Method and apparatus for analyzing breath sample

• US 6,341,520 B1
• Filed: 09/19/2000
• Issued: 01/29/2002
• Est. Priority Date: 08/13/1996
• Status: Expired due to Fees

• Current Assignee: Akira Takenaka, Suzuki Motor Corporation
• Original Assignee: Akira Takenaka, Suzuki Motor Corporation
• Inventors: Takenaka, Akira, Yanagida, Akira, Satoh, Katsuhiko
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): WIGGINS, JOHN DAVID
• Application Number:
  US09/665,058
• Time in Patent Office: 497 Days
• Field of Search: 422/84, 422/89, 436/900, 73/233.6, 73/234.1, 73/234.2, 95/87, 600/529, 600/532
• US Class Current: 73/23.35
• CPC Class Codes: G01N 2030/025 Gas chromatography
• CPC Class Codes: G01N 2030/085 using absorbing precolumn
• CPC Class Codes: G01N 2030/402 purging a device
• CPC Class Codes: G01N 2030/8886 Analysis of industrial production processes
• CPC Class Codes: G01N 30/88 Integrated analysis systems specially adapted therefor, not covered by a single one of the groups G01N30/04 - G01N30/86

Abstract

Method and apparatus for analyzing a breath sample provide user-friendly operation and analysis. The method and apparatus provide automatic operation and coordination of operation of an absorbent sample tube, including desorbing means, a chromatographic precolumn, a chromatographic main column, a detector, a data processor, a sample receiving tube for receiving exhaled breath sample, a sample loop for aspirating a prescribed quantity of breath sample from the sample receiving tube, a sample valve, a standard gas reservoir, and a standard gas valve. All of the foregoing are operated automatically in such that start cycles, detector cycles, fault detection cycles, standardizing, analysis, shutdown and end cycles are performed in a way which allows straightforward and simple measurement of breath sample by a user.

Claims

1. An apparatus for analyzing a breath sample, the apparatus comprising:

(a) desorbing apparatus for desorbing a breath sample absorbed into an absorbent sample tube;

(b) a chromatographic precolumn for passing the breath sample desorbed from the absorbent sample tube in a retention time prescribed for each constituent;

(c) a sample receiving tube for receiving the exhaled breath sample;

(d) a sample loop for aspirating a prescribed quantity of breath sample from the sample receiving tube;

(e) a chromatographic main column for passing the breath sample having passed through the precolumn or the sample loop, in a retention time prescribed for each constituent;

(f) a detector for detecting constituents having passed through the main column;

(g) a data processor for generating a chromatograph for the constituents detected by the detector;

(h) a sample valve which connects the sample loop and the main column when a breath sample is aspirated into the sample loop;

(i) a standard gas bottle for supplying a standard gas;

(j) a standard gas valve which connects the standard gas bottle and the sample loop when testing sensitivity of the main column.

2. Apparatus according to claim 1, further comprising:

(a) a carrier gas bottle;

(b) a first carrier gas line for carrying the breath sample aspirated into the sample loop to the sample valve, the main column and the detector;

(c) a second carrier gas line for carrying the breath sample desorbed from the absorbent sample tube to the sample valve, the precolumn, the main column and the detector;

(d) a first solenoid valve provided between the first carrier gas line and the carrier gas bottle; and

(e) a second solenoid valve provided between the second carrier gas line and the carrier gas bottle.

3. Apparatus according to claim 2, further comprising:

(a) a third carrier gas line for carrying the standard gas aspirated into the sample loop to the sample valve, the main column and the detector; and

(b) a third solenoid valve provided between the third carrier gas line and the standard gas bottle.

4. Apparatus according to claim 3, further comprising:

(a) a fourth carrier gas line which carries the constituents having passed through the precolumn in the breath sample desorbed from the absorbent sample tube;

(b) a fifth carrier gas line which purges the constituents not having passed through the precolumn in the breath sample desorbed from the absorbent sample tube; and

(c) wherein said sample valve comprises;

(i) a first operating position for selecting said second carrier gas line; and

(ii) a second operating position for selecting said fourth and the fifth carrier gas lines.

5. Apparatus according to claim 4, further comprising:

(a) a detector heater for heating the detector; and

(b) a column heater for heating the precolumn and the main column.

6. Apparatus according to claim 5, further comprising:

(a) a controller having a temperature control unit for heating the detector heater and the column heater to a predetermined temperature prior to starting analysis.

7. The apparatus of claim 6, wherein the standard gas comprises hexane and pentane.

8. Apparatus according to claim 6, further comprising:

(a) input apparatus comprising;

(i) a start button for instructing start;

(ii) an analysis start button for instructing start of analysis;

(iii) a shutdown button for instructing shutdown; and

(iv) a test button for instructing a test; and

(b) wherein said controller comprises;

(i) a start controller which purges said columns when receiving a start signal from the start button and heats said detector heater and said column heater to a predetermined temperature;

(ii) an analysis controller which desorbs a breath sample or aspirates a breath when receiving an analysis start signal from the analysis start button and switches over said first to fifth gas lines;

(iii) a shutdown controller which reduces temperature of said detector heater and said column heater and discontinues supply of the carrier gas when receiving a shutdown signal from the shutdown button; and

(iv) a test controller which tests sensitivity and resolution of the detector with the standard gas when receiving a test signal from the test button.

9. Apparatus according to claim 8, further comprising:

(a) a display connected to the controller;

(b) said start controller displaying a message of preparation completion on the display upon completion of start controller; and

(c) said test controller displaying a message of test result on the display upon completion of test controller.

10. Apparatus according to claim 1, wherein said desorbing apparatus comprises:

(a) an absorbent sample tube heater which heats the absorbent sample tube to desorb the breath sample absorbed in said absorbent sample tube;

(b) a secondary concentrating tube for absorbing the breath sample in the interior thereof;

(c) a secondary concentrating tube cooler which cools the secondary concentrating tube for absorbing into said secondary concentrating tube the breath sample desorbed from said absorbent sample tube; and

(d) a secondary concentrating tube heater which heats the secondary concentrating tube for desorbing the breath sample absorbed in said secondary concentrating tube.

11. Apparatus according to claim 1, wherein:

(a) said data processor comprises apparatus for subjecting the detection result of said standard gas to a data processing to calculate sensitivity and resolution of the main column.

12. Apparatus according to claim 1, further comprising:

(a) a rotary valve having ten ports and lines for connecting adjacent ports;

(b) a carrier gas bottle;

(c) a first carrier gas line which connects the carrier gas bottle and the desorbing means;

(d) a first valve provided in the first carrier gas line;

(e) a second carrier gas line which connects the carrier gas bottle and ports of said rotary valve;

(f) a second valve provided in the second carrier gas line;

(g) said ports being connected sequentially from the first port;

(i) an end of the precolumn;

(ii) an end of the main column;

(iii) an end of the sample loop;

(iv) a pump;

(v) the sample receiving tube;

(vi) the other end of the sample loop;

(vii) the second carrier gas line;

(viii) a vent;

(ix) the other end of the precolumn; and

(x) the desorber;

(h) said rotary valve having a first operating position and a second operating position;

(i) the first operating position connecting;

an end of the precolumn and an end of the main column;

an end of the sample loop and the pump;

the sample receiving tube and the other end of the sample loop;

the second carrier gas line and the vent; and

the other end of the precolumn and the desorber; and

(ii) the second operating position connecting;

the desorber and an end of the precolumn;

an end of the main column and an end of the sample loop;

the pump and the sample receiving tube;

the other end of the sample loop and the second carrier gas line; and

the vent and the other end of the precolumn.

13. An apparatus for analyzing a breath sample, the apparatus comprising:

(a) desorbing apparatus for desorbing a breath sample absorbed in an absorbent sample tube;

(b) a chromatographic precolumn for passing the breath sample desorbed from the absorbent sample tube in a retention time prescribed for each constituent;

(c) a sample receiving tube receiving the breath sample;

(d) a sample loop aspirating the breath sample from the sample receiving tube;

(e) a chromatographic main column for passing the breath sample having passed through the precolumn or the sample loop, in a retention time prescribed for each constituent;

(f) a column heater which heats the main column and the precolumn to a prescribed temperature;

(g) a detector detecting the constituents having passed through the main column;

(h) a detector heater heating the detector to a preselected temperature;

(i) a data processor generating a chromatograph of the constituents detected by the detector;

(j) a sample valve which connects the sample loop and the main column when a breath sample is aspirated into the sample loop; and

(k) a controller comprising;

(i) column heat control apparatus which heats said column heater to a preselected temperature in response to the length of the main column;

(ii) detector heat control apparatus for heating the detector to a preselected temperature; and

(iii) completion timing apparatus for setting completion timing of analysis with reference to the retention time in response to a preselected temperature and the object of analysis.

14. An apparatus for analyzing a breath sample, the apparatus comprising:

(a) desorbing apparatus for desorbing breath sample absorbed into an absorbent sample tube;

(b) a chromatographic precolumn for passing breath sample desorbed from the absorbent sample tube in a retention time prescribed for each constituent;

(c) a sample receiving tube receiving exhaled breath sample;

(d) a sample loop for aspirating a prescribed quantity of breath sample from the sample receiving tube;

(e) a chromatographic main column for passing breath sample having passed through the precolumn or the sample loop, in a retention time prescribed for each constituent;

(f) a detector for detecting constituents having passed through the main column;

(g) a data processor for generating a chromatograph for the constituents detected by the detector;

(h) a sample valve comprising a first position which connects the sample loop and the main column when breath sample is aspirated into the sample loop and a second position which connects the precolumn to the main column;

(i) a standard gas bottle for supplying a standard gas;

(j) a standard gas valve which connects the standard gas bottle and the sample loop when testing sensitivity of the main column.