Device and method for the quantitative determination of nitrogen oxides in exhaled air and application thereof

• US 7,704,214 B2
• Filed: 04/30/2002
• Issued: 04/27/2010
• Est. Priority Date: 04/30/2001
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Siemens AG
• Inventors: Fleischer, Maximilian, Rumpel, Eva, Simon, Elfriede, Abraham-Fuchs, Klaus, Meixner, Hans
• Primary Examiner(s): Mallari; Patricia C
• Application Number:
  US10/476,444
• Publication Number:
  US 20040133116A1
• Time in Patent Office: 2,919 Days
• Field of Search: 436/117, 436/118, 422/84, 73/233, 600/532
• US Class Current: 600/532
• CPC Class Codes: A61B 5/082 Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath A61B5/083, A61B5/091 take precedence
• 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 27/4143 Air gap between gate and channel, i.e. suspended gate [SG] FETs work function measurement per se G01N27/002
• CPC Class Codes: G01N 33/0013 by a chemical reaction G01N33/0024 takes precedence
• CPC Class Codes: G01N 33/0037 for NOx
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

A volumetric flow of an analyte, including exhaled air, is fed to a gas sensor unit by used of gas flow device, which can include various sensors for the determination of nitrogen oxides. An oxidation catalyst is used when using an NO₂ sensor, which converts nitrogen monoxide to nitrogen dioxide and the gas sensor unit measures the content of nitrogen dioxide. The nitrogen monoxide content is calculated from the nitrogen dioxide content. In order to eliminate cross-sensitivity moisture and ethanol are also measured. The device can be applied to the determination of nitrogen monoxide content of exhaled air.

Claims

1. Device for quantitative measurement of nitrogen monoxide in exhaled air, comprising:

a gas sensor unit including

at least one gas sensor based on a principle of work function measurement, the at least one gas sensor including a first-type gas-sensitive layer containing a porphine pigment,

an oxidation catalyst for oxidation of nitrogen monoxide to nitrogen dioxide, and

at least one further sensor for the detection of at least one of moisture and ethanol for elimination of cross-sensitivities,

wherein the device is configured to measure the nitrogen monoxide, in the exhaled air of an individual, using the gas sensor unit.

2. Device according to claim 1, further comprising a field effect transistor including the first-type gas-sensitive layer, the field effect transistor being adapted to read the work function and the first-type gas-sensitive layer being in the form of a porous material deposited on a channel area of the field effect transistor.

3. Device according to claim 1, wherein the first-type gas-sensitive layer detects nitrogen oxide, the porphine pigment being a gas-sensitive material.

4. Device according to claim 3, wherein the porphine pigment is at least one of a phthalocyanine, a derivate of a phthalocyanine with the central atom being at least one of copper, lead, tin, nickel, cobalt, or zinc, and a phthalocyanine without a central atom whose free binding sites in the porphine ring are saturated by hydrogen atoms.

5. Device according to claim 4, wherein the phthalocyanine without the central atom is at least one of heliogen blue G and a phthalocyanine with phenylether side chains.

6. Device according to claim 1, wherein the device for determining the nitrogen monoxide in exhaled air is mobile.

7. Device according to claim 1, further comprising:

a gas flow device for the supply of the volumetric flow of at least one of nitrogen dioxide and nitrogen dioxide and at least one component of at least one of moisture, ethanol and temperature.

8. Device according to claim 7, wherein the volumetric flow of the exhaled air is divided in the gas flow device into a part volumetric flow via the oxidation catalyst for oxidation of nitrogen monoxide to nitrogen dioxide and then to the gas sensor unit for measurement of the nitrogen dioxide concentration, and into a further part volumetric flow supplied directly to a further nitrogen dioxide gas sensor for determining the nitrogen dioxide concentration, wherein the nitrogen monoxide concentration of the exhaled air is calculatable by using the individual nitrogen dioxide concentrations.

9. Device according to claim 7, wherein the complete volumetric flow of the exhaled air in the gas flow device is supplied through the oxidation catalyst for oxidation of nitrogen monoxide to nitrogen dioxide and then to a gas sensor unit for measurement of the nitrogen dioxide concentration, wherein the nitrogen monoxide concentration of the exhaled air is calculatable by using the nitrogen dioxide concentration.

10. Device according to claim 8, wherein at least one substance from the group of at least one of permanganate salts and perchlorate salts is applied to a support including at least one of zeolite, aluminum oxide and silica gel as a material for the oxidation catalyst.

11. Device according to claim 1, wherein sensor signals processed in an analytical circuit are supplied to a data network.

12. Device according to claim 2, wherein the first-type gas-sensitive layer detects nitrogen oxide, the porphine pigment being a gas-sensitive material.

13. Device according to claim 12, wherein the porphine pigment is at least one of a phthalocyanine, a derivate of a phthalocyanine with the central atom being at least one of copper, lead, tin, nickel, cobalt, or zinc, and a phthalocyanine without a central atom whose free binding sites in the porphine ring are saturated by hydrogen atoms.

14. Device according to claim 13, wherein the phthalocyanine without the central atom is at least one of heliogen blue G and a phthalocyanine with phenylether side chains.

15. Device according to claim 9, wherein at least one substance from the group of at least one of permanganate salts and perchlorate salts is applied to a support including at least one of zeolite, aluminum oxide and silica gel as the material for an oxidation catalyst.

16. Device according to claim 1, wherein the at least one gas sensor includes:

a hybrid field effect transistor including the first-type gas-sensitive layer, the first-type gas-sensitive layer being represented by a gate electrode spaced apart from a channel area used to read the work function.

17. Device according to claim 16, wherein the hybrid field effect transistor is of a hybrid flip-chip construction.

18. Device according to claim 16, wherein the at least one further sensor includes at least one second-type gas-sensitive layer formed of a material that includes at least one of polyamides and polypyrrolidones for the detection of moisture or includes polysiloxanes for the detection of ethanol.

19. Device according to claim 16, wherein

the hybrid field effect transistor includes a second-type gas-sensitive layer in the form of porous material deposited on the channel area, wherein the hybrid field effect transistor is adapted to read the work function.

20. Device according to claim 16, wherein the first-type gas-sensitive layer detects nitrogen oxide, the porphine pigment being a gas-sensitive material.

21. Device according to claim 20, wherein the porphine pigment is at least one of a phthalocyanine, a derivate of a phthalocyanine with the central atom being at least one of copper, lead, tin, nickel, cobalt, or zinc, and a phthalocyanine without a central atom whose free binding sites in the porphine ring are saturated by hydrogen atoms.

22. Device according to claim 21, wherein the phthalocyanine without a central atom is at least one of heliogen blue G and a phthalocyanine with phenylether side chains.

23. Device according to claim 1, further comprising:

a hybrid field effect transistor including a second-type gas-sensitive layer represented by a gate electrode spaced apart from a channel area used to read the work function.

24. Device according to claim 23, wherein the hybrid field effect transistor is of a hybrid flip-chip construction.

25. Device according to claim 23, wherein the at least one further sensor includes at least one third-type gas-sensitive layer formed of a material that includes at least one of polyamides and polypyrrolidones for the detection of moisture or includes polysiloxanes for the detection of ethanol.

26. Device according to claim 23, further comprising:

a field effect transistor including the first-type gas-sensitive layer, the field effect transistor being adapted to read the work function and the first-type gas-sensitive layer being in the form of porous material deposited on the channel area.

27. Device according to claim 23, wherein the at least one first-type gas-sensitive layer detects nitrogen oxide, the porphine pigment being a gas-sensitive material.

28. Device according to claim 27, wherein the porphine pigment is at least one of a phthalocyanine, a derivate of a phthalocyanine with the central atom being at least one of copper, lead, tin, nickel, cobalt, or zinc, and a phthalocyanine without a central atom whose free binding sites in the porphine ring are saturated by hydrogen atoms.

29. Device according to claim 28, wherein the phthalocyanine without a central atom is at least one of heliogen blue G and a phthalocyanine with phenylether side chains.

30. Device according to claim 2, wherein the at least one further sensor includes a second-type gas-sensitive layer, wherein the second-type gas-sensitive layer is formed of a material that detects moisture and includes at least one of polyamides and polypyrrolidones and includes polysiloxanes for the detection of ethanol.

31. Device according to claim 2, wherein the at least one gas sensor includes the field effect transistor, and the field effect transistor has a hybrid flip-chip construction.