Long-term monitoring of incision performance of ophthalmic laser surgical systems

Abstract

An ophthalmic surgical system for monitoring incision performance includes a laser device that delivers a laser beam having a laser setting energy toward a target to create an optical breakdown in the target, a camera, and a computer. A camera generates an image of an optical breakdown in the target. The computer instructs the laser device to create an optical breakdown in the target to produce a test pattern. The test pattern includes optical breakdown regions, where each region is formed with a different laser set energy. The computer identifies a lowest energy region having a substantially continuous optical breakdown from the image and designates a laser set energy for forming the identified region as a threshold energy.

Description

Technical Field

[0001] The present disclosure relates generally to ophthalmic laser surgical systems and, more particularly, to long-term monitoring of incision performance of ophthalmic laser surgical systems. Background Art

[0002] Certain ophthalmic laser surgery systems include a femtosecond laser that produces photodisruption in tissue to form an incision. To produce photodisruption, the laser directs laser pulses having an energy selected using a laser setting. If the laser setting energy meets (e.g., is at or above) a threshold energy, the pulse produces photodisruption. For safety reasons, photodisruption should be produced at the lowest feasible amount of energy.

[0003] During system manufacturing and initial system checkout, the energy produced by a specific laser setting is tested. However, laser surgical systems change during their service life, such that a larger laser setting energy may be required to meet the threshold energy. Summary of the invention

[0004] In certain embodiments, an ophthalmic surgical system for monitoring incision performance includes a laser device, a camera, and a computer. The laser device delivers a laser beam having a laser setting energy toward a target to form an optical breakdown in the target. The camera generates an image of the optical breakdown in the target. The computer instructs the laser device to form an optical breakdown in the target to produce a test pattern. The test pattern includes optical breakdown areas, wherein each area is formed using a different laser setting energy. The computer identifies the lowest energy area having substantially continuous optical breakdown from the image, and designates the laser setting energy used to form the identified area as a threshold energy.

[0005] Embodiments may not include the following features or may include one, some or all of the following features: Substantially continuous optical breakdown is defined as at least 90% of the pulses forming optical breakdown. The computer accesses a previous test pattern including a previous area of ​​previous optical breakdown and compares the test pattern to the previous test pattern to detect changes in threshold energy. The previous test pattern may have been formed more than a month ago. The areas of the test pattern may be arranged to be substantially similar to previous areas of the previous test pattern, so that each area has a corresponding previous area in the same position. For each area, the laser setting energy to form the area may be substantially the same as the laser setting energy to form the previous area corresponding to the area. The computer may: provide notification of changes in threshold energy; adjust the laser setting energy to compensate for changes in threshold energy; and / or extrapolate based on the test pattern and the previous test pattern to predict future threshold energy. Each area of ​​the test pattern has a substantially rectangular shape. Each area of ​​the test pattern has a substantially triangular shape.

[0006] In certain embodiments, a method for monitoring incision performance includes instructing a laser device by a computer to deliver a laser beam toward a target. The laser beam forms optical breakdown in the target to produce a test pattern, wherein the test pattern includes regions of optical breakdown, each region formed using a different laser setting energy. The method also includes: generating an image of the optical breakdown in the target by a camera; identifying, by a computer, from the image, a lowest energy region with substantially continuous optical breakdown; and designating, by the computer, the laser setting energy used to form the identified region as a threshold energy.

[0007] Embodiments may not include the following features or may include one, some or all of the following features: Substantially continuous optical breakdown is defined as at least 90% of the pulses forming optical breakdown. The method also includes: accessing, by a computer, a previous test pattern including a previous region of previous optical breakdown; and comparing, by a computer, the test pattern with the previous test pattern to detect a change in threshold energy. The previous test pattern may have been created more than a month ago. The regions of the test pattern may be arranged to be substantially similar to previous regions of the previous test pattern, so that each region has a corresponding previous region at the same location. For each region, the laser setting energy to form the region may be substantially the same as the laser setting energy to form the previous region corresponding to the region. The method may also include: providing notification of a change in threshold energy by a computer; adjusting the laser setting energy by a computer to compensate for the change in threshold energy; and / or performing an extrapolation by a computer based on the test pattern and the previous test pattern to predict future threshold energy. According to the method of claim 11, each region of the test pattern has a substantially rectangular shape or a substantially triangular shape.

[0008] In certain embodiments, an ophthalmic surgical system for monitoring incision performance includes a laser device, a camera, and a computer. The laser device delivers a laser beam having a laser setting energy toward a target to form an optical breakdown in the target. The camera generates an image of the optical breakdown in the target. The computer instructs the laser device to form an optical breakdown in the target to generate a test pattern. The test pattern includes optical breakdown areas, wherein each area is formed using a different laser setting energy and has a substantially rectangular or triangular shape. The computer identifies the lowest energy area with substantially continuous optical breakdown from the image, where substantially continuous optical breakdown is defined as at least 90% of the pulses forming optical breakdown. The computer specifies the laser setting energy used to form the identified area as a threshold energy. The computer also accesses a previous test pattern formed more than a month ago that includes a previous area of ​​the previous optical breakdown. The areas of the test pattern are arranged to be substantially similar to the previous areas of the previous test pattern, so that each area has a corresponding previous area at the same location. For each area, the laser setting energy to form the area is substantially the same as the laser setting energy to form the previous area corresponding to the area. The computer compares the test pattern to previous test patterns to detect changes in threshold energy, provides notification of the change in threshold energy, adjusts laser setting energy to compensate for the change in threshold energy, and / or extrapolates from the test pattern and previous test patterns to predict future threshold energies. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 An example of an ophthalmic surgical system that can be used to monitor incision performance of the ophthalmic surgical system according to certain embodiments is shown;

[0010] Figure 2A and Figure 2B Examples of test patterns are shown;

[0011] Figure 3A and Figure 3B An example of analyzing a test pattern and comparing the test pattern to a previously created test pattern is shown; and

[0012] Figure 4 A method for inspecting Figure 1 An example of a method for the incision performance of a system. DETAILED DESCRIPTION

[0013] With reference now to the specification and drawings, example embodiments of the disclosed apparatus, systems, and methods are illustrated in detail. The specification and drawings are not intended to be exhaustive or otherwise limit the claims to the specific embodiments shown in the drawings and disclosed in the specification. Although the drawings represent possible embodiments, the drawings are not necessarily drawn to scale, and certain features may be simplified, exaggerated, removed, or partially cut away to better illustrate the embodiments.

[0014] Laser surgical systems may change during their useful life such that a greater laser setting energy may be required to meet a threshold energy. Embodiments of the systems described herein address this problem. In an embodiment, a laser device forms an optical breakdown in a target to produce a test pattern. The test pattern includes regions of optical breakdown, wherein each region is formed using a different laser setting energy. A computer identifies the lowest energy region with substantially continuous optical breakdown and designates the laser setting energy used to form the identified region as the threshold energy. The computer may compare the test pattern to previously produced test patterns to detect changes in the threshold energy and predict future changes in the threshold energy.

[0015] Embodiments provide efficient, effective, automatic determination of incision performance that can be used to identify and predict changes in threshold energy. In addition, photodisruption is affected by various laser parameters, such as beam profile, beam quality, pulse duration, pulse-to-pulse stability, and focus. Embodiments test the resulting effect of pulses, which automatically accounts for changes in these parameters.

[0016] Figure 1 An example of an ophthalmic surgical system 10 according to some embodiments is shown that can be used to monitor the incision performance of the ophthalmic surgical system. The ophthalmic surgical system 10 can perform any suitable surgical procedure on the eye 22, such as corneal refractive surgery or other ophthalmic laser surgery. The surgical procedure can have a treatment mode that describes the target position of the laser pulse in the cornea.

[0017] In the illustrated example, the system 10 includes a laser device 15, a patient interface 20, a camera 38, and a control computer 30 coupled as shown. The laser device 15 includes controllable components that can be controlled by a computer (such as computer 30), such as a laser source 12, a scanner 16, one or more optical elements 17, and / or a focusing lens 18, coupled as shown. The patient interface 20 includes a contact portion 24 (having an abutment surface 26) and a sleeve 28 coupled as shown. The computer 30 includes logic 31, a memory 32 (which stores a computer program 34), and a display 36 coupled as shown.

[0018] As an overview, the computer 30 instructs the laser device 15 to form optical breakdown in the target to produce a test pattern. The laser device 15 delivers a laser beam having an energy selected by a laser setting toward the target 12 to form optical breakdown. The test pattern includes optical breakdown regions, wherein each region is formed using a different laser setting energy. The camera 38 generates an image of the optical breakdown. The computer 30 identifies the lowest energy region having substantially continuous optical breakdown from the image, and designates the laser setting energy used to form the identified region as a threshold energy.

[0019] In more detail, the target 12 includes a material that reacts to laser pulses in a manner that provides information about how the eye tissue reacts to the laser pulses. For example, polymethylmethacrylate (PMMA) can be used as a substitute for corneal tissue. Laser pulses below a threshold energy do not produce a visible reaction, but reactions above the threshold energy produce a visible mark.

[0020] Turning to the system 10 portion, the laser device 15 includes a laser source 12 and a scanner 16. The laser source 12 generates a laser beam having ultrashort pulses, wherein the propagation direction of the laser beam defines a z-axis. The laser source 12 generates a laser beam having ultrashort pulses. An ultrashort pulse refers to a light pulse having a duration less than a nanosecond (e.g., on the order of picoseconds, femtoseconds, or attoseconds). The laser beam can have any suitable wavelength, such as a wavelength in the range of 300 to 1500 nanometers (nm), such as a wavelength in the range of 300 to 650 nm, 650 to 1050 nm, 1050 to 1250 nm, and / or 1250 to 1500 nm, such as 340 to 350 nm, such as 347 nm ± 1 nm. The focus of the laser beam can create a laser induced optical breakdown (LIOB) in a tissue (e.g., a cornea) to produce photodisruption in the tissue.

[0021] The scanner 16 directs the focal point of the laser beam longitudinally and transversely toward the target 12. The longitudinal direction refers to the direction of propagation of the laser beam, i.e., the z-direction. The scanner 16 can direct the laser beam longitudinally in any suitable manner. For example, the scanner 16 can include a longitudinally adjustable lens, a lens of variable refractive power, or a deformable mirror that can control the z-position of the focal point. The transverse direction refers to the direction orthogonal to the direction of propagation of the beam, i.e., the x-direction and the y-direction. The scanner 16 can direct the laser beam laterally in any suitable manner. For example, the scanner 16 can include a pair of galvanometer-actuated scanning mirrors that can be tilted about mutually perpendicular axes. As another example, the scanner 16 can include an electro-optical crystal that can electro-optically manipulate the laser beam.

[0022] One (or more) optical elements 17 direct the laser beam toward a focusing objective 18. The optical element 17 can act on (e.g., transmit, reflect, refract, diffract, collimate, adjust, shape, focus, modulate, and / or otherwise act on) the laser beam. Examples of optical elements include lenses, prisms, mirrors, diffractive optical elements (DOEs), holographic optical elements (HOEs), and spatial light modulators (SLMs). In an example, the optical element 17 is a mirror. The focusing objective 18 focuses the focal point of the laser beam toward a point of the eye 22 through the patient interface 20. In an example, the focusing objective 18 is an objective lens, for example, an f-theta objective lens.

[0023] The patient interface 20 couples the target 12 to the laser device 15. In an example, the patient interface 20 includes a sleeve 28 having a contact portion 24. The sleeve 28 is removably coupled to the laser device 15 and the target 12. The contact portion 24 may be translucent or transparent to the laser beam.

[0024] The camera 38 records an image of the test pattern formed on the target 12 and delivers image data representing the recorded image of the target 12 to the computer 30. Examples of the camera 38 include a video camera, an optical coherence tomography (OCT) camera, or an eye tracking camera. The display 36 displays the image and the results of the image analysis performed by the computer 30. Examples of the display include a computer screen.

[0025] The computer 30 controls the controllable components of the laser device 15 (e.g., the laser source 12, the scanner 16, the optical element 17, and / or the focusing objective 18) according to instructions (which may be stored in a computer program 34) to photodisrupt the target, thereby forming an optical breakdown that produces a test pattern. The computer 30 analyzes the test pattern by, for example, performing image processing on an image of the test pattern from a camera 38. The computer 30 also controls the camera 38 and the display 36 to generate an image of the test pattern and display the image and the results of the image analysis.

[0026] Figure 2A and Figure 2B An example of a test pattern 50 (50a, 50b) is shown. The test pattern 50 includes regions 54 of optical breakdown, wherein each region is formed using a different laser setting energy. In the test pattern 50a, each region 54a has a substantially rectangular shape, wherein pulses with laser setting energies E1 to E7 form optical breakdown. In the test pattern 50b, each region 54b has a substantially triangular shape, wherein pulses with laser setting energies E1 to E10 form optical breakdown.

[0027] Figure 3A and Figure 3B An example of analyzing a current test pattern 50 made at time T1 and comparing the current test pattern 50 to a previous test pattern 52 made at a previous time T0 is shown. The test pattern 50 includes regions 54 of optical breakdown, wherein each region 54 is formed with a different laser setting energy E1 to E7. Regions 54 (e.g., regions E3 and E4) may have optical breakdown regions 56 and no optical breakdown regions 58. The computer 30 identifies the lowest energy region with substantially continuous optical breakdown, such as region E5. This may be a region in which nearly all or all pulses form optical breakdown 56, such as where at least 80%, 90%, 95%, 98%, and / or 100% of the pulses form optical breakdown. The laser setting energy used to form the identified region is designated as a threshold energy.

[0028] In some embodiments, the regions 54 of the current test pattern 50 are arranged to be substantially similar to the regions 54 of the previous test pattern 52, so that each current region 54 has a corresponding previous region 54 at the same location. For each region, the laser setting energies E1 to E7 for forming the current region are the same as the laser setting energies E1 to E7 for forming the previous region corresponding to the current region. The test pattern can be formed in response to detecting a change in the cut quality and / or periodically, where the time period can be in the range of, for example, 1 month, 1 to 4 months, 4 to 6 months, and / or 6 to 12 months.

[0029] The computer 30 may compare the current test pattern 50 to the previous test pattern 52 to perform any suitable analysis, for example, to detect a change in the threshold energy. For example, the current test pattern 50 indicates that E5 is the threshold energy, while the previous test pattern 52 indicates that E4 is the previous threshold energy, thereby indicating a change in the threshold energy. In some embodiments, the computer 30 may provide notification of the change in threshold energy and / or adjust the laser setting energy to compensate for the change in threshold energy. For example, the computer 30 may add the energy difference E5-E4 to the laser energy setting of the treatment mode.

[0030] In some embodiments, the computer 30 may extrapolate from the current test pattern 50 and the previous test pattern 52 to predict future threshold energies. For example, during the time period T1-T0 between the test patterns 50, 52, an energy change E5-E4 occurs. The computer 30 may predict that a similar energy change E5-E4 may occur during the next time period lasting T1-T0.

[0031] Figure 4 Demonstrates methods for monitoring according to some embodiments Figure 1 An example of a method for measuring the performance of a cutting of a system. In an embodiment, a computer of the system performs or instructs other components to perform the steps of the method. The method begins at step 110, where a laser device of the system delivers a laser beam to a target to create an optical breakdown that produces a test pattern. The test pattern has optical breakdown regions, where each region is formed using a different laser setting energy.

[0032] At step 112, the computer analyzes the image of the optical breakdown recorded by the camera. At step 114, the computer identifies the lowest energy region with substantially continuous optical breakdown. The region with substantially continuous optical breakdown may be a region where at least substantially all pulses form optical breakdown. At step 116, the laser setting energy used to form the identified region is designated as a threshold energy.

[0033] At step 118, the computer accesses a previous test pattern. At step 120, the computer compares the current test pattern to the previous test pattern to detect a change in the threshold energy. At step 122, there may be a change. If there is no change, the method ends. If there is a change, at step 124, the computer provides a notification of the energy change. For example, the computer can display a notification of the energy change on the display 36, along with a description of the change (e.g., the current value and the previous value of the threshold energy). At step 126, the computer adjusts the laser setting energy to compensate for the change. For example, the computer can add the energy change to the laser energy setting of the treatment mode. The method then ends.

[0034] The components (such as computer 30) of the system and device disclosed herein can include interface, logic and / or memory, any of which can include computer hardware and / or software.Interface (such as display 36) can receive the input to components and / or send output from components, and is typically used for exchanging information between, for example, software, hardware, peripherals, users and these combinations.User interface is a type of interface that a user can use to communicate with a computer (for example, send input to a computer and / or receive output from a computer).The example of user interface includes display, graphical user interface (GUI), touch screen, keyboard, mouse, gesture sensor, microphone and loudspeaker.

[0035] Logic may perform the operations of a component. Logic may include one or more electronic devices that process data (e.g., execute instructions for generating outputs from inputs). Examples of such electronic devices include computers, processors, microprocessors (e.g., central processing units (CPUs)), and computer chips. Logic may include computer software that encodes instructions that can be executed by an electronic device to perform operations. Examples of computer software include computer programs, applications, and operating systems.

[0036] The memory can store information and can include tangible, computer-readable and / or computer-executable storage media. Examples of memory include computer memory (e.g., random access memory (RAM) or read-only memory (ROM)), mass storage media (e.g., hard disk), removable storage media (e.g., compact disk (CD) or digital video or universal disk (DVD)), database, network storage device (e.g., server), and / or other computer-readable media. Particular embodiments may involve memory encoded with computer software.

[0037] Although the present disclosure is described according to certain embodiments, it will be apparent to those skilled in the art that modifications (such as changes, substitutions, additions, omissions and / or other modifications) to the embodiments will be apparent. Accordingly, the embodiments may be modified without departing from the scope of the invention. For example, the systems and devices disclosed herein may be modified. The components of the systems and devices may be integrated or separate, or the operations of the systems and devices may be performed by more, fewer components or other components, which will be apparent to those skilled in the art. As another example, the methods disclosed herein may be modified. These methods may include more, fewer steps or other steps, and these steps may be performed in any suitable order, which will be apparent to those skilled in the art.

[0038] To assist the Patent Office and readers in understanding the claims, Applicant does not intend for any claim or claim element to invoke 35 U.S.C. §112(f) unless the words “means for” or “step for” are expressly used in a particular claim. Applicant understands that the use of any other terms (e.g., “mechanism,” “module,” “means,” “unit,” “component,” “element,” “member,” “device,” “machine,” “system,” “processor,” or “controller”) within the claims refers to structures known to persons skilled in the relevant art and is not intended to invoke 35 U.S.C. §112(f).

Claims

1. An ophthalmic surgical system for monitoring incision performance, the ophthalmic surgical system comprising: a laser device configured to deliver a laser beam having a laser setting energy toward a target, the laser beam forming a plurality of optical breakdowns in the target; a camera configured to generate a plurality of images of the optical breakdown in the target; as well as A computer, the computer being configured to: instructing the laser device to form the optical breakdown in the target to produce a test pattern, the test pattern comprising a plurality of optical breakdown regions, each region being formed using a different laser setting energy; identifying from the image a lowest energy region having substantially continuous optical breakdown; as well as The laser setting energy used to form the identified region is designated as the threshold energy.

2. The ophthalmic surgical system of claim 1, wherein the substantially continuous optical breakdown is defined as at least 90% of the pulses forming optical breakdown.

3. The ophthalmic surgical system of claim 1, wherein the computer is further configured to: accessing a previous test pattern including a plurality of previous regions of previous optical breakdown; and The test pattern is compared to the previous test pattern to detect a change in threshold energy.

4. The ophthalmic surgical system of claim 3, wherein the previous test pattern was created more than one month ago.

5. The ophthalmic surgical system of claim 3, wherein the computer is further configured to: Notification of changes to the threshold energy is provided.

6. The ophthalmic surgical system of claim 3, wherein the computer is further configured to: The laser setting energy is adjusted to compensate for the change in the threshold energy.

7. The ophthalmic surgical system of claim 3, wherein the computer is further configured to: Extrapolation is performed based on the test pattern and the previous test pattern to predict future threshold energies.

8. The ophthalmic surgical system of claim 3: The regions of the test pattern are arranged substantially similar to previous regions of the previous test pattern such that each region has a corresponding previous region in the same location; and For each region, the laser setting energy for forming the region is substantially the same as the laser setting energy for forming the previous region corresponding to the region.

9. The ophthalmic surgical system of claim 1, each area of ​​the test pattern having a substantially rectangular shape.

10. The ophthalmic surgical system of claim 1, each area of ​​the test pattern having a substantially triangular shape.

11. A method for monitoring incision performance, the method comprising: instructing the laser device by a computer to deliver a laser beam having a laser setting energy toward a target, the laser beam forming a plurality of optical breakdowns in the target to produce a test pattern, the test pattern comprising a plurality of optical breakdown regions, each region being formed using a different laser setting energy; generating, by a camera, a plurality of images of the optical breakdown in the target; identifying, by the computer, from the images, a lowest energy region having substantially continuous optical breakdown; as well as The laser setting energy used to form the identified area is designated by the computer as a threshold energy.

12. The method of claim 11, further comprising: accessing, by the computer, a previous test pattern comprising a plurality of previous regions of previous optical breakdown; as well as The test pattern is compared to the previous test pattern by the computer to detect a change in threshold energy.

13. The method of claim 12, further comprising: The laser setting energy is adjusted by the computer to compensate for the change in the threshold energy.

14. The method of claim 12, further comprising: Extrapolation is performed by the computer based on the test pattern and the previous test pattern to predict future threshold energies.

15. The method of claim 12: The regions of the test pattern are arranged substantially similar to previous regions of the previous test pattern such that each region has a corresponding previous region in the same location; and For each region, the laser setting energy for forming the region is substantially the same as the laser setting energy for forming the previous region corresponding to the region.

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