Detection of a physiologic parameter with a probe

• US 9,295,426 B2
• Filed: 02/28/2011
• Issued: 03/29/2016
• Est. Priority Date: 06/03/2002
• Status: Active Grant

• Current Assignee: Exostat Medical, Inc. (Vasamed, Inc.)
• Original Assignee: Exostat Medical, Inc. (Vasamed, Inc.)
• Inventors: Anderson, Edward J., Reynolds, Brandon W., Winger, Kent R., Kimball, Victor E.
• Primary Examiner(s): Kahelin, Michael
• Assistant Examiner(s): TRAN, THO Q
• Application Number:
  US13/036,832
• Publication Number:
  US 20110152646A1
• Time in Patent Office: 1,856 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/02 Details of sensors specially adapted for in-vivo measurements
• CPC Class Codes: A61B 2562/247 Hygienic covers, i.e. for covering the sensor or apparatus during use
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/42 Detecting, measuring or recording for evaluating the gastrointestinal, the endocrine or the exocrine systems A61B1/00, A61B5/4857, A61B5/486, A61B5/4866, A61B5/4869 take precedence
• CPC Class Codes: A61B 5/682 Mouth, e.g., oral cavity; tongue; Lips; Teeth
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 8/06 Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00

Abstract

The invention provides a device for contacting a surface of a patient'"'"'s body to determine a physiologic parameter in a measurement region of a tissue of the patient. The device typically comprises a sensor responsive to the physiologic parameter and a probe housing the sensor. The probe is constructed to allow the sensor to be secured at a sensing site adjacent to the measurement region, without disturbing the blood flow within the measurement region of the tissue. The device may also include a means for reducing interference in the sensing area. Preferably, the device further comprises an indicating means operably connected to the sensor for indicating an analyte quantity and/or concentration associated with the physiologic parameter.

Claims

1. A device for contacting a tissue sensing site of a patient to determine a physiologic parameter of the patient, comprising:

a probe body having a longitudinal axis, a top covered portion parallel to said longitudinal axis, said top portion comprising a material that is impermeable and a bottom open portion defining a perimeter structured to be positioned against a surface of the tissue sensing site, said perimeter defining a recess therewithin, said probe body and said perimeter structured to prevent application of excessive pressure to the sensing site to allow for substantially undisturbed blood flow in the tissue; and

a sensor responsive to a concentration of an analyte through a chemical reaction with a reactant, said analyte concentration representative of the physiologic parameter, said sensor having a first end and a sensor body, said first end coupled to said probe body and said sensor body unobstructedly suspended with the recess;

wherein upon placement of the probe body against the sensing site, said impermeable top portion and said perimeter are structured to create a covered, isolated measurement area within the recess such that the sensor is exposed to the tissue sensing site and the covered, isolated measurement area prevents the analyte from dissipating from the measurement area.

2. The device of claim 1, wherein the probe body further comprises a means for reducing interference at the sensing site.

3. The device of claim 2, wherein the means for reducing interference at the sensing site is an integral portion of the probe.

4. The device of claim 1, wherein the probe is constructed to allow the sensor to be secured at the sensing site.

5. The device of claim 4, wherein a surface of the probe is secured to the sensing site with an adhesive.

6. The device of claim 1, wherein the sensor is detachable from the probe body.

7. The device of claim 2, wherein the means for reducing interference is adapted to reduce interference from electromagnetic radiation, air flow or both.

8. The device of claim 3, wherein the means for reducing interference comprises an isolating means for isolating and preventing said analyte from dissipating from the measurement area and for allowing the analyte to come into equilibrium within the measurement area.

9. The device of claim 8, wherein the isolating means for isolating and preventing an analyte from dissipating from the measurement area represents an integral portion of the probe.

10. The device of claim 1, wherein the device is sized to fit into the nares, mouth, or cheek of the patient.

11. The device of claim 1 wherein the analyte is selected from the group consisting of hydrogen ions, CO₂, pCO₂, O₂, glucose, pyruvate, acetyl-CoA, citrate, isocitrate, alpha-ketoglutarate, succinyl-CoA, ADP, ATP, succinate, fumarate, malate oxaloacetate, NAD, NADH, and combinations thereof.

12. The device of claim 1, further comprising an indicating means for indicating analyte concentration in the patient, said indicating means operably connected to the sensor.

13. The device of claim 1, wherein at least a portion of the probe body comprises a material that allows the portion to deform in response to force applied to the probe body so as to avoid substantial blanching the tissue.

14. The device of claim 13, wherein the material is an elastically deformable polymer selected from the group consisting of polyethylene, polypropylene, polybutylene, polyamide, polyimide, polyester, perfluorinated polymer, polystyrene, polyvinyl chloride and elastomers.

15. The device of claim 1, wherein the device includes a holding means for securing the probe body to the sensing site.

16. The device of claim 15, wherein the holding means is selected from the group consisting of a clip, handle, clamp, adhesives, gels, fasteners, strap, belt, hook, sutures, and staples.

17. The device of claim 15, wherein the holding means is adapted to secure the probe body to the sensing site without applying a pressure greater than about 1.5×

10⁴ pascals to the tissue.

18. The device of claim 1, wherein the analyte to which the sensor is responsive is a gas selected from the group consisting of oxygen, carbon dioxide, nitrous oxide, desflurane, enfluran, halothane, isoflurane, methoxyflurane, and sevoflurane.

19. The device of claim 1, further comprising at least one additional sensor.

20. The device of claim 1, wherein the device further comprises a temperature detecting means for detecting temperature at the sensor.

21. The device of claim 20, wherein the temperature detecting means is detachable from the device.

22. The device of claim 1, further comprising a sheath covering the device.

23. The device of claim 22, wherein the device is adapted for single use.

24. The device of claim 22, wherein the sheath has a selectively permeable portion that allows transmission of an analyte therethrough.

25. The device of claim 24, wherein the selectively permeable portion is selected from the group consisting of a silicone, a porous membrane and combinations thereof.

26. The device of claim 22, wherein the sheath includes a rigid portion.

27. The device of claim 22, wherein the sheath is disposable.

28. The device of claim 19, wherein the device is adapted to be reused.

29. The device of claim 1, wherein the sensing site is nonepidermal tissue.

30. The device of claim 29, wherein the tissue is mucosal.

31. The device of claim 1, wherein the sensing site is the patient'"'"'s epidermis.

32. The device of claim 1, wherein the sensor is a Severinghaus-type sensor.

33. The device of claim 1, wherein the sensor is responsive to analyte concentration through generation or alteration of an electrical current.

37. The method of claim 1, wherein the sensing site is mucosal tissue.

34. A method for determining a physiologic parameter of a patient, the method comprising:

(a) providing the probe of claim;

(b) placing the probe body on the sensing site without substantially disturbing blood flow within the tissue such that the impermeable top portion and the perimeter of the bottom portion define an isolated, covered measurement region that prevents analyte from dissipating from the measurement region; and

(c) providing a computing device programmed to derive the physiologic parameter from the response of the sensor to the concentration of the analyte present in the measurement region.

35. The method of claim 34, further comprising, exposing the sensor to at least one analyte at a predetermined concentration in at least one calibrant.

36. The method of claim 34, wherein the analyte is selected from the group consisting of hydrogen ions, CO₂, pCO₂, O₂, glucose, pyruvate, acetyl-CoA, citrate, isocitrate, alphaketoglutarate, succinyl-CoA, ADP, ATP, succinate, fumarate, malate oxaloacetate, NAD, NADH, and combinations thereof.

38. The method of claim 34, further comprising allowing the concentration of the analyte in the measurement region to reach an equilibrium level.

39. The method of claim 34, further comprising immobilizing the probe on the sensing site for a predetermined period.

40. The method of claim 39, wherein deriving an assessment of the concentration of the analyte in the measurement site is initiated, repeated or performed continuously during the predetermined period of time.

41. The method of claim 34, further comprising processing sensor output to a condition of the patient.

42. The method of claim 41, wherein the condition is a regional condition, a systemic condition, perfusion failure, tissue gas concentration, tissue pH or tissue activity.

43. The method of claim 41, said processing is carried out using a predictive algorithm, endpoint detection and/or verification, and/or univariate, multivariate, or neural network analysis.