Techniques for performing safety tests on laser diodes of ophthalmic surgical devices

Abstract

Aspects of the present disclosure provide techniques for performing safety tests on laser diodes associated with ophthalmic surgical devices. Exemplary methods include determining a measured slope efficiency of a laser diode based on a plurality of different current levels applied to an input of the laser diode and a plurality of different output power levels associated with the laser diode, determining a predicted slope efficiency of the laser diode based on a measured operating temperature of the ophthalmic surgical device, determining a result of a safety test of the laser diode based on the measured slope efficiency of the laser diode and the predicted slope efficiency for the laser diode, and outputting an electrical signal indicative of the result of the safety test of the laser diode.

Description

Technical Field

[0001] In various medical procedures, laser light (e.g., a laser treatment beam (“treatment beam”), a laser aiming beam (“aiming beam”), etc.) is used to assist in surgery and / or treat a patient's body. For example, in laser photocoagulation, a laser probe propagates a laser treatment beam to cauterize blood vessels at burn spots on the retina. The laser treatment beam is typically transmitted from a surgical laser system via an optical fiber cable, which terminates proximally at a port adapter connected to the surgical laser system and distally at a laser probe operated by the surgeon. It should be noted that in this specification, the distal end of a component refers to the end closer to the patient's body, and the proximal end of a component refers to the end facing away from the patient's body or, for example, the end closer to the surgical laser system.

Background Art

[0002] In addition to cauterizing blood vessels at the burn spot, the treatment beam may also damage some of the rods and cones present in the retina that provide vision, thereby affecting vision. Since vision is most sensitive at the macula in the center of the retina, the surgeon positions the laser probe to create burn spots in the peripheral areas of the retina. During the surgery, the surgeon operates the probe using an aiming beam that does not cause burns to illuminate the retinal area to be photocoagulated. Since low-power red laser diodes are available, the aiming beam is generally low-power red laser light. Once the surgeon positions the laser probe to illuminate the desired retinal spot with the aiming beam, the surgeon activates the laser treatment beam via a foot pedal or other means to photocoagulate the illuminated area (or, for example, the area surrounding the illuminated area) with the laser treatment beam. After burning a spot on the retina, the surgeon repositions the probe to illuminate a new spot with the aiming light, activates the laser treatment beam to photocoagulate the new spot, repositions the probe, etc., to disperse the desired number of burned laser spots across the retina.

Summary of the Invention

Means for Solving the Problems

[0003] Certain embodiments relate to a method for performing a safety test of a laser diode associated with an ophthalmic surgical device. The method can include measuring an operating temperature of the ophthalmic surgical device, outputting a plurality of different current levels, applying the plurality of different current levels to an input of the laser diode, and determining a plurality of different output power levels associated with the laser diode based on the plurality of different current levels applied to the input of the laser diode, the plurality of different output power levels including different output powers for respective different current levels of the plurality of different current levels. The method can also include determining a measured slope efficiency of the laser diode based on the plurality of different current levels and the plurality of different output power levels, determining a predicted slope efficiency of the laser diode based on the measured operating temperature of the ophthalmic surgical device, determining a result of the safety test of the laser diode based on the measured slope efficiency of the laser diode and the predicted slope efficiency for the laser diode, and outputting an electrical signal indicating the result of the safety test of the laser diode.

[0004] In certain embodiments, an apparatus for performing a safety test of a laser diode of an ophthalmic surgical device is provided. The apparatus includes a temperature sensor configured to measure the operating temperature of the ophthalmic surgical device. The apparatus also includes a power module configured to output a plurality of different current levels, apply the plurality of different current levels to an input of the laser diode, and determine a plurality of different output power levels associated with the laser diode based on the plurality of different current levels applied to the input of the laser diode, the plurality of different output power levels including different output powers for each of the different current levels of the plurality of different current levels. The apparatus also includes one or more processors configured to obtain the measured temperature of the ophthalmic surgical device from the temperature sensor, obtain a display of the plurality of different output power levels and the plurality of different current levels from the power module, determine a measured slope efficiency of the laser diode based on the plurality of different current levels and the plurality of different output power levels, determine an expected slope efficiency of the laser diode based on the measured operating temperature of the ophthalmic surgical device, determine a result of the safety test of the laser diode based on the measured slope efficiency of the laser diode and the expected slope efficiency for the laser diode, and output an electrical signal indicating the result of the safety test of the laser diode.

[0005] To better understand the above features of the present disclosure, a more specific description of the present disclosure, briefly summarized above, can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments and are not to be considered as limiting the scope of the present invention, and that other equally effective embodiments are possible.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0007] For ease of understanding, where possible, the same elements common to each drawing are designated using the same reference numerals. It is contemplated that the elements and features of one embodiment may be advantageously incorporated into other embodiments without further mention.

[0008] In the following description, for the sake of facilitating the understanding of the disclosed subject matter, details are described as examples. However, it should be apparent to those skilled in the art that the disclosed implementations are examples and do not cover all possible implementations. Therefore, it should be understood that the reference to the examples described is not intended to limit the scope of the present disclosure. Any variations and further modifications to the devices, apparatuses, methods described, as well as any further applications of the principles of the present disclosure, are fully contemplated to be readily conceivable by those skilled in the art in the relevant technical field of the present disclosure. In particular, it is fully contemplated that the features, components, and / or steps described with respect to one implementation may be combined with the features, components, and / or steps described with respect to other implementations of the present disclosure.

[0009] As described herein, it should be noted that the distal end, distal segment, or distal portion of a component refers to the end, segment, or portion that is closer to the patient's body during use of that component. On the other hand, the proximal end, proximal segment, or proximal portion of a component refers to the end, segment, or portion that is further away from the patient's body, for example, closer to a surgical laser system.

[0010] As used herein, the term "about" or "approximately" may refer to a variation of + / - 10% from the nominal value. It should be understood that such variations may be included in any value provided herein.

[0011] Exemplary Surgical Laser System FIG. 1 shows an exemplary system 100 for performing laser-assisted ophthalmic procedures according to a particular embodiment. The system 100 includes a surgical laser system 102 having one or more laser sources for generating a laser beam. For example, a first laser source within the surgical laser system 102 can generate a treatment beam at a first wavelength (e.g., about 532 nanometers (nm)), while a second laser source can generate an aiming beam at a second wavelength (e.g., about 635 nm). A user, such as a surgeon, can first trigger the surgical laser system 102 (e.g., via a footswitch, voice command, etc.) to emit the aiming beam onto a desired retinal spot. Once the surgeon positions the laser probe so that the desired retinal spot is illuminated by the aiming beam, the surgeon can actuate the treatment beam via a foot pedal or other means to treat the patient's body (e.g., photocoagulate the desired retinal spot using the treatment beam).

[0012] As shown, the surgical laser system 102 includes a connector or port adapter 114 that couples to an optical port of the surgical laser system 102. FIG. 1 also shows an optical fiber 110 within an optical fiber cable 111 having a distal end that couples to and extends through a probe 108 and a proximal end that couples to and extends through a port adapter 114. Optionally, as further described herein, the optical fiber 110 may include two or more fibers. In the example of FIG. 1, the port adapter 114 includes a ferrule having an opening into which the proximal end of the optical fiber 110 is inserted. The proximal end of the optical fiber 110 includes an interface surface (also referred to as a proximal entrance surface) at which the laser beam from the surgical laser system 102 can be focused when the proximal end of the optical fiber 110 is inserted into the ferrule. The interface surface of the optical fiber 110 includes the exposed proximal ends of one or more cores through which the laser beam can be directed. In the example of FIG. 1, the optical fiber 110 is a multi-core optical fiber (MCF) having four cores. Thus, the interface surface at the proximal end of the optical fiber 110 includes the proximal ends of the four cores at which the laser beam can be focused. Optionally, the optical fiber 110 can be a single-core optical fiber having only one core.

[0013] The surgical laser system 102 can be configured to split a single laser beam generated by a laser source into a plurality of laser beams presenting a laser spot pattern. For example, the surgical laser system 102 can split a aiming beam into four aiming beams and then deliver the four aiming beams to the interface surface of the optical fiber 110 through the openings of the ferrules of the port adapter 114. Further, the surgical laser system 102 can be configured to split a treatment beam into four treatment beams and deliver the four treatment beams to the interface surface of the optical fiber 110 through the openings of the ferrules. In such an example, each of the cores of the optical fiber 110 can transmit a multi-wavelength beam or a combined beam that can refer to a treatment beam combined with an aiming beam. Although specific aspects regarding the core of the optical fiber transmitting a combined beam have been described, it should be noted that the core of the optical fiber 110 can also individually transmit either a treatment beam or an aiming beam depending on which beam is activated and incident on the optical fiber 110.

[0014] In some examples, the surgical laser system 102 can also propagate an illumination beam to the interface surface of the optical fiber 110 (which may also include the proximal end of the cladding holding the core, for example, within the optical fiber 110) to illuminate the interior of the eye, particularly the area of the retina 120 to be photocoagulated. In certain aspects, the illumination beam can be generated by a white light emitting diode (LED).

[0015] The optical fiber 110 delivers the combined beam to the probe 108, and the probe 108 propagates the multi-spot pattern (e.g., four spots) of the combined beam to the retina 120 of the patient's eye 125. The probe 108 includes a probe body 112 and a probe tip 140 that houses and protects the distal end of the optical fiber 110. The distal end portion 145 of the probe tip 140 can also house a lens that focuses the combined beam onto the retina 120.

[0016] FIG. 2 shows an exemplary surgical laser system 202 and its components that can be implemented in accordance with the embodiments described herein. The surgical laser system 202 is an exemplary embodiment of the surgical laser system 102. The surgical laser system 202 includes a laser source 204 that propagates a treatment beam 210, a laser source 206 that propagates an aiming beam 212, and a light source 208 that propagates an illumination beam 214. The surgical laser system 202 further includes a plurality of lenses, diffractive elements, beam splitters, and other optical relay devices for relaying the laser beams and the illumination beam between the respective sources and the desired ports, which together may be referred to as an "optical relay system".

[0017] At the beginning of the surgery, the surgeon may activate the light source 208 to illuminate the inner side of the eyeball to make the retina more visible. As shown in the figure, when emitted by the light source 208, the illumination beam 214 (dot-dashed segments) is received by a collimating lens 222 configured to generate a beam having parallel light rays. In certain embodiments, the collimating lens 222 can be a multi-element achromatic correction lens including two single lenses and one compound lens. Thus, as shown in the figure, the illumination beam 214 exits from the opposite side of the collimating lens 222 with parallel light rays, passes through beam splitters 228 and 226 (sometimes called dichroic mirrors) respectively, and reaches the condenser lens 224. In certain embodiments, the condenser lens 224 can be a multi-element achromatic correction lens including two single lenses and one compound lens. In such embodiments, the condenser lens 224 can have the same design as the collimating lens 222 except that the assembly is reversed (e.g., rotated 180 degrees), thereby forming a 1:1 magnifying imaging system. The beam splitters 228 and 226 can each have different coatings on their two sides 228a and 228b, 226a and 226b. For example, the sides 228a and 226a are coated such that the light propagated there can pass through the beam splitters 228 and 226. Therefore, a significant portion of the illumination beam 214 propagated to the sides 228a and 226a passes through the beam splitters 228 and 226. On the other hand, the sides 228b and 226b are coated to reflect laser beams such as the light or aiming beam 212 and the treatment beam 210 respectively, as detailed below.

[0018] The light - collecting lens 224 then converges the illumination beam 214 onto the interface surface at the proximal end of an optical fiber, such as the optical fiber 110, which is coupled to the port 225 of the surgical laser system 202 via the port adapter 114. As described in connection with FIG. 1, the optical fiber 110 can have four cores in a 2×2 array embedded within a cylindrically shaped cladding of a larger diameter. Thus, the light - collecting lens 224B converges the illumination beam 214 onto the interface surface of the optical fiber 110 such that the illumination beam 214 is propagated to the distal end of a surgical probe (e.g., probe 108 of FIG. 1) coupled to the optical fiber 110 along the entire length of the cladding and through the entire diameter of the cladding and each of the four cores of the optical fiber 110. As described above, the interface surface of the optical fiber 110 includes the proximal ends of the four cores and their cladding, which are respectively exposed from the opening 217 of the port adapter 114 via the ferrule 215.

[0019] Once the surgeon can view the inside of the eye, the surgeon can project spots of one or more desired aiming beams from the distal end of the probe onto the retina. More specifically, after being actuated by the surgeon, the laser source 206 emits an aiming beam 212, e.g., a red laser beam, to the diffractive optical element (DOE) 221. In this specification, the diffractive segments may also be referred to as "segments". In the example of FIG. 2, the DOE 221 is positioned such that the aiming beam 212 is aligned with the central segment of the DOE 221, and the DOE 221 diffracts the aiming beam 212 into aiming beams 212a - d (e.g., four aiming beams). However, the surgeon can change the position of the DOE 221 to diffract the beam into a different number of beams (e.g., two or one). For example, using a voice command or some other function of the surgical laser system 202, the surgeon can position the DOE 221 such that the aiming beam 212 is aligned with different segments of the DOE 221 to diffract the aiming beam 212 into two, one, or some other number of beams.

[0020] When folded, the resulting aiming beam is reflected by beam splitter 228 through beam splitter 226 to condenser lens 224. In an example where aiming beams 212a - d are red aiming beams, beam splitter 228 can be a red dichroic optical element, and aiming beams 212a - d can be reflected from the narrow - band red spectrum notch of beam splitter 228. Then, condenser lens 224 focuses the four aiming beams onto the interface surface at the proximal end of optical fiber 110 such that each of the aiming beams propagates along the entire length of the corresponding core of optical fiber 110 to the distal end of the surgical probe (e.g., probe 108 of FIG. 1). Each of the four aiming beams converges with high coupling efficiency to the corresponding core within the MCF of the four cores, propagates along the length of the core, and reaches the distal end of the MCF. Thereby, the surgeon can project the spots of the four desired aiming beams from the distal end of the probe onto the retina.

[0021] As described above, when the surgeon positions and activates the laser probe so as to project the aiming beam spot onto the retina, the surgeon activates laser source 204 via a foot pedal or other means, etc., to treat the patient's body (e.g., photocoagulate a desired retinal spot using a treatment beam). When activated, laser source 204 emits treatment beam 210 (e.g., a green laser beam) as shown in FIG. 2. Treatment beam 210 reaches beam splitter 213, and beam splitter 213 is configured to allow a substantial portion of treatment beam 210 to pass through while being able to reflect a small portion 231 to sensor 223. Sensor 223 is an optical sensor configured to detect whether laser source 204 is active and to monitor the treatment beam power. After passing through beam splitter 213, when shutter 234 is in the open position allowing treatment beam 210 to pass, treatment beam 210 is received by fixed - type folding mirror 219 configured to reflect treatment beam 210 to beam splitter 218.

[0022] As described above, the surgical laser system 202 may also include a shutter 234 disposed between the laser source 204 and the fixed folding mirror 219. The shutter 234 may be configured to block or permit the treatment beam 210 to reach the fixed folding mirror 219. The surgeon or surgical staff can control the shutter 234 (e.g., via a foot switch, voice command, etc.) to emit the laser aiming beam and fire the treatment laser beam (e.g., by opening the shutter 234) to treat the patient's body (e.g., perform photocoagulation). In any case, the beam splitter 218 can direct the laser beam to the port adapter 114.

[0023] As shown, the treatment beam 210 passes through the beam splitter 218 before reaching the DOE 220. The DOE 220, similar to the DOE 221, diffracts the treatment beam 210 into treatment beams 210a - 210d (e.g., four treatment beams). However, the surgeon can change the position of the DOE 220 to diffract the beam into a different number of beams (e.g., two or one). For example, using a voice command or some other function of the surgical laser system 202, the surgeon can position the DOE 220 to align the treatment beam 210 with different segments of the DOE 220 such that the treatment beam 210 is diffracted into two, one, or some other number of beams. Optionally, the four red laser aiming beams 212a - d in a 2×2 array and the four green laser treatment beams 210a - 210d in a 2×2 array can be coupled and confined within the four cores without protruding into the surrounding cylindrical cladding.

[0024] Next, the treatment beams 210a - 210d are received by the beam splitter 226, and the beam splitter 226 reflects the treatment beams 210a - 210d towards the focusing lens 224. In an example where the treatment beams 210a - d are green treatment beams, the beam splitter 226 can be a green dichroic optical element, and the treatment beams 210a - d can be reflected from the narrow - band green spectral notch of the beam splitter 226. The treatment beams 210a - d are reflected by the beam splitter 226 at an angle with respect to the beam splitter 226, and that angle is equal to the angle at which the aiming beams 212a - d are passed through the beam splitter 226. Thus, when the laser source 204 is activated, the transmitted treatment beams 210a - d and the aiming beams 212a - d are combined (e.g., so as to overlap with each other) to generate combined beams 211a - d, which then reach the focusing lens 224.

[0025] The focusing lens 224 focuses the combined beams 211a - 211d onto the interface surface at the proximal end of the optical fiber 110 such that each of the combined beams 211a - 211d propagates along the entire length of the corresponding core of the optical fiber 110 to the distal end of the surgical probe (e.g., probe 108 of FIG. 1). More specifically, in the example of FIG. 2, the optical fiber 110 is a MCF having four cores such as cores A, B, C, and D. In such an example, the focusing lens 224 focuses the combined beams 211a - 211d onto the interface surface at the proximal end of the optical fiber 110 such that, for example, the combined beam 211a propagates into core A, the combined beam 211b propagates into core B, the combined beam 211c propagates into core C, and the combined beam 211d propagates into core D. FIG. 2 shows an embodiment for splitting the treatment beam 210 into four treatment beams 210a - d and focusing each of the treatment beams 210a - d into a separate core, but it should be understood that only one treatment beam can be used and focused into a single - core optical fiber. Similarly, FIG. 2 shows an embodiment for splitting the aiming beam 212 into four aiming beams 212a - d and focusing each of the aiming beams 212a - d into a separate core, but it should be understood that only one aiming beam can be used and focused into a single - core optical fiber.

[0026] Also, as shown, the surgical laser system 202 of FIG. 2 includes a temperature sensor 244 configured to monitor / sense the temperature of the surgical laser system 202, and one or more processors 252 configured to read and execute programming instructions stored in a memory 254 to operate one or more components of the surgical laser system 202, and a power module 242 configured to supply power to one or more components of the surgical laser system 202 (e.g., laser source 204, laser source 206, etc.). Additionally, FIG. 2 includes a display 256 configured to display information output by the surgical laser system 202 of FIG. 2. Additional aspects regarding the temperature sensor 244, the one or more processors 252, the memory 254, the power module 242, and the display 256 will be described below.

[0027] Aspects regarding the conduct of safety tests of laser diodes within an ophthalmic surgical device As described above, the surgical laser system 202 of FIG. 2 includes a laser source 206 that propagates an aiming beam 212. Optionally, the laser source 206 may include a red laser diode 240 that may be subject to laser classification restrictions for eye safety. For example, the red laser diode 240 may be subject to Class 2 laser restrictions that limit the output of the red laser diode 240 to a continuous wave output power of 1 milliwatt (mW) accessible to the human eye. Optionally, the surgical laser system 202 includes a power module 242 to help ensure that the output power of the red laser diode 240 does not exceed the maximum power level of a Class 2 laser (e.g., 1 mW). For example, the power module 242 may be configured to measure the radiant output power of the red laser diode 240 based on a portion of the aiming beam 212 and adjust the power supplied to the red laser diode 240 based on the measured output power so that the red laser diode 240 does not exceed the maximum power level of a Class 2 laser.

[0028] The above approaches may help avoid situations where the emission output power of the red laser diode 240 exceeds the maximum power level, but these approaches rely on the power module 242 never malfunctioning. However, if the power module 242 malfunctions, and if the power module 242 malfunctions such that the emitted power of the red laser diode 240 appears to be much smaller than the actual emitted power of the red laser diode 240, this scenario results in the power module 242 responding by increasing the current / power supplied to the red laser diode 240 to compensate for the seemingly low power, and as a result, creating a dangerous loop situation where the output power of the red laser diode 240 is driven at a level far higher than the allowable maximum power level.

[0029] Optionally, to avoid situations where the power module 242 malfunctions and the output power of the red laser diode 240 exceeds the maximum power level, a backup system can be created that relies on (1) limiting the current to the red laser diode 240 and (2) tightly controlling the temperature of the red laser diode 240. However, one problem with this type of system is that (a) controlling the current is an insufficient way to control the output power without tightly controlling the temperature as explained above, and (b) tightly controlling the diode temperature is complex and costly.

[0030] For example, FIG. 3 shows a graph 300 including a plurality of curves 302 to 308 plotting the optical output power against the forward current for a red laser diode 240 at different temperatures such as 0°C, 25°C, 40°C, and 50°C. The output power against the forward current of the red laser diode has a characteristic hockey stick shape with three different zones, namely, (1) a light emitting diode (LED) zone 314 in the low current region where the red laser diode 240 is not yet emitting laser light but is emitting incoherent LED light and the linear increase in the output power against the forward current is small, (2) a laser emission zone 316 in the high current region where the diode is emitting laser light and the linear increase in the output power against the forward current is large, and (3) a transition zone 318 between the LED zone 314 and the laser emission zone 316 that typically has a narrow range of small forward currents. As shown in FIG. 3, the slope of the LED zone 314 appears to be zero and the transition zone 318 appears to have a zero current width. However, the slope of the LED zone 314 is not zero but is very small. Similarly, the current width of the transition zone 318 is not zero but is very small.

[0031] As shown by curve 306 in FIG. 3, at a temperature of 40°C, by supplying a forward current of approximately 35 milliamperes (mA) to the red laser diode 240, an output power of the red laser diode 240 at a maximum power level of 1 mW indicated by reference numeral 310 is obtained. However, when the temperature is lower than 40°C, by supplying this same amount of forward current (e.g., 35 mA), an output power of the red laser diode 240 exceeding the maximum power level of 1 mW is obtained. For example, as shown by curve 304, by supplying 35 mA to the red laser diode 240 at a temperature of 25°C, an output power of the red laser diode 240 of approximately 6 mW is provided as shown at 312, and as a result, the red laser diode 240 is no longer classified as a class 2 laser and may cause eye damage.

[0032] Therefore, as can be seen in FIG. 3, due to slight variations in the operating temperature, the output power of the red laser diode 240 may vary significantly. In some cases, these temperature variations may occur, for example, when the surgical laser system 202 is powered on and the surgical laser system 202 begins to warm up due to heat dissipation of various components of the surgical laser system 202. Moreover, due to variations in the laser diodes for each component, each red laser diode may have a different unique relationship between output power and forward current. As a result, the output power may be allowed to significantly exceed the maximum power levels of different red laser diodes by currents and temperatures that maintain the output power below the maximum power level of a certain red laser diode.

[0033] Therefore, aspects of the present disclosure provide techniques for reducing the possibility that a laser diode of an ophthalmic surgical device, such as the red laser diode 240 within the surgical laser system 202, malfunctions beyond the maximum power level of the laser diode. In some cases, these techniques may involve performing a safety test on the laser diode of the ophthalmic surgical device to determine whether the laser diode can be used safely. In some cases, in order to avoid the temperature variations related to the forward current and output power of the laser diode described above, the safety test may take into account the slope efficiency of the laser diode (e.g., the change in the output power of the laser diode divided by the change in the forward current of the laser diode), which may be less affected by variations due to temperature changes.

[0034] Exemplary operations for performing a safety test related to a laser diode FIG. 4 shows an exemplary process 400 for performing a safety test on a laser diode of an ophthalmic surgical device, such as the red laser diode 240 of the surgical laser system 202.

[0035] Process 400 begins by measuring the operating temperature of surgical laser system 202 at 410. Optionally, surgical laser system 202 may measure the temperature using a temperature sensor, such as temperature sensor 244 of surgical laser system 202 shown in FIG. 2.

[0036] At 420, surgical laser system 202 outputs a plurality of different current levels (e.g., 10 mA, 12 mA, 14 mA, 16 mA, and 18 mA) and applies the plurality of different current levels to the input of red laser diode 240. For example, optionally, power module 242 may include a digital / analog converter (DAC) configured to output a plurality of different current levels in response to different voltage levels applied to the DAC and apply them to the input of red laser diode 240. Optionally, power module 242 may include an internal ammeter configured to measure the plurality of different current levels applied to the input of red laser diode 240.

[0037] At 430, surgical laser system 202 determines a plurality of output power levels associated with red laser diode 240 based on the plurality of different current levels applied to the input of red laser diode 240. Optionally, the plurality of output power levels may include different output powers for each of the plurality of different current levels. Optionally, to determine the plurality of different output power levels associated with the laser diode, power module 242 of surgical laser system 202 may be configured to measure a plurality of output voltage levels associated with red laser diode 240. In such a case, each of the plurality of output voltage levels may correspond to a different current level among the plurality of different current levels applied to the input of red laser diode 240 by power module 242.

[0038] Next, the power module 242 can convert a plurality of output voltage levels into a plurality of different output power levels based on a plurality of different current levels applied to the input of the red laser diode 240 and the correlation data stored in the memory 254 of the surgical laser system 202 indicating the correlation between the output voltage level and the output power level of the red laser diode 240. For example, during calibration of the surgical laser system 202, the output voltage level of the red laser diode 240 can be correlated with the output power level of the red laser diode 240 by comparing the measured voltage of the red laser diode 240 for two or more different input current levels with the output power of the red laser diode 240. Thereafter, interpolation can be performed using the measured voltages and output powers for two or more different input current levels to obtain the conversion or correlation relationship between the voltage level and the output power level of the red laser diode 240. Thus, during the safety test, the power module 242 can use the correlation data stored in the memory 254 to convert a plurality of output voltage levels into a plurality of different output power levels for a plurality of different current levels applied to the input of the red laser diode 240.

[0039] The power module 242 can determine the current level (I) applied to the input of the red laser diode 240 and the measured output voltage level (V) corresponding to this applied current level. Thus, the power module 242 can use the formula P = I * V to determine the output power level of the red laser diode 240 for a given current level applied to the input of the red laser diode 240.

[0040] Thereafter, at 440 in FIG. 4, the surgical laser system 202 determines the measured slope efficiency of the red laser diode 240 based on a plurality of different current levels and a plurality of different output power levels. Optionally, the measured slope efficiency of the red laser diode 240 can be determined by one or more processors 252 of the surgical laser system 202. For example, one or more processors 252 can obtain a display of a plurality of different output power levels and a plurality of different current levels from the power module 242. Next, the one or more processors can determine the measured slope efficiency of the red laser diode 240 based on the plurality of different current levels and the plurality of different output power levels.

[0041] As described above, in contrast to the forward current versus output power relationship of the red laser diode 240, the slope efficiency of the red laser diode 240 (e.g., the change in the output power of the red laser diode 240 divided by the change in the forward current of the red laser diode 240) may be less affected by variations due to temperature changes. For example, FIG. 5 includes a graph 500 showing the relationship of slope efficiency (e.g., mW / mA) versus temperature (T C ) for the red laser diode 240. As shown, the slope efficiency (S1) remains relatively the same for operating temperatures from 0° C. to 30° C. Due to the relative stability of the slope efficiency with respect to changes in the operating temperature associated with the red laser diode 240 (e.g., in contrast to the forward current versus output power relationship of the red laser diode 240), it is more reliable to perform a safety test of the red laser diode 240 based on the slope efficiency.

[0042] As described above, the slope efficiency of the red laser diode 240 represents the change in the output power of the red laser diode 240 divided by the change in the forward current of the red laser diode 240. Thus, in some cases, to determine the measured slope efficiency of the laser diode, one or more processors 252 may be configured to determine a first difference between a plurality of different output power levels and a second difference between a plurality of different current levels. Thereafter, one or more processors 252 may determine the ratio of the first difference to the second difference. The measured slope efficiency determined by one or more processors 252 includes the ratio of the determined first difference to the second difference.

[0043] As an example, assume that the power module 242 applies two current levels (e.g., I1 and I2) to the input of the red laser diode 240 and determines two output power levels (e.g., P1 and P2) corresponding to the two current levels. In this example, one or more processors 252 may calculate the slope efficiency (S1) of the red laser diode 240 at the operating temperature and time (t)

Number

[0044] Thereafter, at 450, the surgical laser system 202 determines the predicted slope efficiency of the red laser diode 240 based on the measured operating temperature (T) and one or more calibration parameters associated with when the red laser diode 240 was first calibrated.

[0045] For example, one or more processors 252 may be further configured to determine the predicted slope efficiency of the red laser diode 240 based on the calibration temperature (T cal ) associated with when the red laser diode 240 was first calibrated (e.g., during the manufacture of the surgical laser system 202), the calibration slope efficiency (S cal ) associated with when the red laser diode 240 was first calibrated, and one or more aging correction factors.

[0046] For example, during the calibration of the surgical laser system 202, a calibration temperature (T cal ) and a calibration slope efficiency (S cal ) are recorded and can be stored in the memory 254 of the surgical laser system 202. Optionally, for an LED zone associated with the red laser diode 240, such as the LED zone 314 shown in FIG. 3, a calibration temperature (T cal ) and a calibration slope efficiency (S cal ) can be measured. Optionally, the relationship between the slope efficiency and the temperature of the red laser diode 240 at time zero (e.g., when the surgical laser system 202 is calibrated) based on S cal and T cal is shown in Equation 1 below.

Number

[0047] As shown, Equation 1 includes another parameter known as the "slope of the slope efficiency"

Number

Number

Number

Number

[0048] For example, FIG. 6 includes a graph 600 showing the relationship between the slope efficiency and temperature of the red laser diode 240 based on Equation 1. As shown, FIG. 6 shows the calibration temperature (T cal ) and calibration slope efficiency (S cal ) represented by data points 602. The predicted slope efficiency of the red laser diode 240 can be extrapolated using Equation 1 for different temperature ranges from the minimum operating temperature (T cal ) to the maximum operating temperature (T cal ) based on T min and S max . In FIG. 6, the curve 606 represents the predicted average slope efficiency for the red laser diode 240 at a given temperature. Further, the predicted average slope efficiency for the red laser diode 240 at a given temperature is the slope of the slope efficiency of Equation 1

Number

[0049] In some cases, the relationship between the slope efficiency and temperature of the red laser diode 240 may change over time as the red laser diode ages. For example, as shown in FIG. 7, the slope efficiency (S) of the red laser diode 240 at Tcal tends to increase over time as shown by 702 (although it may slightly decrease), while the slope efficiency

Number

Equation

[0050] Optionally, one or more processors 252 of the surgical laser system 202 may use Equation 2 at 450 in FIG. 4 to determine the predicted slope efficiency of the red laser diode 240 at time t (e.g., the time from the start of the life of the red diode at which the safety test of the red laser diode 240 is performed) and temperature T (e.g., the operating temperature measured at 410 during the safety test). As shown, Equation 2 includes two aging correction coefficients, namely, a first aging correction coefficient (C) and a second aging correction coefficient (R). The first aging correction coefficient (C) is applied to the calibrated slope efficiency (e.g., the slope efficiency S cal ) measured during calibration to correct for the aging effect on the slope efficiency of the red laser diode 240, such as the improved slope efficiency shown at 702 in FIG. 7. A C value of 0 is the case where no correction of the slope efficiency measured during calibration is required. The second aging correction coefficient (R) is applied to the slope of the slope efficiency

Equation

Equation

Equation

[0051] Optionally, to account for uncertainties associated with the first aging correction factor (C), the second aging correction factor (R), and the slope of the slope efficiency

Number

[0052] As shown in FIG. 8, the range of the expected slope efficiency for the red laser diode 240 is extended for different temperatures (e.g., in the range of T min ~T max ) using Equation 2 to generate an area 802 where it is expected that the actual slope efficiency of the red laser diode 240 (e.g., the measured slope efficiency obtained at 440 in FIG. 4) will fall within that range. In FIG. 8, the boundary line 804 represents the expected maximum slope efficiency (S min ~T max ) for the red laser diode 240 for a given temperature in the range of T max ) and can be obtained by adding a plurality of standard deviations to the expected slope efficiency of the red laser diode 240 for the given temperature. Similarly, the boundary line 806 represents the expected minimum slope efficiency (S min ~T max ) for the red laser diode 240 for a given temperature in the range of T mix ) and can be obtained by subtracting a plurality of standard deviations from the expected slope efficiency of the red laser diode 240 for the given temperature.

[0053] Referring now to FIG. 4, at 460, the surgical laser system 202 determines the result of the safety test of the red laser diode 240 based on the measured slope efficiency of the red laser diode 240 obtained at 440 and the predicted slope efficiency for the red laser diode 240 obtained at 450. Thereafter, at 470, the surgical laser system 202 outputs an electrical signal indicating the result of the safety of the laser diode. For example, optionally, the electrical signal can be output by one or more processors 252 and displayed on a display 256 associated with the surgical laser system 202.

[0054] Optionally, to determine the result of the safety test of the laser diode, one or more processors 252 of the surgical laser system 202 can be further configured to determine whether the measured slope efficiency of the red laser diode 240 matches the range of the predicted slope efficiency of the red laser diode 240. FIG. 9 graphically shows the determination of the result of the safety test based on whether the measured slope efficiency of the red laser diode 240 matches the range of the predicted slope efficiency of the red laser diode 240.

[0055] For example, FIG. 9 shows min ~T max a graph 900 including an area 802 representing different ranges of predicted slope efficiency of the red laser diode 240 obtained according to Equation 2 for different temperatures from T

[0056] As shown in FIG. 9, there are four different zones shown in graph 900, each associated with a different safety test result. For example, as shown, graph 900 includes a first zone 902 that coincides with area 802, which is associated with a passing safety test. If the measured slope efficiency of red laser diode 240 (e.g., the measured slope efficiency determined at 440) coincides within the range of the first zone 902, the result of the safety test can be regarded as passing.

[0057] More specifically, for example, as described above, determining the predicted slope efficiency of red laser diode 240 at 450 in FIG. 4 results in, among other things, a range of the predicted slope efficiency of red laser diode 240 that includes a plurality of standard deviations above and below the predicted slope efficiency of red laser diode 240, which yields a predicted maximum slope efficiency (S max ) and a predicted minimum slope efficiency (S min ). Here, the predicted maximum slope efficiency (S max ) and the predicted minimum slope efficiency (S min ) are points on boundary lines 804 and 806, respectively, for time t and temperature T (e.g., the operating temperature measured at 410), and define the first zone 902.

[0058] Thus, if the measured slope efficiency of red laser diode 240 determined at 440 coincides with the range of the predicted slope efficiency of red laser diode 240 (e.g., the measured slope efficiency coincides with the first zone 902 bounded between S max and S min ), the safety test of red laser diode 240 can be regarded as passing. In such a case, an electrical signal output by one or more processors 252 can display on display 256 that red laser diode 240 has passed the safety test. Generally, a passing safety test can be defined according to Equation 3 below.

Equation

[0059] In Equation 3, S expt is the predicted slope efficiency of the red laser diode 240 determined at 450 in FIG. 4 with respect to the measured operating temperature of the surgical laser system 202 at 410 in FIG. 4, [Number] is the third standard deviation of the predicted slope efficiency, and S meas is the measured slope efficiency of the red laser diode 240 determined at 440 in FIG. 4. In other words, in Equation 3 [Number] is the predicted minimum slope efficiency (S min ) with respect to the measured operating temperature of the surgical laser system 202, while in Equation 3 [Number] is the predicted maximum slope efficiency (S max ) with respect to the measured operating temperature of the surgical laser system 202.

[0060] Furthermore, as shown, the graph 900 in FIG. 9 includes a second zone associated with a failed safety test. If the measured slope efficiency of the red laser diode 240 (e.g., the measured slope efficiency determined at 440) falls within the range of the second zone 904 surrounded by the safety boundary line 906, the result of the safety test may be considered a failure.

[0061] As described above, the red laser diode 240 is associated with a specific laser classification for performing ophthalmic surgery, such as laser classification type 2. Optionally, the safety threshold defining the safety boundary line 906 is the maximum output power (P max) may include a ratio (K) of the maximum output power (P2) related to a specific laser classification of the red laser diode 240. In other words, the safety threshold may be determined according to

Number

Number

Number

Number

[0062] Thus, if the measured slope efficiency of the red laser diode 240 does not match the range of the expected slope efficiency of the red laser diode 240 (e.g., the measured slope efficiency is S max ~ S minIf not (i.e., outside the range), and if the measured slope efficiency of the laser diode is less than a safety threshold associated with the laser diode 240 (e.g., defining the safety boundary 906 of the second zone 904), the result of the safety test may be considered a failure. In such a case, the electrical signal output by one or more processors 252 at 470 in FIG. 4 may indicate that the red laser diode 240 has failed the safety test. Optionally, one or more processors 252 of the surgical laser system 202 may be configured to stop the red laser diode 240 in response to the failed safety test.

[0063] Generally, a failing safety test can be defined according to Equation 6 below.

Equation

[0064] In Equation 6, S meas is the measured slope efficiency of the red laser diode 240 determined at 440 in FIG. 4, P max is the maximum output power associated with the normal operation of the red laser diode 240, P2 is the maximum output power associated with a specific laser classification of the red laser diode 240, and S expt is the predicted slope efficiency of the red laser diode 240 determined at 450 with respect to the measured operating temperature of the surgical laser system 202 determined at 410 in FIG. 4,

Equation

[0065] Thus, if the measured slope efficiency of the red laser diode 240 does not match the range of the predicted slope efficiency of the red laser diode 240 (e.g., the measured slope efficiency is outside S max ~S minIf not (between), and if the measured slope efficiency of the laser diode is above the safety threshold associated with the red laser diode, the electrical signal output by one or more processors 252 may indicate a warning state related to the safety test of the laser diode. For example, this warning state may be indicated when the measured slope efficiency of the red laser diode 240 falls within the third zone 908 or the fourth zone 910 of the graph 900 shown in FIG. 9.

[0066] If the measured slope efficiency of the red laser diode 240 falls within the third zone 908, the measured slope efficiency of the red laser diode 240 is lower than expected (e.g., lower than the expected minimum slope efficiency (S min ). If this scenario is caused by a malfunction of the power monitoring circuit incorporated in the red laser diode 240, the power monitoring circuit may misinterpret that insufficient power is supplied to the red laser diode 240, increase the power supplied to the red laser diode 240, and cause some cases where the maximum output power (P2) related to the specific laser classification of the red laser diode 240 is exceeded. However, if the power supplied to the red laser diode 240 does not exceed P2, the red laser diode 240 may be allowed to continue to be used.

[0067] If the measured slope efficiency of the red laser diode 240 falls within the fourth zone 910, the measured slope efficiency of the red laser diode 240 is higher than expected (e.g., higher than the expected minimum slope efficiency (S max ). If this scenario is caused by a malfunction of the power monitoring circuit related to the red laser diode 240, this malfunction may cause the red laser diode 240 to emit less laser light than expected. However, this does not necessarily cause an eye safety problem, so a warning state may be indicated, but the use of the red laser diode 240 may still be allowed.

[0068] The above-described techniques for performing safety tests on red laser diodes based on slope efficiency are advantageous for various reasons. For example, performing a safety test based on slope efficiency may not be vulnerable to diode-to-diode variations in performance characteristics because the confirmation of slope efficiency is based on the performance characteristics of the red laser diode 240 characterized during calibration of the surgical laser system 202 (e.g., a step performed during the manufacturing process of the surgical laser system 202). Additionally, these techniques account for and correct for the effects of aging and temperature differences between the calibration and future use of the surgical laser system 202. For example, these techniques may not be vulnerable to small uncertainties in diode temperature because slope efficiency depends only slightly on temperature. Moreover, the safety tests performed using the techniques presented herein are quick to perform, do not interfere with runtime operation, and provide a high level of confidence that the use of the red laser diode 240 during runtime operation is safe.

[0069] FIG. 10 shows an exemplary diagram illustrating how various components of the ophthalmic surgical device 1000 communicate and operate together. In some embodiments, the ophthalmic surgical device 1000 may include the surgical laser system 202 described with respect to FIG. 2 that performs a process 400 for performing safety tests on laser diodes, such as the red laser diode 240.

[0070] As shown, the ophthalmic surgical device 1000 includes, without limitation, a surgical laser system 1002, a display 1004, an interconnect 1006, and at least one I / O (input / output) device interface 1008 that may enable connection of various I / O devices (e.g., keyboard, display, mouse device, pen input, etc.) to the ophthalmic surgical device 1000.

[0071] Furthermore, as shown in the figure, a surgical laser system 1002, which can be an example of the surgical laser system 202 of FIG. 2, may include, without limitation, a temperature sensor 1010, a power module 1012, a red laser diode 1014, a central processing unit (CPU) 1016, and a memory 1018. The surgical laser system 1002 may also include other components, such as those shown in and described with respect to FIG. 2.

[0072] Optionally, the temperature sensor 1010 may be configured to measure the operating temperature of the ophthalmic surgical device 1000. Furthermore, optionally, the power module 1012 may be configured to output a plurality of different current levels and apply the plurality of different current levels to the input of the red laser diode 1014. Furthermore, optionally, the power module 1012 may be configured to determine a plurality of different output power levels associated with the red laser diode 1014 based on the plurality of different current levels applied to the input of the red laser diode 1014. Optionally, the plurality of different output power levels includes different output powers for each of the different current levels among the plurality of different current levels.

[0073] Optionally, to determine a plurality of different output power levels associated with the laser diode, the power module 1012 may further be configured to measure a plurality of output voltage levels associated with the red laser diode 1014, and each different output voltage level among the plurality of output voltage levels corresponds to a different current level among the plurality of different current levels applied to the input of the red laser diode 1014. Then, the power module 1012 may be configured to convert the plurality of output voltage levels into a plurality of different output power levels based on the plurality of different current levels applied to the input of the red laser diode 1014.

[0074] Optionally, the CPU 1016 may include one or more processors configured to obtain the measured temperature of the ophthalmic surgical apparatus 1000 from the temperature sensor 1010. The CPU 1016 may also be configured to obtain displays of a plurality of different output power levels and a plurality of different current levels from the power module 1012.

[0075] Optionally, the CPU 1016 may further be configured to determine the measured slope efficiency of the red laser diode 1014 based on a plurality of different current levels and a plurality of different output power levels. Optionally, to determine the measured slope efficiency of the laser diode, the CPU 1016 may be configured to determine a first difference between a plurality of different output power levels, determine a second difference between a plurality of different current levels, and determine a ratio of the first difference to the second difference. In such a case, the measured slope efficiency includes the determined ratio.

[0076] Optionally, the CPU 1016 may further be configured to determine the predicted slope efficiency of the red laser diode 1014 based on the measured operating temperature of the ophthalmic surgical apparatus. Optionally, the CPU 1016 may further be configured to determine the predicted slope efficiency of the red laser diode 1014 further based on the calibration temperature associated with when the red laser diode 1014 was first calibrated for the ophthalmic surgical apparatus 1000, the calibration slope efficiency associated with when the red laser diode 1014 was first calibrated for the ophthalmic surgical apparatus 1000, and one or more aging correction factors. Optionally, the indicators of the calibration temperature, the calibration slope efficiency, and the one or more aging correction factors may be stored in the memory 1018.

[0077] Optionally, the CPU 1016 may further

Number

Number

Number

Number

[0078] Optionally, the CPU 1016 can be further configured to determine the result of the safety test of the red laser diode 1014 based on the measured slope efficiency of the laser diode and the predicted slope efficiency for the laser diode. Optionally, the CPU 1016 can be further configured to output an electrical signal indicating the result of the safety test of the laser diode. Optionally, the display 1004 can be configured to receive an electrical signal from the CPU 1016 and display the result of the safety test.

[0079] Optionally, the CPU 1016 can be further configured to obtain the range of the predicted slope efficiency of the red laser diode 1014, and the range of the predicted slope efficiency of the laser diode includes a plurality of standard deviations above and below the predicted slope efficiency of the red laser diode 1014. Optionally, the plurality of standard deviations includes two or three standard deviations.

[0080] Optionally, in order to determine the result of the safety test of the red laser diode 1014, the CPU 1016 may further be configured to determine whether the measured slope efficiency of the red laser diode 1014 matches the range of the predicted slope efficiency of the laser diode.

[0081] Optionally, if the measured slope efficiency of the red laser diode 1014 matches the range of the predicted slope efficiency of the laser diode, the electrical signal output by the CPU 1016 indicates that the red laser diode 1014 has passed the safety test.

[0082] Optionally, if the measured slope efficiency of the red laser diode 1014 does not match the range of the predicted slope efficiency of the red laser diode 1014 and the measured slope efficiency of the red laser diode 1014 is less than the safety threshold related to the red laser diode 1014, the electrical signal output by the CPU 1016 indicates that the red laser diode 1014 has failed the safety test. Optionally, the red laser diode 1014 may be associated with a specific laser classification for performing ophthalmic surgery. Optionally, the safety threshold includes the ratio of the maximum output power related to the specific laser classification to the maximum output power related to the red laser diode 1014. Optionally, the maximum output power related to the specific laser classification and the maximum output power related to the red laser diode 1014 may be stored in the memory 1018.

[0083] Optionally, if the measured slope efficiency of the red laser diode 1014 does not match the range of the predicted slope efficiency of the red laser diode 1014 and the measured slope efficiency of the red laser diode 1014 is greater than or equal to the safety threshold related to the red laser diode 1014, the electrical signal output by the CPU 1016 indicates a warning state related to the safety test of the red laser diode 1014.

[0084] Optionally, the CPU 1016 may read and execute programming instructions stored in the memory 1018 to perform the processes described with respect to FIG. 4 and other operations described herein for performing safety tests on the laser diodes of the ophthalmic surgical device. Similarly, the CPU 1016 may read and store application data present in the memory 1018. The interconnect 1006 transmits programming instructions and application data among the CPU 1016, at least one I / O device interface 1008, the display 1004, the memory 1018, the power module 1012, the temperature sensor 1010, the red laser diode 1014, etc. The CPU 1016 may represent a single CPU, multiple CPUs, a single CPU having multiple processing cores, etc. Also, in certain embodiments, the memory 1018 may include volatile memory (e.g., random access memory). Further, in certain embodiments, the memory 1018 may include non-volatile memory (e.g., a disk drive). Although the memory 1018 is shown as a single unit, it may be a combination of fixed or removable storage devices such as a fixed disk drive, a removable memory card or optical storage, network attached storage (NAS), or a storage area network (SAN).

[0085] Exemplary embodiments Implementation examples are described in the following numbered paragraphs.

[0086] Embodiment 1: An apparatus for performing a safety test on a laser diode of an ophthalmic surgical device, comprising a temperature sensor configured to measure the operating temperature of the ophthalmic surgical device, a power module that outputs a plurality of different current levels, applies the plurality of different current levels to the input of the laser diode, and determines a plurality of different output power levels related to the laser diode based on the plurality of different current levels applied to the input of the laser diode, wherein the plurality of different output power levels include different output powers for each of the different current levels among the plurality of different current levels, a power module configured to obtain the plurality of different output power levels, and one or more processors configured to obtain the measured operating temperature of the ophthalmic surgical device from the temperature sensor, obtain a display of the plurality of different output power levels and the plurality of different current levels from the power module, determine the measured slope efficiency of the laser diode based on the plurality of different current levels and the plurality of different output power levels, determine the predicted slope efficiency of the laser diode based on the measured operating temperature of the ophthalmic surgical device, determine the result of the safety test of the laser diode based on the measured slope efficiency of the laser diode and the predicted slope efficiency of the laser diode, and output an electrical signal indicating the result of the safety test of the laser diode.

[0087] Embodiment 2: To obtain a plurality of different output powers related to the laser diode, the power module further measures a plurality of output voltage levels related to the laser diode, wherein each different output voltage level among the plurality of output voltage levels corresponds to a different current level among the plurality of different current levels applied to the input of the laser diode, and is configured to convert the plurality of output voltage levels into the plurality of different output power levels based on the plurality of different current levels applied to the input of the laser diode. The apparatus according to Embodiment 1.

[0088] Embodiment 3: To determine the measured slope efficiency of the laser diode, one or more processors are further configured to determine a first difference between a plurality of different output power levels, determine a second difference between a plurality of different current levels, and determine a ratio between the first difference and the second difference, and the measured slope efficiency includes the determined ratio, and the apparatus according to Embodiment 1 or 2.

[0089] Embodiment 4: One or more processors are further configured to determine the predicted slope efficiency of the laser diode based further on the calibration temperature associated when the laser diode was first calibrated with respect to the ophthalmic surgical device, the calibration slope efficiency associated when the laser diode was first calibrated with respect to the ophthalmic surgical device, and one or more aging correction factors, and the apparatus according to any one of Embodiments 1 to 3.

[0090] Embodiment 5: One or more processors are further configured to

Number

Number

Number

[0091] Embodiment 6: One or more processors are further configured to obtain a range of the predicted slope efficiency of the laser diode, and the range of the predicted slope efficiency of the laser diode includes a plurality of standard deviations above and below the predicted slope efficiency of the laser diode. The device according to any one of Embodiments 1 to 5.

[0092] Embodiment 7: The plurality of standard deviations includes two or three standard deviations. The device according to Embodiment 6.

[0093] Embodiment 8: To determine the result of the safety test of the laser diode, one or more processors are further configured to determine whether the measured slope efficiency of the laser diode matches the range of the predicted slope efficiency of the laser diode. The device according to Embodiment 6 or 7.

[0094] Embodiment 9: When the measured slope efficiency of the laser diode matches the range of the predicted slope efficiency of the laser diode, the electrical signal output by one or more processors indicates that the laser diode has passed the safety test. The device according to Embodiment 8.

[0095] Embodiment 10: When the measured slope efficiency of the laser diode does not match the range of the predicted slope efficiency of the laser diode and the measured slope efficiency of the laser diode is less than the safety threshold related to the laser diode, the electrical signal output by one or more processors indicates that the laser diode has failed the safety test. The device according to Embodiment 8 or 9.

[0096] Embodiment 11: When the measured slope efficiency of the laser diode does not match the range of the predicted slope efficiency of the laser diode and the measured slope efficiency of the laser diode is greater than or equal to the safety threshold related to the laser diode, the electrical signal output by one or more processors indicates a warning state related to the safety test of the laser diode. The device according to Embodiment 10.

[0097] Embodiment 12: The laser diode is associated with a specific laser classification for performing ophthalmic surgery. The laser diode is associated with a specific laser classification for performing ophthalmic surgery. The safety threshold includes the ratio of the maximum output power related to the specific laser classification to the maximum output power related to the laser diode, and the device according to Embodiment 10 or 11.

[0098] Embodiment 13: The one or more processors are further configured to stop the laser diode in response to a failed safety test, and the device according to any one of Embodiments 10 to 12.

[0099] Embodiment 14: A method for performing a safety test on a laser diode associated with an ophthalmic surgical device, including measuring the operating temperature of the ophthalmic surgical device, outputting a plurality of different current levels, and applying the plurality of different current levels to the input of the laser diode, obtaining a plurality of different output power levels related to the laser diode based on the plurality of different current levels applied to the input of the laser diode, where the plurality of different output power levels include different output powers for each of the different current levels among the plurality of different current levels, obtaining the measured slope efficiency of the laser diode based on the plurality of different current levels and the plurality of different output power levels, obtaining the predicted slope efficiency of the laser diode based on the measured operating temperature of the ophthalmic surgical device, determining the result of the safety test of the laser diode based on the measured slope efficiency of the laser diode and the predicted slope efficiency of the laser diode, and outputting an electrical signal indicating the result of the safety test of the laser diode.

[0100] Embodiment 15: Obtaining a plurality of different output power levels related to a laser diode includes measuring a plurality of output voltage levels related to the laser diode, where different ones of the plurality of output voltage levels correspond to different current levels among a plurality of different current levels applied to the input of the laser diode, and converting the plurality of output voltage levels to a plurality of different output power levels based on the plurality of different current levels applied to the input of the laser diode, according to the method described in Embodiment 14.

[0101] Embodiment 16: Obtaining the measured slope efficiency of a laser diode includes obtaining a first difference between a plurality of different output power levels, obtaining a second difference between a plurality of different current levels, and obtaining a ratio of the first difference to the second difference, where the measured slope efficiency includes the obtained ratio, according to the method described in Embodiment 14 or 15.

[0102] Embodiment 17: Obtaining the predicted slope efficiency of a laser diode is further based on the calibration temperature associated when the laser diode was first calibrated for an ophthalmic surgical device, the calibration slope efficiency associated when the laser diode was first calibrated for an ophthalmic surgical device, and one or more aging correction factors, according to the method described in any one of Embodiments 14 to 16.

[0103] Embodiment 18: Obtaining the predicted slope efficiency of a laser diode

Number

Number

[0104] Embodiment 19: The method further includes obtaining a range of the predicted slope efficiency of the laser diode, and the range of the predicted slope efficiency of the laser diode includes a plurality of standard deviations above and below the predicted slope efficiency of the laser diode, the method according to any one of Embodiments 14 to 18.

[0105] Embodiment 20: The method according to Embodiment 19, wherein the plurality of standard deviations includes two or three standard deviations.

[0106] Embodiment 21: Determining the result of the safety test of the laser diode includes determining whether the measured slope efficiency of the laser diode matches the range of the predicted slope efficiency of the laser diode, the method according to Embodiment 19 or 20.

[0107] Embodiment 22: When the measured slope efficiency of the laser diode matches the range of the predicted slope efficiency of the laser diode, the output electrical signal indicates that the laser diode has passed the safety test, the method according to Embodiment 21.

[0108] Embodiment 23: When the measured slope efficiency of the laser diode matches the range of the predicted slope efficiency of the laser diode, and when the measured slope efficiency of the laser diode is less than the safety threshold related to the laser diode, the output electrical signal indicates that the laser diode has failed the safety test, the method according to Embodiment 21 or 22.

[0109] Embodiment 24: The method according to embodiment 23, wherein when the measured slope efficiency of the laser diode does not match the range of the predicted slope efficiency of the laser diode and when the measured slope efficiency of the laser diode is equal to or greater than a safety threshold related to the laser diode, the output electrical signal indicates a warning state related to the safety test of the laser diode.

[0110] Embodiment 25: The method according to embodiment 23 or 24, wherein the laser diode is associated with a specific laser classification for performing ophthalmic surgery, and the safety threshold includes the ratio of the maximum output power related to the specific laser classification to the maximum output power related to the laser diode.

[0111] Embodiment 26: The method according to any one of embodiments 23 to 25, further comprising stopping the laser diode in response to a failed safety test.

[0112] Embodiment 27: An apparatus comprising means for performing the method according to any of embodiments 14 to 26.

[0113] Embodiment 28: A non-transitory computer-readable medium including executable instructions that, when executed by a processor of the apparatus, cause the apparatus to perform the method according to any of embodiments 14 to 26.

[0114] Embodiment 29: A computer program product embodied on a computer-readable storage medium including code for performing the method according to any of embodiments 14 to 26.

[0115] Additional Considerations As used herein, the phrase referring to a list of items "at least one of" refers to any combination of those items, including a single element. By way of example, "at least one of a, b, or c" is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination of multiple identical elements (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other order of a, b, and c).

[0116] The foregoing description is provided to enable those skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but rather are to cover the full scope consistent with the language of the claims.

[0117] Even when an element is recited in the singular in a claim, it is intended to mean "one or more" rather than "one and only one" unless specifically stated otherwise. Unless otherwise specified, the term "some" refers to one or more. All structural and functional equivalents of the elements of various aspects known or later to be known to those skilled in the art described throughout this disclosure are hereby expressly incorporated by reference and are intended to be included in the claims. Moreover, what is disclosed herein is not intended to be dedicated to the public regardless of whether such disclosure is expressly recited in the claims. No element of a claim is to be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the element is expressly recited using the phrase "step for". As used herein, the term "exemplary" is used in the sense of "serving as an example, instance, or illustration". Any aspect described as "exemplary" herein should not necessarily be construed as preferred or advantageous over other aspects.

Claims

1. An apparatus for performing a safety test of a laser diode of an ophthalmic surgical device, comprising: a temperature sensor configured to measure a first operating temperature of the ophthalmic surgical device; a power module, outputting a plurality of different current levels, applying the plurality of different current levels to an input of the laser diode, and determining a plurality of different output power levels related to the laser diode based on the plurality of different current levels applied to the input of the laser diode, wherein the plurality of different output power levels include different output powers for respective different ones of the plurality of different current levels; a power module configured as such; one or more processors, acquiring the measured operating temperature of the ophthalmic surgical device from the temperature sensor, acquiring a display of the plurality of different output power levels and the plurality of different current levels from the power module, determining a measured slope efficiency of the laser diode based on the plurality of different current levels and the plurality of different output power levels, determining an expected slope efficiency of the laser diode based on the measured operating temperature of the ophthalmic surgical device, determining a result of the safety test of the laser diode based on the measured slope efficiency of the laser diode and the expected slope efficiency of the laser diode, and one or more processors configured to output an electrical signal indicating the result of the safety test of the laser diode. An apparatus comprising the above.

2. To determine the plurality of different output power levels related to the laser diode, the power module further: measures a plurality of output voltage levels related to the laser diode, wherein different ones of the plurality of output voltage levels correspond to different ones of the plurality of different current levels applied to the input of the laser diode; converts the plurality of output voltage levels to the plurality of different output power levels based on the plurality of different current levels applied to the input of the laser diode. The apparatus according to claim 1, configured as such.

3. To determine the measured slope efficiency of the laser diode, the one or more processors further determine a first difference between a plurality of different said output power levels, determine a second difference between a plurality of different said current levels, and determine a ratio of the first difference to the second difference configured as such, the measured slope efficiency includes the determined ratio, the apparatus according to claim 1. **Claim 4** The one or more processors are further configured to determine the expected slope efficiency of the laser diode based on a calibration temperature associated with when the laser diode was first calibrated for the ophthalmic surgical device, a calibration slope efficiency associated with when the laser diode was first calibrated for the ophthalmic surgical device, and one or more aging correction factors, the apparatus according to claim 1. **Claim 5** The one or more processors are further 【Number 1】 configured to determine the expected slope efficiency of the laser diode according to Here, S(t, T) is the predicted slope efficiency of the laser diode at time t and the measured operating temperature T, and S ｃａｌ is the calibration slope efficiency related to the laser diode, C is the first aging correction coefficient for the calibration slope efficiency S ｃａｌ and is 【Number 2】 where is the slope of the calibration slope efficiency, and R is the calibration slope efficiency [Number 3] is the second aging correction coefficient for, T ｃａｌ is the calibration temperature related to the laser diode, the apparatus according to claim 4. **Claim 6** The one or more processors are further configured to determine a range of the expected slope efficiency of the laser diode, the range of the expected slope efficiency of the laser diode including a plurality of standard deviations above and below the expected slope efficiency of the laser diode, the apparatus according to claim 1. **Claim 7** The plurality of standard deviations includes two or three standard deviations, the apparatus according to claim 6. **Claim 8** To determine the result of the safety test of the laser diode, the one or more processors are further configured to determine whether the measured slope efficiency of the laser diode matches the range of the expected slope efficiency of the laser diode, the apparatus according to claim 6. **Claim 9** When the measured slope efficiency of the laser diode matches the range of the expected slope efficiency of the laser diode, the electrical signal output by the one or more processors indicates that the laser diode has passed the safety test, the apparatus according to claim 8. **Claim 10** If the measured slope efficiency of the laser diode does not match the range of the predicted slope efficiency of the laser diode, and if the measured slope efficiency of the laser diode is less than a safety threshold associated with the laser diode, the electrical signal output by the one or more processors indicates that the laser diode has failed the safety test. The apparatus according to claim 8.

11. If the measured slope efficiency of the laser diode does not match the range of the predicted slope efficiency of the laser diode, and if the measured slope efficiency of the laser diode is greater than or equal to the safety threshold associated with the laser diode, the electrical signal output by the one or more processors indicates a warning state related to the safety test of the laser diode. The apparatus according to claim 10.

12. The laser diode is associated with a specific laser classification for performing ophthalmic surgery. The safety threshold includes the ratio of the maximum output power associated with the specific laser classification to the maximum output power associated with the laser diode. The apparatus according to claim 10.

13. The one or more processors are further configured to stop the laser diode in response to the failed safety test. The apparatus according to claim 10.

14. A method for performing a safety test of a laser diode associated with an ophthalmic surgical device, comprising: measuring an operating temperature of the ophthalmic surgical device; outputting a plurality of different current levels and applying the plurality of different current levels to an input of the laser diode; determining a plurality of different output power levels associated with the laser diode based on the plurality of different current levels applied to the input of the laser diode, wherein the plurality of different output power levels include different output powers for each of the different current levels among the plurality of different current levels; determining a measured slope efficiency of the laser diode based on the plurality of different current levels and the plurality of different output power levels; determining a predicted slope efficiency of the laser diode based on the measured operating temperature of the ophthalmic surgical device; Determining a result of the safety test of the laser diode based on the measured slope efficiency of the laser diode and the predicted slope efficiency for the laser diode; Outputting an electrical signal indicating the result of the safety test of the laser diode; A method comprising:

15. Obtaining a plurality of different output power levels associated with the laser diode comprises: Measuring a plurality of output voltage levels associated with the laser diode, wherein different ones of the plurality of output voltage levels correspond to different ones of the plurality of different current levels applied to the input of the laser diode; Converting the plurality of output voltage levels to a plurality of different output power levels based on the plurality of different current levels applied to the input of the laser diode; The method according to claim 14, comprising:

Images