Breath-based sensors for non-invasive molecular detection

• US 7,421,882 B2
• Filed: 12/16/2005
• Issued: 09/09/2008
• Est. Priority Date: 12/17/2004
• Status: Expired due to Fees

• Current Assignee: University of Iowa Research Foundation
• Original Assignee: University of Iowa Research Foundation
• Inventors: Haverhals, Luke M., Leddy, Johna
• Primary Examiner(s): LARKIN, DANIEL SEAN
• Application Number:
  US11/305,799
• Publication Number:
  US 20060130557A1
• Time in Patent Office: 998 Days
• Field of Search: 73/233, 422/84, 436/106, 436/113, 436/116, 436/117, 436/118, 436/128, 436/900, 600/529, 600/532, 600/543
• US Class Current: 73/23.3
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath
• CPC Class Codes: G01N 33/4972 Determining alcohol content for vehicle safety devices B60K28/06
• CPC Class Codes: H01M 2250/00 Fuel cells for particular applications; Specific features of fuel cell system
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1039 halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 436/90 Breath testing

Abstract

A method of diagnosing the health of an individual by collecting a breath sample from the individual and measuring the amount of each of a plurality of analytes in the sample. The amount of each analytes is measured by fitting a time response curve of a sample-evaluation fuel cell in which the fuel cell sample electrode is contacted with the sample with the analysis based on a function of standard time response curves for an equivalent fuel cell configuration obtained separately for each of the analytes on a fuel cell with equivalent construction as sample-evaluation fuel cell. Each of the plurality of analytes is generally indicative of an aspect of the individual'"'"'s health. Suitable analytes include, for example, inorganic compounds as well as compositions that exhibit negative reduction reactions at least for a portion of the time response curve. In particular, acetone exhibits a negative potential/current peak when it is an analyte in a fuel cell in an sample electrode with a counter electrode exposed to oxygen, which may or may not be introduced in the form of air. Various forms of analysis to estimate acetone concentrations in the breath can be used.

Claims

1. A system comprising:

a flow apparatus that is configured to operably receive a breath sample from an individual;

a fuel cell comprising a sample electrode operably coupled to the flow apparatus and a counter electrode exposed to O₂, wherein the sample transported within the flow system operably contacts the sample electrode; and

an analyzer that receives a signal related to the potential of the fuel cell, said signal being a combination of reduction and oxidation at each of said sample and counter electrodes, and evaluates the amount of acetone from a time response of the signal based on a standard time response of the fuel cell with acetone.

2. The system of claim 1 further comprising a sample collector operably connected to the flow apparatus.

3. The system of claim 2 wherein the sample collector comprises a mouthpiece.

4. The system of claim 1 wherein the flow system comprises a pump that facilitates control of the flow through the flow apparatus.

5. The system of claim 1 wherein the fuel cell comprises an ionomer as an electrolyte.

6. The system of claim 5 wherein the ionomer comprises a perfluoronated, sulfonic acid polymer.

7. The system of claim 1 wherein the sample electrode comprises a porous, conductive carbon cloth or paper gas diffusion layer.

8. The system of claim 1 wherein the analyzer comprises a microprocessor.

9. The system of claim 1 wherein the system is a portable unit.

10. The system of claim 1 wherein the O₂ is within air.

11. The system of claim 1, wherein the time response of the signal comprises a curve having a negative peak, wherein a negative peak depth is used to estimate an acetone concentration in the individual'"'"'s breath by comparing the negative peak depth with standard depths evaluated with standard aqueous acetone solutions.

12. The system of claim 1 wherein said analyzer uses an algorithm to evaluate the amount of acetone.