Illumination system for a surgical microscope with adjustable coaxial and oblique beams

Abstract

The surgical microscope is configured to capture an image of the patient's eye and defines an optical axis. The illumination source is configured to emit a plurality of beams at the patient's eye at a plurality of angles relative to the optical axis. A controller is coupled to the surgical microscope and the illumination source, the controller being configured to independently control values ​​of illumination parameters for each of the plurality of beams to facilitate imaging of the patient's eye. The illumination parameters can compensate for reflections from the iris, offset of the eye relative to the optical axis, and reflections of ambient light. The illumination parameters can be controlled according to input received from a surgeon or other user.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 378,492, entitled "COLOR TUNABLE COAXIAL AND OBLIQUE ILLUMINATION FOR OPHTHALMIC MICROSCOPY," filed October 5, 2022, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to the performance of ophthalmic surgery. [Background technology]

[0003] Light received by the eye is focused at the back of the eye, which includes the retina. The area between the cornea and the lens is known as the anterior segment. The part of the eye inside, between the lens and the retina, is known as the posterior segment and is filled with a clear gel known as the vitreous humor. Many eye conditions can be treated by performing ophthalmic treatments on the internal, or posterior, segment of the eye.

[0004] It would be an advancement in the art to facilitate the administration of ophthalmic treatments. Summary of the Invention [Means for solving the problem]

[0005] Aspects of the present disclosure include a surgical microscope configured to capture an image of a patient's eye and defining an optical axis, an illumination source configured to emit a plurality of beams at the patient's eye at a plurality of angles relative to the optical axis, and a controller coupled to the surgical microscope and the illumination source, the controller configured to independently control values ​​of illumination parameters for each beam of the plurality of beams to facilitate imaging of the patient's eye.

[0006] So that the above-recited features of the present disclosure may be understood in detail, a more particular description of the present disclosure briefly summarized above can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only some aspects of the present disclosure, which may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0007] [Figure 1] 1 illustrates a surgical microscope that may use an adjustable illumination source, according to certain embodiments. [Figure 2] 1 illustrates components of an adjustable illumination source, according to certain embodiments. [Figure 3] 1 illustrates a beam from an adjustable illumination source illuminating an eye, according to certain embodiments. [Figure 4] 1 illustrates overlap between beams from an adjustable illumination source illuminating an eye, according to certain embodiments. [Figure 5] 1 illustrates the absorption and transmission of illumination from the iris of the eye, according to certain embodiments. [Figure 6] FIG. 1 illustrates a process flow diagram of a method for illuminating the iris of an eye, according to certain embodiments. [Figure 7] 1 illustrates possible misalignment of the eye with respect to the optical axis of a surgical microscope, according to certain embodiments. [Figure 8] FIG. 1 is a process flow diagram of a method for compensating for ocular misalignment using an adjustable illumination source, according to certain embodiments. [Figure 9] FIG. 10 is a process flow diagram of an alternative method for compensating for ocular misalignment using an adjustable illumination source, according to certain embodiments. [Figure 10] FIG. 1 illustrates a process flow diagram of a method for eliminating reflections from ambient lighting using an adjustable illumination source, according to certain embodiments. [Figure 11] FIG. 10 is a timing diagram illustrating pulsing light from an adjustable illumination source to eliminate reflections from ambient light, in accordance with certain embodiments. [Figure 12] FIG. 1 illustrates a process flow diagram of a method for capturing images with different lighting parameters, according to certain embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0008] For ease of understanding, the same reference numbers have been used, where possible, to refer to the same elements that are common between the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further reference.

[0009] The present disclosure will now be described in detail with reference to the drawings, which are provided as illustrative examples of the present disclosure, to enable those skilled in the art to practice the present disclosure. In particular, the following drawings and examples are not intended to limit the scope of the present disclosure to a single embodiment, and other embodiments are possible by replacing some or all of the elements described or illustrated. Furthermore, when specific elements of the present disclosure can be partially or completely implemented using known components, only those parts of such known components necessary for understanding the present disclosure will be described, and detailed descriptions of other parts of such known components will be omitted so as not to obscure the present disclosure.

[0010] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are "coupled" shall mean that the parts are joined or operate together directly or indirectly (i.e., through one or more intermediate parts or components, wherever a link occurs). As used herein, "directly coupled" means that two elements are in direct contact with each other. As used herein, "fixedly coupled" or "fixed" means that two components are coupled such that they move as a unit while maintaining a constant orientation relative to each other. As used herein, "operably coupled" means that two elements are coupled such that they function together. It should be understood that two elements being "operably coupled" does not require a direct or permanent connection between them. As used herein, "substantially" means that any variation is negligible such that it is within operating tolerances known to those skilled in the art and provides the desired performance and results as described in the embodiments described herein. The recitation of numerical ranges is inclusive of their endpoints.

[0011] In the exemplary embodiments described herein, embodiments showing a singular component should not be considered limiting; rather, the present disclosure is intended to encompass other embodiments including multiples of the same component, and vice versa, unless expressly stated otherwise herein. Furthermore, applicants do not intend any term in this specification or claims to be ascribed an unusual or special meaning unless expressly indicated to be so. Furthermore, the present disclosure encompasses present and future known equivalents to known components referred to herein by way of example.

[0012] 1 , an operating environment 100 may be used by a surgeon 106 to perform an ophthalmic procedure on an eye 102 of a patient 104. The operating environment 100 may include a surgical microscope 108 suspended from a support 110 that facilitates positioning the surgical microscope 108 above the eye 102 at a desired height by the surgeon 106. For example, the surgical microscope 108 may be implemented as an NGENUITY 3D visualization system offered by Alcon Inc. of Fort Worth Texas.

[0013] Referring to FIG. 2 , an adjustable illumination source 200 may be incorporated into or attached to a surgical microscope 108 to provide illumination during ophthalmic treatment according to some or all of the methods disclosed herein. The adjustable illumination source 200 includes an illumination device 202 including one or more light emitters 204. For example, in the illustrated embodiment, the adjustable illumination source 200 includes multiple light emitters 204. Each light emitter 204 may emit light in multiple colors. For example, each light emitter 204 may be implemented as a set of red, green, and blue (RGB) light emitters capable of emitting colors in a range of the visible spectrum. The light emitters 204 may be coupled to coaxial illuminator optics 208 by one or more optical fibers 206 or bundles of optical fibers 206. As used herein, red light may be understood to have a wavelength of 600-700 nm, green light may be understood to have a wavelength of 500-600 nm, and blue light may be understood to have a wavelength of 400-500 nm.

[0014] The coaxial illuminator optics 208 include optical components that allow light reflected from the eye 210 to pass through the coaxial illuminator optics 208 to the optical microscope head 108a and be detected using the digital camera 108b of the surgical microscope 108. A polarizing filter 108c may be positioned at a point in the optical path between the eye 210 and the digital camera 108b. The polarizing filter 108c may change its polarization angle or be turned on and off depending on input from the controller 222.

[0015] The coaxial illuminator optics 208 also receive light from the light emitter 204 and redirect at least a portion of the received light into coaxial beams 212 a, 212 b that are directed onto the eye 210. As used herein, "coaxial" refers to a beam emitted at an angle within 4 degrees, 3 degrees, or 2 degrees of the optical axis 214 of the optical microscope head 108 a, which may include the projection of the optical axis 214 through the coaxial illuminator optics 208. The coaxial illuminator optics 208 may combine the optical path of light reflected from the eye with the optical path of the coaxial beams 212 a, 212 b, such as by a beam splitter, mirror, or other optical element.

[0016] The coaxial beams 212 a, 212 b may be positioned and directed to enhance the “red reflex” from the eye during cataract surgery. During ophthalmic procedures such as cataract surgery, red and near-infrared light incident on the retina results in a red glow from the retina illuminating structures of the eye, which is extremely helpful to the surgeon 106. For example, the exit pupil of the coaxial illuminator optics 208 may be substantially laterally aligned with the entrance pupil of the surgical microscope 108, e.g., in a plane containing the centers of the coaxial beams 212 a, 212 b and the optical axis 214. From the perspective of the patient's eye 210 looking up at the surgical microscope 108, the exit pupil of the coaxial illuminator optics may appear as two circular disks from which the coaxial beams 212 a, 212 b emit. The two entrance pupils of the surgical microscope 108 may be defined by two physical apertures, typically located directly above the objective lenses of the optical microscope head 108 a. From the perspective of the eye 210 looking up at the surgical microscope 108, the entrance pupils appear as two dark circular disks, which are images of the two apertures seen through the objective lens. Thus, the positions and orientations of the coaxial beams 212 a, 212 b can be selected so that, from the perspective of the eye 210, two coaxial illumination exit pupils and two microscope entrance pupils are visible. The positions and orientations of the coaxial beams 212 a, 212 b can be selected so that the two sets of pupils overlap substantially (e.g., 90%), if not completely, laterally, i.e., so that one exit pupil (e.g., the left side) of one coaxial beam 212 a is aligned with one entrance pupil (e.g., also the left side) of the surgical microscope 108, and the other exit pupil (e.g., the right side, opposite the left side of the optical axis 214) of the other coaxial beam 212 b is aligned with the other entrance pupil (e.g., also the right side) of the surgical microscope 108. The entrance pupil of the microscope typically has a diameter of 16 mm and a center-to-center separation of typically 22 mm. The exit pupils of the coaxial beams 212a, 212b may be similarly configured, e.g., 12-18 mm in diameter and 20-25 mm in center-to-center separation.

[0017] The central axes of the coaxial beams 212 a, 212 b may converge toward each other as shown in FIG. 2 , or may be parallel to each other and to the optical axis 214. The amount of overlap of the coaxial beams 212 a, 212 b at the corneal plane 216 may be up to 100%, or may be as little as 30%. As used herein, the beam overlap percentage may refer to the beam area overlap percentage, where the area of ​​each beam is defined as the region having an intensity greater than 50% of the beam's maximum intensity (e.g., the intensity at the center of the beam). The corneal plane 216 may be defined as a plane intersecting the contour of the eye 210. The degree of overlap may be selected based on a trade-off between (a) a higher overlap percentage resulting in more red reflex and therefore more light entering the entrance pupil of the surgical microscope 108, and (b) a lower overlap percentage resulting in illumination and corresponding red reflex over a wide range of eye positions, as discussed below with respect to FIGS. 7, 8, and 9. Accordingly, in embodiments implementing the techniques of FIGS. 7, 8, and 9, a smaller overlap, such as less than 50%, may be used. For example, in an implementation implementing the techniques of FIGS. 7, 8, and 9, the coaxial beams 212a, 212b may be parallel to each other and to the optical axis 214. In other embodiments described herein, the degree of overlap may be less critical and may be between 30% and 100%. One or more of the light emitters 204 may be coupled to oblique optics 218, which directs an oblique beam 220 toward the eye 210. The center of the oblique beam 220 may be substantially aligned with the optical axis 214 at the corneal plane 216, such as within 5 mm.

[0018] In some embodiments, the position and orientation of the oblique beam 220 may be selected to reduce the red reflex induced by the oblique beam 220. In particular, the exit pupil of the oblique optics 218 may be offset from the entrance pupil of the surgical microscope 108. For example, the edge of the exit pupil of the oblique optics 218 closest to the microscope's entrance pupil may be at least 5 mm away from the nearest entrance pupil (the right entrance pupil in the illustrated embodiment) to essentially eliminate the red reflex induced by the oblique beam 220. However, the angle of the oblique beam 220 relative to the optical axis 214 may be limited by (1) the desire to avoid lateral elongation of the projection of the circular oblique beam 220 onto the corneal surface 216, and (2) the desire to avoid lateral separation between the area at the corneal surface 216 illuminated by the oblique beam 220 and the area illuminated by the coaxial beams 212 a, 212 b (which, in most applications, is 175 mm to 200 mm from the exit pupils of the coaxial illuminator optics 208 and the oblique illuminator optics 218). However, mechanical limitations may require that the oblique beam 220 define a non-zero angle with respect to the optical axis 214. For example, the oblique beam 220 may define an angle with respect to the optical axis 214 of 5 to 12 degrees, 7 to 10 degrees, 7 to 9 degrees, or about 8 degrees, with about 8 degrees being a typical angle.

[0019] In the following exemplary embodiment, two coaxial beams 212a, 212b and a single oblique beam 220 are used. It should be understood that three or more coaxial beams 212a, 212b defining three or more angular orientations relative to the optical axis 214 can be used in a similar manner. Likewise, two or more oblique beams 220 having two or more angular orientations relative to the optical axis 214 can be used in a similar manner.

[0020] The controller 222 may be coupled to the lighting device 202 to control its operation. The controller 222 may further be coupled to the digital camera 108b to receive images from the digital camera 108b or possibly to control its operation. The controller 222 may further be coupled to a display device 224. The display device 224 may be a display device within a surgical microscope, which may be a binocular display device. The display device 224 may also be a separate display device present in the operating environment 100 and viewable by the surgeon 106.

[0021] The controller 222 may be coupled to an input device 226. The input device 226 may be implemented as one or more physical buttons, one or more foot pedals, a touchscreen, a pointing device (e.g., a mouse or trackpad), a microphone for receiving voice commands, one or more cameras for detecting gestures, or some other input device. The controller 222 may control the operation of itself and the lighting device 202 according to input received from the input device 226. Additionally, any of the functions attributed to the controller 222 herein may be manually activated by a surgeon or other user via the input device 226. In particular, the surgeon may be provided with sliders for selecting the intensity of each beam 212a, 212b, 220, the intensity of each color of each beam 212a, 212b, 220, or various other parameters that define the performance of any of the methods described herein.

[0022] The controller 222 may be configured to perform various functions on the lighting device 202 and on images received from the digital camera 108b. For example, the controller 222 may include a color detection module 228 configured to analyze the color composition of pixels in the images received from the digital camera 108b against parameters of the light emitted by the lighting device 202 at the time the images were captured. The controller 222 may include a color selection module 230 configured to select the color and intensity to be output by each light emitter 204. The controller 222 may include a color correction module 232 configured to modify the color composition of the images received as an output of the color detection module 228.

[0023] For example, color selection module 230 may select a color of light emitted from light emitter 204 having a first level of composite intensity of blue light selected to maintain phototoxicity below a desired level. Color correction module 232 may then process images received from digital camera 108b to increase the intensity of the blue component of the pixel to simulate illumination with a second level of composite intensity of blue light that is higher than the first level. In this way, phototoxicity experienced by eye 210 is reduced while approximating the same visibility of the ocular features expected by surgeon 106.

[0024] In another example, the color selection module may select the color and intensity of the light emitted by the light emitter 204 to improve the dynamic range of an image captured using the digital camera 108b, e.g., to avoid under- or over-saturation.

[0025] The controller 222 may include adjustment logic 234 configured to adjust the color and intensity of the light emitted by the lighting device 202 based on various criteria, such as according to any of the methods described below with respect to FIGS. 3-12.

[0026] 3 and 4, the coaxial beams 212a, 212b may enter the eye such that the beams 212a, 212b only partially overlap at the corneal plane 216. For example, as shown in FIG. 4, the beams 212a, 212b may overlap along a direction 404 perpendicular to the optical axis and parallel to the offset direction between the coaxial beams 212a, 212b over an area 400 at least as large as the contour 402 of the eye 210, such as 0.9 to 1.3 times the size of the contour 402. The oblique beam 220 may overlap the entire beams 212a, 212b at the corneal plane 216, such as 1 to 1.5 times the size of the combined beams 212a, 212b at the corneal plane 216.

[0027] 5 and 6, the ability to independently control the color and intensity of the coaxial beams 212a, 212b and the oblique beam 220 can be used to reduce unwanted reflections during ophthalmic treatment, such as reflections from the iris 500. For example, with specific reference to FIG. 5, light 502 of the same color as the iris that is incident on the iris 500 is reflected to a greater extent than light 504 of a different color from the iris 500. Reflections from the iris can interfere with the ability to image portions of the eye 210 beyond the pupil 506, such as the retina, lens, vitreous, etc.

[0028] 6 , a method 600 performed by the controller 222 may include, in step 602, selecting default illumination parameters (e.g., color and intensity) for some or all of the coaxial beams 212 a, 212 b and the oblique beam 220 and illuminating the eye 210 with light generated according to the default illumination parameters. The method 600 may include, in step 604, capturing an image of the eye 210 using the digital camera 108 b while illuminating the eye 210 according to the default illumination parameters. The image captured in step 604 may then be analyzed in step 606 to identify one or more attributes of a representation of the eye 210 in the image, such as a representation of the iris 500, and detect the color of the iris 500. The method 600 may then include, in step 608, adjusting the color of some or all of the coaxial beams 212 a, 212 b and the oblique beam 220 according to the detected color of the iris 500. For example, the colors of some or all of the coaxial beams 212 a, 212 b and oblique beam 220 may be tuned to be different from the color of the iris 500. In some applications, light incident on the retina, particularly red and near-infrared light, produces a red reflex, and even if the illumination color is selected to be different from the iris 500, the red reflex can still provide adequate illumination for the surgeon 106 to identify structures and features of the eye 210. For example, selecting an illumination color that lacks blue or green for an iris that is blue or green reduces the reflection from the iris while still providing suitable red light to induce the red reflex.

[0029] Note that the reverse of method 600 can be performed if iris 500 itself is the target of ophthalmic treatment. That is, the adjustments in step 608 can ensure that the light from some or all of coaxial beams 212 a, 212 b and oblique beam 220 matches the color of iris 500 to enhance reflection from iris 500.

[0030] 7, 8, and 9, during an ophthalmic procedure, the patient's eye 210 may move relative to the optical axis 214 of the surgical microscope 108. For example, the eye 210 may rotate by an angle 700 relative to the optical axis 214 and / or translate by a distance 702 from the optical axis 214 along the direction 404. The ability to adjust the intensity and / or color of the coaxial beams 212 a, 212 b may be used to compensate for such rotation and translation, particularly the component of such rotation and the component of translation parallel to the direction 404 in which the coaxial beams 212 a, 212 b are offset from one another.

[0031] The intensity of each of the coaxial beams 212a, 212b and the oblique beam 220 reaching the retina must be limited to avoid harm to the retina, i.e., to avoid "phototoxicity." In particular, the intensity of blue light for each beam must be maintained within a safe level. Because the coaxial beams 212a, 212b and the oblique beam 220 may all define different angles relative to the optical axis 214 and the optical axis of the eye, the spots generated on the retina by each beam 212a, 212b, 220 may not overlap, allowing the phototoxicity of each beam 212a, 212b, 220 to be controlled independently. However, if one or more of the spots of one or more beams 212a, 212b, 220 overlap at the retina, combined phototoxicity can be controlled.

[0032] If the intensities of the coaxial beams 212a, 212b are equal, then the amount of light from the coaxial beams 212a, 212b that enters the eye 210 will also be approximately equal (e.g., within 1%) if the optical axis of the eye 210 is aligned with and parallel to the optical axis 214. However, if the optical axis of the eye 210 is not aligned with and / or parallel to the optical axis 214, then the amount of light from the coaxial beams 212a, 212b that enters the eye 210 will not be equal because the difference increases with increasing angle 700 and distance 702. This imbalance is exacerbated when the angle 700 and distance 702 are in the same direction, i.e., both contribute to movement of the pupil 506 to the same side along the direction 404. This imbalance is reduced when the angle 700 and distance 702 are in opposite directions, i.e., both contribute to movement of the pupil 506 to different sides along the direction 404.

[0033] Movement of the pupil 506 relative to the optical axis 214, which has a component in the direction 404, reduces the amount of light from one of the coaxial beams 212a, 212b that enters the pupil 506. For example, in the scenario of FIG. 7, the amount of light from the coaxial beam 212b decreases due to movement of the pupil 506 away from the center of the coaxial beam 212b at the corneal plane 216. The amount of light from the coaxial beam 212a that enters the pupil 506 may remain substantially constant or may increase. Although not shown, the amount of light from the oblique beam 220 may increase or decrease in a similar or equivalent manner. For example, movement of the pupil 506 away from the oblique optic 218 may reduce the amount of light from the oblique beam 220 that enters the pupil, and movement of the pupil 506 toward the oblique optic 218 may increase the amount of light from the oblique beam 220 that enters the pupil.

[0034] Thus, the intensities of some or all of the coaxial beams 212a, 212b and the oblique beam 220 can be adjusted in response to movement of the pupil 506 having a component in direction 404 so that the resulting intensity of light reaching the retina approaches the intensity of light reaching the retina when the pupil 506 is aligned with and parallel to the optical axis 214.

[0035] 8 , the illustrated method 800 may be used to compensate for movement of the pupil 506. The method 800, executed by the controller 222, may include, at step 802, selecting default illumination parameters (e.g., color and intensity) for some or all of the coaxial beams 212 a, 212 b and the oblique beam 220, and illuminating the eye 210 with light generated according to the default illumination parameters. The default illumination parameters may have equal intensity for the coaxial beams 212 a, 212 b and may be selected to result in a safe level of light reaching the pupil for a range of possible angles 700 and distances 702.

[0036] The method 800 may include, at step 804, capturing an image of the eye 210 using the digital camera 108b while illuminating the eye 210 according to default lighting parameters. The image captured at step 804 may then be analyzed at step 806 to identify one or more attributes of a representation of the eye 210 in the image. For example, step 806 may include identifying a representation of the pupil 506 and detecting an offset of the pupil 506 from the optical axis 214. The offset may be a measure of the number of pixels (or a distance derived from the number of pixels) between the center of the representation of the pupil 506 in the image and the center of the image (or some other pixel location corresponding to the optical axis 214).

[0037] In step 808, method 800 may include adjusting the intensity of one or both of beams 212a, 212b according to the offset detected in step 806. For example, when pupil 506 is aligned with optical axis 214 (see FIG. 3), coaxial beams 212a, 212b may each emit light at 50% of maximum intensity. When pupil 506 is offset from the optical axis toward the center of coaxial beam 212a (see FIG. 7), the intensity of coaxial beam 212a may increase to 66% of maximum intensity, and the intensity of coaxial beam 212b may decrease to 34% of maximum intensity. With a greater offset toward coaxial beam 212a, the intensity of coaxial beam 212a may increase to 82% of maximum intensity, and the intensity of coaxial beam 212b may decrease to 18% of maximum intensity. With even greater offset toward coaxial beam 212a, the intensity of coaxial beam 212a may increase to 98% of the maximum intensity and the intensity of coaxial beam 212b may decrease to 2% of the maximum intensity. The intensities of coaxial beams 212a, 212b may be selected so that the combined intensity of coaxial beams 212a, 212b at the overlap region of the corneal surface is equal to 100% of the maximum intensity of a single coaxial beam 212a, 212b.

[0038] More generally, the beam intensity of the coaxial beams 212a, 212b may be set to Max+F(D), where D is the offset toward the beam and is negative if the offset is away from the beam. F() may be a function that increases with increasing D, such as a multiplication by a scaling factor or some other function. In some embodiments, the intensity of each coaxial beam 212a, 212b may be calculated as a percentage of the maximum intensity of each coaxial beam 212a, 212b as 50*(1+D / D), where D is the maximum expected or compensable offset in either direction from the optical axis 214. Thus, for the left coaxial beam 212a, moving D to the left toward the left coaxial beam 212a (positive D) will result in 100 percent intensity, and moving D to the right away from the left coaxial beam 212a (negative D) will result in 0 percent intensity. For the right coaxial beam 212b, moving Dmax to the right (positive D) towards the right coaxial beam 212b will give 100 percent intensity, and moving Dmax to the left (negative D) away from the right coaxial beam 212b will give 0 percent intensity.

[0039] Method 800 may be repeated periodically from step 804 to compensate for changes in the offset of pupil 506. For example, steps 804-808 may be repeated every 0.5 seconds, every 0.1 seconds, every 10 milliseconds, or some other interval. Following an initial iteration, the illumination parameters used in step 804 may be the illumination parameters selected according to step 808 of the previous iteration.

[0040] 9 , the illustrated method 900 can be used to compensate for pupil 506 movement by modifying the color of the coaxial beams 212 a, 212 b. The method 900, executed by the controller 222, can include, at step 902, selecting default illumination parameters (e.g., color and intensity) for some or all of the coaxial beams 212 a, 212 b and the oblique beam 220 and illuminating the eye 210 with light generated according to the default illumination parameters. The default illumination parameters can have equal intensity for the coaxial beams 212 a, 212 b and can be selected to ensure a safe level of light reaching the pupil for a range of possible angles 700 and distances 702. In some embodiments, the default illumination parameters produce pink light, i.e., a mixture of white and red light, or light with equal green and blue intensities and greater red intensity than the green and blue intensities. Pink light can have the advantage of providing abundant red light to simulate a red reflex with relatively little blue light, contributing to phototoxicity.

[0041] The method 900 may include, at step 904, capturing an image of the eye 210 using the digital camera 108b while illuminating the eye 210 according to default lighting parameters. The image captured at step 904 may then be analyzed at step 906 to identify one or more attributes of a representation of the eye 210 in the image. For example, step 906 may include identifying a representation of the pupil 506 and detecting an offset of the pupil 506 from the optical axis 214. The offset may be a measure of the number of pixels (or a distance derived from the number of pixels) between the center of the representation of the pupil 506 in the image and the center of the image (or some other pixel location corresponding to the optical axis 214).

[0042] At step 908, method 900 may include adjusting the color of one or both of beams 212a, 212b according to the offset detected at step 906. For example, when pupil 506 is aligned with optical axis 214 (see FIG. 3), coaxial beams 212a, 212b may each emit light with an elevated red component (i.e., pink light). When pupil 506 is offset from the optical axis toward the center of coaxial beam 212a (see FIG. 7), the red component of coaxial beam 212a may be increased and the red component of coaxial beam 212b may be decreased to provide a more realistic white illumination color for illuminating the portion of the corneal surface illuminated by coaxial beam 212b.

[0043] More generally, the intensity of the red component of the coaxial beams 212a, 212b may be set equal to R0 + F(D), where D is an offset toward the beam and is negative if the offset is away from the beam. R0 may be a default intensity for the red component, such as less than or equal to 50% of the maximum intensity of the red component. F() may be a function that increases with increasing D, such as a multiplication by a scaling factor or some other function. In some embodiments, the intensity of the red component of each coaxial beam 212a, 212b may be calculated as R0 + R1 * (1 + D / Dmax), where Dmax is as defined above and R1 is less than or equal to R0 / 2. Thus, for the left coaxial beam 212a, moving left by Dmax toward the left coaxial beam 212a (positive D) results in an intensity of the red component of R0+2*R1, and moving right by Dmax away from the left coaxial beam 212a (negative D) results in an intensity of the red component of R0-2*R1. For the right coaxial beam 212b, moving right by Dmax toward the right coaxial beam 212b (positive D) results in an intensity of the red component of R0+2*R1, and moving left by Dmax away from the right coaxial beam 212b (negative D) results in an intensity of the red component of R0-2*R1.

[0044] The green and blue components of each coaxial beam 212a, 212b can (a) remain constant or (b) decrease or increase in response to an increase or decrease in the red component, i.e., G - F(D) / 2, B - F(D) / 2, where G and B are the default intensity levels of the green and blue light. In some embodiments, the intensity of the red component decreases maximally when the light from beams 212a, 212b becomes white light, i.e., when the red, green, and blue components are equal. In some embodiments, the intensity of the red component increases maximally when the light from beams 212a, 212b becomes pure red light, i.e., when the green and blue components are at zero intensity and the red component is at its maximum intensity or some other predefined maximum value.

[0045] Method 900 may be repeated periodically from step 904 to compensate for changes in the offset of pupil 506. For example, steps 904-908 may be repeated every 0.5 seconds, every 0.1 seconds, every 10 milliseconds, or some other interval. Following an initial iteration, the illumination parameters used in step 904 may be the illumination parameters selected according to step 908 of the previous iteration.

[0046] It should be noted that the controller 222 can receive input from the input device 226 specifying the red component in each coaxial beam 212 a, 212 b and possibly the oblique beam 220. For example, the surgeon 106 can adjust a physical slider or rotary dial, or a graphical user interface element that implements a slider or dial. For example, moving the slider or dial in one direction can increase the red component of one of the coaxial beams 212 a, 212 b and decrease the red component of the other coaxial beam 212 b, 212 a. In this manner, the surgeon can manually compensate for misalignment between the pupil 506 and the optical axis 214.

[0047] Methods 800 and 900 provide the advantage of providing light where it is needed based on the current position and orientation of the eye 210, thereby reducing power consumption. Method 900 can be performed automatically by the controller 222 or manually by the surgeon 106 or other user. For example, the input device 226 may include a slider corresponding to an offset of the eye 210, whether actual or arbitrarily selected by the surgeon 106. The surgeon can then move the slider to specify the offset and direction and make a corresponding adjustment to the intensity of the coaxial beams 212 a, 212 b according to one or both of methods 800 and 900.

[0048] 10 and 11, the tunable illumination source 200 may be used to reduce reflections from other light sources in the operating environment 100. For example, the method 1000 may include, at step 1002, pulsing some or all of the coaxial beams 212a, 212b and the oblique beam 220 at a pulse frequency F. The pulses generated using some or all of the coaxial beams 212a, 212b and the oblique beam 220 may be approximately square (see FIG. 11), i.e., approximations of a square wave, subject to limitations imposed by the frequency response of the light emitter 204 and control electronics of the lighting device 202.

[0049] The method 1000 further includes, at step 1004, capturing video images while some or all of the coaxial beams 212a, 212b and the oblique beam 220 are pulsed. For example, as shown in FIG. 11 , the frame rate at which the video images are captured may be twice the pulse frequency F. In this manner, some video frames are captured while some or all of the coaxial beams 212a, 212b and the oblique beam 220 are pulsed on, and at least some of the video frames are captured while some or all of the coaxial beams 212a, 212b and the oblique beam 220 are pulsed off.

[0050] Method 1000 further includes, in step 1006, performing temporal filtering according to the pulse frequency F. For example, for a given pixel location in the video image, the pixel values ​​at that pixel location of all the video images constitute a time series of values ​​that can be temporally filtered to obtain a filtered pixel value. The filtering can be performed using a digital bandpass filter with a center frequency F. Thus, reflections from illumination sources that are not pulsed at the pulse frequency F are attenuated. Then, in step 1008, the video image including the pixels resulting from the filtering of step 1006 can be output, such as to the display device 224 or a storage device, for subsequent viewing.

[0051] Referring to FIG. 12 , the illustrated method 1200 may use the ability to independently control the color and intensity of each light emitter 204, along with different angles of incidence of beams 212 a, 212 b, 220, to enhance visibility of features of the eye 210. Method 1200 may assume that each light emitter 204 incorporates a polarizer that can induce a particular polarization in the output of each light emitter 204, or at least be able to turn polarization on and off. Similarly, the coaxial illuminator optics 208 and / or optical microscope head 108 a may incorporate a polarizing filter 108 c that is also tunable to a particular polarization angle, or at least be able to turn on and off. Capturing images using different illumination polarizations and polarization filtering may also enable more detailed imaging of the anatomical structures of the eye 210.

[0052] The method 1200 may include modulating some or all of the color, intensity, and polarization of the coaxial beam 212a at a frequency F1 in step 1202, modulating some or all of the color, intensity, and polarization of the coaxial beam 212b at a frequency F2 in step 1204, and modulating some or all of the color, intensity, and polarization of the oblique beam 220 at a frequency F3 in step 1206. Note that steps 1202, 1204, and 1206 may not all be performed. Steps 1202, 1204, and 1206 may be performed simultaneously. The frequencies F1, F2, and F3 may be the same or different from each other. The frequencies F1, F2, and F3 may be higher than the flicker fusion threshold of the human eye 210, for example, at least 60 Hz. The modulation of steps 1202, 1204, and 1206 may include generating approximately square-wave pulses having color, intensity, and / or polarization. The modulations of steps 1202, 1204, and 1206 may be out of phase with one another and may have a duty cycle of less than 50 percent. For example, a first frame of a video may be captured with illumination from only the coaxial beam 212a pulses, a second frame may be captured with illumination from only the coaxial beam 212b pulses, and a third frame may be captured with illumination from only the oblique beam 220 pulses. In other embodiments, pulses of multiple beams 212a, 212b, and 220 are emitted simultaneously. The values ​​of the illumination parameters (color, intensity, polarization) may vary from pulse to pulse for the same beam 212a, 212b, and 220. The values ​​of one or more parameters of the beams 212a, 212b, and 220 may change while other parameters remain constant. For example, the polarization may be modulated, but the color and / or intensity remains constant.

[0053] The method 1200 may include, in step 1208, capturing video images of the eye 210 while illuminating the eye 210 according to some or all of steps 1202, 1204, and 1206. For example, one image may be captured for each pulse of each beam 212a, 212b, 220. Step 1208 may include modulating the polarizing filter 108c. Modulating the polarizing filter 108c may include modulating the polarization angle and / or turning polarization on and off. For example, the polarizing filter 108c may be modulated in synchronization with the pulses of the beams 212a, 212b, 220. For example, during capture of a first frame, the polarizing filter 108c can match the polarization of the coaxial beam 212a that illuminates the eye 210 during capture of the first frame, and during capture of a second frame, the polarizing filter 108c can match the polarization of the second coaxial beam 212b that illuminates the eye 210 during capture of the second frame. This process can be repeated for each pair of successive frames. In some embodiments, during capture of a third frame following the first and second frames, the polarizing filter 108c can match the polarization of the oblique beam 220 that illuminates the eye 210 during capture of the third frame. This process can be repeated for sets of three successive frames.

[0054] Method 1200 may include performing temporal filtering according to some or all of pulse frequencies F1, F2, and F3 at step 1210. Temporal filtering may be performed as described above with respect to step 1006 of method 1000. In some embodiments, the frame rate of digital camera 108b may be much higher than the flicker fusion threshold to allow filtering at multiple frequencies above the flicker fusion threshold.

[0055] The method 1200 may include receiving a selection of an illumination scenario at step 1212. The illumination scenario may include a set of values ​​including some or all of the identifier, polarization angle, color, and intensity of the particular beams 212a, 212b, 220. In response to the selected scenario, the method 1200 may include displaying one or more frames of video images captured for the selected scenario at step 1214. For example, frames captured while illuminating the eye 210 with the first coaxial beam 212a having a first polarization.

[0056] The selection received in step 1212 may be received from the surgeon 106 via the input device 226. The selection received in step 1212 may be part of an automated algorithm. For example, images with different lighting scenarios may be played out in a cyclical sequence so that the visual cortex of the surgeon 106 can integrate the different information provided in images captured under illumination with the different lighting scenarios.

[0057] In a first application of method 1200, a first image of a video image is captured with illumination from the first coaxial beam 212a but not from the second coaxial beam 212b, and a second image of a video image is captured with illumination from the second coaxial beam 212b but not from the first coaxial beam 212a. Due to the different angles of the coaxial beams 212a, 212b, the first image and the second image may provide different perceptions of the eye 210.

[0058] In a second example, the tricolor (red, green, and blue intensity values) of some or all of beams 212a, 212b, 220 varies at frequencies F1, F2, and F3, as defined above. The color variations may span the entire color gamut achievable using light emitter 204 or any portion thereof. The video images may then be electronically filtered based on frequency, as described above. Sets of images for each tricolor, e.g., images from the illumination of each beam 212a, 212b, 220, may be displayed in rapid sequence. For example, ten sets of three images for ten different tricolors may be displayed over a short period of time, such as ten seconds.

[0059] In the claims, any reference signs placed between parentheses shall not be construed as limiting the scope of the claim. The word "comprising" or "including" does not exclude the presence of elements or steps other than those listed in a claim. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In any device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain elements are recited in mutually different dependent claims does not indicate that these elements cannot be used in combination.

[0060] While the description provided above provides details for purposes of illustration based on what are presently considered to be the most practical and preferred embodiments, it should be understood that such details are for that purpose only, and that the present disclosure is not limited to the explicitly disclosed embodiments, but rather is intended to encompass modifications and equivalent arrangements within the spirit and scope of the appended claims. For example, it should be understood that the present disclosure contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claims

1. 1. A system for providing ophthalmic treatment, comprising: a surgical microscope configured to capture an image of the patient's eye and defining an optical axis; an illumination source configured to emit a plurality of beams at the eye of the patient at a plurality of angles relative to the optical axis; a controller coupled to the surgical microscope and the illumination source, the controller configured to independently control a value of an illumination parameter for each beam of the plurality of beams to facilitate imaging of the eye of the patient; A system comprising:

2. The system of claim 1 , wherein the lighting parameters include intensity.

3. The system of claim 1 , wherein the lighting parameters include color.

4. The system of claim 1 , wherein the illumination parameters include polarization.

5. The system of claim 1 , wherein the controller is configured to select the values ​​of the illumination parameters to reduce phototoxicity to the eye of the patient.

6. The system of claim 1 , wherein the controller is configured to select the value of the illumination parameter to increase the red reflex of the patient's eye.

7. The controller: illuminating the eye with a first blue light intensity using the plurality of beams; receiving an image from the surgical microscope; increasing the intensity of blue pixel values ​​of the image to simulate illumination with blue light having a second blue light intensity greater than the first blue light intensity; The system of claim 1 configured to:

8. The controller: processing an image of the patient's eye to determine an iris color of the patient's eye; selecting the values ​​of the lighting parameters to reduce reflections from the iris color; The system of claim 1 configured to:

9. The controller: processing an image of the patient's eye to determine an offset of the pupil relative to the optical axis; selecting the value of the illumination parameter to compensate for the offset of the pupil; The system of claim 1 configured to:

10. 10. The system of claim 9, wherein the plurality of beams includes a first beam and a second beam disposed on opposite sides of the optical axis and offset from the optical axis by less than 4 degrees.

11. 11. The system of claim 10, wherein the controller is configured to select the value of the illumination parameter to compensate for the offset by increasing an intensity of the first beam of the plurality of beams on a side of the pupil where the offset is present and decreasing an intensity of the second beam of the plurality of beams on an opposite side of the pupil where the offset is present.

12. 11. The system of claim 10, wherein the controller is configured to select the values ​​of the illumination parameters to compensate for the offset by increasing a red component of the first beam on a side of the pupil where the offset is located and decreasing a red component of the second beam on an opposite side of the pupil where the offset is located.

13. The system of claim 10 , wherein the first beam and the second beam converge toward each other with increasing distance from the surgical microscope.

14. The system of claim 10, wherein the plurality of beams includes a third beam offset from the optical axis by between 5 and 12 degrees.

15. The controller: modulating the values ​​of the illumination parameters of at least some of the plurality of beams at a modulation frequency; temporally filtering the image received from the surgical microscope using a bandpass filter to obtain a filtered image; outputting the filtered image to a display device; The system of claim 1 configured to:

16. The system of claim 15 , wherein the controller is configured to modulate the values ​​of the illumination parameters of the at least some of the plurality of beams by modulating intensities of the at least some of the plurality of beams.

17. The system of claim 15 , wherein the controller is configured to modulate the values ​​of the illumination parameters of the at least some of the plurality of beams by modulating colors of the at least some of the plurality of beams.

18. 16. The system of claim 15, wherein the controller is configured to modulate the values ​​of the illumination parameters of the at least some of the plurality of beams by modulating polarizations of the at least some of the plurality of beams.

19. The system of claim 1 , wherein the controller is configured to independently control the value of the illumination parameter for each beam of the plurality of beams according to input received from a user.

Images