APPARATUS AND METHOD FOR ALCOHOLIC BREATH AND OTHER GAS ANALYSIS

• US 3,830,630 A
• Filed: 06/21/1972
• Issued: 08/20/1974
• Est. Priority Date: 06/21/1972
• Status: Expired due to Term

• Current Assignee: Michael E. Kiefer, Stanford B. Spracklen
• Original Assignee: Michael E. Kiefer, Stanford B. Spracklen
• Inventors: Kiefer, Michael E., Spracklen, Stanford B.
• Primary Examiner(s): Reese, Robert M.
• Application Number:
  US05/264,956
• Time in Patent Office: 790 Days
• Field of Search: 23/232E,254E,255E 73/27R 340/237R 128/2R,2.08
• US Class Current: 436/132
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• CPC Class Codes: G01N 27/16 caused by burning or catalytic oxidation of surrounding material to be tested, e.g. of gas
• CPC Class Codes: G01N 33/4972 Determining alcohol content for vehicle safety devices B60K28/06
• CPC Class Codes: Y10S 436/90 Breath testing
• CPC Class Codes: Y10T 436/204165 Ethanol
• CPC Class Codes: Y10T 436/204998 Inorganic carbon compounds

Abstract

A gas detecting apparatus and method for qualitatively and quantitatively analyzing a gas for a particular constituent depends on sampling of the gas until the level of one constituent can be detected at some predetermined level; then when this level is attained measuring the gas for the presence of another constituent. Measurement of human alcohol content is achieved by first measuring several samples of the CO2 level in the breath and when the CO2 reaches a predetermined minimum level, corresponding to a true lung sample, the apparatus responds and the alcoholic content is measured. A detecting filament bridge configuration measures alcoholic content by catalytic combustion of the alcohol and oxygen over a platinum filament.

Claims

2. In a system as claimed in claim 1 including a housing mounting said system therein as an integral portable unit.

3. In a system as claimed in claim 1 wherein said first and second detector means comprise electrical bridge filament type detector means.

4. In a system as claimed in claim 1 wherein said source comprises a human and said gas the human breath.

5. In a system as claimed in claim 4 wherein said first constituent is CO2 and said second constituent is alcohol.

6. In a system as claimed in claim 5 including an external device adapted for being controlled by said control level and means connecting said control level to said device to control the operation of said device.

7. In a system as claimed in claim 5 wherein said first and second detector means comprise components of an electrical bridge having a first leg in the nature of a filament not subject to alcoholic catalytic action for detecting said carbon dioxide and a second leg in the nature of a catalytic filament for detecting said alcohol, said breath source being caused to pass over said first and second legs in succession.

8. In a system as claimed in claim 3 wherein said percentage X is approximately 4 1/2 percent.

9. The method of analyzing a gas having two constituents of interest comprising the steps of:

a. flowing a sample of the gas to be analyzed past first detecting means adapted to produce a first electrical control level dependent on one of the constituents being present in the sample in a certain first predetermined quantitative percentage b. simultaneously flowing a similar said sample of said gas past second detecting means depending for its detecting state on the obtaining of said first control level and adapted to produce a second electrical control level having a value dependent on the quantitative percentage of the other constituent; and

c. producing a third control level by electrical comparator means connected to and dependent upon said first and second control levels whereby said third control level electrically indicates the presence of the first constituent in at least said first percentage X and the second constituent in some other predetermined percentage Y terms, whether at, below or above Y.

10. The method of claim 9 wherein said gas is human breath, said first constituent is carbon dioxide in the breath and said second constituent is alcohol in the breath.

11. The method of claim 10 wherein said first and second control levels are produced by flowing said samples past electrical filament bridge type detectors forming part of a common bridge detecting network.

12. The method of claim 10 wherein said first percentage is approximately 4 1/2 percent by volume carbon dioxide content.