, further comprising

adjusting the flow of air through the multiple openings and the multiple volume connectors, wherein said adjusting includes

monitoring an amount of said gas escaping from each of the multiple openings and the multiple volume connectors;

and

measuring a rate of flow and a concentration of gas at each of the multiple openings;

adjusting sizes of said multiple volume connectors based on at least one of said determining and said measuring;

wherein gas supplied to the patient is a mixture of gas supplied by the gas supply device and gas produced by the patient during breathing.

33. The method according to claim 32, wherein said calculating further comprises

estimating the amount of said gas produced by the patient using at least one characteristic selected from a group consisting of:

age, gender, body mass, percent lean body mass and the partial pressure of said gas in the arterial blood of the patient.

34. The method according to claim 33, wherein said calculating further comprises

determining the sizes of the multiple openings and multiple volume connectors using a predetermined simulation of normal breathing of the patient.

35. The method according to claim 30, wherein a rate of air flow through one of the multiple openings is based on a rate of flow through at least one other one of the multiple openings.

36. The method according claim 35, wherein said determining further comprises

calculating an amount of gas escaping from each of the multiple openings during some period of time;

and

based on said calculating, adjusting a size of at least one of the multiple openings and at least one size of each of the volume connectors.

37. The method according to claim 30, wherein a rate of flow of a gas through at least a first air opening and at least a second opening is calculated based on an expected rate of production of said gas by the patient, expected respiration rate of the patient, expected depth of respiration by the patient, and an expected concentration of said gas in the air expired by the patient.

38. The method according to claim 37, wherein a volume of expired gas by the patient that is re-breathed by the patient is continuously adjusted based on a volume of gas allowed to escape from said multiple openings and a volume of gas contained in said multiple volume connectors.

39. A method of controlling breathing of a patient, wherein air is supplied to the patient using a patient interface device coupled to an air supply device using a respiratory conduit that includes at least two air flow control devices, positioned between the patient interface device and a pressurized air generating device, and at least two volumes, wherein at least one volume is configured to allow withdrawal of air from at least one location within the volume using at least one of the air flow control devices, comprising:

determining an average concentration of gas in the air flowing out of the second air flow control device;

comparing the average concentration of gas to a predetermined setpoint value of concentration of gas;

computing the difference between the average concentration and the predetermined setpoint value of concentration;

controlling the breathing of the patient by adjusting flow of air through the first air flow control device until the computed difference is substantially eliminated.

40. The method according to claim 39, further comprising

determining concentration of gas flowing through at least one airflow control device;

and

adjusting the flow of air through at least another airflow control device based on the concentration of gas flowing through the at least one airflow control device.

41. The method according to claim 40, further comprising

determining whether the concentration of gas flowing through the at least one airflow control device exceeds the predetermined setpoint value;

and

increasing a flow of air through at least another airflow control device.

42. The method according to claim 40, further comprising

determining whether the concentration of gas flowing through the at least one airflow control device is below the predetermined setpoint value;

and

decreasing a flow of air through the at least another airflow control device.

43. The method according to claim 39, wherein the predetermined setpoint value is calculated for the patient.

44. The method according to claim 39, further comprising

periodically monitoring concentration of gas flowing through at least one airflow control device;

computing a value for the end-tidal concentration of CO₂ in said gas flowing through the at least another airflow device, which represents an estimate of the partial pressure of said CO₂ in the arterial blood of the patient;

comparing said end-tidal CO₂ value to a predetermined range of acceptable end-tidal CO₂ values; and

adjusting the predetermined setpoint for concentration of gas flowing through the at least one airflow control device based on said comparing.

45. The method according to claim 44, further comprising

determining whether the computed end-tidal CO₂ value is lower than the range of acceptable end-tidal CO₂ values;

and

increasing the predetermined setpoint value of concentration of gas flowing through the at least one airflow control device.

46. The method according to claim 44, further comprising

determining whether the computed end-tidal CO₂ value is higher than the range of acceptable end-tidal CO₂ values;

and

decreasing the predetermined setpoint value of concentration of gas flowing through the at least one airflow control device.

47. The method according to claim 39, further comprising

determining whether the patient is in a particular sleep stage;

adjusting at least one parameter based on the particular sleep stage.

48. A system for controlling breathing of a patient, comprising

a respiratory conduit;

said respiratory conduit is configured to be coupled to a patient interface device;

said respiratory conduit is further configured to be coupled to a pressurized air generating device;

said respiratory conduit includes at least two volumes, positioned between said patient interface device and said pressurized air generating device; and

said respiratory conduit includes at least two air flow control devices, wherein said at least one airflow control device is configured to withdraw air from at least one location within said respiratory conduit.