Laser pulse control by subcarrier modulation

Abstract

Systems and methods are disclosed for flexibly controlling laser pulses output from a laser system. An exemplary surgical system includes a laser, a laser energy control system configured to regulate the amount of electromagnetic energy in each laser pulse exiting the laser system, and a laser pulse controller. The control signal communicated by the laser pulse controller may include a subcarrier signal that modulates the amount of electromagnetic energy in the laser pulse exiting the laser system. The control signal may further include a threshold signal and / or a maximum power signal. The subcarrier signal may oscillate between a threshold power and a maximum power.

Description

[Technical field]

[0001] The present disclosure is directed to systems and methods for controlling laser pulses output from a laser system. [Background technology]

[0002] Lasers are used in many different medical procedures, including many different ophthalmic procedures. For example, lasers may be used in cataract surgery, such as to fragment the cataractous lens. In some procedures, the laser is used to first fragment the lens, followed by phacoemulsification of the lens with an ultrasonic handpiece to complete the disintegration for removal of the lens. In other procedures, the laser may be used to complete the fragmentation and / or phacoemulsification of the lens for removal, without the need for separate application of ultrasonic energy. Lasers may also be used in other steps of cataract surgery, such as to make corneal incisions and / or to open the lens capsule.

[0003] Lasers may also be used in glaucoma surgery, for example, to create all or part of a channel through the trabecular meshwork or scleral tissue for drainage of aqueous humor from the eye.

[0004] Lasers may also be used in vitreoretinal surgery. In some procedures, lasers may be used in vitrectomy to cut or break vitreous fibers for removal. Lasers may be incorporated into a vitrectomy probe, and energy from the laser may be applied to the vitreous fibers to cut or break them for removal.

[0005] In other vitreoretinal applications, lasers can be used to photocoagulate retinal tissue to treat problems such as retinal breaks and / or the effects of diabetic retinopathy.

[0006] US Patent Publication No. 2018 / 0360657 discloses an example of an ophthalmic laser system. This application describes the use of lasers to create surgical incisions or photodisrupt eye tissue and for cataract surgery, such as laser-assisted cataract surgery (LACS). US Patent Publication No. 2019 / 0201238 discloses another example of an ophthalmic laser system. This application describes the use of lasers, such as in vitrectomy probes, to cut or break vitreous fibers. US Patent Publication No. 2018 / 0360657 and US Patent Publication No. 2019 / 0201238 are expressly incorporated herein by reference in their entireties. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2018 / 0360657 [Patent Document 2] US Patent Application Publication No. 2019 / 0201238 Summary of the Invention [Problem to be solved by the invention]

[0008] Some laser systems emit pulses having a desired duration and repetition rate. Operating a laser in pulses can achieve desirable power and energy characteristics for a particular application. Additionally, while the energy of the beam emitted by a laser can be controlled by controlling the laser itself, in some systems it may be desirable to control the amount of energy in the laser beam downstream of the laser. Existing systems for laser pulse selection typically suffer from one or more drawbacks, such as power loss, complexity, and cost. Improved systems and methods for laser pulse control are needed. [Means for solving the problem]

[0009] The present disclosure is directed to improved systems and methods for controlling laser pulses output from a laser system.

[0010] In some embodiments, a surgical system includes a laser configured to emit electromagnetic radiation in laser pulses, a laser energy control system configured to regulate an amount of electromagnetic energy in each laser pulse exiting the laser system, and a laser pulse controller configured to communicate control signals to the laser energy control system. The control signals communicated by the laser pulse controller to the laser energy control system can include a subcarrier signal that modulates the amount of electromagnetic energy in the laser pulse exiting the laser system.

[0011] The subcarrier signal may be a periodic pattern, the subcarrier signal may be a square wave pattern, the subcarrier signal may be a sinusoidal pattern.

[0012] The control signals communicated by the laser pulse controller to the laser energy control system may further include a threshold signal representative of a threshold power and / or a maximum power signal representative of a maximum power. The threshold power and / or the maximum power may be adjustable. The subcarrier signal may oscillate between the threshold power and the maximum power.

[0013] In some examples, the surgical system may further include an adjustable input device configured to be actuated over an operating range. The operating range of the adjustable input device may be configured to allow an operator to dynamically control the amount of energy of a laser pulse emitted from the laser output from the laser system. The operating range of the adjustable input device may be configured to allow an operator to dynamically control the amount of energy of a laser pulse emitted from the laser output from the laser system up to an amount of maximum power or between a threshold power and a maximum power. The adjustable input device may include a foot pedal configured to be actuated over an operating range.

[0014] In some examples, the surgical system may further include an optical switching device configured to switch between a first state in which the optical switching device allows laser pulses emitted from the laser to be output from the laser system and a second state in which the optical switching device prevents laser pulses emitted from the laser from being output from the laser system. The optical switching device may include a shutter and a shutter motor.

[0015] In some examples, the laser energy control system may include a wave plate, a wave plate motor, and a polarizer, where the wave plate motor is configured to move the wave plate to different positions corresponding to different percentages of the laser electromagnetic energy allowed to pass through the laser energy control system.

[0016] In some examples, a method of controlling a surgical system includes (i) providing an input to a surgical system including a laser configured to emit electromagnetic radiation in laser pulses, a laser energy control system configured to regulate an amount of electromagnetic energy in each laser pulse exiting the laser system, and a laser pulse controller configured to communicate a control signal to the laser energy control system, the control signal communicated by the laser pulse controller to the laser energy control system including a subcarrier signal that modulates the amount of electromagnetic energy in the laser pulse exiting the laser system, (ii) emitting the electromagnetic radiation from the laser in laser pulses, and (iii) outputting laser pulses from the laser system in accordance with the control signal communicated by the laser pulse controller. The subcarrier signal may be a periodic pattern. The control signal may further include a threshold signal and / or a maximum power signal.

[0017] Further examples and features of embodiments of the invention will be apparent from the drawings and detailed description.

[0018] The accompanying drawings illustrate exemplary implementations of the systems and methods disclosed herein and, together with the description, serve to explain the principles of the present disclosure. [Brief description of the drawings]

[0019] [Figure 1] 1 illustrates an exemplary ophthalmic surgical console with a foot pedal connected thereto. [Diagram 2] 1 illustrates an example of an architecture for a surgical system that includes a laser system. [Diagram 3] 1 illustrates an example of a laser pulse controller architecture. [Figure 4] 1 illustrates an example of a range of motion for an adjustable input device, such as a foot pedal. [Diagram 5] 1 shows an example of a command packet for sending to a laser pulse controller. [Figure 6A-6C] Figure 6A shows an example of a laser pulse emitted from a laser, Figure 6B shows an example of a static pulse control signal, and Figure 6C shows the output of a laser pulse according to the static pulse control signal of Figure 6B. [Figure 7A-7C] FIG 7A shows an example of a laser pulse emitted from a laser, similar to FIG 6A. FIG 7B shows an example of a pulse control signal in linear mode. FIG 7C shows the output of a laser pulse according to the linear mode pulse control signal of FIG 7B. [Figure 8A-8C] FIG 8A shows an example of a laser pulse emitted from a laser, similar to FIG 6A and FIG 7A. FIG 8B shows an example of a subcarrier signal and a threshold signal. FIG 8C shows the output of a laser pulse according to the subcarrier signal and threshold signal of FIG 8B. [Figure 9A-9C] Figure 9A shows an example of a laser pulse emitted from a laser, similar to Figures 6A, 7A and 8A. Figure 9B shows another example of a subcarrier signal and a threshold signal. Figure 9C shows the output of a laser pulse according to the subcarrier signal and threshold signal of Figure 9B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The accompanying drawings can be better understood with reference to the following detailed description.

[0021] For the purpose of promoting an understanding of the principles of the present disclosure, reference will now be made to the implementations shown in the drawings, and specific language will be used to describe those and other implementations. It will nevertheless be understood that the examples shown in the drawings or described herein are not intended to limit the scope of the claims. Any changes and further modifications to the systems, devices, equipment or methods shown or described, and any further applications of the principles of the present disclosure, are fully contemplated as would normally occur to one skilled in the art to which the present disclosure pertains. In particular, features, components and / or steps described with respect to one implementation of the present disclosure may be combined with features, components and / or steps described with respect to other implementations of the present disclosure. For simplicity, the same reference numbers may be used throughout the drawings to refer to the same or similar parts in some cases.

[0022] The designations "first" and "second" as used herein are not intended to indicate or imply any particular location or other characteristic. Rather, when the designations "first" and "second" are used herein, they are used only to distinguish one component from another. The terms "mounted," "connected," "coupled," and the like, mean that one component is mounted, connected, coupled, etc., directly to another component or indirectly through one or more other components, unless such direct or indirect mounting, connection, coupling, etc. is specified.

[0023] FIG. 1 illustrates an exemplary ophthalmic surgical console 100 with a foot pedal 106 connected thereto. The exemplary ophthalmic surgical console 100 may be used in the systems and methods according to the present disclosure. The ophthalmic surgical console 100 may be similar to the ophthalmic surgical console shown and described in U.S. Pat. No. 9,931,447, the entire disclosure of which is expressly incorporated herein by reference. The ophthalmic surgical console 100 may be similar to a known and already used ophthalmic surgical console, such as the CENTURION® Vision System available from Alcon Laboratories, Inc. (Fort Worth, Texas) or the CONSTELLATION® Vision System available from Alcon Laboratories, Inc. (Fort Worth, Texas), or any other ophthalmic surgical console suitable for use with the principles described herein.

[0024] As shown in FIG. 1, an exemplary ophthalmic surgical console 100 includes a housing 102 within which a computer system is disposed and an associated display screen 104 that presents data related to system operation and performance during an ophthalmic surgical procedure.

[0025] The foot pedal 106 is an adjustable input device that an operator may actuate over a range of motion to control one or more functions. The foot pedal 106 may be depressed to various positions over a range of motion to control functions as described further below. Although a foot pedal 106 is illustrated, other adjustable input devices such as hand operated buttons or knobs may be used. The foot pedal 106 or other adjustable input device may be connected to the surgical console 100 by a wired or wireless connection.

[0026] Surgical console 100 includes one or more systems that may be used in performing an ophthalmic surgical procedure. For example, surgical console 100 may include a fluid system that includes an irrigation system for delivering fluid to the eye and an aspiration system for aspirating fluid from the eye.

[0027] An exemplary surgical system according to the present disclosure may include a laser system suitable for one or more ophthalmic procedures. FIG. 2 illustrates an example of a surgical system architecture, including a surgical console 100, an adjustable input device, such as a foot pedal 106, and an exemplary laser system 200. The laser system 200 may include a laser 212, an optical switching device 214, and a laser pulse controller 216. In the illustrated embodiment, the laser pulse controller 216 is or includes a subcarrier pulse controller. In some embodiments, the laser system 200 may be housed within the surgical console 100. In other embodiments, the laser system 200 may be housed within a separate console in communication with the surgical console 100. In other embodiments, one or more portions of the laser system 200, such as the laser 212 and the optical switching device 214, may be housed within a separate console in communication with the surgical console 100, and one or more other portions of the laser system 200, such as the laser pulse controller 216, may be housed within the surgical console 100. In other embodiments, the laser system 200 may be in a stand-alone housing that receives input from a foot pedal or other adjustable input device 106 without the need for a separate surgical console 100.

[0028] In addition to the laser 212, the optical switching device 214, and the laser pulse controller 216, the laser system 200 may have other components. For example, the laser system 200 may include components for operating the laser, such as a power supply, a laser pump, laser energy control elements and a monitor. Additionally, the laser system 200 may include other components in the optical path of the laser output, such as one or more lenses, mirrors, and optical fibers (not shown).

[0029] In some embodiments, the laser system 200 may be suitable for cataract surgery. In some embodiments, the output energy of the laser system is suitable for fragmenting and / or emulsifying the cataractous lens. In some instances, the laser output is used to fragment and / or phacoemulsify the lens to an extent sufficient to remove the lens.

[0030] In some embodiments, the laser system 200 may be suitable for glaucoma surgery. In some embodiments, the output energy of the laser system is suitable for forming or promoting the formation of drainage channels in ocular tissue.

[0031] Laser 212 may be any type of laser suitable for a desired application. Laser 212 may output suitable electromagnetic radiation of any suitable wavelength. For example, laser 212 may emit electromagnetic radiation of one or more wavelengths within the visible, infrared, and / or ultraviolet wavelengths. Laser 212 operates or may be operated to emit a continuous beam of electromagnetic radiation. Alternatively, laser 212 operates or may be operated to emit a pulsed beam.

[0032] In one example, the laser 212 operates in the infrared range. For example, the laser 212 may output electromagnetic radiation in the mid-infrared range, such as in the range of about 2.0 micrometers to about 4.0 micrometers. Some example wavelengths include about 2.5 micrometers to 3.5 micrometers, such as about 2.775 micrometers, about 2.8 micrometers, or about 3.0 micrometers. Such a laser may be suitable, for example, for lens fragmentation in cataract surgery or other procedures.

[0033] Laser system 200 is designed to direct laser electromagnetic radiation from laser 212 to an output port. Laser system 200 may direct laser electromagnetic radiation from laser 212 to an output port through one or more optical components, such as lenses and mirrors.

[0034] An instrument may be optically connected to the laser system 200 to receive the laser electromagnetic radiation from the output port. The instrument may be, for example, a handpiece for an ophthalmic procedure. The instrument or handpiece may be connected to the laser system by a delivery optical fiber. The delivery optical fiber may be flexible and relatively long, allowing an operator flexibility in manipulating the handpiece at some distance from the laser system 200. The laser electromagnetic radiation may be emitted from the laser system 200 and propagated through the optical fiber and the handpiece from the output tip of the handpiece to a desired target, such as a lens or lens fragment in a patient's eye.

[0035] Optical switching device 214 is a device that operates to either cause laser electromagnetic radiation, such as a laser pulse emitted from laser 212, to be output from the laser system, or cause laser electromagnetic radiation, such as a laser pulse emitted from laser 212, to not be output from the laser system. Optical switching device 214 may be switched back and forth between these two states under the control of laser pulse controller 216.

[0036] In some examples, the optical switching device 214 may include a shutter and a shutter motor. Examples of suitable optical switching devices are described and illustrated in U.S. Provisional Patent Application No. 63 / 186,387, which is incorporated by reference herein in its entirety, and U.S. Provisional Patent Application No. 63 / 222,521, which is incorporated by reference herein in its entirety.

[0037] For example, the optical switching device 214 may include a shutter that is moved in and out of the path of the laser electromagnetic radiation by a shutter motor to selectively allow or prevent the laser electromagnetic radiation from being output from the laser system. The shutter motor may be configured to alternately move the shutter between a first position corresponding to a first state of the optical switching device (a state in which the optical switching device allows the laser electromagnetic energy, such as a laser pulse emitted from the laser, to be output from the laser system) and a second position corresponding to a second state of the optical switching device (a state in which the optical switching device prevents the laser electromagnetic energy, such as a laser pulse emitted from the laser, from being output from the laser system). In one example, the shutter includes a mirror and the shutter motor includes a galvanometer motor.

[0038] In another example, the optical switching device 214 may include (i) a shutter having an axis of rotation and at least one open area and at least one solid area disposed about the axis of rotation of the shutter, and (ii) a shutter motor configured to rotate the shutter about the axis of rotation of the shutter. In such an example, a first state of the optical switching device (a state in which the optical switching device allows laser electromagnetic energy, such as laser pulses emitted from the laser, to be output from the laser system) corresponds to a shutter position in which the solid area of ​​the shutter is not in the path of the laser pulses emitted from the laser, and a second state of the optical switching device (a state in which the optical switching device prevents laser electromagnetic energy, such as laser pulses emitted from the laser, from being output from the laser system) corresponds to a shutter position in which the solid area of ​​the shutter is in the path of the laser pulses emitted from the laser.

[0039] The optical switching device 214 may further include a laser energy control system configured to regulate the amount of electromagnetic energy of each laser pulse exiting the laser system. For example, the laser energy control system may include a waveplate, a waveplate motor, and a polarizer, the waveplate motor configured to move the waveplate to different positions corresponding to different percentages of the laser electromagnetic energy allowed to pass through the laser energy control system. Examples of such laser energy control systems are described and illustrated in U.S. Provisional Patent Application No. 63 / 186,387, which is incorporated herein by reference in its entirety, and U.S. Provisional Patent Application No. 63 / 222,521, which is incorporated herein by reference in its entirety, as discussed above.

[0040] In another alternative embodiment, the optical switching device 214 may include a Pockels cell. The Pockels cell optical switching device may be switched, under the control of the laser pulse controller 216, back and forth between a first state in which the Pockels cell optical switching device allows laser pulses emitted from the laser to be output from the laser system, and a second state in which the Pockels cell optical switching device prevents laser pulses emitted from the laser from being output from the laser system. The Pockels cell optical switching device may be operated in stages to allow different proportions of the electromagnetic energy emitted by the laser to be output by the laser system.

[0041] The laser pulse controller 216 is configured to communicate an optical switching control signal to the optical switching device 214. The optical switching control signal is based on inputs to the surgical system including, for example, inputs from an adjustable input device, such as the foot pedal 106, if an adjustable input device is provided.

[0042] The optical switching device 214 may include a power control device and a pulse picking device. The pulse picking device may include any suitable pulse picking device, including but not limited to a shutter-based pulse picking device as described above. The power control device may include any suitable power control device, including but not limited to a waveplate-based power control device as described above. In an alternative embodiment, a Pockels cell configuration may function as a pulse picking device and / or a power control device. The laser system 200 may further include a beam deflector. The laser pulse controller 216 transmits laser power control signals and pulse picking control signals to the optical switching device 214. As described above, a hand piece may be connected to an output port of the laser system 200 by, for example, a cable with optical fiber. The output laser pulse train from the laser system 200 is directed through the optical fiber and the hand piece to a target (e.g., a cataractous lens, a trabecular meshwork, scleral tissue, other tissue, etc.).

[0043] 3 shows an example of an architecture for laser pulse controller 216. As will be appreciated by those skilled in the art, the use of the controller in a processing environment may be in the form of software, firmware, hardware, or any suitable combination of software, firmware, and / or hardware, such as software loaded and executed by a processor. Laser pulse controller 216 may be implemented in the form of software, firmware, hardware, or any suitable combination of software, firmware, and / or hardware, such as software loaded and executed by a processor.

[0044] The exemplary laser pulse controller 216 includes a serial transmitter / receiver (Tx / Rx) module 231 that communicates with a serial communications (Tx / Rx) controller or similar device (e.g., a similar UART, CAN bus, or Ethernet device) of the surgical console 100. In use, the surgical console 100 sends packets of data to the laser pulse controller 216, which are received by the serial Tx / Rx module 231. As described in more detail below, the packets may include data that is based at least in part on input from the adjustable input device 106. A packet parsing module 232 of the laser pulse controller 216 is configured to parse the packet data. In the illustrated example, packet parsing module 232 sends repetition rate data to repetition rate control module 233, mode data to mode detection module 234, power data to mode power control module 235, subcarrier threshold data to threshold control module 236, subcarrier frequency data to subcarrier frequency control module 237, subcarrier duty ratio data to duty ratio control module 238, pulse modulation data to modulation mode control module 239, and subrange data to subrange control module 240. Repetition rate control module 233 also receives a laser trigger input signal indicating the start timing of each laser pulse. Repetition rate control module 233 sends a signal indicative of the repetition rate of the laser to output pulse control module 241, which may also receive the laser trigger input signal. The output pulse control module 241 receives input signals based on respective input data from the mode detection module 234, the mode power control module 235, the threshold control module 236, the subcarrier frequency control module 237, the duty cycle control module 238, the modulation mode control module 239 and the subrange control module 240.

[0045] The output pulse control module 241 of the laser pulse controller 216 sends control signals to the optical switching device 214, which may be based at least in part on input from the adjustable input device 106. The control signals communicated by the laser pulse controller 216 to the optical switching device 214 may include a mode power signal (e.g., Mode_Power_Data) that controls a maximum laser pulse power output. The control signals communicated by the laser pulse controller 216 to the optical switching device 214 may also include a power threshold signal (e.g., Power_Threshold) that sets a threshold amount, as described below. The control signals communicated by the laser pulse controller 216 to the optical switching device 214 may also include a sub-carrier pulse control signal (e.g., Sub-Carrier Pulse Control) that controls a sub-carrier signal, as described below. A repetition rate signal may be sent to control the repetition rate of the laser pulses emitted by the laser.

[0046] As described in more detail below, the subcarrier pulse control signal may be used to provide control of the laser pulse output. In some examples, the subcarrier pulse control signal may be used to establish a subcarrier frequency or cycle. The subcarrier pulse control signal may include a duty ratio, or, as described further below, a separate subcarrier duty ratio signal may be provided that establishes the ratio between the amount of the subcarrier signal waveform above the central axis and the amount of the waveform below the central axis.

[0047] The output pulse control module 241 of the laser pulse controller 216 may also send the message acknowledgement signal to the packet framing module 242. The packet framing module 242 assembles the data from the message acknowledgement signal and sends it as a packet of data to the serial Tx / Rx module 231. The Tx / Rx module 231 then sends the packet of data based on the message acknowledgement signal to the serial Tx / Rx controller of the surgical console 100 to acknowledge the signal from the laser pulse controller 216.

[0048] 4 illustrates an example of a range of motion for an adjustable input device, such as a foot pedal 106. The foot pedal 106 or other adjustable input device may be actuated by an operator across a range of motion to control the laser output. In an example of a foot pedal, the operator presses the foot pedal a desired amount to move the foot pedal to a desired area of ​​the range of motion. In other examples, such as a hand-operated button or knob, the operator moves or adjusts the input device to a desired area of ​​the range of motion. In some embodiments, the foot pedal or other adjustable input device is adjustable in real-time during a surgical procedure, allowing the operator to dynamically control the laser pulses output from the laser system during the procedure.

[0049] Many examples of different functions across the operating range are possible. In the illustrated example, the operating range includes three sub-ranges, although more or fewer sub-ranges may be used.

[0050] The following is a description of one of many examples. When the adjustable input device is moved or adjusted to sub-range 1, the surgical console may be operated for a particular function, such as irrigation, without laser output. When the adjustable input device is moved or adjusted to sub-range 2, the surgical console may be operated for another function, such as aspiration, without laser output. The irrigation function may continue to operate in sub-range 2. When the adjustable input device is moved or adjusted to sub-range 3, the laser system may be operated to output laser electromagnetic energy. The irrigation and / or aspiration functions may continue to operate in sub-range 3. By moving or adjusting the adjustable input device within sub-range 3, the operator may dynamically adjust the laser output as described below.

[0051] Many variations are possible. For example, subranges 2 and 3 in the above example could be reversed, so that laser control is in subrange 2 and suction is in subrange 3.

[0052] In one example, adjustment of the adjustable input device controls the percentage of electromagnetic energy in the laser pulse that is output. That is, the laser emits a laser pulse at a particular energy, and the input from the adjustable input device is used to adjust the laser energy control system of the optical switching device 214 to control the percentage of energy in the laser pulse that is output from the laser system. Based on the input from the adjustable input device, the power level signal sent by the laser pulse controller 216 to the optical switching device 214 can be adjusted to control the amount of energy in the laser pulse that is output from the laser system. For example, the top of sub-range 3 can correspond to 0% laser energy output, the bottom of sub-range 3 can correspond to 100% laser energy output, and positions in between can correspond to increments within the range of 0% to 100%. In another example, the operating range of the adjustable input device is configured to allow an operator to dynamically control the percentage of laser pulses emitted from the laser that are output from the laser system. In another example, adjusting the adjustable input device to sub-range 3 or a particular point in sub-range 3 can act as an on-off switch that triggers operation of the laser system at a set power output.

[0053] For example, one or more inputs to the system from a touch screen (with a graphical user interface), buttons, dials, knobs, foot pedals, adjustable input devices, or other input devices may be used to control the laser system to output only certain laser pulses emitted by the laser. That is, the laser emits laser pulses at a particular repetition rate, and the inputs are used to control the optical switching device 214 to switch back and forth between a first state in which the optical switching device 214 allows the laser pulses emitted from the laser to be output from the laser system, and a second state in which the optical switching device 214 prevents the laser pulses emitted from the laser from being output from the laser system. One or more of the inputs to the system may include or be part of the console 100, the adjustable input device 106, and / or an external control system (e.g., having its own touch screen (with a graphical user interface), buttons, dials, knobs, or other input devices).

[0054] In a particular embodiment, the user input controls the subcarrier frequency, which controls the length of the subcarrier cycle, and the duty ratio. Based on the input, the laser pulse controller sends a signal (e.g., a subcarrier pulse control signal) to the optical switching device to control the subcarrier frequency and the duty ratio. For example, if the laser repetition rate is 1000 Hz, then a subcarrier frequency of 100 Hz will result in 10 pulses per cycle. By selecting an input that controls the duty ratio, a range of different pulse numbers per cycle (e.g., ranges of 1-9, 1-10, 0-9, 0-10, etc.) can be output, thereby controlling the percentage of laser pulses output. As another example, if the laser repetition rate is 1000 Hz, then a subcarrier frequency of 10 Hz will result in 100 pulses per cycle. By selecting an input that controls the duty ratio, a range of different pulse numbers per cycle (e.g., ranges of 1-99, 1-100, 0-99, 0-100, etc.) can be output, thereby controlling the percentage of laser pulses output.

[0055] In some examples, the repetition rate of the laser and the energy output of the laser (including different laser energy outputs, if desired) may be selected by an adjustable input device or another input device, such as a touch screen, button, dial, knob, or other input.

[0056] FIG. 5 shows an example of an instruction packet for sending to a laser pulse controller. The packet includes the following data: Header, Mode, Sculpt Power (or Mode Power), Repetition Rate, Subcarrier Threshold, Subcarrier Frequency, Subcarrier Duty Ratio, Pulse Modulation, Subrange 1, Subrange 2, Subrange 3, and End. The Header identifies the beginning of the packet. The Mode identifies which mode of operation has been selected. The Sculpt Power (or Mode Power) identifies the selected power output of the laser. This may be a maximum output signal representing the maximum power output. The Repetition Rate identifies the rate of pulses emitted from the laser. The Subcarrier Threshold identifies a threshold level or power, as discussed further below. The Subcarrier Frequency identifies the frequency of the subcarrier signal. The Subcarrier Duty Ratio identifies the duty ratio of the subcarrier signal. The Pulse Modulation identifies the type of pulse modulation (e.g., static or linear) with or without a subcarrier signal. Subrange 1, Subrange 2 and Subrange 3 specify the positions to which the adjustable input device has been moved or adjusted, including increments within the ranges (eg, 0 to 100).

[0057] Figure 6A shows an example of laser pulses emitted from a laser, where each upward arrow represents a laser pulse, which indicates the repetition rate of the laser pulses emitted by the laser, which in this example is 1 KHz.

[0058] 6B shows an example of a static pulse control signal. The power level signal is set to 100%. In static mode, the power level is constant, as shown. In linear or variable mode, the power level is adjustable, for example, by an adjustable input device (e.g., a foot pedal).

[0059] Figure 6C shows the output of laser pulses with the static pulse control signal of Figure 6B. As can be seen, all laser pulses are output at 100% power.

[0060] Figure 7A shows an example of a laser pulse emitted from a laser, similar to Figure 6A. As with Figure 6A, this shows the repetition rate of the laser pulses emitted by the laser, which in this example is 1 KHz.

[0061] 7B shows an example of a linear pulse control signal. The power level signal is adjusted over time. In a linear (or variable) mode, the power level is adjustable, for example, by an adjustable input device (e.g., a foot pedal), as shown.

[0062] Figure 7C shows the output of laser pulses according to the linear pulse control signal of Figure 7B. As can be seen, all the laser pulses are output at different levels of power according to the power control signal.

[0063] The modes of operation of Figures 6A-6C and 7A-7C are similar in output to the modes of operation described and shown in U.S. Provisional Patent Application No. 63 / 256,071, the entirety of which is incorporated herein by reference. For example, Figures 6C and 7C show similar output to the Sculpt mode described and shown therein. Figures 8A-8C and 9A-9C show how embodiments herein allow additional control over laser pulse output through the use of subcarrier signals (subcarrier frequency and duty cycle) and threshold signals.

[0064] Figure 8A shows an example of a laser pulse emitted from a laser, similar to Figures 6A and 7A. As with Figures 6A and 7A, this shows the repetition rate of the laser pulses emitted by the laser, which in this example is 1 KHz.

[0065] Figure 8B shows an example of a subcarrier signal, shown as a dashed waveform. In this example, the subcarrier frequency is 100 Hz, and a repetition rate of 1 KHz results in 10 laser pulses per subcarrier cycle.

[0066] In the example shown, the duty ratio of the subcarrier is set to 50% (or 50:50). The duty ratio establishes a ratio between the amount of the subcarrier signal waveform above the central axis and the amount of the waveform below the central axis. That is, the subcarrier signal waveform has a central axis. In the example shown, the central axis corresponds to a power level of 75%. As can be seen, the subcarrier oscillates with a waveform above and below the central axis. In the example shown, with a duty ratio of 50%, 50% of the subcarrier signal waveform is above the central axis and 50% of the subcarrier signal waveform is below the central axis.

[0067] Other duty ratios are possible. For example, when the duty ratio is 30% (or 30:70), 30% of the subcarrier signal waveform is above the central axis and 70% of the subcarrier signal waveform is below the central axis. When the duty ratio is 60% (or 60:40), 60% of the subcarrier signal waveform is above the central axis and 40% of the subcarrier signal waveform is below the central axis. When the duty ratio is 95% (or 95:5), 95% of the subcarrier signal waveform is above the central axis and 5% of the subcarrier signal waveform is below the central axis. The duty ratio can be anywhere in the range of 0% to 100% (including 0% and 100%).

[0068] 8B also shows the subcarrier threshold, shown as a dashed horizontal line. In this example, the threshold signal is at 50% as shown. The threshold signal can be anywhere in the range of 0% to 100% inclusive.

[0069] The threshold signal identifies or represents a threshold level or threshold power. In the example shown, the threshold signal sets a floor or minimum value for the subcarrier signal. In the example shown, the maximum power is set to 100%. As explained further below, the maximum power may be fixed or adjustable. The subcarrier signal oscillates between a threshold power (50% in the example shown) and a maximum power (100% in the example shown).

[0070] As described further below, the subcarrier signal modulates the amount of electromagnetic energy of the laser pulse that exits the laser system. In some embodiments, such as shown in FIG. 8B, the subcarrier signal is a repeating periodic pattern. For example, the subcarrier signal may oscillate between a threshold power and a maximum power, as shown in FIG. 8B. In some examples, such as shown in FIG. 8B, the subcarrier signal may be a square wave pattern. In other examples, the subcarrier signal may be a sinusoidal pattern. Other patterns of subcarrier signals may be used.

[0071] FIG. 8C illustrates the output of laser pulses according to the pulse control signal of FIG. 8B. As can be seen, the subcarrier signal modulates the amount of electromagnetic energy in the laser pulses exiting the laser system. That is, the amount of energy in each laser pulse output from the laser system is adjusted by the subcarrier signal. In the example shown, the laser pulses are modulated in a periodic pattern between 50% power and 100% power.

[0072] In some examples, all of the laser pulses may be output from the laser system according to the power indicated by the subcarrier signal. In other examples, the system may be operated such that when the subcarrier signal indicates a power level below a threshold, the optical switching device is in a state that prevents the laser pulses emitted from the laser from being output from the laser system. That is, the optical switching device is configured to switch between a first state (e.g., when the subcarrier signal indicates a power level above a threshold) in which the optical switching device allows the laser pulses emitted from the laser to be output from the laser system, and a second state (e.g., when the subcarrier signal indicates a power level below a threshold) in which the optical switching device prevents the laser pulses emitted from the laser from being output from the laser system.

[0073] In some examples, such as in the static mode, the input (actuator, button, knob, touch screen, foot pedal, etc.) may be used as an on-off switch to trigger operation of the laser system at a set power output. For example, moving the input to the on position initiates operation of the laser system at the power level shown in FIG. 8C. The input may be an adjustable input device, such as a foot pedal. For example, adjusting the adjustable input device to sub-range 3 or a particular point in sub-range 3 may act as an on-off switch to trigger operation of the laser system at a set power output.

[0074] In some instances, e.g., in linear or variable mode, adjustment of the adjustable input device can be used to control the percentage of electromagnetic energy in the laser pulse that is output. That is, the laser emits a laser pulse at a particular energy, and the input from the adjustable input device is used to adjust the laser energy control system of the optical switching device 214 to control the percentage of energy in the laser pulse that is output from the laser system. For example, the top of sub-range 3 can correspond to 0% laser energy output, the bottom of sub-range 3 can correspond to 100% laser energy output, and positions in between can correspond to increments within the range of 0% to 100%. When used with a sub-carrier signal as shown in Figures 8B and 8C, the maximum power is adjusted by the sub-carrier signal. That is, adjusting the adjustable input device to 100% will result in a laser pulse up to the sub-carrier signal as shown in Figure 8C, but at a lower percentage with a correspondingly lower amount of power.

[0075] Thus, in such examples, the adjustable input device (e.g., a foot pedal) is configured to be actuated over an operating range. The operating range of the adjustable input device is configured to allow an operator to dynamically control the amount of energy of the laser pulse emitted from the laser output from the laser system. In some examples, the operating range of the adjustable input device is configured to allow an operator to dynamically control the amount of energy of the laser pulse emitted from the laser output from the laser system up to an amount of maximum power. In some examples, the operating range of the adjustable input device is configured to allow an operator to dynamically control the amount of energy of the laser pulse emitted from the laser output from the laser system between a threshold power and a maximum power.

[0076] Referring again to FIG. 8C, the output alternates between periods of high and low power. When the power is at or transitioning to low power, the output energy of the laser pulse is minimized. Certain procedures, such as irrigation and / or aspiration of tissue, can be timed to coincide with these periods. When the power is at or transitioning to high power, the output energy of the laser pulse is maximized. Certain procedures, such as destruction of hard tissue, can be timed to coincide with these periods.

[0077] Figure 9A shows an example of laser pulses emitted from a laser, similar to Figures 6A, 7A and 8A. As with Figures 6A, 7A and 8A, this shows the repetition rate of the laser pulses emitted by the laser, which in this example is 1 KHz.

[0078] Figure 9B shows another example of a subcarrier signal, shown as a dashed waveform. In this example, the subcarrier frequency is 100 Hz, and a repetition rate of 1 KHz results in 10 laser pulses per subcarrier cycle.

[0079] In the example shown, the subcarrier duty ratio is set to 50% (or 50:50). As discussed above, the duty ratio establishes the ratio between the amount of the subcarrier signal waveform above the central axis and the amount of the waveform below the central axis. As discussed above, other duty ratios are possible, and can be anywhere in the range of 0% to 100%, inclusive.

[0080] FIG. 9B also shows a subcarrier threshold, shown as a dashed horizontal line. In this example, the threshold signal is at 50% as shown. As discussed above, the threshold signal can be anywhere in the range of 0% to 100% (inclusive). The subcarrier signal oscillates between a threshold power (50% in the example shown) and a maximum power (100% in the example shown). In the example of FIG. 9B, the subcarrier signal can be a sinusoidal pattern. Many other forms of the subcarrier signal are possible (e.g., sawtooth, stepped, etc.).

[0081] FIG. 9C illustrates the output of laser pulses according to the pulse control signal of FIG. 9B. As can be seen, the subcarrier signal modulates the amount of electromagnetic energy in the laser pulses exiting the laser system. That is, the amount of energy in each laser pulse output from the laser system is adjusted by the subcarrier signal. In the example shown, the laser pulses are modulated in a periodic pattern between 50% power and 100% power.

[0082] As discussed above, in some examples, all of the laser pulses may be output from the laser system according to the power indicated by the subcarrier signal, hi other examples, the system may operate such that when the subcarrier signal indicates a power level below a threshold, the optical switching device is in a state that prevents laser pulses emitted from the laser from being output from the laser system.

[0083] In some examples, as discussed above, a configuration such as that shown in Figure 9C may be operated in a static mode, and the input may be used as an on-off switch to trigger operation of the laser system at a set power output. In some examples, as discussed above, a configuration such as that shown in Figure 9C may be operated in a linear or variable mode, and adjustment of the adjustable input device may be used to control the percentage of electromagnetic energy in the output laser pulse.

[0084] An exemplary method of controlling a surgical system as described herein is as follows: The operator selects inputs of an operating mode (e.g., static or linear, with or without subcarrier), maximum power, laser repetition rate, subcarrier frequency, and / or duty cycle. In some embodiments, specific options may be provided for selection, and in response to the operator's selection, the surgical system sets the operating mode, maximum power, laser repetition rate, subcarrier frequency, and / or duty cycle. Alternatively, any of these parameters may be pre-set. The operator operates the system and directs the handpiece laser output to a desired location (e.g., cataractous lens, trabecular meshwork, scleral tissue, other tissue, etc.). Based on the input and optionally other parameters, a control signal is sent (e.g., by a packet as in FIG. 5) to the laser pulse controller. Based on the input, the laser pulse controller sends a control signal to an optical switching device to control the laser output. The laser emits electromagnetic radiation from the laser in laser pulses. Based on the input, the optical switching device selectively controls the energy output of the laser pulses and / or selectively allows particular laser pulses to be output and prevents particular laser pulses from being output. In some embodiments, an operator actuates an adjustable input device (e.g., a foot pedal) over an operating range to dynamically control the power of the laser pulses output from the laser system.

[0085] An operator may dynamically adjust the adjustable input device in real time to adjust the power output, i.e., the power level signal may be based on dynamic input from the adjustable input device. An operator may dynamically adjust the adjustable input device in real time to adjust the power level signal and therefore the amount of energy in the laser pulse that will be output from the laser system.

[0086] The operator can switch between inputs, and the input selected can be based on the type of treatment, the stage of treatment, the condition, or other factors.

[0087] The ability to selectively output laser pulses and / or control the laser output energy is useful in procedures where laser control is advantageous. For example, in cataract surgery, it may be desirable to operate the laser system at high power to initially break up the crystalline lens. It may be desirable to operate the laser system at lower power to break up smaller fragments, so lower energy levels may be preferred. Pulse energy level control of the laser pulses allows for an appropriate level of force to be applied to smaller particles that may otherwise be dislodged before they can be aspirated from the eye by the irrigation system of the handpiece. As another example, in the treatment of glaucoma, it may be desirable to operate the laser system with a single laser pulse or only a few laser pulses to create a flow path through the ocular tissue. It may also be desirable to use soft or low energy for certain glaucoma procedures.

[0088] As will be appreciated by those skilled in the art, the systems and methods disclosed herein have advantages over conventional systems and methods, for example, the systems and methods as described herein allow for easy, flexible and / or dynamic control of laser pulses and energy, improving the ease, time, efficiency, accuracy, outcome and / or cost of a procedure.

[0089] Those skilled in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the specific exemplary embodiments described above. Although exemplary embodiments have been shown and described, a wide range of modifications, changes and substitutions to the above disclosure are contemplated. It is understood that such variations can be made to the above without departing from the scope of the present disclosure. It is therefore appropriate that the appended claims be construed broadly and consistent with the present disclosure.

Claims

1. A surgical laser system, A laser configured to emit electromagnetic radiation in laser pulses, A laser energy control system configured to adjust the amount of electromagnetic energy of each laser pulse emitted from the surgical laser system, A laser pulse controller configured to communicate control signals to the laser energy control system, Includes, A surgical laser system wherein the control signal communicated by the laser pulse controller to the laser energy control system includes a subcarrier signal that modulates the amount of electromagnetic energy of the laser pulses leaving the surgical laser system.

2. The surgical laser system according to claim 1, wherein the subcarrier signal has a periodic pattern.

3. The surgical laser system according to claim 2, wherein the subcarrier signal is a square wave pattern.

4. The surgical laser system according to claim 2, wherein the subcarrier signal is a sinusoidal pattern.

5. The surgical laser system according to claim 1, wherein the control signal communicated to the laser energy control system by the laser pulse controller further includes a threshold signal representing threshold power.

6. The surgical laser system according to claim 5, wherein the control signal communicated to the laser energy control system by the laser pulse controller further includes a maximum power signal representing the maximum power.

7. The surgical laser system according to claim 6, wherein the maximum power is adjustable.

8. The surgical laser system according to claim 6, wherein the subcarrier signal oscillates between the threshold power and the maximum power.

9. The surgical laser system according to claim 1, further comprising an adjustable input device configured to operate over a range of motion.

10. The surgical laser system according to claim 9, wherein the operating range of the adjustable input device is configured to allow an operator to dynamically control the amount of energy of the laser pulses emitted from the laser, which is output from the surgical laser system.

11. The surgical laser system according to claim 9, wherein the control signal communicated by the laser pulse controller to the laser energy control system further includes a maximum power signal representing maximum power, and the operating range of the adjustable input device is configured to allow an operator to dynamically control the amount of energy of the laser pulses emitted from the laser, output from the surgical laser system, up to the amount of maximum power.

12. The control signal communicated by the laser pulse controller to the laser energy control system further includes a threshold signal representing a threshold power and a maximum power signal representing a maximum power, and the operating range of the adjustable input device is configured to allow an operator to dynamically control the amount of energy of the laser pulses emitted from the laser, output from the surgical laser system, between the threshold power and the maximum power, according to claim 9.

13. The surgical laser system according to claim 9, wherein the adjustable input device includes a foot pedal configured to operate over the operating range.

14. The surgical laser system according to claim 1, further comprising an optical switching device configured to switch between a first state in which laser pulses emitted from the laser are output from the surgical laser system and a second state in which laser pulses emitted from the laser are prevented from being output from the surgical laser system.

15. The surgical laser system according to claim 14, wherein the optical switching device includes a shutter and a shutter motor.

16. The laser energy control system is Waveplate and, Waveplate motor and, polarizing plate and The surgical laser system according to claim 1, comprising, wherein the waveplate motor is configured to move the waveplate to different positions corresponding to different proportions of laser electromagnetic energy permitted to pass through the laser energy control system.

17. A method for controlling a surgical laser system, (i) Providing input to the surgical laser system, the surgical laser system A laser configured to emit electromagnetic radiation in laser pulses, A laser energy control system configured to adjust the amount of electromagnetic energy of each laser pulse emitted from the surgical laser system, A laser pulse controller configured to communicate control signals to the laser energy control system, The control signal, which is communicated to the laser energy control system by the laser pulse controller, includes a subcarrier signal that modulates the amount of electromagnetic energy of the laser pulses leaving the surgical laser system, and provides that, (ii) Emitting electromagnetic radiation from a laser in the form of laser pulses, (iii) Outputting laser pulses from the surgical laser system in accordance with the control signal communicated by the laser pulse controller. A method for controlling a surgical laser system, including the following.

18. A method for controlling a surgical laser system according to claim 17, wherein the subcarrier signal has a periodic pattern.

19. A method for controlling a surgical laser system according to claim 17, wherein the control signal communicated to the laser energy control system by the laser pulse controller further includes a threshold signal representing threshold power.

20. A method for controlling a surgical laser system according to claim 19, wherein the control signal communicated to the laser energy control system by the laser pulse controller further includes a maximum power signal representing the maximum power, and the subcarrier signal oscillates between the threshold power and the maximum power.

Images