APPARATUS FOR SPECTROMETRIC BASED OXIMETRY

• US 20100049018A1
• Filed: 11/14/2007
• Published: 02/25/2010
• Est. Priority Date: 11/14/2006
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Cas Medical Systems Incorporated (Edwards Lifesciences Corporation)
• Inventors: Benni, Paul B., Pirc, Douglas, Duffy, Karen, Brocksieper, George
• Granted Patent: US 8,428,674 B2
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue

Abstract

A spectrophotometric sensor assembly for non-invasive monitoring of a blood metabolite within a subject'"'"'s body tissue is provided that includes a pad, a light source, and a light detector The light source is operative to emit light signals of a plurality of different wavelengths. The light detector is operative to detect light emitted by the light source and passed through the subject'"'"'s body tissue. The light detector is at least partially enclosed in EMI shielding. In some embodiments, the light detector and EMI shielding are disposed in a detector housing that encloses the light detector and shielding. The housing is aligned with a detector aperture disposed in the pad.

Claims

1. A near infrared spectrophotometric sensor assembly for non-invasive monitoring of blood oxygenation levels in a subject'"'"'s body tissue, said assembly comprising:

a pad;

at least one light source operative to emit light signals of a plurality of different wavelengths;

at least one light detector operative to detect light emitted by the light source and passed through the subject'"'"'s body tissue;

electromagnetic interference shielding disposed around at least a portion of the light detector;

a detector housing including a base and a cap, wherein the base includes a well sized to receive at least a portion of the light detector, and the cap is sized to receive a remainder of the light detector and shielding not received within the base well; and

wherein the base and the cap mate to enclose the light detector and shielding, and the housing is positioned relative to the pad so that the light detector is aligned with a light detector aperture disposed within the pad.

2. The sensor assembly of claim 1, wherein the base includes a window comprising an optically transparent material.

3. The sensor assembly of claim 2, wherein the cap includes a cap well sized to receive the remainder of the light detector and electromagnetic shielding not received within the base well.

4. The sensor assembly of claim 3, wherein the base and the cap attach to one another.

5. The sensor assembly of claim 4 wherein the cap is hingedly attached to the base.

6. The sensor assembly of claim 1 wherein the cap is hingedly attached to the base.

7. The sensor assembly of claim 1, wherein the detector housing further includes a port for receiving an electrical conductor.

8. The sensor assembly of claim 1, wherein the base is attached to the pad.

9. The sensor assembly of claim 1, wherein the cap is attached to the pad.

10. The sensor assembly of claim 1, wherein the detector housing has an interior cavity formed by the base and the cap, and wherein the light detector and electromagnetic shielding are positionally fixed within the interior cavity.

11. The sensor assembly of claim 10, wherein there is a press fit between the interior cavity and the light detector and electromagnetic shielding.

12. The sensor assembly of claim 1, wherein the electromagnetic shielding includes a solid shield disposed around at least a portion of the light detector.

13. The sensor assembly of claim 12, wherein the electromagnetic shielding further includes an optically transparent electromagnetic shielding disposed around at least a portion of the light detector.

14. The sensor assembly of claim 1, wherein the electromagnetic shielding further includes an optically transparent electromagnetic shielding disposed around at least a portion of the light detector.

15. The sensor assembly of claim 1, wherein the at least one light detector includes a first light detector and a second light detector, and each of said light detectors is disposed within a detector housing.

16. The sensor of claim 15, wherein the first detector includes at least one photodiode electrically connected to a printed circuit board.

17. The sensor of claim 1, further comprising a cover disposed over the light detector and the light source.

18. A spectrophotometric sensor assembly for non-invasive monitoring of a blood metabolite within a subject'"'"'s body tissue, said assembly comprising:

a pad having at least one source aperture and at least one detector aperture;

at least one light source operative to emit light signals of a plurality of different wavelengths, the light source aligned with the source aperture;

at least one light detector operative to detect light emitted by the light source and passed through the subject'"'"'s body tissue;

electromagnetic interference shielding disposed around at least a portion of the light detector;

a detector housing including a first member and a second member, wherein the first member includes a well sized to receive at least a portion of the light detector and electromagnetic shielding; and

wherein the first member and the second member mate to enclose the light detector and electromagnetic shielding, and the housing is positioned relative to the pad so that the light detector is aligned with the light detector aperture.

19. The sensor assembly of claim 18, wherein the light source is operative to emit light signals within the visible and /or near infrared range of 400 nm to 1000 nm.

20. The sensor assembly of claim 19, wherein the second member includes a well sized to receive a remainder of the light detector and electromagnetic shielding not received within the first member well.

21. The sensor assembly of claim 19, wherein the light detector and electromagnetic shielding are received entirely within the first member well.

22. The sensor assembly of claim 21, wherein the second member extends into the first member well.

23. The sensor assembly of claim 18, wherein the first member includes a window comprising an optically transparent material.

24. The sensor assembly of claim 18, wherein the first member and second member are operable to attach to one another.

25. The sensor assembly of claim 24 wherein the second member is hingedly attached to the first member.

26. A near infrared spectrophotometric sensor assembly for non-invasive monitoring of blood oxygenation levels in a subject'"'"'s body tissue, said assembly comprising:

a pad;

a light source operative to emit light signals of a plurality of different wavelengths;

a light detector operative to detect light emitted by the light source and passed through the subject'"'"'s body tissue, the light detector disposed in a detector housing that encloses the light detector, which housing is aligned with the detector aperture in the pad.

EMI shielding applied to surfaces of the detector housing sufficiently to substantially surround the light detector.

27. The sensor assembly of claim 26, wherein the EMI shielding is applied to interior surfaces of the detector housing.

28. The sensor assembly of claim 26, wherein the EMI shielding is applied to exterior surfaces of the detector housing.

29. A near infrared spectrophotometric sensor assembly for non-invasive monitoring of blood oxygenation levels in a subject'"'"'s body tissue, said assembly comprising:

a pad;

a light source operative to emit light signals of a plurality of different wavelengths;

a light detector operative to detect light emitted by the light source and passed through the subject'"'"'s body tissue, the light detector at least partially enclosed in EMI shielding, and the light detector and EMI shielding disposed in a detector housing having a base and a cap that mate to enclose the light detector and shielding, and the housing is aligned with a detector aperture in the pad.

30. The sensor assembly of claim 29, wherein the housing comprises a dielectric material.

31. The sensor assembly of claim 29, wherein the detector housing base extends through the detector aperture and is positioned to permit the detector housing to contact the subject.

32. A near infrared spectrophotometric sensor assembly for non-invasive monitoring of blood oxygenation levels in a subject'"'"'s body tissue, said assembly comprising:

a pad having a source aperture, a first detector aperture, and a second detector aperture;

a light source operative to emit light signals of a plurality of different wavelengths, the light source aligned with the source aperture;

a first light detector at least partially enclosed in EMI shielding, and the first light detector and EMI shielding enclosed within a first detector housing, and the first detector housing is positioned relative to the pad so that the first light detector is aligned with the first detector aperture; and

a second light detector at least partially enclosed in EMI shielding, and the second light detector and EMI shielding enclosed within a second detector housing, and the second detector housing is positioned relative to the pad so that second light detector is aligned with the second detector aperture.

33. The sensor assembly of claim 32, wherein the first detector housing and the second detector housing are independent of one another.