ION-BASED BREATH ANALYSIS SYSTEM

• US 20130168548A1
• Filed: 12/29/2011
• Published: 07/04/2013
• Est. Priority Date: 12/29/2011
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Wang, Xuefeng, Li, Bo, Chen, Cheng-Po, Chen, Rui
• Granted Patent: US 9,089,279 B2
• Time in Patent Office: Days
• US Class Current: 250/288
• 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: G01N 27/622 Ion mobility spectrometry
• CPC Class Codes: G01N 27/624 Differential mobility spectrometry [DMS]; Field asymmetric-waveform ion mobility spectrometry [FAIMS]
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath

Abstract

Disclosed embodiments include systems for analyzing the breath of a patient for the presence of one or more analytes of interest. The systems may include an ion detection system capable of receiving a gas mixture having an analyte of interest expired by a patient, flowing the gas mixture, and ionizing molecules within the gas mixture. The molecules include at least the analyte of interest. The ion detection system is also capable of detecting the ionized analyte of interest.

Claims

1. A breath analysis system, comprising:

a breath sample preparation system, comprising;

a first inlet configured to receive a patient'"'"'s expired breath comprising an analyte of interest;

a second inlet configured to receive a carrier gas; and

a mixing chamber configured to mix at least a portion of the patient'"'"'s expired breath with the carrier gas to generate a gas mixture; and

an ion detection system operatively coupled to the preparation system, comprising;

a gas path configured to flow the gas mixture;

an ionization source disposed along the gas path and configured to ionize at least the analyte of interest within the gas mixture; and

an ion detector disposed along the gas path downstream from the ionization source and configured to detect the ionized analyte of interest.

2. The system of claim 1, wherein the detector comprises one or more electrometers configured to generate an electric current in response to an amount of the ionized analyte.

3. The system of claim 1, wherein the ion detection system comprises an ion filter disposed along the gas path between the ionization source and the ion detector, and the ion filter is configured to separate different ionized molecules of the gas mixture from one another.

4. The system of claim 3, wherein the ion filter comprises at least two ion filter electrodes configured to generate a direct current (DC) electric field such that the molecules ionized by the ionization source flow through the gas path and reach the ion detector at respective times characteristic of their respective mobilities within the DC electric field.

5. The system of claim 3, wherein the ion filter comprises an RF waveform generator configured to generate a radiofrequency (RF) electric field such only ionized molecules with predetermined characteristics flow through the RF electric field and are able to reach the ion detector.

6. The system of claim 5, wherein the ion filter comprises at least two filter electrodes configured to generate a DC electric field such that the ionized molecules having the predetermined characteristics flow through the RF and DC electric field and reach the ion detector at respective times characteristic of their respective mobilities within the RF and DC electric field.

7. The system of claim 1, wherein the ion detection system comprises a heater and a temperature sensor to regulate a temperature of the gas mixture within the gas path.

8. The system of claim 1, wherein the ionization source comprises a UV lamp, a β

-emitter, a corona discharge source, a flame ionization source, or any combination thereof.

9. The system of claim 1, wherein the ionization source is tuned to an ionization potential of the analyte of interest.

10. The system of claim 9, wherein the analyte of interest comprises an anesthetic agent, a metabolite of an anesthetic agent, or a combination thereof.

11. The system of claim 1, wherein the preparation system comprises one or more filters disposed between the first inlet and the mixing chamber, or the second inlet and the mixing chamber, or a combination thereof, and the one or more filters are configured to remove moisture, carbon dioxide (CO₂), sputum, food particles, interfering compounds, or a combination thereof, from the patient'"'"'s expired breath, or from the carrier gas, or a combination thereof.

12. The system of claim 1, comprising a transfer path coupling the breath sample preparation system with the ion detection system, and the transfer path is configured to heat the gas mixture, maintain a temperature of the gas mixture, or a combination thereof.

13. The system of claim 1, comprising a pump configured to motivate the gas mixture through the gas path.

14. A breath analysis system, comprising:

an ion detection system, comprising;

an inlet configured to receive a gas mixture having an analyte of interest expired by a patient;

a gas path configured to flow the gas mixture;

an ionization source disposed along the gas path and configured to ionize molecules within the gas mixture, the molecules comprising at least the analyte of interest; and

an ion detector disposed along the gas path downstream from the ionization source and configured to detect the ionized analyte of interest.

15. The system of claim 14, wherein the ion detection system comprises a substrate having the inlet and the gas path, and the ionization source and ion detector are mounted on the substrate.

16. The system of claim 15, wherein the substrate is a printed circuit board.

17. The system of claim 14, wherein the ion detection system is integrated onto a single circuit board comprising a processor configured to control the operation of at least the ion detection system.

18. The system of claim 14, wherein the ion detection system comprises an ion filter disposed along the gas path between the ionization source and the ion detector, and the ion filter is configured to separate different ionized molecules of the gas mixture from one another.

19. The system of claim 18, wherein the ion filter comprises an RF waveform generator configured to generate a radiofrequency (RF) electric field, or at least two filter electrodes configured to generate a DC electric field, or a combination thereof.

20. The system of claim 14, comprising a breath sample preparation system configured to prepare a patient'"'"'s expired breath for analysis by the ion detection system, comprising:

a breath inlet configured to receive the patient'"'"'s expired breath comprising the analyte of interest;

a carrier gas inlet configured to receive a carrier gas;

a mixing chamber configured to mix at least a portion of the patient'"'"'s expired breath with the carrier gas to generate the gas mixture; and

an outlet configured to fluidly couple the preparation system to the inlet of the ion detection system such that the gas mixture is able to flow from the preparation system to the ion detection system.

21. The system of claim 20, wherein the preparation system comprises a filter disposed between the breath inlet and the mixing chamber, wherein the filter is configured to remove moisture, carbon dioxide (CO₂), sputum, food particles, interfering compounds, or a combination thereof, from the patient'"'"'s expired breath.

22. The system of claim 20, comprising a temperature sensor configured to monitor a temperature of the gas mixture before ionization by the ionization source, or a humidity sensor configured to monitor a moisture level of the gas mixture before ionization by the ionization source, or a combination thereof.

23. A breath analysis system, comprising:

an ion detection system, comprising;

a substrate comprising one or more thru holes configured to enable the breath analysis system to integrate onto a circuit board, wherein the substrate comprises;

an inlet configured to receive a gas mixture having an analyte of interest from a patient'"'"'s expired breath; and

a gas path fluidly coupled to the inlet and formed within the substrate, wherein the gas path is configured to flow the gas mixture within the substrate toward an outlet of the substrate;

an ionization source coupled to the substrate and disposed along the gas path, wherein the ionization source is configured to ionize at least the analyte of interest within the gas mixture;

an ion filter coupled to an inner surface of the substrate along the gas path and configured to separate the ionized analyte of interest from other components of the gas mixture; and

an ion detector coupled to the inner surface of the substrate along the gas path and downstream from the ion filter, wherein the ion detector is configured to generate a signal in response to detecting the presence of the ionized analyte of interest.

24. The system of claim 23, comprising a breath sample preparation system configured to prepare the patient'"'"'s expired breath for analysis by the ion detection system, comprising:

a breath inlet configured to receive the patient'"'"'s expired breath;

a carrier gas inlet configured to receive a carrier gas;

a mixing chamber configured to mix at least a portion of the patient'"'"'s expired breath with the carrier gas to generate the gas mixture; and

an outlet configured to fluidly couple the preparation system to the inlet of the ion detection system such that the gas mixture is able to flow from the preparation system to the ion detection system.

25. The system of claim 24, wherein the preparation system comprises a filter disposed between the breath inlet and the mixing chamber, wherein the filter is configured to remove moisture, carbon dioxide (CO₂), sputum, food particles, interfering compounds, or a combination thereof, from the patient'"'"'s expired breath.

26. The system of claim 23, wherein the ion detection system comprises a resistive heater and a temperature sensor coupled to the substrate, wherein the resistive heater and the temperature sensor are configured to enable temperature control of the gas mixture within the gas path to reduce temperature effects on ionization of the gas mixture and detection of the analyte of interest.