Multiple optical fiber event sensor and method of manufacture

• US 5,166,990 A
• Filed: 08/29/1991
• Issued: 11/24/1992
• Est. Priority Date: 08/10/1990
• Status: Expired due to Fees

• Current Assignee: Puritan Bennett Corp. (Medtronic Plc)
• Original Assignee: Puritan Bennett Corp. (Medtronic Plc)
• Inventors: Shern, Thomas A., Homick, Richard, Nelson, Alan, Bankert, Charles S., Hui, Henry K., Riccitelli, Samuel D.
• Primary Examiner(s): Lee, John D.
• Application Number:
  US07/751,818
• Time in Patent Office: 453 Days
• Field of Search: 385/12, 385/117, 385/118, 385/123, 385/141, 385/147, 385/902, 606/2, 606/10-12, 606/15, 606/16, 128/637, 128/692
• US Class Current: 385/12
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: G01N 2021/773 Porous polymer jacket; Polymer matrix with indicator
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 21/783 for analysing gases

Abstract

The multiple optical fiber event sensor apparatus includes a semipermeable generally cylindrical shaft, one or more optical fiber gas sensor modules within the shaft, and an optical fiber pH sensor module extending beyond the distal end of the shaft, with the sensor modules arranged in an axially staggered relationship. The shaft contains a potting matrix for axially fixing the position of the optical fibers, and includes a gas permeable portion surrounding the one or more gas sensor modules, and a hydrophilic portion covering at least part of the pH sensor module. A hemodynamically shaped, rounded distal end is also provided on the distal end of the shaft. The device provides for a multiplicity of individual sensors incorporated in a single shaft which minimizes cross-interference and thrombus formation when used as an intravascular multi-sensor.

Claims

1. A multiple optical fiber sensor apparatus for intravascular use in measuring blood constituents, comprising:

a semi-permeable shaft having proximal and distal ends and an exterior surface;

a plurality of optical fibers extending longitudinally into said shaft, each of said optical fibers including a sensor module on a distal portion of said optical fiber, said sensor modules being disposed in axially staggered relationship, with at least one of said sensor modules comprising a gas sensor module disposed within a proximal portion of said shaft, and one of said sensor modules comprising a pH sensor module disposed distal to said gas sensor module;

a semipermeable potting matrix disposed in said shaft, said potting matrix surrounding said optical fibers and at least a portion of said sensor modules for fixing the position of said sensor modules with respect to said shaft, each of said gas sensor modules being disposed in a gas permeable portion of said potting matrix and at least a portion of said pH sensor module being disposed in a hydrophilic portion of said potting matrix; and

a rounded, hemodynamically shaped distal end portion adjoining said distal end of said shaft.

2. The apparatus of claim 1, wherein said rounded, hemodynamically shaped distal end portion has an exterior surface which is substantially parallel to and concurrent with the distal exterior surface of said shaft and is smoothly joined thereto, whereby said rounded distal end portion and said shaft are blood compatible and non thrombogenic.

3. The apparatus of claim 1, further including a gas permeable tubular sleeve having proximal and distal ends, with said semipermeable potting matrix substantially filling said sleeve.

4. The apparatus of claim 3, wherein said gas permeable sleeve is formed of hydrophobic material and is covered by an exterior layer of hydrophilic material.

5. The apparatus of claim 3, further including a guide member having an axial opening therethrough disposed within a distal portion of said sleeve.

6. The apparatus of claim 5, wherein said pH sensor module extends through said opening of said guide member.

7. The apparatus of claim 5, wherein said guide member comprises an annular guide ring disposed in the distal end of said tubular sleeve, and said annular guide ring and said tubular sleeve are formed together.

8. The apparatus of claim 5, wherein said guide member comprises an annular guide ring, and said guide ring is secured within the distal end of said tubular sleeve.

9. The apparatus of claim 8, wherein said rounded, hemodynamically shaped distal end portion is formed substantially from said gas permeable portion of said matrix and includes a concavity at a radially central location on the distal end of said end portion, at least a portion of said pH sensor module and at least a portion of said hydrophilic matrix portion being disposed in said concavity.

10. The apparatus of claim 9 wherein said tubular sleeve and said rounded distal end portion are formed of hydrophobic material and covered with a layer of hydrophilic material.

11. The apparatus of claim 3, further including a plug disposed within a distal portion of said sleeve, said plug having proximal and distal ends, with said distal end of said plug forming a substantial portion of the hemodynamically shaped, rounded distal end portion, and said plug having a generally longitudinal channel extending through said plug, through which said optical fiber for said pH sensor module extends.

12. The apparatus of claim 11, wherein said channel terminates in a concavity in a radially central portion of said rounded end portion, and at least a portion of said pH sensor module and at least a portion of said hydrophilic matrix portion are disposed in said concavity.

13. The apparatus of claim 11, wherein said plug is formed of hydrophobic material, and said tubular sleeve and said plug are covered with a layer of hydrophilic material.

14. The apparatus of claim 3, wherein said pH sensor module is disposed within said sleeve.

15. The apparatus of claim 14, wherein said distal end portion is formed of relatively impermeable material.

16. The apparatus of claim 1, wherein said shaft includes an exterior layer of hydrophilic material.

17. The apparatus of claim 16, wherein said layer of hydrophilic material is formed from a compound selected from the group consisting of hydrogel, cellulose, and combinations thereof.

18. The apparatus of claim 1, wherein said at least one gas sensor module comprises a blood oxygen sensor.

19. The apparatus of claim 1, wherein said at least one gas sensor module comprises a blood carbon dioxide sensor.

20. The apparatus of claim 1, wherein said at least one gas sensor module comprises a blood oxygen and a blood carbon dioxide sensor.

21. The apparatus of claim 1, wherein said semipermeable potting matrix is formed from a compound selected from the group consisting of silicone, hydrogel, polyurethane and combinations thereof.

22. The apparatus of claim 1, wherein said gas permeable portion of said matrix comprises a hydrophobic material.

23. The apparatus of claim 1, wherein said gas permeable portion of said matrix comprises a hydrophilic material.

24. The apparatus of claim 1, wherein said hemodynamically shaped rounded distal end is essentially hemispheric.

25. The apparatus of claim 1, wherein said hemodynamically shaped rounded distal end is essentially parabolic.

26. The apparatus of claim 1, wherein said hemodynamically shaped rounded distal end is in the shape of an ogive.

27. The apparatus of claim 1, wherein said pH sensor module projects slightly from said hemodynamically shaped, rounded distal end portion at a radially central location thereon.

28. The apparatus of claim 1, wherein said pH sensor module projects slightly from said hemodynamically shaped, rounded distal end at a location on said distal end portion at which stagnation of blood flow normally occurs when said apparatus is disposed intravascularly.

29. An intravascular multiple sensor apparatus, comprising:

a gas permeable, generally cylindrical shaft having proximal and distal ends;

a plurality of optical fibers having proximal and distal ends and extending longitudinally within said shaft, the distal portion of each said optical fiber having a sensor module, at least one of said sensor modules being a gas sensor module disposed within said shaft, and one other of said sensor modules being a pH sensor module;

a gas permeable polymeric matrix portion having proximal and distal end disposed within said shaft, said gas permeable polymeric matrix surrounding said gas sensor modules and fixing the position of said optical fibers with respect to said shaft;

a hydrophilic polymeric matrix portion disposed within said shaft, said hydrophilic polymeric matrix portion surrounding said pH sensor module; and

a hemodynamically shaped, rounded distal end portion adjoining said distal end of said shaft, said end portion having an exterior surface which is substantially parallel to and concurrent with the distal exterior surface of said shaft, and smoothly joined thereto.

30. The apparatus of claim 29, wherein said shaft is covered with a layer of hydrophilic material.

31. The apparatus of claim 30, wherein said layer of hydrophilic material is formed from a compound selected from the group consisting of hydrogel, cellulose, and combinations thereof.

32. The apparatus of claim 29, wherein said shaft includes a gas permeable tubular member having proximal and distal ends, and said tubular member contains said g as permeable polymeric matrix and at least one gas sensor module.

33. The apparatus of claim 32, further including a guide member having a central opening therethrough within the distal end of said tubular member, with said optical fiber terminating in a pH sensor module extending through said central opening.

34. The apparatus of claim 33, wherein said guide member comprises an annular guide ring disposed in the distal end of said tubular member, and said annular guide ring and said tubular member are formed unitarily.

35. The apparatus of claim 34, wherein said hemodynamically shaped, rounded distal end portion is formed substantially from said gas permeable matrix portion and includes a central concavity at the distal end of said end portion in which said pH sensor module and at least a portion of said hydrophilic matrix portion are disposed.

36. The apparatus of claim 33, wherein said guide member comprises an annular guide ring disposed in the distal end of said tubular member, and said annular guide ring and said tubular member are bonded together.

37. The apparatus of claim 36, wherein said hemodynamically shaped, rounded distal end portion is formed substantially from said gas permeable matrix portion and includes a radially central concavity at the distal end of said end portion in which said pH sensor module and at least a portion of said hydrophilic matrix portion are disposed.

38. The apparatus of claim 37, wherein said tubular member and said gas permeable portion of said rounded distal end portion are formed of hydrophobic material, and are covered with a layer of hydrophilic material formed from a compound selected from the group consisting of hydrogel, cellulose, and combinations thereof.

39. The apparatus of claim 33, wherein said guide member comprises a generally cylindrical plug having proximal and distal ends, with said distal end of said tubular plug forming a substantial portion o the hemodynamically shaped, rounded distal end portion, said central opening comprising a channel extending from said proximal end of said plug to terminate in a central concavity at the distal end of said plug in which said pH sensor module and at least a portion of said hydrophilic matrix portion are disposed.

40. The apparatus of claim 39, wherein said tubular member and said plug are formed of hydrophobic material, and are covered with a layer of hydrophilic material formed from a compound selected from the group consisting of hydrogel, cellulose, and combinations thereof.

41. The apparatus of claim 32, wherein said pH sensor module is disposed within said tubular member.

42. The apparatus of claim 29 wherein one of said gas sensor modules comprises a blood oxygen sensor.

43. The apparatus of claim 29, wherein said gas permeable polymeric matrix is formed from a compound selected from the group consisting of silicone, hydrogel, polyurethane, and combinations thereof.

44. The apparatus of claim 29, wherein said at least one gas sensor module comprises a blood carbon dioxide sensor.

45. The apparatus of claim 29, wherein said at least one gas sensor module comprises a blood oxygen sensor and a blood carbon dioxide sensor.

46. The apparatus of claim 29, further comprising sensor means to sense a physiologic parameter of a patient.

47. The apparatus of claim 46 wherein said sensor means comprises means to sense temperature.

48. The apparatus of claim 46 wherein said sensor means comprises means to sense blood pressure.

49. The apparatus of claim 29, wherein said hemodynamically shaped rounded distal end is in the shape of a hemisphere.

50. The apparatus of claim 29, wherein said hemodynamically shaped rounded distal end has a parabolic shape.

51. The apparatus of claim 29, wherein said hemodynamically shaped rounded distal end is in the shape of an ogive.

52. The apparatus of claim 29, wherein said pH sensor projects slightly from said hemodynamically shaped, rounded distal end portion at a radially central location thereon at which stagnation of blood flow normally occurs when said apparatus is disposed intravascularly.

53. A method for manufacturing an intravascular multiple optical fiber sensor having a generally longitudinal semi-permeable shaft, a plurality of optical fibers having proximal and distal ends extending longitudinally through said shaft and terminating at their distal ends in a sensor module, with at least one of said sensor modules comprising a gas sensor module and one of said sensor modules comprising a pH sensor module, a semipermeable potting matrix disposed in said shaft with a gas permeable portion of said matrix surrounding said gas sensor modules and a hydrophilic portion of said potting matrix surrounding at least a portion of said pH sensor module, and a rounded, hemodynamically shaped distal end portion adjoining a distal end of said shaft, comprising the steps of:

axially staggering the distal ends of a bundle of said optical fibers, with at least one optical fiber gas sensor module being disposed proximally and said optical fiber for the pH sensor module extending most distally;

locating said distally located pH sensor module in a radially central position with respect to the distal end of said multiple sensor;

surrounding said optical fibers with uncured gas permeable polymeric material and curing said gas permeable polymeric material to form said shaft;

forming said generally rounded distal end portion of said multiple sensor; and

covering at least a portion of said pH sensor module with hydrophilic material to complete the hemodynamic shape of said distal end portion.

54. The method of claim 53, wherein said step of locating said pH sensor module optical fiber comprises positioning a guide member having a central opening therethrough at a distal position relative to said gas sensor modules, and inserting said pH sensor module optical fiber through said guide member.

55. The method of claim 53, wherein said optical fibers are introduced into a tubular member having proximal and distal ends, and an annular guide ring is placed transversely in the distal end of the tubular member for radially centering the distal pH sensor module with the hemodynamically rounded distal end of the multiple sensor.

56. The method of claim 55, wherein said tubular member is formed of gas permeable hydrophobic material, and further comprising the steps of subjecting the exterior surface of said tubular member to a high voltage corona discharge, and covering said tubular member with a layer of hydrophilic material to provide the shaft of said multiple sensor with hydrophilic surface characteristics.

57. The method of claim 55, wherein said tubular member and said distal end portion of said multiple sensor are formed of hydrophobic material, and further comprising the steps of subjecting the exterior surface of said tubular member and said distal end portion of said multiple sensor to a high voltage corona discharge, and covering the hydrophobic surfaces of said tubular member and said distal end portion of said multiple sensor with a layer of hydrophilic material to provide said multiple sensor with hydrophilic surface characteristics.