Direct selective laser trabeculoplasty

Abstract

This application relates to direct selective laser trabeculoplasty. The application relates to a system (20) including a radiation source (48) and a controller (44) configured to display a real-time image sequence of a patient's (22) eye (25), while displaying the image sequence, to irradiate the eye with one or more aiming beams (84) visible in the images, to receive confirmation input from a user after irradiating the eye with the aiming beams, and to treat the eye by irradiating a corresponding target area of ​​the eye with the radiation source using multiple treatment beams in response to receiving the confirmation input. Other embodiments are also described.

Description

[0001] This application is a divisional application of the application filed on July 1, 2019, with application number 201980043641.6 and invention title "Direct Selective Laser Trabeculectomy".

[0002] Cross-reference of related applications

[0003] This application claims the benefit of (i) U.S. Provisional Application No. 62 / 692,868, filed July 2, 2018, entitled “Direct laser selective trabeculoplasty process (DSLT) and Safeties”; (ii) U.S. Provisional Application No. 62 / 739,238, filed September 30, 2018, entitled “Eye tracking flash illumination”; and (iii) U.S. Provisional Application No. 62 / 748,461, filed October 21, 2018, entitled “Crossed ranging beams”. The corresponding disclosure of each of the foregoing references is incorporated herein by reference. Invention Field

[0004] This invention relates to ophthalmic devices and methods for treating glaucoma, ocular hypertension (OHT), and other diseases. background

[0005] In a trabeculoplasty procedure, a radiation source uses one or more therapeutic beams to irradiate the trabecular meshwork in the patient's eye, thereby reducing intraocular pressure.

[0006] Geffen, Noa, et al. described a study in “Transcleral selective laser trabeculoplasty without a gonioscopy lens” (Journal of glaucoma 26.3(2017):201-207) that aimed to investigate the results of selective laser trabeculoplasty (SLT) performed directly on the sclera without a gonioscopy lens.

[0007] Belkin's U.S. Patent Application Publication 2015 / 0366706 (the disclosure of which is incorporated herein by reference) describes an apparatus including a probe and a processor. The probe is positioned adjacent to a patient's eye and configured to illuminate the trabecular meshwork of the eye using one or more light beams. The processor is configured to select one or more target regions of the trabecular meshwork and control the probe to illuminate the selected target regions using light beams. Invention Overview

[0008] According to some embodiments of the present invention, a system including a radiation source and a controller is provided. The controller is configured to display a real-time image sequence of a patient's eye, and while displaying the image sequence, to cause the radiation source to irradiate the eye with one or more aiming beams visible in the images. The controller is also configured to receive confirmation input from a user after the radiation source has irradiated the eye with the aiming beams, and in response to receiving the confirmation input, to treat the eye by causing the radiation source to irradiate a corresponding target area of ​​the eye with multiple treatment beams.

[0009] In some embodiments, the system further includes:

[0010] Focusing lens; and

[0011] One or more beam guiding elements,

[0012] The controller is configured to irradiate the eye with the therapeutic beam by passing it through a focusing lens toward a beam guiding element, such that the beam is focused by the focusing lens before being guided toward a corresponding target area by the beam guiding element.

[0013] In some embodiments, the aiming beam is impinged on at least a portion of each of the target areas.

[0014] In some embodiments, the controller is also configured to overlay a marker that passes through each of the target regions onto each of the images.

[0015] In some embodiments, the marker is oval.

[0016] In some embodiments, at least a portion of each of the target regions is located within 1 mm of the limbus of the eye.

[0017] In some embodiments, the controller is further configured to:

[0018] Overlay markers on each element in the image, and

[0019] Before treating the eye, the image is processed to verify the correct positioning of the aiming beam relative to the marker.

[0020] The controller is configured to treat the eye in response to verifying the positioning of the aiming beam.

[0021] In some embodiments, the controller is configured to verify the positioning of the aiming beam by verifying that the aiming beam overlaps with the marker.

[0022] In some embodiments, the controller is configured to verify the positioning of the aiming beam by verifying that the aiming beam is outside the mark.

[0023] In some embodiments, the controller is configured to treat the eye such that the corresponding edge of the treatment beam enters the corresponding portion of the eye on which a mark is superimposed.

[0024] In some embodiments, the marker is oval.

[0025] In some embodiments, the controller is further configured to:

[0026] Display a still image of the eye before displaying the live image.

[0027] Based on user input, the elliptical portion of the eye is identified in a still image, and

[0028] In response to identifying the elliptical portion of the eye, an elliptical marker is overlaid on the elliptical portion of the eye in each of the images.

[0029] In some embodiments, the controller is configured to overlay an oval marker onto the oval portion of the eye in the following manner:

[0030] After identifying the elliptical portion of the eye, the offset from the center of the corneal limbus to the center of the elliptical portion is identified in the still image, and

[0031] For each image in the image:

[0032] Identify the limbus center in the image, and

[0033] An elliptical marker is superimposed on the image so that the center of the elliptical marker is located at the identified offset from the center of the limbus.

[0034] In some embodiments, the controller is configured to recognize the oval portion of the eye in the following manner:

[0035] Display (i) the elliptical marker and (ii) the rectangle circumscribed by the elliptical marker on the still image, and

[0036] After displaying the elliptical marker and the rectangle, in response to the user adjusting the rectangle, the elliptical marker is adjusted so that the elliptical marker remains bounded by the rectangle until the elliptical marker is superimposed on part of the eye.

[0037] In some embodiments, the controller is also configured to identify the limbus of the eye in a still image, and the controller is configured to display an oval mark on the limbus.

[0038] In some embodiments, the system further includes a camera configured to:

[0039] Acquire images, and

[0040] Before acquiring the image, acquire a still image of the eye.

[0041] Furthermore, the controller is configured to:

[0042] Based on still images of the eye, identify static regions, including the pupil of the eye, within the camera's field of view, and

[0043] The eye is treated by ensuring that each of the treatment beams enters the eye outside the static area.

[0044] In some embodiments, the system further includes one or more beam guiding elements.

[0045] The controller is configured to treat the eye by sequentially aiming the beam guiding element at the target area and emitting a therapeutic beam at the beam guiding element.

[0046] The controller is also configured to prevent the beam guiding element from being aimed at static areas, even when no therapeutic beam is being emitted.

[0047] In some embodiments, the controller is configured to identify static regions in the following manner:

[0048] The user receives limbal localization input indicating the location of the limbus in a still image, and

[0049] Static regions are identified based on the location of the limbus.

[0050] In some embodiments,

[0051] The image is the first image, and the aiming beam is the first aiming beam.

[0052] The system also includes a camera configured to acquire multiple second images of the eye while treating it, and

[0053] The controller is configured to treat the eyes by repeatedly performing the following operations:

[0054] Verify the positioning of the corresponding second aiming beam in the second image, and

[0055] In response to this verification, a corresponding therapeutic beam from the therapeutic beams is emitted toward the eye.

[0056] In some embodiments, the controller is configured to verify positioning by verifying that the distance between the second aiming beam and a corresponding one in the target area is less than a predetermined threshold.

[0057] In some embodiments, the controller is configured to emit a corresponding therapeutic beam into a corresponding one of the therapeutic beams in the target area.

[0058] In some embodiments, the system further includes a lighting source, and the controller is further configured to cause the lighting source to intermittently flash visible light toward the eye, such that the light illuminates the eye at least during the respective acquisition of the second image.

[0059] In some embodiments, the peak average intensity of light during the duration of each flash is 0.003 mW / cm². 2 and 3mW / cm 2 between.

[0060] In some embodiments, the controller is configured to cause the lighting source to flicker at a frequency of at least 60 Hz.

[0061] In some embodiments, the frequency is at least 100 Hz.

[0062] In some embodiments, the system further includes an illumination source, and the controller is also configured to illuminate the eye with near-infrared light at least during the corresponding acquisition of the second image.

[0063] In some embodiments, the controller is also configured to cause the lighting source to intermittently flash visible light to the eyes while treating the eyes.

[0064] In some embodiments, the system further includes an optical unit that includes a radiation source and a plurality of beam emitters.

[0065] Furthermore, the controller is configured to illuminate the eye with multiple ranging beams by the beam emitter before the radiation source illuminates the eye with the aiming beam. These ranging beams are shaped into different corresponding portions of a predetermined combination pattern, such that the predetermined combination pattern is formed on the eye only when the optical unit is at a predetermined distance from the eye.

[0066] In some embodiments, the ranging beam is shaped to define two vertical shapes, and a predetermined combination pattern includes a cross.

[0067] In some embodiments, the system further includes an optical unit that includes a radiation source, and the controller is configured to cause the radiation source to illuminate a target area when the optical unit is tilted upward toward the eye and the eye is tilted downward toward the optical unit.

[0068] In some embodiments, the system further includes a wedge, and the optical unit is tilted upward toward the eye by being mounted on the wedge.

[0069] According to some embodiments of the present invention, a system is also provided, the system comprising a wedge; an optical unit mounted on the wedge such that the optical unit is tilted upward, the optical unit including a radiation source; and a controller. The controller is configured to treat a patient's eye by irradiating a corresponding target area of ​​the eye with a plurality of therapeutic beams while the eye is tilted downward toward the optical unit.

[0070] According to some embodiments of the present invention, a method is also provided, comprising displaying a real-time image sequence of a patient's eye. The method further comprises, while displaying the image sequence, irradiating the eye with one or more aiming beams visible in the images. The method further comprises, after irradiating the eye with the aiming beams, receiving confirmation input from a user, and, in response to receiving the confirmation input, treating the eye by irradiating corresponding target areas of the eye with multiple treatment beams.

[0071] The invention will be more fully understood from the following detailed description of embodiments of the invention taken in conjunction with the accompanying drawings, in which: Brief description of the attached diagram

[0072] Figure 1 This is a schematic diagram of a system for performing trabeculoplasty according to some embodiments of the present invention;

[0073] Figure 2 This is a schematic diagram of a trabeculoplasty apparatus according to some embodiments of the present invention;

[0074] Figure 3 This is a schematic diagram of a pre-treatment procedure according to some embodiments of the present invention; and

[0075] Figure 4 This is a schematic diagram of an example algorithm for performing an automated trabeculectomy procedure according to some embodiments of the present invention.

[0076] Detailed description of the embodiments

[0077] Overview

[0078] Embodiments of the present invention provide an automated trabeculoplasty device configured to safely and effectively perform trabeculoplasty procedures on the eye. The trabeculoplasty device includes a controller and an optical unit comprising a radiation source, a camera, and a beam guiding element. As described in detail below, the controller is configured to control the radiation source and the beam guiding element in response to feedback from the camera, such that the beam guiding element guides a radiation beam emitted by the radiation source toward a suitable location on the eye. The emitted radiation beam includes both a treatment beam that irradiates the trabecular meshwork of the eye and a targeting beam to aid in aiming the treatment beam.

[0079] Typically, before the procedure, the controller displays a live video of the eye, with two ellipses superimposed on it: an inner ellipse marking the limbus of the cornea; and an outer ellipse offset from the inner ellipse by a small distance, passing through or near each of the target areas to be irradiated by the treatment beam. The controller also simulates the procedure by sweeping the aiming beam across the outer ellipse, typically causing the aiming beam to penetrate at least a portion of each target area. Advantageously, this simulation helps the physician visualize the path along the eye to which the treatment beam is aimed, i.e., the path where the target areas are located. After the physician confirms the aimed path along the eye, the controller directs the radiation source to fire the treatment beam at the target areas.

[0080] It is important to note that since each radiating beam typically enters the eye with a non-infinitely small spot size, this application generally describes each beam as an "area" (whose area is a function of the spot size) that enters the eye, rather than a "point" that enters the eye. Therefore, for example, this application refers to a "target area," not a "target point." However, in the context of this application (including the claims), mentioning the calculation of the location of a target area may refer to implicitly calculating the location of the area by calculating the location of a single point within the area (such as the center or edge of the beam, which is the point at the center or edge of the area it is aiming at). (Even if the center or edge of the beam subsequently deviates slightly from the calculated point, this application (including the claims) can assume that the beam has entered the calculated target area.)

[0081] Typically, before simulating the procedure described above, the controller acquires a still image of the eye and identifies the limbus in the still image. The controller then overlays the aforementioned inner ellipse onto the limbus. Subsequently, the controller allows the physician to modify the positioning and / or shape of the inner ellipse so that it conforms to the physician's defined limbus markings. (Since the limbus is often not very clearly defined, the physician-defined limbus position may differ slightly from the position automatically identified by the controller.) For example, the controller may circumscribe a rectangle around the inner ellipse, allowing the physician to adjust the ellipse by dragging the sides or corners of the circumscribed rectangle.

[0082] As the inventors have observed, the trabecular meshwork is most effectively irradiated when the treatment beam enters the eye at or near the limbus (which can be identified by the user or automatically by the controller as described above). Therefore, in some embodiments of the invention, the controller directs the radiation source toward the limbus or a portion of the eye near the limbus. For example, at least a portion of each target region may be located within 1 mm (e.g., within 400 micrometers) of the limbus. As a specific example above, the center of each target region may be located within 1 mm (e.g., within 400 micrometers) of the limbus, such that the center of each treatment beam enters the eye within 1 mm (e.g., within 400 micrometers) of the limbus.

[0083] During both the simulated and actual treatment, the camera acquires images of the eye at relatively high frequencies (e.g., frequencies greater than 40 Hz or 50 Hz), and the controller tracks eye movement by identifying the center of the limbus in each acquired image. In response to identifying the center of the limbus, during the simulated treatment, the controller can move the inner and outer ellipses such that the inner ellipse remains positioned on the physician-defined limbus, and the outer ellipse maintains a constant distance from the inner ellipse, even as the eye moves. Similarly, during the procedure, the controller can calculate the center or edge of each target region by adding an appropriate (x,y) offset to the identified limbus center. Advantageously, due to this feedback process, the safety and effectiveness of the procedure are greatly improved.

[0084] Furthermore, as an additional safety measure, the controller can define an area in the aforementioned still image, referred to herein as the "forbidden zone." The forbidden zone includes the pupil of the eye, typically along with a portion of the eye surrounding the pupil. The forbidden zone is static because it is defined by the camera's field of view (FOV) and is not adjusted even in response to detected eye movement. The controller thus prevents any of the therapeutic beams from hitting the forbidden zone. Moreover, even when the radiation source is inactive, the controller prevents the beam guiding element from aiming at the forbidden zone. Therefore, the retina of the eye is protected from any potential (though unlikely) stray beams of light.

[0085] In some embodiments, the trabeculoplasty device further includes a visible light source, and the controller is configured to cause the visible light source to flash visible light toward the eye, such that the visible light is on at least during the acquisition of each image. Advantageously, the flashing of light reduces the time required to acquire images, ensuring that the location of the target area calculated in response to the image does not significantly shift before the aiming beam or treatment beam is fired onto the target area. Furthermore, the flashing causes the pupil of the eye to constrict, thus also protecting the retina from any potential stray beams.

[0086] Typically, this light flashes at a sufficiently high frequency and / or each light pulse has a sufficiently long duration, making the flashing imperceptible to the patient. However, the total energy of this flashing light is low enough that it does not damage the retina.

[0087] Alternatively, to reduce the time required for image acquisition without causing patient discomfort, near-infrared light can be used to illuminate the eyes. Furthermore, optionally, visible light can be flashed at the eyes so that it is on during and / or between image acquisitions.

[0088] Embodiments of the present invention also provide a technique that helps position a trabeculoplasty device at the correct distance (or "range") from the eye. Typically, this type of positioning is achieved by aiming two circular ranging beams from the device at the eye and moving the device toward or away from the eye until the two beams overlap. However, as the inventors have observed, this technique can be difficult to use to position the trabeculoplasty device for various reasons; for example, the sclera is covered by the conjunctiva, which can distort and reflect the ranging beams, making it difficult to discern whether the beams overlap. Therefore, in embodiments of the present invention, the ranging beams are given different corresponding shapes such that the beams form a specific pattern only when the trabeculoplasty device is located at the correct distance from the eye. For example, the ranging beams can be shaped into a vertical ellipse such that the ranging beams form a cross shape on the eye only at the correct range.

[0089] In some embodiments, to reduce obstruction of the sclera by the upper eyelid, the optical unit of the trabeculoplasty device is mounted on a wedge, causing the camera and radiation source to be tilted upwards. The patient's line of sight is then tilted downwards toward the optical unit, exposing the upper portion of the patient's sclera.

[0090] Although this specification primarily relates to trabeculoplasty procedures, the techniques described herein can also be applied to automated photocoagulation procedures, iridotomy procedures, capsulotomy procedures, lens extraction, or any other related ophthalmic procedures. Targets of radiation may include the trabecular meshwork and / or any other suitable portion of the eye, such as endothelial stem cells of the eye or scleral venous sinus cells. Embodiments of the invention can be used to treat glaucoma, ocular hypertension (OHT), and other conditions.

[0091] System Description

[0092] First refer to Figure 1 This is a schematic diagram of a system 20 according to some embodiments of the present invention, the system 20 including a trabeculoplasty apparatus 21 for performing trabeculoplasty. Further reference... Figure 2 This is a schematic diagram of a trabeculectomy apparatus 21 according to some embodiments of the present invention.

[0093] The trabeculoplasty device 21 includes an optical unit 30. The optical unit 30 includes a radiation source 48 configured to illuminate the eye 25 of the patient 22 using the aiming beam and treatment beam described herein. The optical unit 30 also includes one or more beam guiding elements, including, for example, one or more galvo mirrors 50 (collectively referred to as “galvo scanners”) and / or beam combiners 56. Before emitting each beam 52 from the radiation source 48, or while emitting the beam, the controller 44 aims the beam guiding elements at a desired target area on the eye 25, such that the beam is guided toward the target area by the beam guiding elements. For example, the beam may be deflected by the galvo mirror 50 toward the beam combiner 56, which may then deflect the beam through an aperture 58 at the front of the optical unit, such that the beam enters the target area. Each beam emitted by the radiation source may have an elliptical (e.g., circular) shape, a square shape, or any other suitable shape.

[0094] Typically, the radiation source comprises two lasers: one for emitting the aiming beam described herein, and the other for emitting the therapeutic beam described herein. As an illustrative example only, the therapeutic laser may include Ekspla... TM The NL204-0.5K-SH laser (e.g., modified to include an attenuator, energy meter, and mechanical shutter), while the aiming laser may include LaserComponents. TM FP-D-635-1DI-CF laser. Typically, both the aiming beam and the treatment beam include visible light.

[0095] As an alternative to or complement to a laser, a radiation source may include any other suitable emitter configured to emit radiation belonging to any suitable portion of the electromagnetic spectrum, including, for example, microwave radiation, infrared radiation, X-ray radiation, gamma radiation, or ultraviolet radiation.

[0096] In some embodiments, each beam 52 passes through a beam expander (not shown) that expands and then re-collimates the beam before it reaches the scanning galvanometer. In such embodiments, the optical unit 30 typically includes an F-theta lens 51, which is configured to subsequently focus each beam in the direction of the beam by the scanning galvanometer.

[0097] In other embodiments, a focusing lens is disposed between the radiation source and the scanning galvanometer; for example, the beam expander described above may include a focusing lens instead of a collimating lens, or the optical unit may include a focusing lens in addition to the beam expander. In such embodiments, each beam is focused by the focusing lens before being guided by the beam guiding element, making a flat focusing lens 51 unnecessary.

[0098] The optical unit 30 also includes a camera 54. Before and during the procedure, the camera 54 typically acquires multiple images of the patient's eyes at a relatively high frequency. The controller 44 processes these images and, in response, controls the radiation source 48 and the beam guiding elements, as referenced below. Figures 3 to 4 As described. Figure 2 As shown, camera 54 can be positioned behind beam combiner 56 so that the camera receives light via beam combiner.

[0099] Typically, the optical unit 30 also includes an illumination source 60, which includes, for example, one or more light-emitting diodes (LEDs), such as a ring of LEDs surrounding the aperture 58. In such embodiments, the controller 44 can cause the illumination source 60 to flash light intermittently toward the eye, as referenced below. Figure 4 Further description. (For ease of explanation, in...) Figure 2 The connection between controller 44 and lighting source 60 is not explicitly shown.

[0100] Optical unit 30 is mounted on XYZ platform 32, which is controlled by control mechanism 36 such as a joystick. Using control mechanism 36, a user of system 20 (such as an ophthalmologist or another doctor) can position the optical unit in the appropriate location before treating the patient's eye. In some embodiments, XYZ platform 32 includes locking elements configured to prevent platform movement after positioning.

[0101] In some embodiments, the XYZ platform 32 includes one or more motors, and a control mechanism 36 is connected to an interface circuit 46. When a user manipulates the control mechanism, the interface circuit 46 converts the activity into appropriate electronic signals and outputs these signals to a controller 44. In response to these signals, the controller controls the motors of the XYZ stage. In other embodiments, the XYZ platform 32 is manually controlled by manipulating the control mechanism.

[0102] Typically, before the radiation source emits any beam of light towards the eye, the user uses control mechanism 36 to position the optical unit at a predetermined distance D from the eye. To aid in this positioning, the optical unit may include a plurality of beam emitters 62 (including, for example, corresponding laser diodes) configured to illuminate the eye with a plurality of ranging beams 64, for example, such that the angle between the beams is between 30 degrees and 100 degrees. See below for reference. Figure 3 Further described, the ranging beam 64 is shaped into different corresponding portions defining a predetermined combined pattern, such that the predetermined combined pattern is formed on the eye only when the optical unit is at a predetermined distance from the eye. Therefore, in response to observing the combined pattern, the user can determine that the optical unit is at a predetermined distance.

[0103] System 20 also includes a headrest 24, which is mounted on a horizontal surface 38, such as a tray or tabletop. The headrest 24 includes a forehead support 26 and a chin support 28. During the trabeculoplasty procedure, the patient 22 presses his forehead against the forehead support 26 while placing his chin on the chin support 28.

[0104] In some embodiments, the headrest 24 further includes a securing strap 27 configured to secure the patient's head from behind, thereby keeping the patient's head pressed against the headrest. The securing strap 27 may comprise a single segment of the headrest extending from one side of the head and configured to fasten to the headrest at the opposite side of the head, or may comprise two segments extending from opposite sides of the head and configured to fasten to each other behind the head. Optionally, the securing strap may include a sensor configured to detect when the securing strap is properly tightened. For example, tightening the securing strap may cause a circuit to close, and the sensor may then detect the current flow through the circuit and generate an output in response (e.g., by illuminating an LED).

[0105] In some embodiments, the headrest 24 further includes one or more sensors, which may be disposed, for example, on the forehead rest or chin rest. Each of these sensors may be configured to generate an output indicating whether the patient's head is resting on the headrest as desired. Examples of suitable sensors include capacitive sensors, resistive inductors, and piezoelectric sensors. Alternatively or additionally, the headrest may include one or more switches or force-sensitive resistors, such as Sparkfun. TM 9375.

[0106] In some embodiments, a physical block is placed around the eyes to contain any radiation reflected from them. For example, a cover may be placed on the chin rest and / or on the patient's head. Alternatively or additionally, the cover may be coupled to a face of device 21.

[0107] In some embodiments, device 21 further includes a base unit 34 mounted on surface 38, and XYZ platform 32 mounted on base unit 34. In such embodiments, controller 44 and interface circuitry 46 may be disposed within the base unit. In other embodiments, XYZ platform is mounted directly on surface 38.

[0108] Usually, such as Figure 1As shown, when illuminating the patient's eye, the optical unit is tilted upwards and directed toward the eye, while the eye tilts downwards to gaze at the optical unit; that is, the optical path 23 between the eye and the optical unit is tilted rather than horizontal. For example, the optical path 23 can be oriented at an angle θ between five and twenty degrees. Advantageously, this orientation reduces obstruction of the patient's eye by the upper eyelid and associated anatomical structures. Optionally, to provide additional exposure to the eye, one or both of the eyelids can be retracted using a finger, speculum, or another tool.

[0109] In some embodiments, such as Figure 1 As shown, the tilting orientation of the optical path is achieved by mounting the optical unit on a wedge 40, which is mounted on the XYZ stage. In other words, the optical unit is mounted on the XYZ stage via the wedge 40.

[0110] As an alternative to or supplement to the use of wedge 40, the tilting orientation of the optical path can be achieved by tilting the patient's head backward. For example, the forehead rest 26 and / or chin rest 28 may include adjustable-length straps, and the patient's head can be tilted backward by adjusting the length of the straps. (For example, the forehead strap can be tightened.) To facilitate this adjustment, the adjustable-length strap may include a worm gear actuator, hook and loop fastener, snap, locking pin, knot, and / or any other suitable mechanism.

[0111] In other embodiments, for example, by angled headrest 24 (or at least chin rest 28) toward the optical unit, the patient’s head is tilted slightly forward, so that the patient’s head rests more securely on the headrest.

[0112] System 20 also includes a monitor 42, which is configured to display an image of the eye acquired by a camera, as shown in the following reference. Figure 3 Detailed description. Monitor 42 can be placed in any suitable location, such as on surface 38 next to device 21. In some embodiments, monitor 42 includes a touchscreen, and the user inputs commands to the system via the touchscreen. Alternatively or additionally, system 20 may include any other suitable input device that can be used by the user, such as a keyboard or mouse.

[0113] In some embodiments, the monitor 42 is directly connected to the controller 44 via a wired or wireless communication interface. In other embodiments, the monitor 42 is connected to the controller 44 via an external processor, such as a processor belonging to a standard desktop computer.

[0114] It needs to be emphasized that, Figure 2 The configuration shown is provided as an example only. Furthermore, as... Figure 2As an alternative or supplement to the components shown, device 21 may include any suitable components. For example, the device may include an additional light source, such as an LED, which the patient can look at during the procedure. Such a light source may, for example, be placed near aperture 58 or next to the camera.

[0115] In some embodiments, at least some of the functions of the controller 44 as described herein are implemented in hardware, for example, using one or more application-specific integrated circuits (ASICs) or field-programmable gate arrays (FPGAs). Alternatively or additionally, the controller 44 may perform at least some of the functions described herein by executing software and / or firmware code. For example, the controller 44 may include a central processing unit (CPU) and random access memory (RAM). Program code comprising software programs and / or data may be loaded into RAM for execution and processing by the CPU. The program code and / or data may be downloaded to the controller electronically, for example, via a network. Alternatively or additionally, the program code and / or data may be provided and / or stored on a non-transitory tangible medium, such as magnetic, optical, or electronic memory. Such program code and / or data, when provided to the controller, create a machine or dedicated computer configured to perform the tasks described herein.

[0116] In some embodiments, the controller includes a system-on-module (SOM), such as Variste. TM DART-MX8M.

[0117] In some embodiments, the controller 44 is located external to the device 21. Alternatively, the controller may cooperate with another external processor to perform at least some of the functions described herein.

[0118] Pre-treatment procedures

[0119] Now for reference Figure 3 This is a schematic diagram of a pre-treatment procedure according to some embodiments of the present invention.

[0120] Through the introduction, Figure 3 The procedure shown consists of three steps, referred to as steps A through C in the diagram. For each of these steps, Figure 3 An image of eye 25 is shown, which is captured by camera 54. Figure 2 ) is obtained and controlled by controller 44 Figure 2 The images are displayed on monitor 42. Typically, a graphical user interface (GUI) 68 is also displayed on monitor 42 next to each image. GUI 68 may include text boxes containing relevant alphanumeric data and / or user instructions, buttons for confirming or rejecting a specific treatment plan, and / or any other relevant widgets.

[0121] In step A, the user places the optical unit 30 ( Figure 2 The optical unit is positioned so that the center of the eye is approximately at the center of the camera's field of view (FOV). The user also positions the optical unit at the correct distance from the eye so that the treatment beam has an appropriate spot size on the eye. (See above reference.) Figure 2 As described, this positioning is typically aided by a ranging beam 64, which is shaped to define different corresponding portions of a predetermined combined pattern 66, such that the pattern 66 is formed on the eye only when the optical unit is at the correct distance. Typically, the user forms the combined pattern on the sclera of the eye near the limbus. (Typically, the controller displays a sequence of real-time images of the patient's eye while adjusting the positioning of the optical unit.)

[0122] For example, such as Figure 3 As shown, the ranging beam can be shaped to define two perpendicular shapes, such as two perpendicular ellipses, rectangles, or straight lines, which only form a cross shape on the eye when the optical element is at the correct distance. Alternatively, the ranging beam can be shaped to define two arcs or semicircles forming a circle, or two triangles or arrows forming a rhombus or X shape. Any suitable optical element, such as a diffractive optical element (DOE), a hologram, or an axonometric prism, can be used to help generate these patterns.

[0123] In other embodiments, only a single ranging beam is emitted, and a computer-generated pattern is superimposed on the image of the eye. When the optical unit is at the correct distance, the ranging beam and the computer-generated pattern overlap or form a combined pattern 66.

[0124] In response to observing pattern 66, the user instructs the controller to indicate the correct distance between the optical unit and the eye. For example, the user can click the appropriate button on GUI 68. In response to this input, the controller proceeds to step B of the pre-treatment procedure.

[0125] In step B, the controller displays a still image 71 of the eye. Subsequently, based on input from the user, the controller identifies elliptical (e.g., circular or nearly circular) portions of the eye, such as the limbus 69. For example, the controller may identify a portion of the eye in response to the user overlaying an elliptical marker 78 onto it. The location of the marker 78 can then be used to calculate the corresponding location of the treatment beam target area, as further described below.

[0126] For example, the controller may display a marker 78 and a rectangle 80 surrounding (or “enclosing”) the marker on a still image. The user can then adjust the rectangle 80, for example, by dragging its sides or corners using a mouse or touchscreen. (In some embodiments, the system allows the user to switch between coarse and fine adjustment of the rectangle.) In response to the user adjusting the rectangle, the controller may adjust the marker 78 such that the marker remains circumscribed by the rectangle until the marker is superimposed on the user-defined limbus (or another part of the eye). The user can then (e.g., via GUI 68) instruct the controller that the marker is superimposed on the user-defined limbus.

[0127] In some embodiments, the controller superimposes two horizontal lines tangent to the top and bottom extremities of marker 78 and two vertical lines tangent to the left and right ends of marker 78, respectively, without requiring the lines to intersect each other, thereby defining a rectangle. In such embodiments, the user can adjust marker 78 by dragging the lines.

[0128] Typically, before allowing the user to adjust the marker 78, the controller uses an edge detection algorithm or any other suitable image processing technique to identify the limbus in a still image and then displays the marker 78 on the limbus. (Note that the controller can approximate the shape of the limbus with any suitable shape, such as an ellipse aligned with the vertical and horizontal axes or rotated at any suitable angle.) Advantageously, by initializing the placement of the marker 78 in this way, the time required to adjust the marker is reduced. (Since the limbus is generally not a well-defined feature, the location of the limbus identified by the user is usually slightly different from the location of the limbus initially identified by the controller; therefore, as described above, the user is allowed to adjust the marker.)

[0129] As an alternative to or supplement to the adjustment rectangle, the user can directly adjust the marker 78 by inputting relevant parameters. For example, for an elliptical (e.g., circular) marker, the user can input the coordinates of the marker's center and one or both of the marker's diameters. Alternatively, the user can adjust the marker by adjusting the inputs to the limbus recognition algorithm executed by the controller (such as a threshold for edge detection). As another option, the user can directly manipulate the marker 78.

[0130] In an alternative embodiment, marker 78 is not shown at all. In this embodiment, if the marker is shown, the user can indicate the location of the limbus by dragging a rectangle or line that surrounds the marker. As another alternative, for greater accuracy, a non-elliptical marker of another shape that more precisely corresponds to the shape of the limbus 69 can be used instead of the elliptical marker 78.

[0131] Typically, during execution Figure 3Prior to the pre-treatment procedure shown, the user (using GUI 68 or any other suitable input interface) specifies the corresponding locations of several target areas relative to the portion of the eye to be identified in step B. Alternatively, these parameters can be predefined before the user uses the system.

[0132] For example, a user can specify an elliptical path for target regions adjacent to the limbus by specifying the number of target regions and the distance from (or from) the limbus where the center or edge of each target region is located. Alternatively, a user can specify one or more arcuate paths by specifying, in addition to the parameters described above, the following parameters: (i) the angular span of each arc and (ii) the position of each arc. (For example, a user can specify 180 degrees around the lower or upper half of the limbus, or 90 degrees at the upper and lower halves respectively.) Given this input, and given the position of the limbus as indicated by the user, the controller calculates the corresponding positioning of the target region, typically relative to the center of the limbus as identified by the controller. (In some embodiments, the controller calculates the positioning of the ellipse or arc specified by the user, but does not calculate the specific positioning of the target region on the ellipse or arc until step C described below is performed.)

[0133] As a purely illustrative example, the user can specify a distance d1 between the center or edge of each target region and the user-marked limbus, with different corresponding angles θi relative to the limbus center. The user can then adjust marker 78 during step B such that the center of the marker is located at (x0 + Δx, y0 + Δy), where (x0, y0) is the limbus center identified by the controller. In this case, assuming marker 78 is a circle of radius R, the controller can calculate the offset from the limbus center of each target region's center or edge as (Δx + (R + d1)cos(θi)). i ), △y+(R+d1)sin(θ i (Note that d1 can be zero, meaning that the center or edge of each target area can coincide with the user-marked limbus, such that the corresponding center or edge of the treatment beam (respectively) enters the limbus as marked by the user.) Subsequently, during this procedure, refer to the following... Figure 4 Furthermore, the controller can track the center of the limbus and, for each target area, calculate the location of the area by adding this offset to the location of the center.

[0134] Typically, in step B, the controller also identifies a static region 76 (also referred to herein as a “no-go zone”) within the field of view (FOV) of the still image camera, which includes the pupil 74 of the eye, typically along with a “buffer zone” comprising a large portion of the cornea 72 of the eye surrounding the pupil 74. The size of the buffer zone is typically set based on the maximum expected movement of the eye.

[0135] In some embodiments, region 76 is identified based on the location of the limbus, either automatically identified by the controller or marked by the user. For example, the controller may identify region 76 as the set of all points within the field of view (FOV) located inside the limbus at a distance greater than a predetermined distance from the limbus. Alternatively, for example, the controller may identify a point at the center of the limbus or the center of the pupil and then center region 76 around that center point. In such embodiments, region 76 may have any suitable shape, such as ellipse or rectangle, and may have any suitable size. Reference is made below. Figure 4 Describe the importance of region 76. (Note that region 76 does not need to be displayed on monitor 42.)

[0136] Following step B, the controller proceeds to step C, where the trabeculectomy procedure is simulated. In response to viewing the simulation, the user can provide confirmation input to the controller, for example, by clicking an appropriate button (such as the "Start" button) in the GUI 68. This input confirms that the controller should continue the procedure.

[0137] More specifically, in step C, the controller displays a real-time image sequence of the eye (i.e., real-time video), and simultaneously illuminates the eye with one or more aiming beams 84, which are visible in the images. Typically, the aiming beams are red; for example, the wavelength of each aiming beam may be between 620 nm and 650 nm. In some embodiments, the color of the aiming beam is different from the color of the treatment beam; for example, although the aiming beam may be red, the treatment beam may be green, for example, with a wavelength between 515 nm and 545 nm (e.g., 532 nm).

[0138] When the aiming beam is directed at the eye, the controller controls the beam guiding element so that if a therapeutic beam is to be emitted, it will be directed at the calculated target area. Therefore, the corresponding center of the aiming beam can sequentially coincide with the center of each target area. Alternatively, if a plan-field focusing lens 51 is used... Figure 2 Furthermore, if the color of the aiming beam differs from the color of the treatment beam, the chromatic aberration introduced by the flat-field focusing lens may cause a slight offset between the aiming beam and the target area. However, even in this case, the aiming beam will typically penetrate at least a portion of each target area.

[0139] In some embodiments, the controller scans along the eye across a single aiming beam, such that the aiming beam enters at least a portion of each target region. In other embodiments, the controller fires multiple aiming beams, such that each aiming beam enters at least a portion of a different corresponding target region.

[0140] Typically, during simulation, the controller overlays marker 78 onto the portion of the eye identified in step B. To compensate for any eye movement, the controller typically identifies the limbal center in each image and places marker 78 at an appropriate offset from the limbus. For example, if the final location (step B) of the center of marker 78 in a still image is (x0 + Δx, y0 + Δy), the controller may place marker 78 at a position offset (Δx, Δy) from the limbal center in each of the live images.

[0141] As an alternative to or supplement to the overlay mark 78, the controller may overlay another mark 82 on each of the target regions in the image, passing through each target region (e.g., through its center) or close to each target region. The positioning of the mark 82 can be adjusted in response to eye movement by maintaining it at an appropriate offset from the mark 78. For example, if the distance between the center of each target region and the limbus marked by the user is d1, the mark 82 may maintain a distance of d1 from the mark 78. In some embodiments, the color of the mark 82 is different from the color of the mark 78.

[0142] Typically, during simulation, the controller verifies that each of the aiming beams is correctly guided by the beam guiding element. For example, the controller may process feedback signals from the encoder used for galvanometer 50. Alternatively or additionally, the controller may verify the relative positioning of the aiming beams with respect to markers 78, 82, and / or any other suitable markers superimposed on each in the image by processing the image. For example, the controller may verify that each aiming beam (e.g., the center of each aiming beam) overlaps with marker 82, and / or that the edge of each aiming beam contacts marker 78. (In the context of this application, including the claims, this may be based on knife-edge measurement, 1 / e...) 2 Width measurement, full width at half maximum (FWHM) measurement, or any other suitable measurement to define the “edge” of the beam. As another example, the controller can verify that the center or edge of each aimed beam is positioned at the appropriate distance from mark 78.

[0143] In response to verifying the positioning of the aiming beam, if the user provides the aforementioned confirmation input, the controller can continue the trabeculoplasty procedure.

[0144] In some embodiments, treatment is aborted if the user does not confirm the simulation. In other embodiments, the user can adjust the path followed by the aiming beam (e.g., via GUI 68). This adjustment can be performed by returning to step B and adjusting marker 78, and / or by adjusting the distance from marker 78 where each target region is located. In such embodiments, the simulation can be repeated for each new path defined by the user until the user confirms the path.

[0145] Treatment Procedure

[0146] In response to receiving the aforementioned confirmation input from the user, the controller treats the eye by irradiating the target area with a corresponding therapeutic beam. The peak power of the therapeutic beam is much higher than that of the aiming beam. Furthermore, the wavelength of the therapeutic beam is generally more suitable for treating the trabecular meshwork of the eye compared to the wavelength of the aiming beam.

[0147] More specifically, during treatment, the controller continues to scan the target area with the aiming beam while acquiring an image of the eye, or fires a corresponding aiming beam towards the target area. See below for reference. Figure 4 Further described, the controller verifies the positioning of the aiming beam in each of the images and, in response, fires a therapeutic beam toward the eye. For example, the controller may fire the therapeutic beam toward the target area or the next target area into which the aiming beam enters.

[0148] Typically, the controller directs each of the treatment beams into the eye outside of zone 76. Figure 3 This area 76 is also referred to herein as the "restricted area." (As mentioned above, area 76 is static because it is defined according to the camera's field of view (FOV) and therefore does not move with the eye.) Furthermore, as an additional precaution, the controller may prevent the beam guiding element from aiming at (i.e., "traveling through") area 76 even when no therapeutic beam is being fired. (Typically, the controller also takes these precautions when firing the aiming beam during the pre-treatment procedure.)

[0149] Typically, when acquiring each image during a treatment procedure, the controller activates the illumination source 60 ( Figure 2 Flashing visible light (e.g., white, red, or green light) towards the eyes. This flashing can reduce the required exposure time for the camera by, for example, three times or more; thus, for example, the required exposure time can be reduced from 9 ms to 3 ms. Each flash can begin before image acquisition and / or end after image acquisition. Typically, the peak average intensity over the duration of each flash is 0.003 mW / cm². 2 Up to 3mW / cm 2 This is usually high enough to reduce the required camera exposure time and constrict the pupil of the eye without harming the patient.

[0150] Typically, the light flickers at a sufficiently high frequency so that the patient will not notice the flicker and will instead perceive steady illumination. For example, the light may flicker at a frequency of at least 60 Hz, such as at least 100 Hz. (In such embodiments, the duration of each flicker (or “pulse”) is typically less than 3 ms, such as less than 2 ms or 1 ms.) Because the flicker frequency may be higher than the frame rate (i.e., the frequency at which images are acquired), some flickering may occur between image acquisitions. For example, the flicker frequency may be an integer multiple of the image acquisition frequency, such that the flickering is synchronized with the image acquisition. By way of illustrative example only, at a frame rate of 60 Hz, the flicker frequency could be 120 Hz or 180 Hz.

[0151] Alternatively, the light can be flashed at a lower frequency, but the duration of each flash can be increased to make the perceived illumination more stable. For example, if a patient experiences a flickering effect at a frequency of 100 Hz and a duty cycle of 20%, the duty cycle can be increased to 40% by increasing the pulse width without changing the frequency.

[0152] In some embodiments, the illumination source 60 is configured to emit near-infrared light. In such embodiments, near-infrared light can be continuously illuminating the patient during treatment or at least while acquiring images, in order to reduce the required camera exposure time without disturbing the patient. Optionally, the illumination source 60 may also flash visible light toward the eye during and / or between image acquisition to further reduce the required exposure time and / or cause pupil constriction.

[0153] Now for reference Figure 4 It provides some further details about the trabeculoplasty procedure. Figure 4 This is a schematic diagram of an example algorithm 86 for performing an automated trabeculectomy procedure according to some embodiments of the present invention.

[0154] To initiate the simulation after user approval, at imaging and localization step 88, the controller flashes light toward the eye, acquires an image of the eye using a camera during the flash, and locates the center of the limbus in the acquired image. Subsequently, at target calculation step 90, the controller calculates the localization of the next target region by adding an appropriate (x, y) offset to the position of the center of the limbus. After confirming this localization, the target region is illuminated, as further described below. The controller then acquires another image, calculates the localization of the next target region, verifies this localization, and illuminates the target. In this manner, the controller repeatedly illuminates the target region.

[0155] More specifically, for each calculated target area, the controller checks at the first target check step 92 whether the target area is (even partially) located within a restricted area, which will be referred to as the static area in the camera's field of view (FOV). (To perform this check, the controller does not necessarily need to explicitly calculate the boundary of the target area; for example, the controller may check whether a point at the center of the target area is greater than a predetermined distance from the boundary of the restricted area, equal to or slightly greater than the radius of the aiming beam or treatment beam). If not, the controller performs a second target check step 94, where, assuming the target area is preceded by a previous target area, the controller checks whether the target area is at an acceptable distance from that previous target area. For example, the controller may check whether the distance between the target area and the previous target area is less than a predetermined threshold, indicating that the eye is relatively stationary. If the target area is not at an acceptable distance from the previous target area, or if the target area is within a restricted area, the controller returns to the imaging and positioning step 88.

[0156] If the calculated target area passes both the first target inspection step 92 and the second target inspection step 94, the controller aims the beam guiding element at the target area at the aiming step 96. Subsequently, the controller emits an aiming beam at the beam guiding element at the aiming beam emission step 98, such that the aiming beam is guided by the beam guiding element toward the target area. Alternatively, single aiming beams can be emitted continuously, making it unnecessary to perform the aiming beam emission step 98.

[0157] Subsequently, the controller performs imaging and positioning step 88. Then, at the limbal center check step 100, the controller checks whether the center of the limbus has moved (relative to the most recently acquired image) beyond a predetermined threshold. If so, the controller returns to the target calculation step 90 and recalculates the position of the target region relative to the center of the limbus. Otherwise, at the aiming beam identification step 102, the controller identifies the aiming beam in the image.

[0158] After identifying the aiming beam, the controller checks at the first aiming beam check step 106 whether the aiming beam is within the restricted area. If the aiming beam is within the restricted area (indicating rapid eye movement or system malfunction), the controller terminates the procedure. Otherwise, at the second aiming beam check step 108, the controller checks whether the distance between the aiming beam and the calculated target area is within a predetermined threshold. If not, the controller returns to the target calculation step 90. Otherwise, the controller fires the treatment beam at the treatment beam firing step 110, causing the treatment beam to enter the target area.

[0159] Typically, in addition to identifying and verifying the positioning of the targeting beam, the controller checks each image for any obstructions that might hinder the target area, including, for example, eyelids, eyelashes, fingers, growths (such as pterygium), blood vessels, or speculum. If an obstruction is identified, the target area can be moved to avoid it. Alternatively, the target area can be skipped entirely, or the treatment procedure can be terminated.

[0160] Typically, any suitable image processing technique, optionally combined with user input, can be used to identify obstacles. For example, prior to a treatment procedure, the user may select (e.g., referring to a still image) one or more portions of the eye that constitute a potential obstacle. The controller can then use template matching, edge detection, or any other suitable technique (including, for example, recognizing changes between successive images) to identify the selected portions of the eye. Such techniques can also be used to identify other static or dynamic obstacles that the user does not need to identify beforehand. (It should be noted that the definition of "obstacle" may vary from application to application; for example, in some applications, a specific blood vessel may constitute an obstacle, while in others, it may be desirable to irradiate the blood vessel.)

[0161] After the treatment beam emission step 110, the controller checks at the final check step 112 whether the entire target area has been treated. If so, the controller terminates the program. Otherwise, the controller returns to the target calculation step 90.

[0162] Advantageously, the time between acquiring each image and emitting the treatment beam is typically less than 15 ms, for example, less than 10 ms. In some embodiments, this delay is further reduced by emitting the treatment beam between the aiming step 96 and the aiming beam emission step 98 (or, if single aiming beams are emitted consecutively, between the aiming step 96 and the imaging and positioning step 88) rather than after the second aiming beam inspection step 108. (In such embodiments, the aiming beam is used for post-hoc verification that the treatment beam was emitted correctly.)

[0163] In some embodiments, a separate routine executed by the controller monitors the time from each image acquisition. If the time exceeds a predetermined threshold (such as a threshold between 10 ms and 15 ms), the treatment beam is not fired until the next image is acquired and the target localization is recalculated.

[0164] Those skilled in the art will recognize that the present invention is not limited to what has been specifically shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications that would occur to those skilled in the art upon reading the foregoing description and which are not found in the prior art.

Claims

1. An ophthalmic system comprising: A radiation source configured to emit a therapeutic beam of radiation; A camera, configured to capture images of the eye; as well as The controller is configured to: Based on the image of the eye, a static region including the pupil of the eye is identified within the field of view of the camera, and By repeatedly performing the following operations, the radiation source irradiates multiple target areas of the eye with the therapeutic beam: Calculate the location of the next target region. Based on the calculated location, check whether the next one in the target area is located within the static area, and If the next one in the target area is not in the static area, then the radiation source irradiates the next one in the target area.

2. The system according to claim 1, further comprising: One or more beam guiding elements are configured to direct the therapeutic beam toward the target region. The controller is also configured to prevent the beam guiding element from aiming at the static area even when no therapeutic beam is being emitted.

3. The system according to claim 1, wherein, Checking whether the next element in the target area is located within the static area includes checking whether the center of the next element in the target area is greater than a predetermined distance from the boundary of the static area.

4. The system according to claim 1, wherein, The static region includes a portion of the cornea of ​​the eye that surrounds the pupil.

5. The system according to any one of claims 1-4, wherein, The controller is configured to identify the static region based on the position of the corneal limbus of the eye in the image.

6. The system according to claim 5, further comprising: Receive limbal positioning input from the user, indicating the location of the limbus.

7. The system according to claim 5, wherein, The controller is also configured to identify the location of the limbus.

8. The system according to claim 5, wherein, The controller is further configured to identify the static region as the set of all points in the field of view located inside the limbus and at a distance greater than a predetermined distance from the limbus.

9. The system according to claim 5, wherein, The controller is also configured to identify the static region by locating the static region at the center of the limbus or the center of the pupil.

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