METHOD AND DEVICE FOR DETERMINING THE EYE POSITION

• US 20130120712A1
• Filed: 05/27/2011
• Published: 05/16/2013
• Est. Priority Date: 06/19/2010
• Status: Active Grant

• Current Assignee: Chronos Vision GmbH
• Original Assignee: Chronos Vision GmbH
• Inventors: Spasovski, Saso
• Granted Patent: US 9,861,279 B2
• Time in Patent Office: Days
• US Class Current: 351/209
• CPC Class Codes: A61B 3/113 for determining or recording eye movement

Abstract

The invention relates to a method and device for determining eye position, wherein a light pattern is produced on the surface of an eye by means of a light source and an image of the light pattern produced on the eye is recorded by means of an image recording apparatus, wherein points of the transition region between the sclera and the iris of the eye are determined from the image of the light pattern by means of an image processing apparatus. The coordinates of the calculated points are calculated by triangulation or stereovision, and the position of the iris plane or a plane oriented parallel thereto is determined from said coordinates. The limbus of the eye and the center thereof can also be determined in three dimensions.

Claims

1-21. -21. (canceled)

22. A method for determining the eye position, in which points of the transition region between sclera and iris of the eye are established, the coordinates of which points are calculated and this is used to determine the position of the iris plane or a plane aligned parallel thereto, wherein

a light pattern is projected onto a surface of the eye such that it intersects the transition region between sclera and iris, and

an image of the light pattern projected onto the eye surface is captured, from which the points of the transition region between sclera and iris are established.

23. The method as claimed in claim 22, wherein the coordinates of the points are calculated by triangulation or by stereovision.

24. The method as claimed in claim 22, wherein the points on the sclera are situated in the direct vicinity of the iris.

25. The method as claimed in claim 22, wherein the points are established from discontinuities in the captured light pattern at the boundary between sclera and iris or from a brightness gradient and/or color gradient of the light pattern.

26. The method as claimed in claim 22, wherein the light pattern projected onto the eye is formed from line fragments.

27. The method as claimed in claim 22, wherein the light pattern is projected onto the eye at an angle of incidence.

28. The method as claimed in claim 22, wherein the light pattern is formed from light stripes or light rings, which are aligned parallel and concentrically, respectively, to one another.

29. The method as claimed in claim 22, wherein the light pattern is formed from light stripes in the shape of a cross.

30. The method as claimed in claim 22, wherein the degree and the direction of a tilt of the eye are established from the normal vector of the plane spanned by the points.

31. The method as claimed in claim 22, characterized by a calibration, in which the light pattern is projected onto a planar surface, which is displaced relative to the image capture apparatus during the calibration.

32. The method as claimed in claim 22, wherein the light pattern is moved over the eye or that time-varying light patterns are created.

33. The method as claimed in claim 22, wherein the light pattern which is created on one eye of a pair of eyes is used to establish the viewing direction or eye position of the other eye.

34. The method as claimed in claim 22, wherein both eyes are in the field of view of the camera.

35. The method as claimed in claim 22, wherein a twist of the head or the head torsion is established from the angle between a line connecting both pupil centers and a constant reference line.

36. A device for capturing the eye position, comprising

an image capture apparatus, and

an image processing unit for establishing a plurality of points at which the sclera of the eye adjoins the iris,

wherein the image processing unit calculates the spatial coordinates of the established points and, from this, establishes the position of the iris plane or a plane aligned parallel thereto,

wherein

provision is made for an apparatus for projecting a light pattern onto a surface of the eye, and

the image capture apparatus is designed for capturing the light pattern projected onto the surface of the eye, wherein

the image processing unit establishes those points from the captured light pattern at which the light pattern intersects the transition region between sclera and iris.

37. The device as claimed in claim 36, wherein the image processing unit is designed such that it establishes the points on the sclera in the direct vicinity of the iris.

38. The device as claimed in claim 36, wherein the image processing unit is designed such that it identifies the points from discontinuities in the projected light pattern at the boundary between sclera and iris or from a brightness gradient and/or color gradient of the light pattern.

39. The device as claimed in claim 36, wherein the projection apparatus is controlled such that line fragments are projected onto the eye as light pattern.

40. The device as claimed in claim 36, wherein one or more glass fiber bundles, which is arranged in front of the image capture apparatus in order to capture the projected light pattern on the eye.

41. The device as claimed in claim 36, wherein a control apparatus for a laser ablation unit which, if the eye position changes, tracks the ablation beam thereof or deflects said ablation beam from the eye or interrupts said ablation beam.

42. The device as claimed in claim 36, wherein a fluorescence-light sensor for capturing ablation points on the eye which were hit by the ablation beam, wherein the computer unit establishes the spatial coordinates of the captured ablation points.