METHOD FOR OPTIMIZING THE GAS CONVERSION RATE IN A RESPIRATORY GAS ANALYZER

• US 20110077544A1
• Filed: 09/27/2010
• Published: 03/31/2011
• Est. Priority Date: 09/28/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hornung, Oliver, Pohle, Roland, Von Sicard, Oliver, Fleischer, Maximilian, ABRAHAM-FUCHS, Klaus, Magori, Erhard, Krüger-Sundhaus, Thomas, Hiltawsky, Karsten
• Granted Patent: US 9,301,709 B2
• Time in Patent Office: Days
• 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

Abstract

A method for optimizing a gas conversion rate in a respiratory gas analyzer, more particularly for nitric oxide (NO) in the respiratory gas, and an associated device are disclosed.

Claims

1. A device for measuring at least one gas analyte in exhaled air via a gas sensor unit including at least one gas sensor, comprising:

an arrangement for gas conversion, wherein the arrangement for gas conversion includes an effective cross section of greater than 0.01 cm² and less than 100 cm², and includes an effective volume of greater than 0.05 ml and less than 100 ml.

2. The device as claimed in claim 1, wherein the at least one gas analyte is nitrogen monoxide and the arrangement for gas conversion is an arrangement for oxidizing nitrogen monoxide to nitrogen dioxide.

3. The device as claimed in claim 2, wherein the arrangement for oxidizing nitrogen monoxide to nitrogen dioxide includes an oxidizing agent.

4. The device as claimed in claim 2, wherein the arrangement for oxidizing nitrogen monoxide to nitrogen dioxide includes a catalyst for catalyzing the oxidation of nitrogen monoxide to nitrogen dioxide.

5. The device as claimed in claim 1, wherein the arrangement for gas conversion is provided as a consumable.

6. The device as claimed in claim 1, wherein the arrangement for gas conversion is provided in a separate unit.

7. The device as claimed in claim 1, wherein the arrangement for gas conversion includes a cylindrical design with a cross section of 0.5-2 cm² and a length of approximately 0.2-1 cm.

8. The device as claimed in claim 1, further comprising:

means for determining a conversion rate of the arrangement for gas conversion, the conversion rate being corrected in respect of the usage state of the arrangement for gas conversion.

9. The device as claimed in claim 8, wherein the means for correcting the conversion rate comprises:

means for determining the usage state of the arrangement for gas conversion and

means for calculating the corrected conversion rate with the aid of the usage state.

10. The device as claimed in claim 9, wherein the means for determining the usage state of the arrangement for gas conversion comprises a flow sensor for determining a gas volume flowing through the arrangement for gas conversion, wherein the usage state is measured with the aid of the overall volume of gas that has flown through the arrangement for gas conversion at any given time.

11. The device as claimed in claim 9, wherein the means for determining the usage state of the arrangement for gas conversion comprises means for counting the usage cycles of the device, wherein the usage state is measured with the aid of the overall number of usage cycles that the device has passed through at any given time.

12. The device as claimed in claim 9, wherein the means for calculating the corrected conversion rate has a computational arrangement for calculating the corrected conversion rate with the aid of the usage state, which computational arrangement is suitable for calculating the corrected conversion rate as a function of the usage state or with the aid of stored or entered correction factors, wherein the correction factor to be used is correlated to the usage state.

13. The device as claimed in claim 12, wherein the means for correcting the conversion rate additionally comprises:

a first and a second gas conversion arrangement with differing volumes V1 and V2, respectively, wherein different concentrations c1 and c2 are measured after the conversion in the case of identical initial concentrations of the gas analyte to be measured, wherein c2=q′

*c1 holds true, wherein q′

changes as a function of the usage state and can be used for calculating a corrected conversion rate with the aid of stored or entered correction factors or a function of q′

.

20. The device as claimed in claim 7, wherein the arrangement for gas conversion includes a cylindrical design with a cross section of 1 cm² and a length of 0.6 cm.

14. A method for detecting a gas analyte, comprising:

converting the gas analyte into a detectable gas analyte by a gas conversion arrangement;

determining a concentration of the detectable gas analyte;

establishing a conversion rate of the gas conversion arrangement; and

establishing a concentration of the gas analyte with the aid of the established conversion rate and the concentration of the detectable gas analyte.

15. The method as claimed in claim 14, wherein a corrected conversion rate is established as a function of the usage state of the gas conversion arrangement.

16. The method as claimed in claim 14, wherein the usage state is measured with the aid of the entire volume of gas that, integrated up to any given time, has flown through the arrangement for gas conversion.

17. The method as claimed in claim 14, wherein the usage state is measured by the number of usage cycles that the device has passed through at any given time.

18. The method as claimed in claim 14, wherein the corrected conversion rate is calculated as a function of the usage state or with the aid of a stored or entered correction factor, wherein the correction factor to be used correlates with the usage state.

19. The method as claimed in claim 14, wherein the calculating of the corrected conversion rate additionally comprises:

measuring two different concentrations c1 and c2 after the conversion by a first and a second gas conversion arrangement with differing volumes V1 and V2, respectively, with an identical initial concentration of the gas analyte to be measured, wherein c2=q′

*c1 holds true, wherein the factor q′

changes as a function of the usage state and

calculating the corrected conversion rate as a function of the factor q′

or with the aid of a stored or entered factor q′

.