Device and method for monitoring asthma

• US 6,585,661 B1
• Filed: 06/11/2001
• Issued: 07/01/2003
• Est. Priority Date: 12/18/1998
• Status: Expired due to Fees

• Current Assignee: University of Virginia
• Original Assignee: University of Virginia Patent Foundation (University of Virginia)
• Inventors: Gaston, Benjamin M., Hunt, John F.
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): WINGOOD, PAMELA LYNN
• Application Number:
  US09/857,820
• Time in Patent Office: 750 Days
• Field of Search: 600/529-544
• US Class Current: 600/532
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath

Abstract

A device (10) and method for non-invasively monitoring asthma and other respiratory diseases. The method includes collecting condensate from a subject'"'"'s breath, testing the condensate to determine its acidity level or ammonium concentration, and evaluating these properties to determine the presence, absence or status of a respiratory disease in the subject. The method may also include, prior to the testing step, standardizing the volatile substances that may be present within the condensate in a degassing or gas standardizing step. The device (10) includes a mouthpiece apparatus (20) configured to receive breath from a subject, a condensation apparatus (60) to condense the subject'"'"'s breath and produce a condensate, and a collection apparatus (100) having a collection chamber (102) containing means for testing the condensate to determine its chemical properties. The device (10) also include a system for removing or standardizing the volatile substances that may be present with the condensate.

Claims

1. A method for monitoring a respiratory disease in a subject, said method comprising:

collecting condensate from a subject'"'"'s breath, said condensate having an acidity level and ammonium concentration;

testing said condensate to determine said acidity level or ammonium concentration; and

evaluating said acidity level or ammonium concentration to determine the presence, absence or status of a respiratory disease in the subject.

2. The method of claim 1, wherein said step of evaluating said acidity level or ammonium concentration to determine the presence, absence or status of a respiratory disease in the subject comprises determining the presence, absence or status of an inflammatory respiratory disease.

3. The method of claim 2, wherein said step of determining the presence, absence or status of an inflammatory respiratory disease comprises determining the presence, absence or status of asthma.

4. The method of claim 1, wherein said step of determining the presence, absence or status of an inflammatory respiratory disease comprises determining the presence, absence or status of a respiratory disease that is a member of the group consisting of asthma, bronchiolitis, cystic fibrosis, smoking induced diseases, tuberculosis, and occupational lung diseases.

5. The method of claim 1, wherein said step of determining said acidity level or ammonium concentration of said condensate comprises using means for testing said condensate to determine said acidity level.

6. The method of claim 5, wherein said step of using means for testing said condensate to determine said acidity level or ammonium concentration comprises using an electronic acidity monitor.

7. The method of claim 5, wherein said step of using means for testing said condensate to determine said acidity level or ammonium concentration comprises introducing a reagent to said condensate.

8. The method of claim 7, wherein said step of introducing a reagent to said condensate comprises introducing to said condensate a colorimetric acidity indicator selected from a group consisting of phenylphthalein, bromthymol blue or methyl red.

9. The method of claim 1, wherein said condensate comprises volatile substances, and said method further comprises standardizing said volatile substances within said condensate prior to said testing step.

10. The method of claim 9, wherein said step of standardizing said volatile substances within said condensate comprises a gas standardizing step.

11. The method of claim 10, wherein said gas standardizing step comprises introducing atmospheric air to said condensate.

12. The method of claim 9, wherein said step of standardizing said volatile substances within said condensate comprises a degassing step.

13. The method of claim 12, wherein said degassing step comprises introducing an inert gas to said condensate.

14. The method of claim 13, wherein said step of introducing an inert gas to said condensate comprises introducing argon or helium to said condensate.

15. The method of claim 1, wherein said step of collecting condensate from a subject'"'"'s breath comprises collecting condensate from a human subject.

16. The method of claim 1, wherein said step of collecting condensate from a subject'"'"'s breath comprises condensing breath that has been exhaled through the subject'"'"'s mouth.

17. The method of claim 16, wherein said step of collecting condensate from a subject'"'"'s breath further comprises condensing breath that has been exhaled through the subject'"'"'s nose and mouth.

18. The method of claim 1, wherein said step of collecting condensate from a subject'"'"'s breath comprises:

introducing the subject'"'"'s breath into a condensation apparatus, said condensation apparatus producing a condensate from said breath; and

moving said condensate into a collection apparatus.

19. The method of claim 18, wherein said step of moving said condensate into a collection apparatus comprises moving said condensate by force of gravity.

20. The method of claim 19, wherein said step of moving said condensate into a collection apparatus comprises moving said condensate using a pump.

21. The method of claim 1, wherein said step of collecting condensate from a subject'"'"'s breath comprises:

introducing a sample of said breath into a condensation apparatus capable of producing a condensate from said breath; and

collecting in a collection apparatus said condensate produced by said condensation apparatus;

recirculating said breath through said condensation apparatus until said collection apparatus has collected a volume of condensate sufficient for testing.

22. The method of claim 1, wherein said step of collecting condensate from a subject'"'"'s breath comprises:

providing a condensation apparatus;

cooling said condensation apparatus in a home freezer;

removing said condensation apparatus from said home freezer; and

introducing a sample of said breath into said cooled condensation apparatus.

23. The method of claim 22, wherein said step of cooling said condensation apparatus comprises cooling said condensation apparatus to a temperature at least as low as 0°

C.

24. The method of claim 23, wherein said step of cooling said condensation apparatus comprises cooling said condensation apparatus to a temperature at least as low as −

40°

C.

25. The method of claim 1, wherein said step of evaluating said acidity level or ammonium concentration to determine the presence, absence or status of a respiratory disease in the subject comprises evaluating said acidity level or ammonium concentration to diagnose a respiratory disease in the subject.

26. The method of claim 1, wherein said step of evaluating said acidity level or ammonium concentration to determine the presence, absence or status of a respiratory disease in the subject comprises evaluating said acidity level or ammonium concentration to determine the severity of a respiratory disease in the subject.

27. The method of claim 1, wherein said step of evaluating said acidity level or ammonium concentration to determine the presence, absence or status of a respiratory disease in the subject comprises evaluating said acidity level to determine whether a course of treatment for a respiratory disease in the subject should be started, altered or discontinued.

28. The method of claim 1, wherein said step of evaluating said acidity level or ammonium concentration to determine the presence, absence or status of a respiratory disease in the subject comprises evaluating said acidity level to predict an impending exacerbation of a respiratory disease in the subject.

29. A method for monitoring asthma in a subject, comprising:

providing a device comprising a mouthpiece apparatus, a condensation apparatus and a collection apparatus;

receiving a subject'"'"'s breath in said mouthpiece apparatus;

condensing said breath in said condensation apparatus to form a condensate, said condensate having chemical properties;

collecting said condensate in said collection apparatus;

testing said condensate within said collection apparatus to determine said chemical properties; and

evaluating said chemical properties to determine the presence, absence or status of asthma in the subject.

30. The method of claim 29, wherein said step of testing said condensate within said collection apparatus to determine said chemical properties comprises testing said condensate to determine the acidity level of said condensate.

31. The method of claim 29, wherein said step of testing said condensate within said collection apparatus to determine said chemical properties comprises testing said condensate to determine the ammonium concentration of said condensate.

32. A device for monitoring a respiratory disease in a subject, said device comprising:

a mouthpiece apparatus configured to receive breath from a subject;

a condensation apparatus configured for operative connection to said mouthpiece apparatus, and being further configured to condense the subject'"'"'s breath and produce a condensate having chemical properties; and

a collection apparatus configured for operative connection to said condensation apparatus, said collection apparatus comprising a collection chamber containing means for testing said condensate to determine said chemical properties, wherein the subject'"'"'s breath may be received, condensed and evaluated in a single device to determine the presence, absence or status of a respiratory disease in the subject, wherein said means for testing said condensate comprises a reagent disposed within said collection chamber.

33. The device of claim 32, wherein said reagent is a solid reagent.

34. The device of claim 32, wherein said condensate has an acidity level and said reagent is useful for measuring said acidity level of said condensate.

35. The device of claim 34, wherein said reagent comprises a colorimetric acidity indicator selected from a group consisting of phenylphthalein, bromthymol blue or methyl red.

36. The device of claim 32, wherein said condensate has an ammonium concentration and said reagent is useful for measuring said ammonium concentration of said condensate.

37. The device of claim 32, wherein said means for testing said condensate comprises a reagent chamber containing at least one reagent.

38. The device of claim 32, wherein said means for testing said condensate comprises a retainer configured to hold a material, said material comprising a reagent.

41. The device of claim 32, wherein said collection chamber is detachable and disposable.

42. The device of claim 41, wherein said collection chamber comprises a plastic test tube.

43. The device of claim 32, wherein said collection chamber comprises a measuring gradient.

44. The device of claim 32, wherein said mouthpiece apparatus comprises proximal end, a distal end, and a mouthpiece disposed at said proximal end of said mouthpiece apparatus.

45. The device of claim 44, wherein said mouthpiece apparatus further comprises a first one-way valve configured to permit air to be drawn into said mouthpiece apparatus, and a second one-way valve configured to permit air to pass from said mouthpiece to said distal end of said mouthpiece apparatus.

46. The device of claim 45, wherein said mouthpiece apparatus further comprises a particle filter disposed between said mouthpiece and said distal end of said mouthpiece apparatus.

47. The device of claim 32, wherein said condensation apparatus comprises an inner tube surrounded by an insulator.

48. The device of claim 47, wherein:

said inner tube has an outer surface; and

said condensation apparatus further comprises an outer tube disposed between said inner tube and said insulator, said outer tube having an inner surface, and said inner surface of said outer tube and said outer surface of said inner tube defining a heat transfer chamber.

49. The device of claim 45, wherein said heat transfer chamber contains a cooling material.

50. The device of claim 49, wherein said outer tube has a first port therein providing access to said heat transfer chamber, and a second port therein providing access to said heat transfer chamber, wherein said cooling material may be inserted into said heat transfer chamber through said first port and removed through said second port.

51. The device of claim 48, wherein said inner tube is made of aluminum, said outer tube is made of plastic and said insulator is made of foam plastic.

52. The device of claim 32, wherein said collection apparatus further comprises a connector portion configured to connect said collection chamber to said condensation apparatus.

53. The device of claim 52, wherein said connector portion comprises a T-connector having a first T-portion and a second T-portion, said first T-portion being configured to connect said T-connector to said collection chamber and said second T-portion providing a port to atmosphere, wherein uncondensed breath passing through said condensation apparatus and into said T-connector may vent to atmosphere.

54. The device of claim 53, wherein said device further comprises an apparatus to standardize volatile substances within said condensate.

55. The device of claim 54, wherein said apparatus to standardize volatile substances within said condensate comprises a degassing apparatus.

56. The device of claim 55, wherein said degassing apparatus comprises a pump.

57. The device of claim 56, wherein:

said collection chamber has a top end and a bottom end, said top end having a first port therein, and at least a portion of said condensate being disposed in said bottom end of said collection chamber;

a pipette is disposed in said collection chamber, said pipette having a body portion, a first end and a second end, said first end being disposed in communication with atmosphere through said second port in said T-portion, said second end having a tip portion disposed in said condensate, and said body portion being sealingly engaged with said first port of said top end of said collection chamber; and

said top end of said collection chamber has a second port therein, said second port connecting said collection chamber to said pump at a first end of said pump, said pump being open to atmosphere at a second end, wherein said pump may draw air from, or force air through, said port in said second T-portion of said T-connector, through said condensate.

58. The device of claim 54, wherein said apparatus to standardize volatile substances within said condensate comprises a gas standardizing apparatus.

59. The device of claim 58, wherein said gas standardizing apparatus comprises a pressurized gas container.

60. The device of claim 59, wherein:

said collection chamber has a top end and a bottom end, said top end having a first port therein, and at least a portion of said condensate being disposed in said bottom end of said collection chamber;

a pipette is disposed in said collection chamber, said pipette having a body portion, a first end and a second end, said first end being disposed in communication with atmosphere through said second port in said T-portion, said second end having a tip portion disposed in said condensate, and said body portion being sealingly engaged with said top end of said collection chamber has a second port therein, said second port being open to atmosphere, and said pressurized gas container is connected to said collection apparatus in communication with said collection chamber through said first port in said top end of said collection chamber, wherein said pressurized gas container may force a gas through said condensate.

61. The device of claim 60, wherein said gas is an inert gas.

62. The device of claim 61, wherein said gas is argon or helium.

39. A device for monitoring a respiratory disease in a subject, said device comprising:

a mouthpiece apparatus configured to receive breath from a subject;

a condensation apparatus configured for operative connection to said mouthpiece apparatus, and being further configured to condense the subject'"'"'s breath and produce a condensate having chemical properties; and

a collection apparatus configured for operative connection to said condensation apparatus, said collection apparatus comprising a collection chamber containing means for testing said condensate to determine said chemical properties, wherein the subject'"'"'s breath may be received, condensed and evaluated in a single device to determine the presence, absence or status of a respiratory disease in the subject, wherein said means for testing said condensate comprises an electrode monitor, said electrode monitor at least partially disposed within said condensate.

40. The device of claim 39, wherein said electronic monitor is configured to connect to said collection chamber.