Detection of conditions by analysis of gases or vapors

• US 6,190,858 B1
• Filed: 08/23/1999
• Issued: 02/20/2001
• Est. Priority Date: 01/02/1997
• Status: Expired due to Term

• Current Assignee: Genmark Diagnostics Incorporated (Roche Holding AG)
• Original Assignee: Osmetech PLC (Roche Holding AG)
• Inventors: Persaud, Krishna Chandra, Syms, Allan John
• Primary Examiner(s): Leary, Louise N.
• Application Number:
  US09/331,749
• Time in Patent Office: 547 Days
• Field of Search: 435/4, 435/5, 435/7.2, 435/7.21, 435/7.22, 435/7.31, 435/7.32, 435/29, 435/30, 435/34, 435/283.1, 435/286.6, 435/286.5, 435/287.1, 435/287.5
• US Class Current: 435/4
• CPC Class Codes: C12Q 1/04 Determining presence or kind of microorganism; Use of selective media for testing antibiotics or bacteriocides; Compositions containing a chemical indicator therefor C12Q1/6897 takes precedence
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array electrochemical electrode arrays G01N27/27
• CPC Class Codes: G01N 33/497 of gaseous biological material, e.g. breath
• CPC Class Codes: G01N 33/98 involving alcohol, e.g. ethanol in breath

Abstract

The invention discloses a method for monitoring at least one condition in a patient comprising the steps of (a) obtaining samples from the patient over a period of time; (b) flowing the samples, or gases associated with or produced by the samples, over at least one gas sensor; c) measuring the response or responses of the at least one gas sensor; and (d) correlating the response or responses with the occurrence or state of the at least one condition. A method for identifying a micro-organism comprising the steps of (a) providing at least one gas sensor; (b) compiling a database of responses to at least one known micro-organism under a variety of culturing conditions; c) abstracting gas or vapor from a detection region and flowing the same over the at least one gas sensor and observing the response of the sensor or sensors; and (d) comparing the response to the database.

Claims

1. A method for monitoring at least one condition in a patient comprising the steps of:

obtaining samples from the patient over a period of time;

flowing the samples, or gases associated with or produced by the samples, over at least one gas sensor;

measuring the response or responses of the at least one gas sensor; and

correlating the response or responses with the occurrence or state of the at least one condition.

2. The method according to claim 1 in which the samples comprise respiratory gases.

3. The method according to claim 1 in which the samples comprise swabbed samples obtained from the patient.

4. The method according to claim 1 in which the samples comprise blood.

5. The method according to claim 1 in which the condition monitored is a disease state.

6. The method according to claim 5 in which the progression and/or the regression of the disease state is monitored.

7. The method according to claim 5 in which the condition is a bacterial infection.

8. The method according to claim 5 in which the condition is a viral, fungal or parasitic infection.

9. The method according to claim 1 in which the response or responses are correlated with the effectiveness of a course of treatment.

10. The method according to claim 1 in which the response or responses are correlated with progress of a healing process.

11. The method according to claim 1 in which the response or responses are correlated with the occurrence or state of the condition or conditions by a trained neural network.

12. The method according to claim 1 in which an array of gas sensors is employed.

13. The method according to claim 12 in which the pattern of responses of the sensors in the array is correlated with the occurrence of or state of the at least one condition.

14. The method according to claim 1 in which the samples are obtained continuously from the patient.

15. The method according to claim 14 in which the samples, or gas associated with or produced by the samples, are continuously flowed over the at least one gas sensor.

16. The method according to claim 15 in which the response or responses of the at least one gas sensor is measured continuously.

17. The method according to claim 14 in which a plurality of measurements are made over a period of time.

18. The method according to claim 14 in which the samples comprise respiratory gases obtained from a ventilator.

19. The method according to claim 14 in which the samples comprise blood undergoing a dialysis treatment.

20. The method according to claim 19 in which gases produced by a waste product containing solution are measured by the at least one gas sensor.

21. The method according to claim 20 in which the removal of urea from the blood sample is monitored by measuring ammonia evolved from the waste product containing solution.

22. The method for identifying a micro-organism comprising the steps of:

providing at least one gas sensor;

compiling a database of responses to at least one known micro-organism under a variety of culturing conditions;

abstracting gas or vapor from a detection region and flowing the same over said the at least one gas sensor and observing the response of the sensor or sensors; and

comparing the response to the database.

23. The method according to claim 22 in which the database further comprises responses to at least one known bacterium.

24. The method according to claim 22 in which the database comprises responses to a plurality of different isolates of a single bacterial species.

25. The method according to claim 22 in which the micro-organism comprises a virus, fungus or parasite.

26. The method according to claim 22 in which the database comprises responses to at least one known micro-organism cultured under a variety of nutrient conditions.

27. The method according to claim 22 in which the database comprises responses to at least one known micro-organism cultured at a variety of temperatures.

28. The method according to claim 22 in which the database comprises responses to at least one known micro-organism obtained at different stages in the life cycle of the micro-organism.

29. The method for identifying at least one condition in a patient according to claim 22 in which gas and/or vapor produced by the patient, or by a sample obtained from the patient, is flowed over the at least one gas sensor.

30. The method according to claim 29 in which the at least a portion of the database is compiled from the responses of at least one gas sensor to gas and/or vapor produced by a patient, or by a sample obtained from the patient.

31. The method according to claim 22 in which the database comprises responses to at least one known micro-organism obtained at different stages during the course of treatment.

32. The method according to claim 22 in which an array of gas sensors is employed.

33. The method according to claim 22 in which the compilation of the database comprises training a neural network.

34. The method according to claim 22 in which the response of the sensors is used to provide information about the detection region.

35. The method according to claim 22 in which the gas sensor or sensors comprise a gas sensitive material.

36. The method according to claim 35 in which an electrical property of the gas sensitive material varies on exposure to gases.

37. The method according to claim 36 in which the gas sensitive material comprises semiconducting polymer.

38. The method according to claim 35 in which the gas sensor or sensors comprise MOS, quartz resonator or SAW devices.