OPTICAL COHERENCE TOMOGRAPHY (OCT) IMAGING SYSTEMS HAVING ADAPTABLE LENS SYSTEMS AND RELATED METHODS AND COMPUTER PROGRAM PRODUCTS

• US 20090268161A1
• Filed: 04/24/2009
• Published: 10/29/2009
• Est. Priority Date: 04/24/2008
• Status: Active Grant

• Current Assignee: Bioptigen, Inc. (Danaher Corporation)
• Original Assignee: Bioptigen, Inc. (Danaher Corporation)
• Inventors: Izatt, Joseph A., Buckland, Eric L., Myers, Glenn A., Hart, Robert H.
• Granted Patent: US 8,783,866 B2
• Time in Patent Office: Days
• US Class Current: 351/208
• CPC Class Codes: A61B 3/102 for optical coherence tomography [OCT]
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence

Abstract

OCT imaging systems are provided for imaging a spherical-type eye including a source having an associated source arm path and a reference arm having an associated reference arm path coupled to the source path. The reference arm path has an associated reference arm path length. A sample is also provided having an associated sample arm path coupled to the source arm and reference arm paths. A lens having a focal power optimized for a diameter of the spherical-type eye is provided along with a reference arm path length adjustment module coupled to the reference arm. The reference arm path length adjustment module is configured to automatically adjust the reference arm path length such that the reference arm path length is based on an eye diameter of the subject.

Claims

1. An optical coherence tomography (OCT) system for imaging an eye, the system comprising a lens system configured to adjust such that the lens system can image both anterior and posterior regions of the eye without changing any lenses in the lens system.

2. The OCT system of claim 1, wherein the lens system comprises three lens complexes, each of the lens complexes comprising at least one lens.

3. The OCT system of claim 2, wherein the lens system comprises first, second and third lenses.

4. The OCT system of claim 3:

wherein the first lens comprises a collimator lens and has a focal length of f1;

wherein a distance D1A distal to the collimator lens is a galvanometer configured to steer a light beam over a region of interest in the eye;

wherein the second lens is a distance D1B distal from the galvanometer and has a focal length f2; and

wherein a distance D2A distal to the second lens is a plane perpendicular to an optical axis dividing a distance D2 into two parts, the distance D2A and a distance D2B.

5. The OCT system of claim 4, wherein the distance D1B and the distance D2A are approximately equal to the focal length f2 and the distance D2B is variable.

6. The OCT system of claim 5, wherein the distance D1A is adjustable.

7. The OCT system of claim 6, wherein the third lens comprises an objective lens, has a focal length f3 and is the variable distance D2B to the right of the plane.

8. The OCT system of claim 7, further comprising:

a distance D_cornea from the objective lens to an anterior surface of the cornea;

a distance D_pivot to a pivot point at a point optically conjugate to a position of the galvanometer, where scanning beams cross; and

a distance D_focus in air where the optical beams are in focus.

9. The OCT system of claim 8, wherein D_pivot is approximately equal to the focal length f3 beyond the objective lens and wherein the distance D_focus is determined by the following lens formula:

1/D2B+1/D_focus=1/f3,

wherein the index of refraction of a media in which D2B and D_focus reside is approximately equal to 1.

10. The OCT system of claim 7, wherein the lens system has a first configuration wherein the probe bore tip containing the objective lens is extended to increase the distance D2B to a threshold value.

11. The OCT system of claim 10, wherein the threshold value is determined using the lens formula to place a distance D_focus at a proper distance from the objective lens for imaging the cornea and to optimize a depth of focus to a desired value for imaging the cornea.

12. The OCT system of claim 7, wherein the lens system has a second configuration wherein a handheld probe of the OCT system and the lens system is driven closer to the eye and wherein an operator of the handheld probe slowly draws the probe bore tip toward a nominal lens position, which shortens the distance D2B, lengthens a distance D_focus and keeps a distance D_pivot constant.

13. The OCT system of claim 12, wherein the distance D2B is between f3 and 2*f3 such that an anterior segment of the eye provides a portion of optical power used to focus an optical beam on intermediate structures of the eye.

14. The OCT system of claim 7, wherein the lens system has a third configuration where a handheld probe of the OCT system is moved closer to the eye and an operator of the probe contracts the probe bore tip back to a nominal retina position, which occurs when D2B=f3 and continues moving the probe inward until a distance D_cornea is approximately equal to a design working distance to the eye and a distance D_pivot places a pivot point in an iris plane.

15. The OCT system of claim 1, wherein a reference arm path length of the OCT system is adjusted to accommodate subject eye lengths in a sample arm of the OCT system.

16. The OCT system of claim 1, wherein a reference arm path length of the OCT system is adjusted to accommodate subject path lengths to target structures within the eye, target structures ranging from anterior of the cornea to posterior of the retina.

17. The OCT system of claim 16, wherein anterior to posterior structures of a spherical-type sample are imaged continuously by synchronous coordination of a working distance between an objective lens and an anterior surface of the sample, and the reference arm path length.

18. The OCT system of claim 17, wherein the continuous anterior to posterior imaging is accomplished automatically using a data processing system, wherein the relationship between working distance and the reference arm path length is determined by a pre-defined function or look-up table.

19. The OCT system of claim 1, wherein the lens system has an associated focus adjustment that enables the OCT system to be focused based on refractive correction.

20. The OCT system of claim 1, wherein the system is a wide field imaging system providing a field of view of about equal to or greater than 50 degrees.

21. The OCT system of claim 1, wherein the system is a wide field imaging system providing a field of view of about equal to or greater than 140 degrees in combination with rotation about a pupil.

22. The OCT system of claim 1, wherein the OCT system is portable such that the OCT system is provided to the subject where the subject is located.

23. The OCT system of claim 22, wherein the portable OCT system is configured to provide imaging to a subject independent of the orientation of the subject.

24. The OCT system of claim 22, wherein the portable OCT system comprises a video and/or digital fundus camera.

25. The OCT system of claim 22, wherein the portable OCT system further comprises a foot pedal and/or finger trigger configured to control focus adjustment, reference arm path length adjustment and/or trigger acquisition of an image.

26. An optical coherence tomography (OCT) imaging system for imaging an eye, the system comprising optics configured to image an eye having a spherical shape.

27. The OCT system of claim 26, wherein an amount of optical power used to obtain an OCT image of the eye having a spherical shape is a function of a spherical radius of the eye.

28. The OCT system of claim 26, wherein the eye is a rodent eye.

29. The OCT system of claim 26, further comprising a telecentric lens that is a doublet pair configured to create a telecentric plane with a substantially flattened field curvature at the telecentric plane.

30. The OCT system of claim 29, wherein the doublet pair yields a telecentric plane having a field curvature radius of greater than about 100 mm.

31. The OCT system of claim 29, further comprising a focusing lens set configured to have substantially greater power to accommodate the spherical shaped eye.

32. The OCT system of claim 31, wherein power for a mouse is about +80 D and wherein power for a rat having an eye diameter of about 6.4 mm is about 73 Diopters.

33. A method for imaging an in eye using optical coherence tomography (OCT) system, the method comprising imaging both anterior and posterior regions of the eye without changing any lenses in the lens system.

34. A method for imaging an eye in an optical coherence tomography (OCT) imaging system, the method comprising imaging an eye having a spherical shape using optics configured to image spherical shaped objects.

35. A method for imaging an eye in an optical coherence tomography (OCT) imaging system, the method comprising imaging continuously from an anterior position of the eye to a posterior position of the eye by synchronous coordination of a working distance between a lens and a sample and a reference arm path length.

36. A computer program product for imaging in an eye using optical coherence tomography (OCT) system, the computer program product comprising:

computer readable storage medium having computer readable program code embodied in said medium, the computer readable program code comprising;

computer readable program code configured to image both anterior and posterior regions of the eye without changing any lenses in the lens system.

37. A computer program product for imaging in an eye using optical coherence tomography (OCT) system, the computer program product comprising:

computer readable storage medium having computer readable program code embodied in said medium, the computer readable program code comprising;

computer readable program code configured to image an eye having a spherical shape using optics configured to image spherical shaped objects.

38. An optical coherence tomography (OCT) imaging system for imaging a spherical-type eye, the system comprising:

a source having an associated source arm path;

a reference arm having an associated reference arm path coupled to the source path, the reference arm path having an associated reference arm path length;

a sample having an associated sample arm path coupled to the source arm and reference arm paths;

a lens having a focal power optimized for a diameter of the spherical-type eye; and

a reference arm path length adjustment module coupled to the reference arm, the reference arm path length adjustment module configured to automatically adjust the reference arm path length such that the reference arm path length is based on an eye diameter of the subject.

39. The OCT system of claim 38, wherein the reference arm path length is adjusted to accommodate subject eye diameters in the sample arm ranging from about 1.0 mm to about 15 mm.

40. The OCT system of claim 38, further comprising a lens system comprising at least one lens in the sample arm path and at least one surface of the eye, the lens system having a field curvature that matches a curvature of a retina of the spherical eye of the subject.

41. The OCT system of claim 38, wherein the subject is a mouse.

42. The OCT system of claim 38, wherein the subject is a rat.

43. The OCT system of claim 38, wherein the subject is a macaque.

44. An optical imaging lens for imaging a back surface of a ball-lens subject or ball-lens type eye comprising:

an achromatic doublet pair; and

an optical power determined from a function or table and corresponding to a diameter or curvature of subject surfaces, wherein the optical power is greater than or equal to +30 D.