CONFOCAL EYE FUNDUS SCANNING SYSTEM

Abstract

A confocal fundus scanner that includes—a lighting device (11) for generating one light beam; a detector (12) for forming a digital image on the basis of received signals; optical units (131, 132, 133, 134, 135, 136) positioned to make light beam passing through them to direct it along an illumination path (A) to a target position (O) and to send a reflection back to the detector (12) along an image path (B); —a scanning device (14) having a movable wall (141) with a first slot (142) which is positioned to intercept the image path (B) and a second slot (143) positioned to intercept the illumination path (A). The slots (142, 143) are configured and positioned to move simultaneously and to shape the light beams in linear cross-section light blades.

Claims

1. A confocal fundus scanner comprising the following components: a lighting device (11) configured to generate at least one light beam; a detector (12) capable of emitting a signal when struck by light to form a digital image; optical units (131, 132, 133, 134, 135, 136) positioned with respect to the lighting device (11) and the detector (12) so as to have the light beam passing therethrough to direct it along an illumination path (A) towards a predefined target position (O) and to send a reflection of that light beam from the target position (O) towards said detector (12) along an image path (B); a scanning device (14) with a movable wall (141) with a first slot (142) which is positioned to intercept said image path (B) and a second slot (143) positioned to intercept said illumination path (A); the first slot (142) being configured and positioned to form from said light beam an illumination light strip with a linear section; the second slot (143) being configured and positioned so as to form from said reflection a strip of reflected light having a linear section; the wall (141) being configured such that as a result of their own movement, the first and second slots (142, 143) are jointly displaced.

2. The device according to claim 1 wherein the first slot (142) and second slot (143) are mutually integral and are respective parts of a unitary slot.

3. An apparatus according to claim 1 wherein the wall (141) rotates about an axis of rotation (X).

4. The apparatus according to claim 3 in which the optical groups (131, 132, 133, 134, 135, 136) are configured so as to define a first optical axis (C) along which the illumination path (A) intercepts the wall (141) and a second optical axis (D) along which the illumination path (A) intercepts the wall (141); in which the first optical axis (C) is parallel to the second optical axis (D).

5. The device according to claim 3 in which the axis of rotation (X) is parallel to the first and second optical axes (D).

6. The device according to claim 3, in which the first slot (142) and second slot (143) develop in a direction of development which is radial to the axis of rotation (X).

7. The device according to claim 6, in which the wall (141) is disc-shaped and wedged on an axis of an electric motor (16) which defines the axis of rotation (X).

8. The device according to claim 3 in which the axis of rotation (X) is perpendicular to the first and second optical axes (D).

9. The device according to claim 3 in which the first slot (142) and second slot (143) develop in a direction of development which is parallel to the axis of rotation (X).

10. The device according to claim 9 in which the wall (141) extends along a cylindrical or frustoconical surface.

11. An apparatus according to claim 2 wherein the wall (141) rotates about an axis of rotation (X).

12. The apparatus according to claim 11 in which the optical groups (131, 132, 133, 134, 135, 136) are configured so as to define a first optical axis (C) along which the illumination path (A) intercepts the wall (141) and a second optical axis (D) along which the illumination path (A) intercepts the wall (141); in which the first optical axis (C) is parallel to the second optical axis (D).

13. The device according to claim 11 in which the axis of rotation (X) is parallel to the first and second optical axes (D).

14. The device according to claim 11, in which the first slot (142) and second slot (143) develop in a direction of development which is radial to the axis of rotation (X).

15. The device according to claim 12, in which the first slot (142) and second slot (143) develop in a direction of development which is radial to the axis of rotation (X).

16. The device according to claim 13, in which the first slot (142) and second slot (143) develop in a direction of development which is radial to the axis of rotation (X).

17. The device according to claim 11, in which the wall (141) is disc-shaped and wedged on an axis of an electric motor (16) which defines the axis of rotation (X).

18. The device according to claim 4 in which the first slot (142) and second slot (143) develop in a direction of development which is parallel to the axis of rotation (X).

19. The device according to claim 6 in which the first slot (142) and second slot (143) develop in a direction of development which is parallel to the axis of rotation (X).

20. The device according to claim 8 in which the wall (141) extends along a cylindrical or frustoconical surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG. 1 shows a simplified diagram of a confocal fundus scanner according to the invention;

[0038] FIG. 2 shows a particular enlargement of the simplified diagram in FIG. 1;

[0039] FIG. 3 and FIG. 4 show two different perspective views of an embodiment of a fundus scanner according to the invention.

DETAILED DESCRIPTION

[0040] In particular, in FIG. 1, a confocal fundus scanner is globally indicated by the reference number 10 and comprises: [0041] a lighting device 11 configured to generate at least one light beam; [0042] a detector 12 capable of emitting a signal when struck by light to form a digital image; [0043] optical groups 131, 132, 133, 134, 135, 136 positioned with respect to the lighting device 11 and the detector 12 so as to be traversed by the light beam to direct it along an illumination path A towards a predefined target position O and to send a reflection of this light beam from the target position O towards the detector 12 along an image path B; [0044] a scanner 14 having a movable wall 141 with a first slot 142 which is positioned to intercept image path B and a second slot 143 positioned to intercept illumination path A.

[0045] The second slot 143 is configured and positioned to form an illuminating light strip with a linear cross-section from the light beam.

[0046] The first slot 142 is configured and positioned so as to form, by reflection, a strip of reflected light with a linear cross section.

[0047] The first slot 142 and the second slot 143 are in positions relative to the target position O, so as to be corresponding to the retina of the patient's eye, under conditions of use.

[0048] The optical groups 131, 132, 133, 134, 135, 136 can be configured to optically combine the first slot 142 and the second slot 143 with the target position O.

[0049] The wall 141 is configured such that, as a result of a movement of the wall 141, the first slot 142 and the second slot 143 are displaced in an interlocking manner.

[0050] In other words, the wall 141 has the first slot 142 and the second slot 143 which are monolithically movable with the wall 141, for example they may be made of two parts of the wall 141 which are monolithically attached to each other, or which are integral, i.e. they form a unitary body.

[0051] This allows the fundus to be scanned while avoiding or greatly reducing the noise and/or vibration generated by traditional devices.

[0052] In particular, as shown in FIGS. 3 and 4, the first slot 142 and the second slot 143 are mutually integral and are respective parts of a single slot, which in FIGS. 3 and 4 for simplicity is indicated by reference 144.

[0053] The wall 141 may rotate about an axis of rotation X, for example to allow the passage of the first slot 142 and the second slot 143 to intercept or intersect the illumination path A and the image path B, respectively, in a cyclic manner. In this way, it is possible to obtain a particularly strong structure with wall 141 intercepting image path B and illumination path A and, by rotating, forming the illuminated light strip and the reflected light strip when the first slot 142 and the second slot 143 intersect the illumination path A and the image path B respectively.

[0054] The speed of rotation of the wall 141 can be fixed or adjustable and can be set to define the scanning speed, i.e. the speed at which the illuminating light strip travels across the fundus placed, in use, in the target position O.

[0055] For example, as shown in FIGS. 3 and 4, the wall 141 may have multiple unitary slots 144, or separated first and second slots if they are not integral, i.e. forming a single slot.

[0056] Clearly, the radial dimensions of the wall 14, relative to the axis of rotation X, can be chosen according to the size of the lighting device 11 and the detector 12 that will face the wall 141.

[0057] In particular, the wall 141 may be a thin disc wedged on the axis of an electric motor 145.

[0058] The lighting device 11 may comprise: [0059] a first light source 111, comprising for example an array of leds, capable of emitting light in the visible field, preferably white, to perform the imaging function; [0060] a second light source 11 configured to emit light radiation not located in the visible field, for example infrared radiation, and configured to generate targets in the target position O, with the scanner 10 being configured to allow a retina to be photographed in the target position O, if necessary automatically; [0061] a reflecting body configured to route the light rays emitted by the first 111 and second 112 light sources along the illumination path A.

[0062] The illumination path A and the image path B may be aligned along a plane to which the axis of rotation X belongs if the first slot 142 and the second slot 143 extend in a radial direction with respect to the axis of rotation X, so as to obtain a precise interception of the second slot 143 by the reflection of the light beam, filtered by the first slot 142, and reflected by the target position O.

[0063] The optical groups 131, 132, 133, 134, 135 and 136 are configured so as to define a first optical axis C along which the illumination path A intercepts the wall 141 and a second optical axis D along which the illumination path A intercepts the wall 141.

[0064] The axis of rotation X may be parallel to the first and second optical axes D as they intercept the wall 141 and the first and second slots 142 and 143.

[0065] The first optical axis C may be parallel to the second optical axis D as they intercept the wall 141 and the first and second slots 142 and 143 and they may be located on the same plane as the axis of rotation X in order to have optimal synchronisation, in action, between the interaction of the first slot 142 with the light beam directed towards the target position O, and the interaction between the reflection of the light beam coming from the target position O and the second slot 143, in order to achieve optimal acquisition of an image of the fundus placed at the target position O.

[0066] In a preferred embodiment of the present invention, for reasons of simplicity and robustness of construction, the first slot 142 and the second slot 143, or the unitary slot 144 if these form two parts, develop in a direction of development which is radial to the axis of rotation X.

[0067] However, in general, the axis of rotation X can be warped with respect to the optical axes C and D, and the wall can have different shapes.

For example, in an embodiment not shown in the accompanying figures, the wall could be frustoconical in shape and the first slot and the second slot may extend along a plane radial to the axis of rotation of said wall.

[0068] The axis of rotation could be inclined with respect to the first and second optical axes at an angle equal to that of the opening of the conical sheet on which the wall develops so that when intercepting the first and second optical axes, the first and second slots extend perpendicularly to them.

[0069] In another possible embodiment of the present invention, the wall could develop along a surface that is, for example, cylindrical, coaxial with the axis of rotation and perpendicular to said first and second optical axes.

[0070] In this case, the first slot and the second slot can develop in a direction of development that is parallel to the axis of rotation.

[0071] The wall could in turn be cylindrical and the lighting and sensor could be surrounded by it.

[0072] This embodiment would be smaller in size in the direction perpendicular to the first and second optical axes but certainly larger transversely, compared to the other embodiments described above.

[0073] Optical groups 131, 132, 133, 134, 135 and 136 may include: [0074] a first optical group 131, facing the detector 12 and configured to compensate for optical aberrations; [0075] a second optical unit 132 following the first optical unit and configured to create an image of a retina present at the target position O, on the detector 12; [0076] a third optical unit 133 configured to conjugate the patient's retina, namely the target position O, with the second slot 143; [0077] a fourth optical unit 134 configured to condense light produced by the lighting device 11 onto the first slot 142; [0078] a fifth optical unit 135 configured to conjugate the patient's retina, namely the aim position O with the first slot 142; [0079] a sixth optical unit 136 comprising a scanning lens 136a and a target unit 136b configured to create a combined pupil and retina point.

[0080] The device 10 according to the present invention may include an optical body 16 adapted to separate the image path B from the illumination path A and which, for example, may comprise a perforated mirror so that the illumination path

[0081] A intercepts a specular surface of this perforated mirror which is annular to an aperture which is crossed by the image path B, it is thus possible to ensure a high cleaning of the fundus image.

[0082] For example, a perforated mirror as described above is particularly useful for obtaining wide field imaging.

[0083] In other embodiments of the present invention, the perforated mirror may provide multiple holes, possibly diffusely distributed.

[0084] The optical body 16 may be in a position optically associated with the pupil of the eye to be scanned where the position of the retina is in the target position O.

[0085] It is understood, therefore, that a confocal fundus scanner according to the present invention achieves the mandated task and aims by providing a structured solution that is more reliable and robust than currently known solutions.

[0086] In particular, a confocal fundus scanner allows the acquisition of an image of the fundus by scanning the fundus with full synchronization between the illuminating light strip and the light strip that constitutes the reflection of the fundus, in particular by allowing a very clean image to be obtained by the light reflected by the surfaces of the lenses of the optical groups as well as the cornea.

[0087] In addition, a confocal fundus scanner requires fewer and simpler maintenance interventions, which benefits its productivity, as it does not require re-alignment of the slots as they are made in a single body or monolithic manner.

[0088] The confocal fundus scanner according to the present invention is, moreover, easily achievable with known production technologies.

[0089] The invention thus designed is susceptible to numerous modifications and variants, all of which fall within the protection of the accompanying claims.

[0090] In addition, all of the details may be replaced by other technically equivalent elements.

[0091] Where the operational features and techniques mentioned are followed by reference signs or numbers, these reference signs or numbers have been affixed for the sole purpose of increasing the intelligibility of the description and the claims themselves and therefore do not in any way restrict the interpretation of each element identified, merely by way of example, by these reference signs or numbers.