Apparatus for producing images of an object and in particular for observing the rear portions of the eye

• US 5,177,511 A
• Filed: 05/03/1991
• Issued: 01/05/1993
• Est. Priority Date: 11/08/1986
• Status: Expired due to Term

• Current Assignee: Heidelberg Engineering GmbH
• Original Assignee: G. Rodenstock Instruments GmbH
• Inventors: Feuerstein, Manfred, Kuhl, Claus H., Plesch, Andreas, Klingbeil, Ulrich
• Primary Examiner(s): Bovernick, Rodney B.
• Application Number:
  US07/697,495
• Time in Patent Office: 613 Days
• Field of Search: 351/205, 351/221, 351/206, 351/207, 351/208, 128/303.1, 128/745, 606/4, 606/5, 606/6
• US Class Current: 351/205
• CPC Class Codes: A61B 2017/00694 with means correcting for movement of or for synchronisation with the body
• CPC Class Codes: A61B 3/1025 for confocal scanning
• CPC Class Codes: A61F 13/45 characterised by the shape cup-shaped type tampons A61F13/2045
• CPC Class Codes: A61F 2009/00846 Eyetracking
• CPC Class Codes: A61F 2009/00897 Scanning mechanisms or algorithms
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00821 for coagulation

Abstract

An apparatus for producing images of an object and, in particular, for observing the rear portions of the eye by an illumination device, the light of which is focused on the object to be imaged and which preferably is provided with at least one laser. A scanning device, which produces a scanning motion of the light from the illumination device on the object to be imaged. A detector device has at least one detector which receives the light reflected from the object to be imaged an assessement and synchronization unit produces the image from the time-sequential output signal from the detector device.

It is possible to gain essential ground-laying information about the object to be imaged, e.g. the fundus of the eye, by special types of illumination and/or the analysis of the scattered back light according to the most varied criteria.

Claims

1. An apparatus for producing images of an object, comprising an illumination device, the light of which is focused on the object to be imaged and which is provided with at least one laser;

a scanning device which produces a scanning motion of the light from said illumination device on said object to be imaged;

a detector device having at least one detector which receives the light reflected from said object to be imaged; and

an assessment and synchronization unit which produces the image from a time-sequential output signal from said detector device comprising individual detectors arranged conjugate to one of different planes and to different regions of a plane one of shutters and polarization filters being arranged at selected detectors for selective reception of light reflected from different planes, areal distribution of the intensity of said light in a particular plane and a polarization state of said light.

2. An apparatus according to claim 1, wherein said illumination device projects light of several wavelengths simultaneously onto said object to be imaged (R), and for the light of each wavelength at least one a wavelength-selective individual detector is provided.

3. An apparatus according to claim 2, wherein the entrance and/or exit pupils of the light beams of differing wavelengths are different.

4. An apparatus according to claim 3, wherein the representations by said light of differing wavelengths have differing depths of focus.

5. An apparatus according to claim 1, wherein said assessment unit presents the output signals from said individual detectors on one or several monitors.

6. An apparatus according to claim 1, wherein said assessment unit couples said output signals from said individual detectors in real time and presents the coupled signal on a monitor.

7. An apparatus according to claim 1, wherein said assessment unit feeds said output signals from said individual detectors into an image memory and couples the stored signals.

8. An apparatus according to claim 1, wherein said detector device receives said light reflected from said object to be imaged via said scanning device and, selective shutter devices are provided.

9. An apparatus according to claim 1, wherein a detector arrangement, which determines the distribution of the intensity of said reflected light, is provided in a plane conjugate to the pupil (P) of the eye for observing the fundus of the eye.

10. An apparatus according to claim 9, wherein said assessment unit determines from said output signals from said individual detectors characteristic features of said distribution of intensity, including the main point of said reflected light and directional asymmetries.

11. An apparatus according to claim 10, wherein said individual detectors are sectors of a circle and are arranged in a circle.

12. An apparatus according to claim 1, wherein a detector arrangement is provided in a plane conjugate to said object to be imaged, which determines the distribution of intensity of said reflected light in said plane.

13. An apparatus according to claim 12, wherein said assessment unit determines from said output signals from said individual detectors the characteristic features of said distribution of intensity including transverse scattering within the retina.

14. An apparatus according to claim 1, wherein a number of individual detectors, before which analyzers are provided in a plane conjugate to said object to be imaged.

15. An apparatus according to claim 14, further comprising four individual detectors, wherein no optically effective element is arranged before the first individual detector, a first linear analyzer is arranged before the second individual detector, a second linear analyzer turned 45°

to said first analyzer is arranged before the third individual detector, and a quarter-wave plate is arranged before the fourth individual detector, and

said assessment unit determines the degree of polarization, the polarization direction and the ellipicity from the output signals.

16. An apparatus according to claim 1,

wherein before said detector device are connected at least partially structured filters and/or variable shutters.

17. An apparatus according to claim 16, wherein areal light modulators, which can be triggered electronically, from said filters.

18. An apparatus according to claim 17, wherein said light modulators are LCD elements having regions, which can be triggered separately.

19. An apparatus according to claim 16, wherein said filters can be shifted or turned in a longitudinal direction and/or oblique to the detection beam path.

20. An apparatus according to claim 1, wherein, in addition, markings can be projected onto said fundus of the eye.

21. An apparatus according to claim 20, wherein said projection of said markings occurs by modulation of said illumination light.

22. An apparatus according to claim 21, wherein at least one of an additional source of light and an additional deflection unit is provided for said projection of said markings.

23. An apparatus according to claim 22, wherein said deflection unit is provided with one of an acousto-optical demodulator and a wobble unit.

24. An apparatus according to claim 20, wherein said projection of said marks occurs for the purpose of fundus perimetry.

25. An apparatus according to claim 1, wherein said scanning device is an x/y scanning device which is provided with a rotatable polygonal mirror drum and a galvanometer mirror.

26. An apparatus according claim 1,

wherein for the illumination of the surrounding area an additional light source is provided, the light (B) of which expansively illuminates said object to be imaged.

27. An apparatus according to claim 1,

wherein the beam of an operational laser is additionally mirrored in.

28. An apparatus according to claim 1, wherein a control unit is configured to redirect at least one of an observation beam path and an operational laser beam and to selectively switch off the laser.

29. An apparatus according to claim 28, wherein said control unit additionally permits setting the operational parameters including treatment planning.

30. An apparatus according to claim 1,

wherein a field-of-view shutter, which produces a dark-field illumination for at least one part of said individual detectors, is arranged before said detector device.

31. An apparatus according to claim 1,

wherein at least one of a fundus angiograph and markings can be congruently superimposed on the received image.

32. An apparatus according to claim 1,

wherein said control unit is provided with an image processing device for processing the images received simultaneously or consecutively.

33. An apparatus according to claim 1,

wherein said illumination device, said scanning device and said detector device form a confocal arrangement and said field-of-view shutters of at least some of said individual detectors are substantially larger than the diameter of the image point on said fundus of the eye.

34. An apparatus according to claim 1, wherein field-of-view-determining shutters and their detectors are arranged spaced and stationary in planes conjugate to said differing planes.

35. An apparatus according to claim 34, wherein light conducting means connect said shutters and said detectors.

36. An apparatus for producing images of an object and for observing the rear portions of the eye, comprising

an illumination device, the light of which is focused on the object to be imaged and which is provided with at least one laser wherein said illumination device projects light of several wavelengths simultaneously onto said object to be imaged (R), and for the light of each wavelength at least one and a wavelength-selective individual detector is provided;

a scanning device, which produces a scanning motion of the light from said illumination device on said object to be imaged;

a detector device, having at least one detector, which receives the light reflected from said object to be imaged; and

an assessment and synchronization unit which produces the image from the time-sequential output signal from said detector device.

37. An apparatus according to claim 36, wherein before said detector device are connected at least partially structured filters and/or variable shutters.

38. An apparatus according to claim 36, wherein markings can be projected onto said object to be imaged and onto said fundus of the eye.

39. An apparatus according to claim 36, wherein for the illumination of the surrounding area an additional light source is provided, the light of which expansively illuminates said object to be imaged and in particular said fundus of the eye.

40. An apparatus according to claim 36, wherein the beam of an operation coagulation laser is additionally mirrored in.

41. An apparatus according to claim 36, wherein a control unit is configured to redirect at least one of an observation beam path and an operational laser beam and to selectively switch off the laser.

42. An apparatus according to claim 36, wherein a field-of-view shutter is arranged before said detector device to produce a dark-field illumination for said individual detectors.

43. An apparatus according to claim 36, wherein a fundus angiograph and/or markings can be congruently superimposed on the received image.

44. An apparatus according to claim 36, wherein said control unit is provided with an image processing device for processing the images received simultaneously or consecutively.

45. An apparatus for producing images of an object and for observing rear portions of an eye, comprising:

an illumination device whose light is focused on an object to be imaged and which is provided with at least one laser;

a scanning device operatively arranged to produce a scanning motion of the light from said illumination device on the object to be imaged;

a detector device having at least one detector receiving light reflected from the object to be imaged;

an assessment and synchronization unit producing the image from a time-sequential output signal from said detector device; and

at least one of partially structured filters and variable shutters connected before said detector device so as to detect intensity distribution of the light reflected at the fundus of the eye.

46. An apparatus for producing images of an object and for observing rear portions of an eye, comprising:

an illumination device whose light is focused on an object to be imaged and which is provided with at least one laser;

a scanning device operatively arranged to produce a scanning motion of the light from said illumination device on the object to be imaged;

a detector device having at least one detector receiving light reflected from the object to be imaged;

an assessment and synchronization unit producing the image from a time-sequential output signal from said detector device; and

an additional light source configured to illuminate a surrounding area, such that the light of the additional light source expansively illuminates a fundus of the eye for effecting fundus perimetry.