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

Abstract

An ophthalmic surgery system for monitoring incision performance includes a laser device, a camera, and a computer. The laser device directs a laser beam at a target at a laser setting energy to cause photodisruption in the target. The camera generates an image of the photodisruption in the target. The computer instructs the laser device to cause photodisruption in the target to generate a test pattern. The test pattern includes regions where photodisruption occurred, each region generated at a different laser setting energy. The computer identifies from the image the lowest energy region where nearly continuous photodisruption occurred and designates the laser setting energy used to generate the identified region as a threshold energy.

Description

[Technical Field]

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

[0002] Certain ophthalmic laser surgery systems include a femtosecond laser that produces photodisruption in tissue to create an incision. The laser delivers laser pulses at an energy selected using a laser setting to produce the photodisruption. If the laser setting energy meets (e.g., is above) a threshold energy, the pulse will produce a photodisruption. For safety reasons, the photodisruption should be produced with the minimum amount of energy possible. Summary of the Invention [Problem to be solved by the invention]

[0003] The energy obtained from a particular laser setting is tested during system manufacturing and initial system inspection, but laser surgical systems change over their lifespan, such that greater laser setting energies are required to deliver a threshold energy. [Means for solving the problem]

[0004] In certain embodiments, an ophthalmic surgery system for monitoring incision performance includes a laser device, a camera, and a computer. The laser device directs a laser beam at a target at a laser setting energy to cause photodisruption in the target. The camera generates an image of the photodisruption in the target. The computer instructs the laser device to cause photodisruption in the target to generate a test pattern. The test pattern includes regions of photodisruption, each region generated at a different laser setting energy. The computer identifies from the image the lowest energy region where nearly continuous photodisruption occurred and designates the laser setting energy used to generate the identified region as a threshold energy.

[0005] Embodiments may include none, one, some, or all of the following features: Nearly continuous photodisruption is defined as at least 90% of the pulses causing photodisruption; the computer accesses a past test pattern that includes areas where past photodisruption occurred and compares the test pattern to the past test pattern to detect changes in threshold energy; the past test pattern may have been generated more than one month ago; the multiple regions of the test pattern may be arranged substantially similar to past regions of the past test pattern, with each region having a corresponding past region in the same location; for each region, the laser set energy that generated the region may be substantially the same as the laser set energy that generated the previous region corresponding to the region; the computer may report changes in threshold energy and adjust the laser set energy to compensate for the change in threshold energy and / or predict future threshold energies by extrapolating from the test pattern and past test patterns; each region of the test pattern has a substantially rectangular shape; each region of the test pattern has a substantially triangular shape.

[0006] In certain embodiments, a method for monitoring incision performance includes directing, by a computer, a laser device to direct a laser beam at a target at a laser set energy. The laser beam causes photodisruption in the target to generate a test pattern, the test pattern including multiple regions of photodisruption, each region generated at a different laser set energy. The method also includes generating, by a camera, an image of the photodisruption in the target; identifying, by a computer, from the image, a lowest-energy region where substantially continuous photodisruption occurred; and designating, by the computer, the laser set energy used to generate the identified region as a threshold energy.

[0007] Embodiments may include none, one, some, or all of the following features: Nearly continuous photodisruption is defined as at least 90% of the pulses causing photodisruption. The method also includes the steps of accessing, by a computer, a past test pattern including past regions of past photodisruption, and comparing, by a computer, the test pattern with the past test pattern to detect a change in threshold energy. The past test pattern may have been generated more than one month ago. The multiple regions of the test pattern may be arranged substantially similar to the past regions of the past test pattern, with each region having a corresponding past region in the same location. For each region, the laser set energy that generated the region may be substantially the same as the laser set energy that generated the previous region corresponding to the region. The method may also include the steps of notifying, by a computer, of a change in threshold energy; adjusting, by a computer, the laser set energy to compensate for the change in threshold energy; and / or extrapolating, by a computer, from the test pattern and the past test patterns to predict a future threshold energy. In the method of claim 11, each region of the test pattern has a substantially rectangular or substantially triangular shape.

[0008] In certain embodiments, an ophthalmic surgery system for monitoring incision performance includes a laser device, a camera, and a computer. The laser device directs a laser beam at a target at a laser setting energy to cause photodisruption in the target. The camera generates an image of the photodisruption in the target. The computer instructs the laser device to cause photodisruption in the target to generate a test pattern. The test pattern includes regions of photodisruption, each region generated at a different laser setting energy and having an approximately rectangular or triangular shape. The computer identifies from the image a region with the lowest energy where substantially continuous photodisruption occurred, defined as at least 90% of the pulses generating photodisruption. The computer designates the laser setting energy used to generate the identified region as a threshold energy. The computer also accesses previous test patterns generated more than one month ago that include regions where previous photodisruption occurred. The test pattern regions are arranged substantially similar to previous regions in previous test patterns, with each region having a corresponding previous region in the same position. For each region, the laser setting energy that generated that region is substantially the same as the laser setting energy that generated the previous region corresponding to that region. The computer compares the test pattern to past test patterns to detect changes in threshold energy, reports the change in threshold energy, adjusts the laser setting energy to compensate for the change in threshold energy, and / or predicts future threshold energies by extrapolating from the test pattern and past test patterns. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an example of an ophthalmic surgical system that can be used to monitor its incision performance, according to certain embodiments. [Figure 2A-2B] 2A and 2B show several examples of test patterns. [Figure 3A-3B] 3A and 3B show an example of analyzing a test pattern and comparing the test pattern with previously generated test patterns. [Figure 4]FIG. 4 illustrates an example of a method for verifying the lancing performance of the system of FIG. 1, according to certain embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0010] With reference to the following description and drawings, exemplary embodiments of the disclosed devices, systems, and methods are shown in detail. The description and drawings are not intended to be exhaustive or to otherwise limit the claims to the specific embodiments illustrated and disclosed herein. While the drawings represent possible embodiments, the drawings are not necessarily to scale, and certain features may be simplified, exaggerated, omitted, or partially separated to more clearly illustrate the embodiments.

[0011] Laser surgical systems change over their service life, such that delivering a threshold energy requires a higher laser setting energy. Several embodiments of the systems described herein address this issue. In these embodiments, a laser device generates a test pattern by causing photodisruption at a target. The test pattern includes regions of photodisruption, each generated at a different laser setting energy. A computer identifies the lowest energy region where nearly continuous photodisruption occurred and designates the laser setting energy used to generate the identified region as the threshold energy. The computer can detect changes in the threshold energy and compare the test pattern with previously generated test patterns to predict future changes in the threshold energy.

[0012] Embodiments provide efficient and effective automated determination of cutting performance that can be used to identify and predict changes in threshold energy. Furthermore, photodisruption is affected by various laser parameters, such as beam shape, beam quality, pulse duration, pulse-to-pulse stability, and focusing. Embodiments test the resulting effects of pulsing to automatically reflect changes in these parameters.

[0013] 1 illustrates an example of an ophthalmic surgical system 10 that can be used to monitor its incision performance, according to certain embodiments. The ophthalmic surgical system 10 can perform any suitable surgical procedure on an eye 22, such as corneal refractive surgery or other ophthalmic laser surgery. The surgical procedure may have a treatment pattern that describes the target locations of laser pulses within the cornea.

[0014] In the illustrated example, system 10 includes a laser device 15, a patient interface 20, a camera 38, and a control computer 30, coupled as shown. Laser device 15 includes controllable elements such as a laser source 12, a scanner 16, one or more optical elements 17, and / or a focusing objective lens 18, coupled as shown and controllable by a computer, such as computer 30. Patient interface 20 includes a contact portion 24 (having an abutment surface 26) and a sleeve 28, coupled as shown. Computer 30 includes logic 31, a memory 32 (storing a computer program 34), and a display 36, coupled as shown.

[0015] In general, computer 30 instructs laser device 15 to cause photodisruption in a target to generate a test pattern. Laser device 15 directs a laser beam at target 12 at an energy selected by the laser setting to cause photodisruption. The test pattern includes regions of photodisruption, each region created at a different laser setting energy. Camera 38 generates images of the photodisruption. Computer 30 identifies from the image the lowest energy region where nearly continuous photodisruption occurred and designates the laser setting energy used to create the identified region as the threshold energy.

[0016] More specifically, target 12 includes a material that reacts to a laser pulse to provide information about how ocular tissue responds to the laser pulse. For example, polymethylmethacrylate (PMMA) can serve as a corneal tissue surrogate. Laser pulses below a threshold energy do not produce a visible response, while responses above the threshold energy produce a visible mark.

[0017] Turning to the components of system 10, laser device 15 includes laser source 12 and scanner 16. Laser source 12 generates a laser beam having an ultrashort pulse, the propagation direction of the laser beam defining a z-axis. Laser source 12 generates a laser beam having an ultrashort pulse. Ultrashort pulses refer to light pulses having durations on the order of less than nanoseconds, such as picoseconds, femtoseconds, or attoseconds. The laser beam may have any suitable wavelength, such as a wavelength in the range of 300-1500 nanometers (nm), e.g., 300-650, 650-1050, 1050-1250, and / or 340-350 nm, e.g., 1250-1500 nm, e.g., 347 nm±1 nm. The focal point of the laser beam can cause laser-induced photodisruption (LIOB) in tissue (e.g., the cornea), resulting in photodisruption in the tissue.

[0018] The scanner 16 focuses the laser beam longitudinally and laterally 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 focus the laser beam longitudinally in any suitable manner. For example, the scanner 16 can include a longitudinally adjustable lens, a variable power lens, or a deformable mirror that can control the z-position of the focus. The lateral direction refers to directions perpendicular to the direction of propagation of the beam, i.e., the x- and y-directions. The scanner 16 can focus the laser beam laterally in any suitable manner. For example, the scanner 16 can include a pair of galvanometer-actuated scanner mirrors that can be tilted about mutually orthogonal axes. As another example, the scanner 16 can include an electro-optic crystal that can electro-optically guide the laser beam.

[0019] One (or more) optical elements 17 direct the laser beam toward a focusing objective lens 18. The optical element 17 can act on (e.g., transmit, reflect, refract, diffract, collimate, condition, 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 this example, the optical element 17 is a mirror. The focusing objective lens 18 focuses the laser beam through the patient interface 20 toward a point on the eye 22. In this example, the focusing objective lens 18 is an objective lens, such as an f-theta objective lens.

[0020] The patient interface 20 couples the target 12 to the laser device 15. In this example, the patient interface 20 includes a sleeve 28 having a contact portion 24. The sleeve 28 removably couples to the laser device 15 and the target 12. The contact portion 24 may be translucent or transparent to the laser beam.

[0021] Camera 38 records an image of the test pattern generated on target 12 and delivers image data representing the recorded image of target 12 to computer 30. Examples of camera 38 include a video, optical coherence tomography (OCT), or eye-tracking camera. Display 36 displays the image and the results of the image analysis performed by computer 30. Examples of displays include a computer screen.

[0022] Computer 30, according to instructions (which may be stored in computer program 34), controls the controllable elements of laser device 15 (e.g., laser source 12, scanner 16, optics 17, and / or focusing objective lens 18) to cause photodisruption of a target to generate a test pattern. Computer 30 analyzes the test pattern, for example, by performing image processing on images of the test pattern from camera 38. Computer 30 also controls camera 38 and display 36 to generate images of the test pattern and display the images and the results of the image analysis.

[0023] 2A and 2B show examples of test patterns 50 (50a, 50b). Test pattern 50 includes regions 54 where photo-damage occurred, each region being generated with a different laser energy setting. In test pattern 50a, each region 54a has a generally rectangular shape, and pulses of laser energy settings E1 to E7 cause photo-damage. In test pattern 50b, each region 54b has a generally triangular shape, and pulses of laser energy settings E1 to E10 cause photo-damage.

[0024] 3A and 3B illustrate an example of analyzing a current test pattern 50 generated at time T1 and comparing the current test pattern 50 with a previous test pattern 52 generated at a previous time T0. The test pattern 50 includes regions 54 where photodisruption occurred, each region 54 generated at a different laser setting energy E1-E7. Regions 54, such as regions E3 and E4, may include a region 56 where photodisruption occurred and a region 58 where no photodisruption occurred. The computer 30 identifies the lowest energy region where nearly continuous photodisruption occurred, such as region E5. This may be the region 56 where nearly all or all of the pulses generated photodisruption, e.g., at least 80%, 90%, 95%, 98%, and / or 100% of the pulses generated photodisruption. The laser setting energy used to generate the identified region is designated as the threshold energy.

[0025] In certain embodiments, the regions 54 of the current test pattern 50 are positioned substantially similar to the regions 54 of the past test patterns 52, such that each current region 54 has a corresponding past region 54 in the same location. For each region, the laser setting energy E1-E7 that produced the current region is the same as the laser setting energy E1-E7 that produced the past region corresponding to the current region. Test patterns may be generated in response to a detected change in incision quality and / or periodically, with time periods ranging from, for example, 1 month, 1-4 months, 4-6 months, and / or 6-12 months.

[0026] Computer 30 can compare current test pattern 50 with previous test patterns 52 using any suitable analysis to detect, for example, a change in threshold energy. For example, current test pattern 50 may indicate a threshold energy of E5, while previous test pattern 52 may indicate a previous threshold energy of E4, indicating a change in threshold energy. In certain embodiments, computer 30 may signal the change in threshold energy and / or adjust the laser setting energy to compensate for the change in threshold energy. For example, computer 30 may add the energy difference E5-E4 to the laser energy setting of the treatment pattern.

[0027] In certain embodiments, computer 30 can predict future threshold energies by extrapolating from current test pattern 50 and past test patterns 52. For example, an energy change E5-E4 occurred during the time period T1-T0 between test patterns 50 and 52. Computer 30 can predict that a similar energy change E5-E4 will likely occur during the next time period spanning T1-T0.

[0028] Figure 4 shows an example of a method for monitoring the cutting performance of the system of Figure 1, according to certain embodiments. In these embodiments, a computer in the system performs or directs other elements to perform the steps of the method. The method begins in step 110, when a laser device in the system directs a laser beam at a target to cause photodisruption and generate a test pattern. The test pattern has regions where photodisruption has occurred, each region generated at a different laser energy setting.

[0029] The computer analyzes the photodisruption images recorded by the camera in step 112. The computer identifies the lowest energy region where nearly continuous photodisruption occurred in step 114. The region where nearly continuous photodisruption occurred may be a region where at least nearly all pulses caused photodisruption. The laser setting energy used to create the identified region is designated as the threshold energy in step 116.

[0030] The computer accesses past test patterns in step 118. The computer compares the current test pattern with past test patterns in step 120 to detect a change in threshold energy. There may be a change in step 122. If there is no change, the method ends. If there is a change, the computer notifies the user of the energy change in step 124. For example, the computer may display a notification of the energy change on display 36 along with a description of the change (e.g., the current and past values ​​of the threshold energy). The computer adjusts the laser setting energy to compensate for the change in step 126. For example, the computer may apply the energy change to the laser energy setting of the treatment pattern. The method then ends.

[0031] Elements of the systems and devices disclosed herein (e.g., computer 30) may include interfaces, logic, and / or memory, any of which may include computer hardware and / or software. An interface (e.g., display 36) can receive input to and / or send output from an element and is typically used to exchange information between, for example, software, hardware, peripherals, a user, and combinations thereof. A user interface is a type of interface that a user can use to communicate with a computer (e.g., send input to and / or receive output from a computer). Examples of user interfaces include a display, a graphical user interface (GUI), a touchscreen, a keyboard, a mouse, a gesture sensor, a microphone, a speaker, etc.

[0032] Logic can perform the operations of the elements. Logic may include one or more electronic devices that process data, e.g., execute instructions to generate output from input. Examples of such electronic devices may include computers, processors, microprocessors (e.g., central processing units (CPUs)), computer chips, etc. Logic may include computer software that encodes instructions executable by electronic devices to perform operations. Examples of computer software include computer programs, applications, operating systems, etc.

[0033] A memory can store information and may include a tangible, computer-readable, and / or computer-executable storage medium. Examples of memory include computer memory (e.g., random access memory (RAM) or read-only memory (ROM)), mass storage media (e.g., hard disks), removable storage media (e.g., compact discs (CDs) or digital video or versatile discs (DVDs)), databases, network storage (e.g., servers), and / or other computer-readable media. Certain embodiments may be directed to memory encoded with computer software.

[0034] While the present disclosure has been described in terms of specific embodiments, modifications of these embodiments (such as variations, substitutions, additions, omissions, and / or other changes) will be apparent to those skilled in the art. Accordingly, modifications may be made to these embodiments without departing from the scope of the invention. For example, modifications may be made to the systems and devices disclosed herein. As will be apparent to those skilled in the art, the elements of the systems and devices may be integrated or separate, and the operations of the systems and devices may be performed by more, fewer, or other elements. As another example, modifications may be made to the methods disclosed herein. These methods may include more, fewer, or other steps, and these steps may be performed in any suitable order, as will be apparent to those skilled in the art.

[0035] To assist the Patent Office and readers in interpreting the claims, applicants note that unless a particular claim expressly uses the phrase "means for" or "step for," no claim or claim element is intended to invoke 35 U.S.C. 112(f). The use of any other terminology in the claims (e.g., "mechanism," "module," "instrument," "unit," "element," "component," "device," "machine," "system," "processor," or "controller") is understood by applicants to refer to structures known to those of ordinary skill in the relevant art, and is not intended to invoke 35 U.S.C. 112(f).

Claims

1. 1. An ophthalmic surgery system for monitoring incision performance, comprising: a laser device configured to project a laser beam at a target at a laser setting energy, the laser beam causing a plurality of photodisruptions in the target; a camera configured to generate a plurality of images of the optical disruption within the target; A computer, instructing the laser device to cause the photodisruption in the target to generate a test pattern, the test pattern including a plurality of areas where the photodisruption has occurred, each of the areas being generated at a different laser setting energy; identifying a lowest energy region from the image where the substantially continuous photodisruption occurred; a computer configured to designate the laser setting energy used to generate the identified region as a threshold energy; and 1. An ophthalmic surgical system comprising:

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

3. The computer further comprises: accessing a past test pattern including a plurality of past regions of past optical breakdown; Comparing the test pattern with previous test patterns to detect changes in threshold energy. The ophthalmic surgical system of claim 1 , configured to:

4. The ophthalmic surgery system of claim 3 , wherein the previous test patterns were generated more than one month ago.

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

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

7. The ophthalmic surgical system of claim 3 , wherein the computer is further configured to predict future threshold energies by extrapolating from the test pattern and past test patterns.

8. the regions of the test pattern are arranged substantially similarly to previous regions of previous test patterns, such that each region has a corresponding previous region in the same position; For each of the regions, the laser setting energy that generated the region is approximately the same as the laser setting energy that generated the previous region corresponding to the region. The ophthalmic surgery system of claim 3 .

9. The ophthalmic surgical system of claim 1 , wherein each of the regions of the test pattern has a generally rectangular shape.

10. The ophthalmic surgical system of claim 1 , wherein each of the regions of the test pattern has a generally triangular shape.

11. 1. A method for monitoring dissection performance, comprising: directing, by a computer, a laser device to direct a laser beam at a target at a laser set energy, such that the laser beam causes multiple photodisruptions in the target to generate a test pattern, the test pattern including multiple photodisruption regions, each region generated at a different laser set energy; generating, with a camera, a plurality of images of the optical disruption within the target; identifying, by the computer, from the image, a region of lowest energy where the substantially continuous photodisruption occurred; designating, by the computer, the laser setting energy used to create the identified region as a threshold energy; A method comprising:

12. accessing, by the computer, past test patterns including a plurality of past regions of past optical breakdown; comparing the test pattern with previous test patterns to detect changes in threshold energy by the computer; The method of claim 11 further comprising:

13. 13. The method of claim 12, further comprising the step of adjusting, by the computer, the laser energy setting to compensate for changes in the threshold energy.

14. The method of claim 12 , further comprising the step of: predicting, by the computer, future threshold energies by extrapolating from the test patterns and past test patterns.

15. the regions of the test pattern are arranged substantially similarly to previous regions of previous test patterns, such that each region has a corresponding previous region in the same position; for each of the regions, the laser setting energy that generated the region is approximately the same as the laser setting energy that generated the previous region corresponding to the region; The method of claim 12.

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