Sampling Circuit for Measuring Analytes

• US 20100081955A1
• Filed: 09/30/2008
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Battista, John Andrew JR., Wood, Lockett E. JR., Kadlec, Ron J.
• Granted Patent: US 8,652,064 B2
• Time in Patent Office: Days
• US Class Current: 600/532
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices

Abstract

This disclosure describes an apparatus and method for measuring analytes in exhaled air. The device contains an inlet through which exhaled air is received. A tube, having a number of different paths running throughout the device, is coupled to the inlet which enables the exhaled air to be re-circulated through the device. At least one portion of the tube is configured in a non-linear fashion. This particular portion of the tube may be used to temporarily store a sample of the exhaled air. The device also contains a converter configured to partially convert an analyte in the exhaled breath from a first state to a second state as the exhaled air is being re-circulated. An analyte sensor is also included to measure the levels of the converted analyte in the exhaled breath.

Claims

1. An apparatus for measuring an analyte in exhaled air, the apparatus comprising:

an inlet through which the exhaled air is received;

a tube coupled to the inlet, the tube having a plurality of paths and a non-linear portion, the non-linear portion being configured to temporarily store at least a portion of the exhaled air;

a pump configured to circulate the exhaled air through the tube;

a converter configured to partially convert the analyte from a first state to a second state; and

an analyte sensor for measuring the analyte.

2. The apparatus of claim 1, where the non-linear portion is configured as a coil.

3. The apparatus of claim 1, wherein the converter is a catalytic converter.

4. The apparatus of claim 1, further comprising one or more valves coupled to the tube, wherein the one or more valves are configured to change the flow path of the exhaled air through the tube from a first path of the plurality of paths to a second path of the plurality of paths.

5. The apparatus of claim 1, wherein the converter is configured to receive the partially converted air at least a second time and perform at least a second partial conversion of the analyte from the first state to the second state.

6. The apparatus of claim 1, wherein the analyte is nitric oxide and the converter is configured to partially convert the nitric oxide to nitrogen dioxide.

7. The apparatus of claim 6, wherein the sensor is configured to measure nitrogen dioxide.

8. An apparatus for measuring an analyte in exhaled air, the apparatus comprising:

an inlet through which exhaled air is received;

a tube coupled to the inlet, wherein at least a portion of the tube is configured to store a sample of the exhaled air, the portion of the tube being in a non-linear configuration;

a pump configured to circulate the exhaled air through the tube; and

a converter configured to receive the exhaled air at least a first time and a second time, wherein when the exhaled air is received the first time, the converter partially converts the analyte from a first state to a second state and wherein when the analyte is received the second time, the converter further converts the analyte from the first state to the second state.

9. A method for measuring an analyte in exhaled air, the method comprising:

receiving exhaled air into an inlet;

circulating the exhaled air through a tube, wherein the tube has a plurality of paths and wherein at least a portion of the tube is arranged in a non-linear configuration;

passing the exhaled air through a converter, wherein each time the exhaled air is passed through the converter, the converter partially converts the analyte from a first state to a second state; and

measuring the converted analyte with an analyte sensor.

10. The method of claim 9, further comprising arranging the flow path of the exhaled air through the tube using a plurality of valves.

11. The method of claim 10, further comprising prohibiting the analyte sensor from measuring the converted analyte until a minimum conversion threshold has been achieved.

12. The method of claim 9, wherein the analyte is nitric oxide and the converter is configured to convert the nitric oxide to nitrogen dioxide.

13. The method of claim 9 further comprising, storing a sample of the exhaled air in the non-linear portion.

14. The method of claim 9, wherein the non-linear portion is configured as a coil.

15. An apparatus for measuring an analyte in exhaled breath, the apparatus comprising:

an inlet through which exhaled air is received;

a tube coupled to the inlet, the tube having a non-linear portion configured to store the exhaled air; and

an analyte sensor for measuring an analyte in the exhaled air.

16. The apparatus of claim 15, further comprising a converter configured to partially convert the analyte from a first state to a second state.

17. The apparatus of claim 16, wherein the converter is a catalytic converter.

18. The apparatus of claim 16, wherein converter partially converts the analyte from nitric oxide to nitrogen dioxide.

19. The apparatus of claim 15, wherein the analyte sensor is configured to measure nitrogen dioxide.

20. The apparatus of claim 15, wherein the non-linear portion is configured as a coil.