Patient sensor for optical cerebral oximeters and the like

• US 5,584,296 A
• Filed: 12/15/1994
• Issued: 12/17/1996
• Est. Priority Date: 12/01/1992
• Status: Expired due to Term

• Current Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Original Assignee: Somanetics Corporation (Medtronic Plc)
• Inventors: Cui, Weijia, Scheuing, Richard S.
• Primary Examiner(s): Sykes, Angela D.
• Assistant Examiner(s): NASSER, ROBERT L
• Application Number:
  US08/356,863
• Time in Patent Office: 733 Days
• Field of Search: 128/633-4, 128/664-6, 356/41
• US Class Current: 600/479
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/6814 Head

Abstract

An optical sensor for use in clinical patient examination by spectrophotometric apparatus, having a body with softly deformable material which is conformable to a selected area on the body of the patient and internally-mounted electro-optical source and receivers for obtaining patient pathology data by transmission of selected wavelengths through a tissue volume adjacent the selected area, including substantially non-deforming light-transfer members disposed in alignment with the source and detectors and between them and the patient, to provide substantially constant and unchanging light-transfer passages or conduits therebetween. In the most preferred form, the light-transfer members comprise generally tubular elements having light-reflective interior walls, and the sensor body comprises either a layered structure of opaque, soft polymeric foam or the like (e.g. , cellular urethane) or a substantially one-piece, molded or other such structure of generally comparable or analogous material and characteristics.

Claims

1. An optical sensor unit for use as a patient interface in obtaining spectrophotometric data during in vivo examination, comprising in combination:

a body having at least one side comprising a soft and deformable material providing at least limited longitudinal and lateral flexibility for conforming to the surface topography of a selected area on a patient;

an electrically actuated light source carried on said body, for producing and emitting light of selected wavelengths to irradiate internal patient tissue after passing through said surface;

at least one electrically responsive light-detector carried on said body at a particular spacing from said light source, for receiving resultant light of said selected wavelengths from said patient after passage thereof through said internal tissue and producing corresponding electrical signals; and

a generally tubular and substantially non-deforming light-transfer member disposed in direct alignment with at least one of said source and detector and having a first open end portion disposed immediately adjacent thereto and in generally concentric alignment therewith, said light-transfer member extending from the location of said at least one source and detector through at least portions of said deformable material and having a second open end disposed to contact said patient and convey said light thereto, said, non-deforming light-transfer member having an open internal passage extending between said first and second open ends and being non-deforming to retain its initial size and shape throughout use during patient examination and provide a light-transfer passage of constant and unchanging size and shape throughout the distance between said patient and said at least one source and detector and through said at least portions of said deformable material regardless of the deformation imparted to said deformable material in operably conforming the sensor to a particular patient surface topography, said tubular light-transfer member having an overall axial length at least as great as the thickness of a wall of said light-transfer member measured in a radial direction.

2. An optical sensor as recited in claim 1, wherein said light-transfer member has generally opaque walls defining said open passage.

3. An optical sensor as recited in claim 2, wherein said walls defining said passage have optically reflective surfaces along said passage.

4. An optical sensor as recited in claim 1, wherein said member includes a generally regular and continuous tubular portion defining said open passage.

5. An optical sensor as recited in claim 4, wherein said generally tubular portion is disposed in an aperture extending through said one side and is secured in place with respect thereto.

6. An optical sensor as recited in claim 5, including means for sealing said tubular portion in substantially light-tight relation with respect to said aperture.

7. An optical sensor as recited in claim 5, wherein said portion extends at least slightly beyond the outer surface of said deformable material.

8. An optical sensor as recited in claim 1, wherein said body comprises a layered structure having at least two layers secured to one another.

9. An optical sensor as recited in claim 1, wherein said body includes a primary strata comprising a one-piece molded structure of flexible material, said molded structure carrying said light source and said light-detector and defining a pair of open passages, each of said passages extending from a different one of said source and detector through said primary strata.

10. An optical sensor as recited in claim 1, including means defining at least a pair of said passages each providing a separate passage for a respective one of said source and said detector.

11. An optical sensor as recited in claim 10, wherein said means comprises a pair of generally rigid tubular members defining said passages and said passages comprise openings.

12. An optical sensor as recited in claim 11, wherein said tubular members are open-ended, and including means for connectively sealing one open end of each of said tubular members in substantially light-fight relation with its respective source or detector.

13. An optical sensor as recited in claim 12, wherein said tubular members extend substantially through said deformable material, and including means for sealing said members in substantially light-tight relation with respect to said material.

14. An optical sensor as recited in claim 12, including means for securing said tubular members to at least portions of their respective source and detector.

15. An optical sensor as recited in claim 1, including at least one thin sheet-like member of electrically conductive material extending around at least portions of said detector to shield it from ambient sources of electric and magnetic noise and distortion, said shield member disposed on the opposite side of said deformable material from that which contacts said patient.

16. An optical sensor as recited in claim 15, wherein said light-transfer member extends through said thin shield member.

17. An optical sensor as recited in claim 1, further including a circuit board underlying and carrying at least said detector, said board supporting said light-transfer member.

18. An optical sensor as recited in claim 17, wherein said light-transfer member is secured to said circuit board.

19. An optical sensor as recited in claim 18, wherein said light-transfer member is connected in light-tight relation to said deformable material.

20. An optical sensor as recited in claim 17, including at least one thin sheetlike member of conductive material extending around at least portions of said detector and of said circuit board to shield such portions from ambient sources of electric and magnetic noise and distortion, said shield member disposed on the opposite side of said deformable material from that which contacts said patient.

21. An optical sensor as recited in claim 20, wherein said light-transfer member extends through said thin shield member.

22. An optical sensor as recited in claim 21, wherein said light-transfer member is secured to said circuit board.

23. A thin, lightweight, highly compliant and conformable electrically-operated optical sensor having constant and non-distorting light-transmittal passages, for use with clinical spectrophotometric patient-examination apparatus, comprising:

a primary strata comprised of soft and readily deformable material, said strata having a first side for conformably contacting a selected surface area on said patient, a second side opposite the first, and a plurality of passages extending between said sides for transmitting selected light wavelengths to and from said patient through said primary strata;

at least one thin, lightweight and flexible substrate member disposed adjacent to and at least partially covering said second side of said primary strata, said primary strata and said at least one substrate member secured together to form a flexible and readily conformable patch-like sensor body for application to said selected area;

at least two electrically operated light-responsive optical components disposed generally between said primary strata and said at least one substrate member and secured in alignment with respective individual such passages, including a first such component to produce and transmit said selected light wavelengths in response to electrical signal actuation and a second such component to receive said wavelengths and produce corresponding electrical signals; and

means defining a non-compliant and substantially non-distortable light-transfer element disposed in at least one of said passages, for conveying said selected wavelengths therethrough to or from said optical components along a light-transfer path having fixed and unchanging geometry despite deformation of said sensor body in conforming it to said selected area, said light-transfer element having a wall surrounding and defining said light-transfer path, said wall having a thickness at one end measured in a direction perpendicular to said light-transfer path that is less than the overall length of said light-transfer element.

24. A thin, lightweight, compliant optical sensor as defined in claim 23, wherein said optical components are secured to at least one of said primary strata and said substrate member.

25. A thin, lightweight, compliant optical sensor as defined in claim 23, wherein said at least two optical components are mounted generally independently of one another and separately secured in alignment with corresponding separate ones of said light-transfer elements.

26. A thin, lightweight, compliant optical sensor of claim 25, wherein said transfer elements comprise open-end tubular members and said at least two optical components are secured directly to an open end of their said corresponding separate light-transfer elements.

27. The thin, lightweight, compliant optical sensor of claim 26, wherein at least one of said at least two optical components is at least partially secured in position by direct attachment to at least one of said primary strata and said substrate member.

28. The thin, lightweight, compliant optical sensor of claim 26, wherein at least one of said at least two optical components is at least partially secured in position by said direct securement to its corresponding light-transfer element.

29. The thin, lightweight, compliant optical sensor of claim 25, wherein at least one of said electro-optical components is disposed further from said first side of said primary strata than another of said components and the light-transfer element associated with said further component is longer than the light-transfer element associated with said other such component.

30. The thin, lightweight, compliant optical sensor of claim 23, wherein said light-transfer element defines an open-ended passage at the location where it contacts said patient.

31. The thin, lightweight, compliant optical sensor of claim 30, wherein said light-transfer element comprises a hollow tubular member.

32. A thin, lightweight, compliant optical sensor of substantially unitary construction, for use with clinical spectrophotometric patient-examination apparatus, comprising:

a primary strata formed as a thin, generally fiat one-piece member of soft deformable material, said strata having a first side for conformably contacting a selected area on said patient, a second side opposite the first, a plurality of integral mounting stations for electrically operated light-responsive optical components for transmitting and receiving selected light wavelengths, and light-transmissive passages extending through at least portions of said primary strata and said first side thereof for communicating said light wavelengths to and from said patient;

at least two of said electrically operated optical components, each disposed at a corresponding mounting station on said primary strata to transmit or receive said selected light wavelengths; and

means for securing said optical components in place on said mounting stations and for sealing said components from ambient contamination;

said primary strata comprising an integrally molded member having said mounting stations molded in place therein, and said light-transmissive passages including passage defining means defining a substantially non-compliant and non-distortable light-transfer passage in said primary strata for conveying said selected wavelengths therethrough along a path having fixed and unchanging geometry despite deformation of said sensor in conforming it to said selected area, said light-transfer passages having an opening extending through at least portions of said molded member, said passage deriving means having a wall surrounding and defining said light-transfer passage, said passage defining means having a length that is at least as great as a thickness of said wall measured at one end.

33. A thin, lightweight, compliant sensor as defined in claim 32, wherein said at least two optical components are mounted generally independently of one another and separately secured to separate ones of said mounting stations.

34. A thin, lightweight, compliant optical sensor as defined in claim 32, wherein said optical components are molded into said primary strata.

35. A thin, lightweight, compliant optical sensor as defined in claim 32, including a generally rigid tubular member disposed in said one-piece member and defining said opening.