Light engine calibration system and method

Abstract

Embodiments of the present disclosure generally relate to systems and methods for calibrating light emitting diode (LED) light engines. The systems and methods described herein include characterizing the performance of red-green-blue (RGB) LED light engines so as to be able to display calibrated dimensionless output values that accurately reflect the perceived illumination luminance produced by the light engine for a particular output color.

Description

[0001] Priority Statement

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 223,692, filed July 20, 2021, entitled “LIGHT ENGINE CALIBRATION SYSTEMS ANDMETHODS”, by inventors Jing Xu, Jason L. Lee, Hari Krishna Kapparapu, and Dean Richardson, which is hereby incorporated herein by reference in its entirety, as fully and completely set forth herein. Technical Field

[0003] This disclosure relates to systems and methods for calibrating light-emitting diode (LED) light engines, and more specifically to systems and methods for calibrating red-green-blue (RGB) LED light engines to facilitate the use of dimensionless output setting values ​​that reflect the luminance of the observed illumination. Background Technology

[0004] Ophthalmic microsurgery often requires precise cutting and / or removal of various eye tissues. During such procedures, adequate illumination of the patient's internal eye is crucial, and this is typically achieved using illumination probes from ophthalmic lighting systems. For example, a user (such as a surgeon or other medical professional) can insert an illumination probe into the patient's eye to illuminate the interior for surgical purposes. Typically, the probe is connected to the optical port of the ophthalmic lighting system via a fiber optic cable. Ophthalmic lighting systems, which can be housed in a surgical console, include a light engine (i.e., the illumination source). The lighting system may also include other optical elements, such as collimating and focusing optics, which facilitate the transmission of the beam generated by the light engine into optical fibers extending into the fiber optic cable and probe.

[0005] A light engine is typically a red-green-blue (RGB) light-emitting diode (LED) light engine, which produces a range of different output colors and brightness levels by mixing the light generated by the three LED colors operating at different drive currents. However, since the output of each individual LED color is typically a non-linear function of the input current, the resulting combined output usually also varies non-linearly with the input. Therefore, adjustments to the desired output brightness setting of the LED light engine by, for example, a surgeon, will not linearly increase or decrease the brightness of the observation illumination, which may lead to reduced surgical efficiency and / or a frustrating user experience for the surgeon.

[0006] Therefore, there is a need for LED luminaire calibration systems and methods that can promote dimensionless output settings that accurately reflect the perceived brightness of LED luminaires. Summary of the Invention

[0007] This disclosure relates to systems and methods for calibrating light-emitting diode (LED) light engines, and more specifically to systems and methods for calibrating LED light engines to facilitate the utilization of dimensionless output setting values ​​that reflect perceived illuminance.

[0008] In some embodiments, a method is provided for generating calibrated illumination light using an optical engine of an illumination system. The method includes: obtaining a first set of data for the optical engine, wherein the first set of data includes measured output flux data of the optical engine and a color sensor luminance reading, wherein the measured output flux data and the color sensor luminance reading correspond to drive intensity data of input parameters of the optical engine; determining a first mapping between the measured output flux data and the drive intensity data; determining a second mapping between the measured output flux data and the color sensor luminance reading; determining a third mapping between the drive intensity data and the color sensor luminance reading based on the first and second mappings; determining a fourth mapping between a plurality of dimensionless output setting values ​​of the illumination system and the drive intensity data based on the third mapping; receiving one of the plurality of dimensionless output setting values ​​from user input; matching the one of the plurality of dimensionless output setting values ​​with a corresponding drive intensity of the input parameters of the optical engine using the fourth mapping; and generating illumination light with a desired output flux using the optical engine. Attached Figure Description

[0009] To gain a detailed understanding of the features described above, the briefly summarized disclosure can be described in more detail with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only illustrate exemplary embodiments and should not be construed as limiting their scope, and other equally effective embodiments are permissible.

[0010] Figure 1 An exemplary surgical console, including a lighting system for ophthalmic surgery, is shown according to certain embodiments of this disclosure.

[0011] Figure 2 Certain embodiments according to this disclosure are shown. Figure 1 The lighting system.

[0012] Figure 3 This disclosure illustrates certain embodiments of ophthalmic surgery procedures. Figure 1 It is part of the lighting probe of the lighting system.

[0013] Figure 4 Certain embodiments according to this disclosure are shown. Figure 1A block diagram of selected components of the light engine controller for the lighting system.

[0014] Figure 5 Certain embodiments according to this disclosure are shown. Figure 1 An example graphical user interface for a surgical system.

[0015] Figure 6 Calibration is illustrated using certain embodiments according to this disclosure. Figure 1 A flowchart of a method for a light engine in a lighting system.

[0016] Figure 7A Certain embodiments of the present disclosure are shown in Figure 6 Example table of initial test data used during the method.

[0017] Figure 7B Some embodiments of the present disclosure are shown as described in Figure 6 The example fitted polynomial curve is determined during the method.

[0018] Figure 7C Some embodiments of the present disclosure are shown as described in Figure 6 The method includes example experimental tables and corresponding example graphs.

[0019] Figure 7D Some embodiments of the present disclosure are shown as described in Figure 6 The example fitted polynomial curve is determined during the method.

[0020] Figure 7E Some embodiments of the present disclosure are shown as described in Figure 6 Example experimental tables were determined during the method.

[0021] Figure 7F Some embodiments of the present disclosure are shown as described in Figure 6 The example fitted polynomial curve is determined during the method.

[0022] Figure 7G Some embodiments of the present disclosure are shown as described in Figure 6 Example experimental tables were determined during the method.

[0023] Figure 7H Some embodiments of the present disclosure are shown as described in Figure 6 Example experimental tables were determined during the method.

[0024] Figure 7I Some embodiments of the present disclosure are shown as described in Figure 6 Example experimental tables were determined during the method.

[0025] Figure 7J Some embodiments of the present disclosure are shown as described in Figure 6 The example fitted polynomial curve is determined during the method.

[0026] For ease of understanding, the same reference numerals are used where possible to denote common elements in the figures. It is contemplated that elements and features in one embodiment may be advantageously combined in other embodiments without further description. Detailed Implementation

[0027] In the following description, details are illustrated by way of example to aid understanding of the disclosed subject matter. However, it will be clear to those skilled in the art that the disclosed embodiments are exemplary and not an exhaustive list of all possible embodiments. Therefore, it should be understood that references to the described examples are not intended to limit the scope of this disclosure. Those skilled in the art to which this disclosure pertains will generally be fully capable of conceiving any changes and further modifications to the described apparatus, instruments, and methods, as well as any further applications of the principles of this disclosure. Specifically, it will be fully contemplated that features, components, and / or steps described for one embodiment can be combined with features, components, and / or steps described for other embodiments of this disclosure.

[0028] It should be noted that, as described herein, the distal, distal, or distal portion of a component refers to the end, segment, or portion that is closer to the patient's target tissue during its use. On the other hand, the proximal, proximal, or proximal portion of a component refers to the end, segment, or portion that is farther from the patient's target tissue.

[0029] As used herein, the term "about" can refer to a change of + / - 10% from the nominal value. It should be understood that such a change can be included in any value provided herein.

[0030] This disclosure relates to systems and methods for calibrating light-emitting diode (LED) light engines, and more specifically to systems and methods for calibrating LED light engines so that the perceived brightness and color of the produced output light correspond to desired user input settings.

[0031] As mentioned above, in some existing LED lighting systems, the output of the light engine is a non-linear function of the input. Therefore, when the desired output setting of the light engine is adjusted, the observed characteristics of the resulting illumination may not change in an intuitively linear manner. For example, an RGB LED lighting source can produce a series of different output colors and brightness levels by mixing the light generated by three LEDs operating at different drive currents. Since the output of each individual LED is typically a non-linear function of the input current, the resulting combined output will also vary non-linearly with the input. Therefore, when a user of an existing lighting system (e.g., a surgeon) attempts to increase or decrease the brightness of the illumination by adjusting the light engine settings during surgery, the actual change in brightness may not correspond to the surgeon's desired setting adjustment. Consequently, the surgeon may need to repeatedly adjust the light engine settings to achieve the desired brightness, thereby reducing the efficiency of the surgery and the surgeon's user experience.

[0032] Therefore, the methods and systems described herein can be used to calibrate an illumination engine such that changes in the observed luminance of the generated illumination light linearly correspond to increases or decreases in a user-input luminance setting value. For example, in some embodiments described herein, a surgical system (e.g., a surgical console) may include a display device that displays the desired luminance setting value of the RGB LED illumination system as a full-scale percentage (e.g., between 0% and 100%). The user can adjust the luminance setting percentage via a suitable toggle key (e.g., a knob, button, or touchscreen interface). The adjustment of the luminance setting percentage is transmitted to the light engine interface, where a control module converts the luminance setting percentage into an appropriate electrical input to produce an observed illumination luminance level corresponding to the adjusted luminance setting percentage.

[0033] Figure 1 An example surgical system 100, including a lighting system, is shown according to certain aspects of this disclosure. In some examples, the surgical system 100 is a surgical system for ophthalmic surgery, including but not limited to surgical systems sold by Alcon of Fort Worth, Texas. The system 100 can be used for various ophthalmic surgeries, such as anterior segment surgery, posterior segment surgery, vitreoretinal surgery, vitrectomy, cataract surgery, and / or other surgeries. The surgical system 100 includes a console 104 and an associated display 106. The display 106 can display data, such as data relating to system operation and / or system performance during surgery, which can be arranged in a graphical user interface (GUI).

[0034] Typically, console 104 includes one or more systems or subsystems that enable the surgeon to perform a variety of surgical procedures, such as ophthalmic surgery. For example, console 104 may include a lighting system (in... Figure 2 (Referring to 200), the illumination light generated by its light source can be directed into a body cavity to allow the surgeon to perform operations within that cavity. The light generated by the light source can be transmitted to the eye via an optical fiber arranged within an optical fiber cable 102 and terminating distally at an illumination probe 108. In some embodiments, the light may pass through one or more optical elements, such as one or more lenses, mirrors, and / or attenuators, before or after entering the optical fiber. In some embodiments, a cannula (commonly referred to as a cannula) can be used. Figure 3 A cannula (labeled 310) is used to deliver the optical fiber and / or illumination probe 108 of the illumination system into the eye. An incision can be formed or opened using a cannula to penetrate the wall of a body cavity, such as through the sclera of the eye. In some cases, the cannula can be inserted into an incision formed by the user (such as a surgeon or other medical professional) using another surgical instrument. The cannula typically includes a lumen through which the surgeon can insert one or more surgical instruments or probes to perform surgery within the lumen.

[0035] The exemplary surgical tool shown as handheld device 112 can be coupled to console 104 and can form part of surgical system 100. Handheld device 112 represents any type of ophthalmic surgical probe, including, for example, a vitrectomy probe, illumination probe, aspiration probe, irrigation probe, lens emulsification device, diathermy probe, or other types of devices. In the illustrated embodiment, handheld device 112 is a vitrectomy probe for removing vitreous humor from the eye. Handheld device 112 can be coupled to one or more systems or subsystems included in console 104. For example, handheld device 112 can be coupled to a vitrectomy system that controls a pump and / or vacuum for vitreous humor removal. The vitrectomy system can also provide power to handheld device 112 and control the operation of handheld device 112. In some embodiments, handheld device 112 can be a vitrectomy device, such as an oscillating vitrectomy device.

[0036] Figure 2 This disclosure demonstrates certain aspects of the content. Figure 1 The lighting system 200 may include a lighting probe 108 (e.g., an internal illuminator or chandelier internal illuminator) connected to the console 104 via a fiber optic cable 102, the fiber optic cable including one or more optical fibers disposed therein. The proximal end 212 of the fiber optic cable 102 is connected to the console 104 using a connector 206.

[0037] Console 104 provides the light source, in Figure 2 In this example, the control console includes a light engine 208 and an optical focusing element 210. The light engine 208 communicates with the controller 218 and may include any suitable type of light source, such as one or more light-emitting diodes (LEDs). For example, in some embodiments, the light engine 208 includes one or more sets of red-green-blue (RGB) LEDs. In operation, upon receiving a control signal from the controller 218, the light engine 208 converts the control signal into an electrical input, which is provided to one or more drive circuits and / or electrical components to drive the light source, such as an RGB LED. In some embodiments, the control signal and / or electrical input includes one or more of the following: pulse width modulation (PWM) duty cycle, drive current, or other suitable types of control parameters applicable to the circuit design and drive scheme of the lighting system 200. After converting the control signal and providing the appropriate electrical input to the light source, the light engine 208 emits a light beam, which the optical focusing element 210 then converges and focuses onto an opening at the proximal end of the connector 206, where the opening exposes the proximal ends of one or more optical fibers extending through the fiber optic cable 102. The illumination probe 108 is then operable to transmit a beam of light received from a light source, such that light is projected from the distal end 214 of the illumination probe to illuminate region 216, for example, to illuminate a portion of the eye during ophthalmic surgery.

[0038] For example, Figure 3 A cross-sectional view of an eye 300 is shown, in which a portion of an illumination probe 108 is positioned via a cannula 310 through the eye wall 304 to provide a light source in the internal portion of the eyeball. The distal end 214 of the illumination probe 108 uses a beam of light 308 to illuminate the internal region of the eye 300.

[0039] Figure 4 A block diagram illustrating selected components of an implementation of a controller (e.g., controller 218) associated with or coupled to a lighting system (e.g., lighting system 200), which is part of a surgical console (e.g., console 104), as referenced above. Figures 1 to 2 As stated above.

[0040] like Figure 4As shown, controller 218 includes processor 402 that communicates with memory 410. Controller 218 is further communicatively connected via bus 416 to display interface 404 and communication interface 420 of console 104, as well as lighting system 200. In some embodiments, controller 218 is configured to interface with lighting system 200 and other components of console 104 via bus 416. In some embodiments, communication interface 420 may be configured to enable controller 218 to connect to an external computing system, such as computing system 460, via a network, either wired or wirelessly. The network may include one or more switches, routers, local area networks (e.g., Ethernet), wide area networks (e.g., the Internet), etc. Computing system 460 may be a locally deployed computing system or may correspond to computing resources provided by a private or public cloud. Controller 218 may also be connected to one or more displays, such as display 106, via display interface 404.

[0041] Memory 410 may include permanent, volatile, fixed, removable, magnetic, and / or semiconductor media. Memory 410 may be configured to store one or more machine-readable commands, instructions, data, and / or the like. In some embodiments, such as Figure 4 As shown, memory 410 may include one or more instruction sets and / or instruction sequences, such as operating system 412, calibration application 414, etc. Examples of operating system 412 may include, but are not limited to, UNIX or UNIX-like operating systems. A series of operating systems, or another suitable operating system.

[0042] The calibration application 414 can be configured to perform light engine calibration operations as described herein, including but not limited to operations related to calibrating the observed output flux or luminance relative to received setting values. For example, the light engine calibration application 414 can configure the controller 218 to perform a set of operations (e.g., operation 600) to determine one or more functions for converting a user-provided desired lighting setting (e.g., desired luminance, etc.) into a calibrated control signal for the light engine 208. Once determined, these functions can then be stored in the memory 410 for retrieval during operation of the lighting system 200. For example, during operation of the lighting system 200, a user can input a desired lighting setting via a user interface on the display 106. The processor 402 then uses the desired lighting setting as input to one or more determined functions and outputs a calibrated control signal, which is then transmitted to the lighting system 200. The drive circuitry 406 of the light engine 208 then converts the calibrated control signal into a corresponding electrical input, which is provided to the light engine 208 to generate illumination light corresponding to the desired lighting setting.

[0043] Note that although processor 402 and memory 410 are shown as components of controller 218, lighting system 200 may also include its own dedicated processor and memory, which can perform the same or similar functions as processor 402 and memory 410 described above. That is, lighting system 200 may include dedicated processor and memory, and the dedicated memory may include a calibration application configured to perform light engine calibration operations as described herein. In such an embodiment, once one or more light engine calibration functions are determined, these functions can be stored in memory 410 of controller 218 for use during operation of lighting system 200.

[0044] In some embodiments, the light engine calibration operation is performed on a separate computing system (e.g., computing system 460) that communicates with console 104 and / or lighting system 200. In such embodiments, computing system 460 includes a dedicated processor and memory that stores a calibration application for performing the light engine calibration operation described herein (e.g., operation 600) to derive one or more functions for translating desired lighting settings into calibrated control signals for light engine 208. In some embodiments, these one or more functions may then be sent and stored in memory 410 or a memory dedicated to lighting system 200.

[0045] Figure 5 An example GUI 500 that can be displayed on, for example, a display 106 of a surgical system 100 is shown. The GUI 500 can display data, for example, related to system operation and / or system performance during surgery, and / or data related to the operation or performance of one or more surgical devices (e.g., handheld device 112). The GUI 500 can further display one or more graphical control elements such as windows, toolbars, menus, buttons, icons, etc., which allow a user (e.g., a surgeon) to adjust one or more modes, parameters, or settings during surgery and alternate between displayed data.

[0046] exist Figure 5 In the example shown, GUI 500 includes a window 508 for displaying information related to the operation of one or more illuminators (e.g., illumination probe 108) of the lighting system 200. The displayed information may include lighting output parameters or settings for one or more illuminators, such as color and flux (e.g., luminance). For example, as... Figure 5As shown, a single illuminator (e.g., depicted as "illuminator 1") is identified and its output settings are displayed. The displayed output settings include a color setting 512 and a flux or brightness setting 514. The color setting is currently set to "cool white," which identifies the current color of the illumination light emitted by illuminator 1. The flux or brightness setting identifies its current flux as a unitless value on a 0% to 100% percentage range. Therefore, the displayed flux setting 514 corresponds to a proportion of the maximum illumination luminous flux that the corresponding light engine of illuminator 1 can produce.

[0047] In some embodiments, the values ​​of, for example, color setting 512 and brightness setting 514 can be adjusted by the surgeon via one or more toggle keys 516 of window 508 or other suitable control elements. For example, during surgery, the surgeon can control the performance of one or more illuminators of lighting system 200 via GUI 500, for example, by pressing one or more toggle keys 516 to change the displayed values ​​of the lighting output settings(s). In turn, changing the value of the displayed output settings can signal controller 218 to adjust the performance of the corresponding light engine 208 of the illuminator, for example, by modulating the electrical input parameters applied to the illuminator. However, as mentioned above, when light engine 208 is an RGB LED light engine, the resulting output of light engine 208 is a non-linear function of the input. Therefore, in some existing systems, when adjusting the brightness setting (e.g., flux setting 514) of light engine 208, the resulting illumination brightness may not correspond to the brightness setting adjustment in an intuitively linear manner. Therefore, the surgeon may need to repeatedly adjust the flux setting 514 of light engine 208 to obtain the desired brightness, thereby reducing the efficiency of the surgery and the surgeon's user experience. The following description addresses this deficiency by providing a method for calibrating an RGB LED light engine, such that the observed brightness of the generated illumination light linearly corresponds to an increase or decrease in the output setting value input by the user. In some embodiments, the methods described below can be performed by a computer or controller (e.g., controller 218) of the surgical system 100 or lighting system 200. For example, the methods described below can be performed by a computer running spreadsheet software or spreadsheet data software (e.g., a personal computer in a laboratory environment or a cloud-based computing resource (e.g., a NumPy notebook)).

[0048] Figure 6 A flowchart illustrating a method 600 for calibrating an RGB LED light engine (e.g., light engine 208) of a lighting system, according to certain aspects of this disclosure, is provided. Figures 7A to 7J The operation of method 600 according to certain aspects of this disclosure is illustrated schematically. Therefore, for clarity, Figure 6 as well as Figures 7A to 7JLet's describe them together here.

[0049] Calibration of the RGB LED light engine 208 involves analyzing the input-output data exhibited by the light engine 208 and performing a series of empirical fits and scaling normalizations. This series of empirical fits and scaling normalizations produces a set of constants that allow unitless output setting values ​​(e.g., ranging from 0% to 100%) to be accurately mapped to the corresponding RGB LED drive parameters to achieve the desired color. Therefore, a consistent and intuitive relationship is established between the user's output setting adjustments and perceived changes in illumination brightness, tailored to the individual light engine 208. Thus, calibration of the RGB LED light engine 208 enables the reliable and repeatable conversion of user-selected desired output setting values ​​into RGB LED drive parameters, thereby generating the corresponding observed (e.g., output) illumination brightness level in real time while maintaining the desired color balance.

[0050] Now go to Figure 6 At operation 602 of method 600, initial test data for the light engine 208 is obtained, and a first polynomial fitting or function is calculated using this initial test data to model the relationship between the output throughput of the light engine 208 and the drive strength of the main electrical input parameters of the light engine 208 for a specific preset color. The test data for the light engine 208 may include any suitable set of test or inspection data that provides the output characteristics, such as chromaticity characteristics, exhibited by the light engine 208 for one or more preset colors across a range of one or more electrical input parameters. In some embodiments, the electrical input parameters include drive current, duty cycle of a pulse width modulation (PWM) signal, etc.

[0051] For example, in some embodiments, test data for the light engine 208 is collected by applying an LED drive current to the light engine 208, adjusting the duty cycle of its PWM signal, and measuring the output characteristics (e.g., output flux) of the light engine 208 over the entire duty cycle time range via one or more sensors. In such embodiments, adjusting the duty cycle of the PWM signal (e.g., via continuous knob adjustment) instead of adjusting the applied drive current allows a fixed current value to be maintained during testing, thereby providing predictability and localization of individual input points on the calculated input-output curve and avoiding certain problems associated with nonlinearity in the input and observed output of the LED light engine (e.g., light engine 208). In some embodiments where the duty cycle time of the PWM signal is used as an electrical input parameter, the PWM signal is first filtered and converted into an analog drive current before being applied to the light engine 208. In some embodiments, output characteristics are collected for each of a plurality of different drive inputs (e.g., drive currents) over the entire duty cycle time range.

[0052] Figure 7A An exemplary table 700 is shown, containing test data specifically obtained for a particular light engine 208. As shown, Table 700 includes at least data related to the chromaticity and luminance of the light engine 208 for a variety of preset colors, organized according to the International Commission on Illumination (CIE) xy color space. For example, the CIE system characterizes colors using two color coordinates x and y (shown in columns Sp2 and Sp3 of Table 700, respectively) and a luminance parameter Y (shown in column Sp4). Note that in some examples, the numbers in column Sp4 are not exactly CIE Y, but are highly non-linearly related to it. Therefore, in Table 700, each pair of different coordinates (spanning rows) in columns Sp2 and Sp3 corresponds to a specific preset color, and the luminance parameter Y in column Sp4 corresponds to the drive value of the electrical input parameter applied to the light engine 208 to propagate light with that preset color. For illustrative purposes, Table 700 shows five pairs of example x, y color coordinates (0.3, 0.3; 0.4, 0.3; 0.345, 0.38; 0.3, 0.4; and 0.4, 0.4), each pair representing a different preset color desired by the user. To calibrate the light engine 208 for each of the five preset color coordinates, test data for the light engine 208 is collected for each preset color, and the remaining operations of method 600 are performed separately, concurrently with, or sequentially with this collection. Therefore, each row (e.g., column) of test data in Table 700 is specific to the corresponding preset color coordinates in columns Sp2 and Sp3.

[0053] In some embodiments, the test data is collected and provided by the manufacturer of the light engine 208. In other embodiments, the test data is collected by the manufacturer or assembler of the surgical system or lighting system (e.g., system 100 or 200). Typically, the test data (e.g., including measured raw output characteristics of the light engine 208 across the entire range of drive values ​​for the main electrical input parameters) is collected using one or more color sensors, which may be internal to the light engine 208 or the lighting system 200. Figure 7A The example shown depicts data from two color sensors, but for the method described herein, one sensor is sufficient. Because each light engine has a unique set of test data, in some embodiments, test data is collected for each light engine (e.g., light engine 208) to be used in the surgical system (e.g., surgical system 100), and method 600 is performed separately from this collection.

[0054] like Figure 7AAs shown, Table 700 includes the measured output flux value of the light engine 208 (e.g., measured by a calibrated radiometer, in lumens) in column Sp26 and a series of corresponding drive intensity values ​​for a specific electrical input parameter in column Sp4. In this example, the PWM duty cycle is used as the electrical input parameter. As described above, at operation 602, the relationship between the drive intensity value in Sp4 and the measured output flux value in Sp26 is determined and analyzed for a specific color, and its fitted polynomial curve (also referred to herein as the first function) is generated. Figure 7B Figure 702 shows an example fitted curve for the color coordinates (0.345, 0.38), where the driving intensity is plotted along the X-axis and the measured output flux is plotted along the Y-axis. As shown, the example fitted curve is characterized by the following polynomial function:

[0055] Flux (lm) = (-1.615884e -06 )×(driving value) 2 +(1.446163e -02 )×(driving value).

[0056] At operation 604, after forming a fitted polynomial curve to model the relationship between the measured output flux of the light engine 208 in lumens and the drive intensity of the main electrical input parameter, the polynomial fitting is used to estimate the output flux of the light engine 208 at the maximum drive intensity value, i.e., the estimated maximum output flux. Typically, the maximum drive intensity value is the maximum input parameter value achievable by the lighting system 200 in which the light engine 208 is to be installed (e.g., mounted). For example, in embodiments where a PWM signal is used as an input parameter, the maximum drive intensity value is the maximum PWM duty cycle allowed by the lighting system 200. In such embodiments, the maximum duty cycle may be limited by, for example, the communication rate between the controller of the surgical system 100 or lighting system 102 (e.g., light engine controller 218) and the light engine 208, or by the clock rate of the control signal. Therefore, for the purposes of this disclosure, the estimated maximum output flux corresponds to 100% output setting of the light engine 208 when converted to a unitless output setting value. Therefore, if the user (e.g., a surgeon) selects a desired output flux setting of 100%, the light engine 208 will produce an observed output that is substantially equal to the estimated output flux determined at operation 604.

[0057] For illustrative purposes, an example calculation of the estimated maximum output flux is shown below. The calculation below utilizes... Figure 7BThe calculation uses a polynomial fit or first function for the color coordinates (0.345, 0.38) and further utilizes an example maximum drive strength value of 3200, which corresponds to the system's maximum PWM duty cycle. Note that the maximum drive strength value for the electrical input parameters may differ for any given surgical system and / or lighting system and may depend on its processing and / or computational specifications.

[0058] 29.73 (lm) = (-1.615884e) -06 ) × (3200) 2 + (1.446163e -02 ) × (3200).

[0059] Using the polynomial fitting above, the calculated maximum output flux of 3200 is 29.73 lumens. Therefore, in this example, 29.73 lumens can correspond to 100% flux at a specific color coordinate (0.345, 0.38).

[0060] At operation 606, now that the estimated maximum output flux of the light engine 208 is obtained for the color coordinates (0.345, 0.38), the mapping of the full range of target output (e.g., in lumens) for each desired output setting step (e.g., in percentage) can be determined. In other words, multiple target output flux values ​​of the light engine 208 are mapped to unitless output setting values ​​over a percentage range of 0% to 100%. The target output flux value for each output setting can be calculated using the following formula:

[0061] Flux (lm) = (Estimated maximum output flux) × (Desired output setting (%))

[0062] For illustrative purposes, Figure 7C The table 704 and the corresponding graph 706 are shown to illustrate the mapping from the target output to the output setting step at operation 606, as in Figure 7A and Figure 7B The example applies to the Light Engine 208. Figure 7C In the example, the estimated maximum output flux is 29.73 lm. Therefore, the target output flux corresponding to 5% of the expected output setting is 1.49 lm, the target output flux corresponding to 10% of the expected output setting is 2.97 lm, the target output flux corresponding to 15% of the expected output setting is 4.46 lm, and so on. As shown in graph 706, the mapping values ​​form a linear relationship or function between the target output flux and the output setting value.

[0063] After determining the target output flux value for each desired output setting, the light engine 208 converts the target output flux value back to the corresponding drive strength value (e.g., PWM duty cycle time). These corresponding drive strength values ​​can be input into the light engine 208 to reproduce the target output flux value. Typically, this conversion is performed in multiple operations starting with operation 608.

[0064] At operation 608, a second polynomial fit (also referred to herein as the second function) is calculated to model the relationship between the measured output flux values ​​of the light engine 208 (e.g., found in column Sp26 of the initial table 700) and the calibrated color sensor Y values ​​(e.g., calibrated luminance readings found in column Sp9 as measured by the first color sensor, and calibrated luminance readings found in column Sp14 as measured by the second color sensor). Although luminance readings from two independent sensors are presented in table 700, as previously stated, a single set of luminance readings from a single color sensor is sufficient for operation 608. Therefore, the two sets of readings are redundant, and values ​​from either the first or second color sensor can be used.

[0065] The color sensor Y-values ​​listed in columns Sp9 or Sp14 are color sensor readings proportional to the luminous flux of the light engine 208 when it illuminates the color sensor. The light illuminating the color sensor is a small fraction of the total flux from the light engine 208, which is directed toward the sensor via an internal optical beam splitter. Therefore, this small fraction of luminous flux is highly correlated with the output flux of the light engine 208. Thus, the color sensor Y-value provides a constant for all desired preset colors, and the relationship between the color sensor Y-value and the measured output flux of the light engine 208 can be used as a bridge to convert the output setting value (i.e., the percentage represented in Table 704) into a desired drive intensity that will cause the light engine 208 to produce a target output flux value previously mapped to the output setting value. Figure 7D The curves 708 and 710 show Figures 7A to 7C The example illustrates the relationship between the measured output flux and the color sensor Y-value. Specifically, graph 708 depicts the measured output flux along the X-axis and the calibrated color sensor Y-value along the Y-axis, while graph 710 displays the same data on an inverted or opposite axis. As both graphs show, the measured flux and color sensor Y-reading exhibit a linear relationship, and typically only a single polynomial fit or function is computed to model the relationship.

[0066] At operation 610, using the modeling relationship between the measurement flux of the light engine 208 and the Y-value of the color sensor, an additional mapping between the target output flux value and the adjusted Y-value of the color sensor for each desired output setting is determined. To illustrate the mapping at operation 610, Figure 7E Representative Table 712 is shown. Representative Table 712 includes the target output flux value for each desired output setting, as found in Table 704, and further includes columns labeled “corr Ya” and “corr Yb” for mapping to the previously determined output setting and the target output flux value (e.g., calculated for it). The adjusted color sensor Y value for each output setting can be determined using the following formula, where “a” is a coefficient of the fitting parameter as determined at operation 608:

[0067] The adjusted color sensor Y = (a) × (flux (lm)).

[0068] At operation 612, the adjusted color sensor Y values, as determined for each target output flux value and desired output setting value for the light engine 208, are mapped to the drive strength values ​​of the main electrical input parameters found in column Sp4 of the initial data table 700. Therefore, a third polynomial fit or third function is computed to model the direct relationship between the adjusted color sensor Y values ​​(e.g., represented by the “corr Ya” and “corr Yb” columns in table 712) and the drive strength, which typically yields two fitting parameters. Figure 7F Example graph 714 is depicted, showing the adjusted color sensor Y-values ​​plotted along the X-axis and the drive intensity values ​​plotted along the Y-axis. In the representative graph 714, data from each of the two color sensors is shown; however, as previously mentioned, data from only a single color sensor can be used. The relationship shown in graph 714 is color-dependent, and therefore must be calculated for each desired preset color of the light engine 208 during calibration.

[0069] At operation 614, the adjusted color sensor Y value, target output flux value, and output setting value (e.g., in dimensionless (percentage) units) are further mapped to the adjusted drive strength value. The adjusted drive strength can be determined using the following formula, where "a" and "b" are coefficients of the fitting parameters determined at operation 612:

[0070] Adjusted drive = (a) × (adjusted color sensor Y) 2 +(b)×(adjusted color sensor Y).

[0071] Once the adjusted drive strength values ​​are determined, the following formula is used to calculate each adjusted drive strength value relative to the maximum drive strength (in Figures 7A to 7F In the example, the percentage (%) of the maximum drive strength value (3200):

[0072] Adjusted drive % = (Adjusted drive) / (Maximum drive) × 100%.

[0073] Figure 7G The text presents a representative table 716, which is filled with information based on... Figures 7A to 7F The example shows the adjusted drive strength and drive strength percentage of the light engine 208. As shown, the maximum drive strength percentage calculated at operation 614 is less than 100% (93.45% for the first color sensor and 93.40% for the second color sensor). Therefore, at operation 616, the calculated adjusted drive strength is scaled to produce an adjusted drive strength value covering the full range from 0% to 100% of the maximum drive strength. Figure 7H Another representative table, 718, is shown, which includes scaled adjusted drive strength values. As shown, the previously unscaled adjusted drive strength values ​​are magnified to 100%, thus equal to 3200, and cover the full range of achievable drive strengths for major electrical input parameters, such as the maximum supported PWM duty cycle for driving LEDs. Note that although magnification is applied at operation 616... Figures 7A to 7H The example shown is for reference only; however, in some embodiments, the adjusted drive strength may be scaled down. Typically, the adjusted drive strength value can be scaled using the following formula:

[0074] Scaling adjusted drive % = (a) × (adjusted drive %)

[0075] Where "a" is the scaling factor determined by the following formula:

[0076] a = (maximum drive) / (maximum adjusted drive).

[0077] After scaling, the scaled adjusted drive values ​​are now mapped to the previously associated adjusted and unscaled drive strength and drive strength percentage, adjusted color sensor Y values ​​(for one or more sensors), target output throughput values, and output settings (e.g., data found in Representative Table 712). Figure 7I Table 720, a representative representation of the aforementioned scaling mapping, is shown for reference.

[0078] Using a scaling map (e.g., data found in representative table 720), the final relationship between the output setting value (in percentage) and the scaled and adjusted percentage of drive intensity can be determined for a specific preset color. Therefore, at operation 618, a fourth polynomial fit or fourth function is computed to model the relationship between the output setting value and the scaled and adjusted percentage of drive intensity, which typically produces two fit parameters. Figure 7J A representative graph 722 depicts this relationship, showing the output setting value plotted along the X-axis and the scaled and adjusted percentage of drive intensity plotted along the Y-axis. Two fitting parameters derived from the modeling relationship enable the customization of the desired output setting value of the light engine 208 into an adjusted drive intensity of the light engine 208's primary electrical input parameter, thereby allowing the light engine 208 to produce illumination light with a perceived brightness matching the desired output setting value. Therefore, when a user (e.g., a surgeon) adjusts the desired output setting of the light engine 208 (e.g., when using a surgical system with an illuminator), the perceived brightness of the light engine 208 will correspond to the output setting adjustment.

[0079] In summary, embodiments of this disclosure generally relate to systems and methods for calibrating light-emitting diode (LED) light engines, and more specifically to systems and methods for calibrating LED light engines to facilitate the utilization of dimensionless output setting values ​​that reflect observed luminance. The methods and systems described herein address shortcomings in certain existing LED lighting systems where adjustments to the desired output setting of the light engine result in non-linear and non-intuitive adjustments to the observed luminance. Therefore, the methods and systems described herein can be used to calibrate light engines such that the observed luminance of the produced illumination corresponds linearly to an increase or decrease in the user-input output setting value.

[0080] As used herein, the phrase “at least one” in a list of items refers to any combination of those items, including a single member. For example, “at least one of a, b, or c” is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination of multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other order of a, b, and c).

[0081] The foregoing description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments. Therefore, the claims are not intended to limit themselves to the embodiments shown herein, but are given the full scope consistent with the language of the claims.

[0082] In the claims, unless otherwise specified, references to singular elements are not intended to mean "one and only one," but rather "one or more." Unless otherwise specified, the term "some" means one or more. All structural and functional equivalents of elements in the various aspects described throughout this disclosure that are known or will be known hereafter to a person skilled in the art are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, regardless of whether such disclosure is expressly recited in the claims, the contents disclosed herein are not intended for public use. In accordance with 35 U.SC §112(f), no element of any claim will be interpreted unless it is expressly recited using the phrase "means for…" or, in the case of a method claim, using the phrase "steps for…". The word "exemplary" herein is used to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects.

[0083] Example Implementation

[0084] Example 1: A method for generating calibrated illumination light using an illumination system with a light engine, the method comprising: receiving a user input corresponding to a dimensionless output setting value of the illumination system; mapping the dimensionless output setting value to a corresponding adjusted drive intensity of the light engine input using a mapping method, wherein the mapping is obtained by: obtaining a first set of data of the light engine, wherein the first set of data includes measured output flux data of the light engine and a color sensor luminance reading, wherein the measured output flux data and the color sensor luminance reading correspond to drive intensity data of the light engine input parameters; determining the measured output flux data and the drive intensity... The data establishes a first relationship between the measured output flux data and the color sensor luminance reading; a second relationship between the drive intensity data and the color sensor luminance reading; a third relationship between the drive intensity data and the color sensor luminance reading; and a fourth relationship between the dimensionless output setting value and the drive intensity data of the light engine input parameters, wherein the fourth relationship enables the dimensionless output setting value to be converted into a corresponding adjusted drive intensity of the light engine input parameters, the corresponding adjusted drive intensity being used to drive the light engine to generate illumination light with a desired output flux; and the light engine is driven using the adjusted drive intensity to generate illumination light with the desired output flux.

Claims

1. A method for generating calibrated illumination light using a light engine of an illumination system, the method comprising: Obtain a first set of data from the optical engine, wherein the first set of data includes the measured output flux data of the optical engine and the brightness reading of the color sensor, wherein the measured output flux data and the brightness reading of the color sensor correspond to the drive intensity data of the input parameters of the optical engine; Determine a first mapping between the measured output flux data and the drive intensity data; Determine a second mapping between the measured output flux data and the color sensor brightness reading; Based on the first mapping and the second mapping, a third mapping is determined between the driving intensity data and the color sensor brightness reading; Based on the third mapping, a fourth mapping is determined between the multiple dimensionless output setting values ​​of the lighting system and the drive intensity data; Receive one of the multiple dimensionless output setting values ​​from user input; The fourth mapping is used to match one of the plurality of dimensionless output setting values ​​with the corresponding drive intensity of the light engine input parameters; and The light engine is used to generate illumination light with the desired output flux.

2. The method as described in claim 1, wherein, The first mapping corresponds to a polynomial fit between the measured output flux data and the driving intensity data.

3. The method as described in claim 1, wherein, The second mapping corresponds to a polynomial fit between the measured output flux data and the color sensor brightness reading.

4. The method of claim 1, wherein, The third mapping corresponds to a polynomial fit between the drive intensity data and the color sensor brightness reading.

5. The method of claim 1, wherein, The fourth mapping corresponds to a polynomial fit between the plurality of dimensionless output setting values ​​and the drive intensity data.

6. The method of claim 1, wherein, The first mapping is used to estimate the maximum output throughput of the optical engine.

7. The method of claim 6, wherein, The maximum output flux of the optical engine is used to determine the target output flux value across the entire range, with each target output flux value corresponding to one of the plurality of dimensionless output setting values.

8. The method of claim 7, wherein, The second mapping is used to determine adjusted color sensor brightness readings, each of which corresponds to a value in the full range of target output flux values.

9. The method of claim 8, wherein, The third mapping is used to determine the adjusted drive intensity corresponding to each of the adjusted color sensor brightness readings.

10. The method of claim 9, wherein, The adjusted drive intensity is scaled to correspond to the target output flux value across the full range.

11. The method of claim 1, wherein, The second mapping between the measured output flux data and the color sensor brightness reading is determined independently of the color of the light generated by the light engine.

12. The method of claim 11, wherein, The determination of the first mapping, the third mapping, and the fourth mapping depends on the color of the light generated by the light engine.

Images