Variable coupler fiberoptic sensor and sensing apparatus using the sensor

• US 6,463,187 B1
• Filed: 05/21/1999
• Issued: 10/08/2002
• Est. Priority Date: 08/24/1998
• Status: Expired due to Fees

• Current Assignee: Empirical Technologies Corporation
• Original Assignee: Empirical Technologies Corporation
• Inventors: Adkins, Charles, Gerdt, David, Baruch, Martin C.
• Primary Examiner(s): Bovernick, Rodney
• Assistant Examiner(s): Kang, Juliana K.
• Application Number:
  US09/316,143
• Time in Patent Office: 1,236 Days
• Field of Search: 385/12-13, 385/32.31, 385/43.39, 385/46, 600/528
• US Class Current: 385/12
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence

Abstract

A variable coupler fiberoptic sensor utilizes a coupler having a fused coupling region that can be deflected to change the light distribution to a plurality of output fibers without putting the coupling region under tension. A compact, rugged, and highly sensitive sensor design is achieved by use of a coupler having a fused coupling region arranged substantially in a U-shape to allow the input and output fiberoptic leads to extend from the same side of the sensor structure.

Claims

1. Fiberoptic sensing apparatus, comprising:

a fiberoptic coupler in which a plurality of optical fibers are joined through a fused coupling region, said optical fibers including at least one input optical fiber and a plurality of output optical fibers, said fiberoptic coupler distributing light incident to said input optical fiber among said plurality of output optical fibers; and

a support member;

said coupler being mounted to said support member and configured such that at least a portion of said coupling region is curved and can be deflected to change the light distribution among said output fibers with said coupling region being under substantially no tension.

2. Fiberoptic sensing apparatus according to claim 1, wherein said portion of said coupling region lies substantially on a plane.

3. Fiberoptic sensing apparatus according to claim 2, wherein said deflection is along a direction perpendicular to said plane.

4. Fiberoptic sensing apparatus according to claim 2, further comprising a resilient member having a surface to be displaced in response to forces fiberoptic sensed by the sensing apparatus, said surface being disposed adjacent to said portion of said coupling region in a direction perpendicular to said plane and displaceable along said direction in order to deflect said portion of said coupling region along said direction in response to said forces.

5. Fiberoptic sensing apparatus according to claim 4, wherein said input and output optical fibers are single mode optical fibers.

6. Fiberoptic sensing apparatus according to claim 1, wherein said support member has a surface with channel portions in which said input and output fibers are received, and part of said coupler including said portion of said coupling region extends from said channel portions.

7. Fiberoptic sensing apparatus according to claim 6, wherein said support member has an opening in communication with said channel portions and in which said portion of said coupling region is received.

8. Fiberoptic sensing apparatus according to claim 7, wherein said support member is a plate member.

9. Fiberoptic sensing apparatus according to claim 8, wherein said plate member is planar.

10. Fiberoptic sensing apparatus according to claim 8, wherein said plate member is configured to conform generally with a wrist of a patient.

11. Fiberoptic sensing apparatus according to claim 7, wherein said portion of said coupling region is encapsulated in a body of resilient material.

12. Fiberoptic sensing apparatus according to claim 11, wherein said body of resilient material protrudes convexly outwardly from said opening.

13. Fiberoptic sensing apparatus according to claim 1, wherein said support member is disposed on a frame member configured to conform generally with a wrist of a patient, said frame member being provided with a fluid column having a first portion with a membrane disposed to receive pulsations from a radial artery at the wrist of the patient and a second portion having a membrane to which said pulsations are transmitted via the fluid and which is disposed to transmit motion of said pulsations to said portion of said coupling region.

14. Fiberoptic sensing apparatus according to claim 13, wherein said portion of said coupling region rests on said membrane of said second portion of said fluid column.

15. Fiberoptic sensing apparatus according to claim 1, further comprising an electro-optic circuit optically coupled to said plurality of output fibers to convert light received from said output fibers to an electrical output having a level dependent upon an amount of deflection of said portion of said coupling region.

16. Fiberoptic sensing apparatus according to claim 15, wherein said electro-optic circuit comprises a plurality of photodetectors optically coupled to said plurality of output fibers, respectively, and a differential amplifier circuit to which outputs of said photodetectors are connected.

17. Fiberoptic sensing apparatus according to claim 16, further comprising a display device connected to an output of said electro-optic circuit.

18. Fiberoptic sensing apparatus according to claim 15, wherein said input and output optical fibers are single mode optical fibers.

19. Fiberoptic sensing apparatus according to claim 1, wherein said support member is a plate member.

20. Fiberoptic sensing apparatus according to claim 19, wherein said plate member is planar.

21. Fiberoptic sensing apparatus according to claim 19, wherein said plate member is configured to conform generally with a wrist of a patient.

22. Fiberoptic sensing apparatus according to claim 1, wherein said portion of said coupling region is encapsulated in a body of resilient material.

23. Fiberoptic sensing apparatus according to claim 22, wherein said body of resilient material has a convex surface disposed to be coupled to movement of an external medium.

24. Fiberoptic sensing apparatus according to claim 1, wherein said support member is constructed to conform generally with a wrist of a patient.

25. Fiberoptic sensing apparatus according to claim 1, further comprising a gel coupling or a fluid coupling to couple said coupling region to movement of an external medium.

26. Fiberoptic sensing apparatus according to claim 1, wherein said input and output optical fibers are single mode optical fibers.

27. Fiberoptic sensing apparatus, comprising:

a fiberoptic coupler In which a plurality of optical fibers are joined through a fused coupling region, said optical fibers including at least one input optical fiber and a plurality of output optical fibers, said fiberoptic coupler distributing light incident to said input optical fiber among said plurality of output optical fibers; and

a support member;

said coupler being mounted to said support member and configured such that said fused coupling region has substantially a U-shape of which at least a portion can be deflected to change the light distribution among said output optical fibers.

28. Fiberoptic sensing apparatus according to claim 27, wherein said support member has a surface with channel portions in which said input and output fibers are received, and part of said coupler including said coupling region extends from said channel portions.

29. Fiberoptic sensing apparatus according to claim 28, wherein said support member has an opening in communication with said channel portions and in which said coupling region is received.

30. Fiberoptic sensing apparatus according to claim 29, wherein said support member is a plate member.

31. Fiberoptic sensing apparatus according to claim 30, wherein said plate member is planar.

32. Fiberoptic sensing apparatus according to claim 30, wherein said plate member is configured to conform generally with a wrist of a patient.

33. Fiberoptic sensing apparatus according to claim 29, wherein said coupling region is encapsulated in a body of resilient material.

34. Fiberoptic sensing apparatus according to claim 33, wherein said body of resilient material protrudes convexly outwardly from said opening.

35. Fiberoptic sensing apparatus according to claim 27, wherein said support member is disposed on a frame member configured to conform generally with a wrist of a patient, said frame member being provided with a fluid column having a first portion with a membrane disposed to receive pulsations from a radial artery at the wrist of the patient and a second portion having a membrane to which said pulsations are transmitted via the fluid and which is disposed to transmit motion of said pulsations to said coupling region.

36. Fiberoptic sensing apparatus according to claim 35, wherein a portion of said coupling region rests on said membrane of said second portion of said fluid column.

37. Fiberoptic sensing apparatus according to claim 27, further comprising an electro-optic circuit optically coupled to said plurality of output fibers to convert light received from said output fibers to an electrical output having a level dependent upon an amount of deflection of said coupling region.

38. Fiberoptic sensing apparatus according to claim 37, wherein said electro-optic circuit comprises a plurality of photodetectors optically coupled to said plurality of output fibers, respectively, and a differential amplifier circuit to which outputs of said photodetectors are connected.

39. Fiberoptic sensing apparatus according to claim 38, further comprising a display device connected to an output of said electro-optic circuit.

40. Fiberoptic sensing apparatus according to claim 37, wherein said input and output optical fibers are single mode optical fibers.

41. Fiberoptic sensing apparatus according to claim 27, wherein said support member is a plate member.

42. Fiberoptic sensing apparatus according to claim 41, wherein said plate member is planar.

43. Fiberoptic sensing apparatus according to claim 41, wherein said plate member is configured to conform generally with a wrist of a patient.

44. Fiberoptic sensing apparatus according to claim 27, wherein said portion of s aid coupling region is encapsulated in a body of resilient material.

45. Fiberoptic sensing apparatus according to claim 44, wherein said body of resilient material has a convex surface disposed to be coupled to movement of an external medium.

46. Fiberoptic sensing apparatus according to claim 27, wherein said support member is constructed to conform generally with a wrist of a patient.

47. Fiberoptic sensing apparatus according to claim 27, further comprising a gel coupling or a fluid coupling to couple said coupling region to movement of an external medium.

48. Fiberoptic sensing apparatus according to claim 27, wherein said coupler is mounted to said support member such that said coupling region lies substantially on a plane and can be deflected transversely to said plane by flexing thereof along a height of said U-shape.

49. Fiberoptic sensing apparatus according to claim 48, wherein said input and output optical fibers are single mode optical fibers.

50. Fiberoptic sensing apparatus according to claim 27, wherein said coupler is mounted to said support member such that said coupling region lies substantially on a plane, and further comprising a resilient member having a surface to be displaced in response to forces sensed by the fiberoptic sensing apparatus, said surface being disposed adjacent to said coupling region in a direction perpendicular to said plane and displaceable along said direction to deflect a portion of said coupling region along said direction in response to said forces.

51. Fiberoptic sensing apparatus according to claim 50, wherein said input and output optical fibers are single mode optical fibers.

52. Fiberoptic sensing apparatus according to claim 27, wherein said input and output optical fibers are single mode optical fibers.