APPARATUS AND METHOD FOR DIAGNOSTIC GAS ANALYSIS

• US 20110066060A1
• Filed: 11/16/2010
• Published: 03/17/2011
• Est. Priority Date: 09/16/2002
• Status: Active Grant

• Current Assignee: Circassia AB
• Original Assignee: Aerocrine AB (Circassia Group Plc)
• Inventors: Hemmingsson, Tryggve, Gustafsson, Fredric, von Bahr, Pontus, Jakobsson, Anders
• Granted Patent: US 8,597,580 B2
• Time in Patent Office: Days
• US Class Current: 600/532
• CPC Class Codes: A61B 5/0803 Recording apparatus specially adapted therefor
• 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: A61B 5/486 Bio-feedback A61B5/375 takes precedence
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01N 1/22 in the gaseous state specially adapted for biological material G01N33/497; measuring breath flow A61B5/087
• CPC Class Codes: G01N 21/766 of gases
• CPC Class Codes: G01N 27/28 Electrolytic cell components
• CPC Class Codes: G01N 33/0016 by regulating a physical variable, e.g. pressure or temperature
• CPC Class Codes: G01N 33/0037 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
• CPC Class Codes: Y10T 436/177692 Oxides of nitrogen
• CPC Class Codes: Y10T 436/179228 Both nitrogen oxide and dioxide
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]

Abstract

A handheld, small but accurate and reliable device for diagnostic NO measurements using a NO sensor, where the parameters governing the taking of the sample are different from the parameters optimal for the accuracy of said NO sensor I described. By temporarily storing a portion of the exhaled air, and feeding this to the sensor at a flow rate adapted to the NO sensor, the accuracy and sensitivity of a system/method involving NO sensors, in particular electrochemical NO sensors, can be increased. The method for diagnostic NO measurements comprises steps for controlling the inhalation of NO free air, as well as the exhalation, both by built-in means and by audible and/or visual feedback to the patient.

Claims

1. A device for diagnostic measurement of NO in exhaled breath, comprising an inlet through which a patient exhales at a first flow rate and pressure, and an electrochemical sensor for determining the level of NO, wherein the device further comprises a buffer chamber for temporarily storing a sample of the exhaled air, and a sample feeder for feeding a portion of the sample from the buffer chamber to the sensor at a second flow rate, wherein the second flow rate is smaller than the first flow rate.

2. The device according to claim 1, wherein the device comprises a flow regulator for controlling the exhalation flow.

3. The device according to claim 2, wherein the flow regulator has the function of controlling the exhalation flow to 20-800 ml/s.

4. The device according to claim 2, wherein the flow regulator has the function of controlling the exhalation flow to 45-55 ml/s.

5. The device according to claim 1, wherein the sample feeder supplies the sensor with a steady flow of about 0.5 ml/s to about 15 ml/s.

6. The device according to claim 1, wherein the sample feeder supplies the sensor with a steady flow of about 2 ml/s to about 10 ml/s.

7. The device according to claim 1, wherein the sample feeder supplies the sensor with a steady flow of about 0.5 ml/s to about 15 ml/s during a time period longer than the duration of the exhalation.

8. The device according to claim 1, wherein the sample feeder supplies the sensor with a steady flow of about 2 ml/s to about 10 ml/s during a time period longer than the duration of the exhalation.

9. The device according to claim 1, further comprises a humidity equalizer for equalizing the humidity of the sample.

10. The device according to claim 9, wherein humidity equalizer is a length of tube made from a catalytic membrane material.

11. The device according to claim 1, further comprising an exhaled breath controller.

12. The device according to claim 11, wherein the exhaled breath controller includes a pressure sensor.

13. The device according to claim 11, wherein the exhaled breath controller a pressure sensor and a feedback assembly that outputs feedback to a patient that uses the device according to measurements taken by the pressure sensor.

14. The device according to claim 11, wherein the exhaled breath controller includes a flow sensor.

15. The device according to claim 11, wherein the exhaled breath controller includes a flow sensor and a flow controller for controlling the flow based on measurements of the flow sensor.

16. The device according to claim 11, wherein the exhaled breath controller includes a flow sensor and a feedback assembly that outputs feedback to a patient that uses the device according to measurements taken by the flow sensor.

17. The device according to claim 1, wherein the buffer chamber terminates in a valve which is open during an initial phase of exhalation, and then closes to collect a sample of the exhaled breath in the buffer chamber.

18. The device according to claim 1, further comprising an interface for receiving a memory assembly on which data linked to a specific user is stored and the device is configured to record NO measurement data on the memory assembly.

19. The device according to claim 18, wherein the device is configured to adapt operation to at least one of different users or different user groups based on the data stored on the memory assembly.

20. A method for diagnostic NO measurements using a device comprising an electrochemical NO sensor, comprising the steps of

receiving breath exhaled by a patient with the device,

controlling a flow rate and pressure of the exhaled breath to at least one preset value defining a first flow rate,

temporarily storing a sample of the exhalation air in a buffer chamber,

feeding at least a portion of the sample from the buffer chamber to the electrochemical NO sensor at a second flow rate, and

determining the NO concentration in the sample,

wherein the second flow rate is smaller than the first flow rate.

21. The method according to claim 20, wherein the electrochemical sensor is exposed to the sample for a period of time longer than the duration of the exhalation.

22. The method according to claim 20, wherein the first flow rate is about 20 ml/s to about 800 ml/s.

23. The method according to claim 20, wherein the first flow rate is about 45 ml/s to about 55 ml/s.

24. The method according to claim 20, wherein the second flow rate is about 0.5 ml/s to about 15 ml/s.

25. The method according to claim 20, wherein the second flow rate is about 2 ml/s to about 10 ml/s.

26. The method according to claim 20, further comprising outputting at least one of audible or visual feedback to the patient during the exhalation in order to support coordination of the exhalation with determination of NO concentration.

27. The method according to claim 26, wherein the feedback is configured to help the patient to maintain a desirable flow, pressure, and duration of exhalation.

28. The method according to claim 20, further comprising receiving information with the device relating to at least one of medication taken by the patient or state of health of the patient.

29. A non-transitory computer readable medium storing a program comprising executable instructions configured to control operation of a device for diagnostic measurement of NO in exhaled breath, including:

control flow rate and pressure of the exhaled breath to at least one preset value defining a first flow rate;

control temporary storage of a sample of the exhaled breath in a buffer chamber;

control feeding of at least a portion of the sample from the buffer chamber to an electrochemical NO sensor at a second flow rate that is smaller than the first flow rate; and

determine NO concentration in the sample.

30. A device for diagnostic measurement of NO in exhaled breath using an electrochemical sensor, comprising means for receiving the exhaled breath at a first flow rate, means for temporarily storing a sample of the exhaled breath, and means for feeding a portion of the sample from the means for temporarily storing to the electrochemical sensor at a second flow rate, wherein the second flow rate is smaller than the first flow rate.