Breath sampler

• US 5,081,871 A
• Filed: 02/25/1991
• Issued: 01/21/1992
• Est. Priority Date: 02/02/1989
• Status: Expired due to Fees

• Current Assignee: United States Department Of Health And Human Services
• Original Assignee: United States Department Of Health And Human Services
• Inventors: Glaser, Robert A.
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US07/659,490
• Time in Patent Office: 330 Days
• Field of Search: 73/863.02, 73/863.12, 73/863.21, 73/863.23, 73/863.25, 73/864.51, 73/863.31, 73/23.3, 422/83-85, 422/88, 422/89, 422/92, 55/270, 128/719, 128/730, 29/213.1, 29/221.6
• US Class Current: 73/863.23
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: G01N 1/2247 Sampling from a flowing stream of gas
• CPC Class Codes: G01N 1/405 by adsorption or absorption
• CPC Class Codes: G01N 2001/2276 Personal monitors
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath

Abstract

An apparatus for sampling volumetric quantities of human exhaled breath has three conduits and may be provided in "Y" or "T" shaped configuration. The free end of one of the conduits is adapted to connect with the mouth of the subject being tested. Another of the conduits is adapted to pass ambient air to the subject, this conduit being provided with a suitable filtering mechanism such as a charcoal inhalation canister and an inlet check valve. The third of the three conduits supports an appropriate sampling canister for receiving exhaled breath from the subject, and this conduit also is provided with a one-way check valve. In another aspect of the invention, there is also provided a method for collecting a sample of exhaled breath from a subject to collect therefrom a selected analyte and to accurately quantify its presence in the subject'"'"'s breath.

Claims

1. A portable, through-flow breathing system for collecting breath samples from a human subject for subsequent determination of selected analyte content thereof, comprising:

a tubular body having a minimal volume compatible with having engageable first and second ends;

first conduit means for conveying through the tubular body the subject'"'"'s essentially once-exhaled breath, said first conduit means fluidly communicating with said tubular body at a location intermediate said first and second ends;

second conduit means fluidly communicating with said first end of said tubular body, said second conduit means including air filtering means and selectively operable first valve means for admitting ambient air through said filtering means and into said tubular body when a subject inhales through said second conduit means; and

third conduit means fluidly communicating with said second end of said tubular body, said third conduit means including low impedance, compact analyte collection means for concentrating a collected analyte for prolonged storage pending analysis thereof located therein and selectively operable second valve means for admitting the essentially once-exhaled breath from said tubular body into said sample collection means when the subject exhales through said first conduit means,

said tubular body and said first, second and third conduit means being formed to be compact and lightweight in combination to facilitate convenient holding thereof by the human subject during use, and

said first valve means being closed when said second valve means is open, and said second valve means being closed when said first valve means is open thereby ensuring sampling of only a through-flow of the subject'"'"'s essentially once-exhaled breath.

2. The apparatus of claim 1, wherein:

said tubular body has a substantially "T-shaped" configuration.

3. The apparatus of claim 1, wherein:

said first, second and third conduit means each have a respective longitudinal axis, the longitudinal axis of said first conduit means being disposed at respective predetermined angles to the corresponding axes of said second and third conduit means.

4. The apparatus of claim 3, wherein:

said predetermined angles each comprise at least 90 degrees.

5. The apparatus of claim 1, wherein:

said first and second valves in said second and third conduit means each comprise a check valve.

6. The apparatus of claim 5, wherein:

each of said check valves is removable from its respective conduit means.

7. The apparatus of claim 1, wherein:

said sample collection means comprises a container including at least one bed of a selected sorbent material.

8. The apparatus of claim 7, wherein:

said at least one bed of sorbent material comprises a bed of charcoal cloth for collection of an analyte.

9. The apparatus of claim 1, wherein:

said tubular body includes an opening and further comprises connection means provided at said opening for connecting thereat to means for carrying out sidestream sampling in known manner.

10. The apparatus of claim 1 wherein:

at least one of the sample collection means and the air filtering means comprises a removable canister containing a selected sorbent.

11. The apparatus of claim 10, wherein:

the sorbent comprises charcoal cloth.

12. A method for measuring the concentration of a selected analyte in a sample of essentially once-exhaled breath provided by a subject, comprising the steps of:

prefiltering air inhaled by the subject from the ambient atmosphere with a filter capable of significantly removing such of the selected analyte as is present in the ambient air, to thereby ensure accurate subsequent measurement of the concentration of the selected analyte in the sample comprising the subject'"'"'s essentially once-exhaled breath;

passing the breath sample directly through a selected sorbent example capable of sorbing the selected analyte therefrom, wherein the sorbent element is formed and disposed to present a low impedance flow passage to the breath sample passed therethrough;

determining the volume of the breath sample from which analyte has been sorbed by the sorbent example;

desorbing the sorbed analyte from the sorbent element;

measuring an amount of the selected analyte desorbed from the sorbent; and

determining a concentration of the selected sorbent in the determined volume of essentially once-exhaled breath provided by the subject.

13. The method of claim 12, wherein:

the breath sample contains air from more than one exhalation.

16. The method of claim 12 or 14, wherein:

the analyte is desorbed by thermal desorption.

17. The method of claim 12 or 14, wherein:

the breath sample is an alevolar breath sample.

14. A method for measuring the concentration of a selected analyte in a multi-breath sample of essentially once-exhaled breath from a subject, comprising the steps of:

passing a sample comprising multiple breaths, each being essentially once-exhaled, from the subject directly through a selected sorbent capable of retaining at least one analyte present in said sample;

desorbing the at least one retained analyte from the sorbent;

measuring a volume of said breath sample; and

thereby determining a concentration of the desorbed analyte in the multiple breaths provided by the subject.

15. The method of claim 14, comprising the further step of:

prefiltering air inhaled by the subject from the ambient atmosphere with a filter capable of significantly removing the at least one selected analyte therefrom to ensure accurate measurement of the concentration of such of the at least one selected sorbed analyte as was present in the sample of the subject'"'"'s substantially once-exhaled breath.

18. Apparatus for collecting from a subject a sample of essentially once-exhaled breath containing a selected analyte, for subsequent determination of a concentration of the selected analyte in the sampled exhaled breath, comprising:

a tubular conduit having a first opening to receive a flow-through of essentially once-exhaled breath from the subject, a second opening and a third opening to permit inhalation of ambient air by the subject; and

means for collecting a sample of the selected analyte from said essentially once-exhaled breath, connected to said second opening,

wherein the second and third openings contain respective first and second valve means to permit only said essentially once-exhaled breath to pass through the sample collection means.

19. The apparatus of claim 18, wherein:

the sample collection means contains a sorbent capable of retaining at least the selected analyte.

20. The apparatus of claim 18, wherein:

said first and second valve means comprise respective check valves.

21. The apparatus of claim 20, wherein:

said sample collection means has a check valve located at least upstream thereof to minimize collection of ambient inhaled air with said exhaled breath.