Light exposure quantification strategy for prevention of phototoxicity during ophthalmic surgery

Abstract

A system (10) and method (70) for quantifying light exposure of a patient's retina (25) during ophthalmic surgery. A light source (32) illuminates the patient's retina (25) with directional light (LL) during the surgery to produce an illuminated retina surface. A camera (36) collects image data (38) of the illuminated retina surface (25I). An electronic control unit, ECU (50), is in communication with the camera (36) and an indicator device (40), receives the image data (38), calculates a cumulative energy spectral density of the directional light (LL) incident on the retina (25), and performs a control action indicative of possible phototoxicity in response to the cumulative energy spectral density exceeding a phototoxicity threshold, the control action including enabling the indicator device (40). The illuminated retina surface (25I) can be divided into virtual zones (Z1, Z2), the ECU (50) mapping the cumulative energy spectral density to the illuminated retina surface (25I). Each of the optional zones (Z1, Z2) has a corresponding cumulative energy spectral density.

Description

Background Technology

[0001] This disclosure relates to an automated strategy for quantifying retinal exposure to light energy during ophthalmic surgery. Certain ophthalmic surgeries require high-magnification magnification and imaging of the retina and surrounding tissues within the vitreous cavity of the patient's eye. During such surgeries, the retina is illuminated by a bright light source, primarily emitted by a manually operated light conduit / intraocular illuminator or another suitable directional light source. Vitrectomy is a representative procedure that uses such directional light to illuminate the vitreous cavity. As understood in the art, vitrectomy involves the precise removal of vitreous fluid gel to facilitate access to and repair of torn or detached retina, macular holes, or diseased / damaged ocular tissue. Cataract surgery and other ophthalmic surgeries similarly utilize internal and / or external directional light for illumination and imaging purposes.

[0002] The retina, a thin and highly fragile lining located on the inner posterior surface of the eyeball, acts as an appendage to the brain. That is, sensory neurons, intricate neural circuits, and synaptic connections in the retina respond to incident light with corresponding nerve impulses, which are ultimately transmitted to the brainstem via the optic nerve. Due to the photosensitivity of the fragile retinal tissue, directed light energy incident on the retinal surface poses a risk of phototoxicity, a risk that is highly variable and factor-dependent.

[0003] Currently, light output during ophthalmic surgery is characterized relative to models using worst-case assumptions. Because surgical lighting skills, techniques, and durations vary significantly among surgeons, predictions made using worst-case models rarely align with actual phototoxic risks or exposures. Consequently, surgeons may be distracted during surgery by overly aggressive phototoxicity warnings and false alarms. Summary of the Invention

[0004] This document discloses an automated method and system for preventing phototoxicity, used to accurately quantify the exposure of a patient's retina to directed light energy during ophthalmic surgery. During such surgery, the potential toxicity of light energy varies considerably based on many factors, including the linear distance between the retina and the light source, the exposed surface area of ​​the retina, the duration of exposure to light energy on that area, and the spectral content and intensity of the light energy. By measuring the working image of the retina during surgery and quantifying the distribution of light energy in terms of cumulative energy spectral density, surgeons are provided with a more accurate assessment of the true light energy exposure and the resulting toxic risks. This, in turn, allows surgeons or any other attending clinician to make more informed decisions regarding retinal illumination. Benefits of this teaching include the ability to use higher intensity light and / or apply light with different spectral contents, perhaps for an extended period before a phototoxicity hazard warning appears. Once a phototoxicity hazard is indicated, an appropriate warning or notification is issued, and in some embodiments, the control settings for the light source may be adjusted.

[0005] In an exemplary embodiment, a system for quantifying light exposure of a patient's retina during ophthalmic surgery includes a light source, a camera, an indicator device, and an electronic control unit (ECU). The light source is configured to illuminate the patient's retina with directional light during ophthalmic surgery to create an illuminated retinal surface. When this occurs, the camera collects digital or analog image data of the illuminated retinal surface. The ECU, in communication with the camera, receives the image data and subsequently calculates the cumulative spectral energy density of the directional light energy incident on the retina. The ECU then displays the incident light energy information via the aforementioned indicator device, which itself has various possible configurations as described herein. In another embodiment, the ECU may communicate with the light source and may continue to perform control actions relative to the light source based on an assessment of potential phototoxicity.

[0006] As used herein, the term "cumulative energy spectral density" refers to the energy density of incident light, obtained by integrating over time and distributed across different wavelengths (i.e., the light energy of the retina at a specific bandwidth of the electromagnetic spectrum, and the cumulative exposure of such light at associated frequencies and intensities). This control action is performed in response to the cumulative energy spectral density of the transmitted / incident light exceeding a phototoxicity threshold, which may be determined by the user / surgeon or based on a calibrated preset value, and the control action includes activating an indicator device.

[0007] As described in this article, the ECU integrates the energy level of the directional light during ophthalmic surgery, starting from the initial illumination of the retina. In other words, integration is not triggered when the light source is turned on, but only when effective illumination of the retina begins (i.e., when light energy is incident on the retina).

[0008] The ECU can optionally determine the aforementioned cumulative energy spectral density as multiple different cumulative densities to provide a higher level of accuracy. In one example, the ECU can calculate the cumulative light energy based on multiple light sources (such as light guides / probes and chandeliers). In another example, the ECU can calculate the cumulative density for multiple different regions or areas of the illuminated retinal surface. In this embodiment, the ECU is able to perform a control action in response to any of these regions having a cumulative energy spectral density exceeding a phototoxicity threshold, which itself can be several region-specific thresholds to account for potential differences in photosensitivity across exposed areas of the retina.

[0009] In some embodiments, the indicator device envisioned herein includes a display screen. The ECU automatically presents to the surgeon via the display screen a pattern, or "thermograph," of the light energy distribution on the illuminated retinal surface. Thus, the thermograph represents the distribution of cumulative energy spectral density, thereby precisely locating locations where the energy concentration delivered to the retina is relatively high or relatively low. Fundus images can be used as an optional background for this thermograph; that is, the thermograph can be presented as an overlay of the fundus image or displayed on top of the fundus image to accurately indicate areas corresponding to localized "hot spots," such as areas exposed to disproportionately high amounts of incident light energy. Alternative methods include changing the color of the overlay image in a manner similar to adding yellow highlights to portions of the displayed image that exceed a threshold.

[0010] In some aspects of this disclosure, the ECU can be configured to automatically adjust the control settings of the light source in response to exceeding multiple phototoxicity thresholds. For example, the wavelength and / or intensity of the directional light can be modified as needed without manual intervention by a surgeon. In such embodiments, control actions may include real-time automatic adjustment of the wavelength and / or intensity via the ECU.

[0011] A method for quantifying light energy exposure of a patient's retina during ophthalmic surgery is also disclosed. Embodiments of the method include illuminating the patient's retina with directional light from a light source during ophthalmic surgery to create an illuminated retinal surface, and collecting image data of the illuminated retinal surface using a camera. The method also includes receiving the image data from the camera via an ECU, and then calculating the cumulative energy spectral density of the directional light energy incident on the retina during the ophthalmic surgery via the ECU. In response to the cumulative energy spectral density exceeding a phototoxicity threshold, the method includes performing a control action via the ECU, wherein the control action indicates the possible presence of phototoxicity, the control action including activating an indicator device.

[0012] In a possible embodiment, the ECU includes a processor, an input / output (I / O) circuitry, and a memory that communicates with the processor, a light source, an indicator device, and a camera. The memory stores computer-readable instructions that, when executed by the processor, cause the ECU to receive collected image data from the camera during ophthalmic surgery. The collected image data depicts the illuminated surface of the retina. Executing these instructions also causes the ECU to calculate the cumulative energy spectral density of directional light incident on the retina during ophthalmic surgery and, in response to the cumulative energy spectral density exceeding a phototoxicity threshold, to perform a control action indicating potential phototoxicity, including activating the indicator device. This threshold can be any value set by the surgeon based on prior surgical experience and medical judgment. Alternatively, the threshold can be based on a calibration process that quantifies an appropriate safety threshold.

[0013] The above-described features and advantages of this disclosure, as well as other possible features and advantages, will become apparent from the following detailed description of the best mode for carrying out this disclosure, taken in conjunction with the accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of an operating room setup using an automated system to quantify light exposure in order to prevent potential phototoxicity or exposure conditions during representative ophthalmic surgeries.

[0015] Figure 2 yes Figure 1 A schematic diagram of an embodiment of the automation system shown.

[0016] Figure 3 This is an exemplary schematic diagram of a thermal image based on a fundus image, according to one aspect of this disclosure.

[0017] Figure 4 It describes the use of Figure 1 The flowchart illustrates an exemplary method for quantifying light energy exposure using an automated system.

[0018] The foregoing and other features of this disclosure will become more fully apparent from the following description taken in conjunction with the accompanying drawings and the appended claims. Detailed Implementation

[0019] This document describes embodiments of the present disclosure. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms. The figures are not necessarily drawn to scale. Some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but only as a representative basis for teaching those skilled in the art to employ the present disclosure in different ways. Those skilled in the art will understand that the various features shown and described with reference to any of the figures can be combined with features shown in one or more other figures to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, for a particular application or implementation, various combinations and modifications of features consistent with the teachings of this disclosure may be desired.

[0020] In the following description, certain terms may be used for illustrative purposes only and are therefore not intended to be limiting. For example, terms such as “above” and “below” refer to directions referenced in the accompanying drawings. Terms such as “front,” “rear,” “before,” “after,” “left,” “right,” “rear,” and “side” describe the orientation and / or position of portions of a component or element within a consistent but arbitrary frame of reference, as will become clear from the text describing the component or element under discussion and the associated accompanying drawings. Furthermore, terms such as “first,” “second,” and “third” may be used to describe individual components. Such terms may include the words specifically mentioned above, their derivatives, and words with similar meanings.

[0021] Referring to the accompanying drawings, similar reference numerals refer to similar parts. Figure 1 A representative ophthalmic surgical operating room 10 is schematically depicted. As those skilled in the art will understand, such an operating room 10 may be equipped with a multi-axis surgical robot 12 and an operating table 14. When the operating room 10 is used to perform representative vitreoretinal surgery, or other surgical or diagnostic procedures, the surgical robot 12 is connected to an ophthalmic microscope 16 through which the surgeon (not shown) can observe the patient's ocular anatomy at high magnification. Using associated hardware and software, the surgeon can observe high-magnification images 18 and 118 of the patient's retina 25, for example, via corresponding high-resolution medical displays 20 and 200.

[0022] Figure 1 An exemplary surgical operating room 10 also includes a cabinet 22 containing an electronic control unit (ECU) 50, an exemplary embodiment of which is shown in... Figure 2The image is depicted and described in detail below. The cabinet 22 is shown juxtaposed with the display screen 20, but in other embodiments, the cabinet can be positioned anywhere within the operating room 10. This cabinet 22 (which may be constructed of a lightweight and easily sterilizable material, such as painted aluminum or stainless steel) serves to house the ECU 50 and protect its constituent hardware from potential dust, debris, and moisture intrusion.

[0023] Within the scope of this disclosure, vitreoretinal surgical procedures performed in operating room 10 involve the use of directional task illumination to illuminate the retina 25. This light is primarily composed of, for example, directional task illumination. Figure 2 The light source 32 shown emits light, with additional illumination provided by an external lamp 17 mounted to the ophthalmic microscope 16. Over time and based on many variable factors, the use of this light may pose a phototoxic risk that could affect the photosensitivity of the retina 25. To mitigate this risk, the ECU 50 of this disclosure is configured to automatically quantify the light energy exposure of the retina 25, with the ultimate goal of delivering an accurately derived alarm or warning to the attending surgeon. The ECU 50 may also perform optional active control actions to reduce exposure, as described below.

[0024] refer to Figure 2 The illustration shows a representative patient's eye 30 undergoing ophthalmic surgery 13 (in this case, invasive vitreoretinal surgery). During this type of ophthalmic surgery 13, the light source 32 described above is inserted into the vitreous cavity 15 of the patient's eye 30. Light LL emitted from the light source 32 and light from... Figure 1 Some of the light from the microscope lamp 17 falls within a predetermined wavelength range depending on the task being illuminated. In some embodiments, the light source 32 may be embodied as a light guide or intraocular illuminator, possibly having controllable intensity and / or spectral content (i.e., specific wavelengths and associated colors of light within the electromagnetic spectrum). An exemplary application that can be envisioned is a surgeon desiring a blue light frequency shift to improve visibility, where the light source 32 may be configured to adjust its output spectrum in response to commands from the surgeon. A variety of different illumination techniques can be used to emit light LL, such as, but not limited to, red / green / blue (RGB) lasers, light-emitting diodes (LEDs), halogen bulbs, etc.

[0025] During ophthalmic surgery 13, the surgeon may also insert surgical instruments 34 into the vitreous cavity 15 to perform a given surgical task on or near the retina 25. Non-limiting exemplary embodiments of the surgical instruments 34 include: forceps, squeezing handles, bladed vitrectomy probes, scissors, illuminated or unilluminated laser probes, and / or infusion tools. The directional light LL is emitted from the distal end E1 of the light source 32, wherein the directional light LL is incident on the exposed surface of the retina 25 to produce an illuminated retinal surface 25I. The light source 32 is coupled to an associated filtered power supply (PS) 37, such as a filtered wall-mounted power outlet or battery pack and power inverter suitable for ensuring reliable generation and transmission of the directional light (arrow LL).

[0026] During ophthalmic surgery 13, a digital or analog camera 36 or another high-resolution medical imaging device 38 collects image data of the illuminated retinal surface 25I. The collected image data 38 is then transmitted to an ECU 50 for processing according to a phototoxicity algorithm (L-TOX ALGO) 70. The method enabled by algorithm 70... Figure 4 The description is presented in the diagram and further detailed below. The indicator device (IND) 40 also communicates with the ECU 50 and is configured to respond to indicator control signals (arrow CC) from the ECU 50. 40 Enabled / turned on in response to indicator control signals (arrow CC). 40 Depending on the specific configuration of the indicator device 40, the indicator device 40 can provide appropriate auditory, visual and / or tactile alarms or warnings.

[0027] For example, the indicator device 40 can be embodied as a speaker, in which case the indicator control signal (arrow CC) 40 This can cause the indicator device 40 to emit an audible tone. Alternatively, the indicator device 40 may include color-coded lights that receive indicator control signals (arrow CC). 40 This causes the indicator device 40 to illuminate in an easily identifiable manner (e.g., using red light). In any embodiment, the ECU 50 may also use the display screen 20 and / or 200 as part of the indicator device 40 to present a visual graphic depiction of the concentration or distribution pattern of light energy on the illuminated retinal surface 25I.

[0028] Within the scope of this disclosure, the phototoxicity alarm rate is reduced compared to conventional methods operating under worst-case modeling scenarios of the types described above. Alternatively, in some embodiments, the ECU 50 is configured to receive light output data from the light source 32 (arrow F). BLAs electronic feedback signals, these signals indicate intensity, wavelength, temperature, and / or other relevant output parameters. In such an embodiment, the ECU 50 then quantifies the actual distribution and energy spectral density of the directional light LL from the light source 32 on the illuminated retinal surface 25I.

[0029] Still referencing Figure 2 The ECU 50 is configured to receive, in real time, collected image data 38 from the camera 36 during ophthalmic surgery 13. The received collected image data 38 depicts the illuminated retinal surface 25I and describes the corresponding light intensity level for each constituent pixel of the image. The ECU 50 estimates or calculates the cumulative energy spectral density of the directional light LL incident on the retina 25 during the ophthalmic surgery 13, wherein the ECU 50 uses digital image data 38 for estimation or calculation and, in different embodiments, may use light output data (arrow F). BL The ECU 50 then performs an estimation or calculation. As mentioned above, the term "cumulative energy spectral density" as used herein considers the light energy density over the electromagnetic spectrum at different wavelengths (i.e., particularly the wavelength range associated with phototoxicity risk). The ECU 50 then performs appropriate control actions to indicate the possible presence of phototoxicity relative to one or more corresponding phototoxicity thresholds.

[0030] Although the ECU 50 is schematically depicted as a monolithic housing for clarity and simplicity, the ECU 50 may include one or more networked devices, each having a central processing unit (CPU) or other processor 52 and sufficient memory 54 (including non-transitory (e.g., tangible) media involved in providing data / instructions that can be read by the CPU 52). Instructions embodying algorithm 70 may be stored in memory 54 and executed by the CPU 52 to perform a variety of different functions described herein, thereby implementing the method. Memory 54 may take many forms, including but not limited to non-volatile and volatile media.

[0031] As will be understood, non-volatile media may include optical discs and / or magnetic disks or other persistent storage, while volatile media may include dynamic random access memory (DRAM), static RAM (SRAM), etc., any or all of which may constitute the main memory of ECU 50. Input / output (I / O) circuitry 56 may be used to facilitate connection and communication with a number of different peripheral devices used during ophthalmic surgery 13, including camera 36, ​​light source 32, indicator device 40, and (multiple) displays 20 and / or 200. Other hardware not depicted but commonly used in the art may be included as part of ECU 50, including but not limited to local oscillators or high-speed clocks, signal buffers, filters, etc.

[0032] Within the scope of this disclosure, the ECU 50 is software-programmed, hardware-equipped, and therefore configured to integrate the power level of the directional light LL incident on the retina 25 over time during the duration of ophthalmic surgery 13. In this way, the ECU 50 obtains the aforementioned cumulative energy spectral density. That is, the ECU 50 does not consider the full duration for which the light source 32 is turned on, i.e., whether the directional light LL from the light source 32 actually illuminates any part of the retina 25, but rather evaluates the distribution and concentration of the spectral energy from the distributed light LL on the retina 25 in a more meaningful way (e.g., in watts per minute, watts per hour, etc.), thereby making it possible to distinguish different areas of the retina 25.

[0033] Brief Reference Figure 3 , Figure 2 The retina 25 is shown as a representative fundus image 42. As understood in the art, a fundus image is a color, black-and-white, or grayscale image of several different key structures of the retina 25, primarily the optic disc 44, the retinal artery 46 and the peripheral veins originating therefrom, and the macula 48. The fundus image 42, commonly used in ophthalmic practice and therefore well-known, can be used as the background for the displayed thermal image 45. In this configuration, the ECU 50 can be configured to digitally or otherwise divide the illuminated retinal surface 25I into multiple virtual regions and map the cumulative energy spectral density onto the illuminated retinal surface 25I such that each of the multiple regions has a corresponding cumulative energy spectral density.

[0034] In this configuration, ECU 50 can optionally be... Figure 2 During ophthalmic surgery 13, a thermal image 45 is overlaid onto a fundus image 42. This information is transmitted via... Figure 1 The display screens 20 and / or 200 display up to 200 in real time. Therefore, the heatmap 45 visually provides information that clearly indicates the cumulative energy spectral density at... Figure 2 The distribution or concentration on the illuminated retinal surface 25I is shown. This method provides for the consideration of the entire retina 25 as having equal light sensitivity, or as receiving equal amounts of light. Figure 2 For exposure under directional light LL, the grain size or local precision level is larger.

[0035] In progress Figure 2 During a typical ophthalmic surgery 13, the surgeon may be expected to move the distal E1 around the vitreous cavity 15. Therefore, the total exposed surface area of ​​the retina 25 may be illuminated unevenly, and the degree of illumination depends largely on the position / distance and orientation of the distal E1 relative to the retina 25, as well as the intensity of the directional light LL and other toxicity-related spectral content. Figure 2 The density or concentration of directional light LL received by some areas of the illuminated retinal surface 25I may be greater than that of other areas, such as when a surgeon lingers in a specific area of ​​the retina 25 during a complex surgical repair. Therefore, from a qualitative point of view, the ECU 50 can consider areas receiving a higher cumulative light energy density as local "hot spots". Figure 3 The two such zones are schematically represented as zones Z1 and Z2, which are depicted for illustrative purposes only as being on either side of the macula 48.

[0036] The ECU 50 of this disclosure is configured to process this parallax by integrating the power both spatially (i.e., over the surface area of ​​the retina 25) and temporally (i.e., relative to the duration of exposure). The ECU 50 then performs appropriate control actions in response to the cumulative energy spectral density of at least one of a plurality of different zones Z1 and / or Z2, or the cumulative energy spectral density of the entire illuminated retinal surface 25I, exceeding a corresponding phototoxicity threshold. Such thresholds may be the same in different embodiments or zone-specific, as described above, wherein the ECU 50 uses a higher threshold, for example, in zones where the tissue of the retina 25 is more phototolerant than other tissues.

[0037] In other embodiments, the total cumulative energy spectral density of the directional light LL incident on the retina 25 can be used (e.g., in watts per square millimeter (W / mm²)). 2 Using the same unit (e.g., watts per rod), different phototoxicity thresholds can also be applied to different areas of the retina 25 as described above. For example, the phototoxicity threshold corresponding to areas of the retina 25 where photoreceptors are more concentrated than in other areas can be lower than the corresponding phototoxicity thresholds in other areas, achieving an effective level of "watts per rod" or "watts per cone" accuracy within the scope of this disclosure. Such phototoxicity thresholds can be adjusted over time based on postoperative history or other factors to provide improved long-term results.

[0038] Now for reference Figure 4 The method is implemented by executing computer-readable instructions embodying algorithm 70. That is, executing instructions stored or recorded in... Figure 2 The instructions in the memory (M) of the ECU 50 shown can cause the processor 52 and other hardware of the ECU 50 to execute a method. Therefore, for clarity, this method is referred to hereinafter as method 70.

[0039] A representative embodiment of method 70 begins with logic block B72, which includes directional light LL from light source 32 and possibly from [other sources] during ophthalmic surgery 13. Figure 1 The microscope lamp 17 provides some additional light to illuminate Figure 2 The patient's retina 25 is illuminated by a focused beam of directional light LL, which illuminates the retinal surface 25I. Therefore, the surgical steps prior to implementing logic block B72 may include making an incision in the eye 30, inserting a cannula (not shown), and inserting the light source 32 into the vitreous cavity 15. Once the distal end E1 of the light source 32 is present within the vitreous cavity 15 and is powered by the power supply 37, the light source 32, in some embodiments, initiates the transmission of light output data (arrow FB) to the ECU 50. L Again, this light output data (arrow FBL) is primarily facilitated by light source 32, but in some embodiments, it may also describe the light emitted by microscope lamp 17. Method 70 then proceeds to logic block B74.

[0040] Figure 4 The logic block B74 can be involved in receiving light output data from the light source 32 (arrow FB). L The light output data describes the intensity and spectral content of the directional light emitted by the light source when illuminating the patient's retina. Logic block B74 also includes data collected using camera 36. Figure 2 Image data 38 may include a two-dimensional or three-dimensional image of the illuminated retinal surface 25I. In some embodiments, camera 36 may be coupled with... Figure 1 The ophthalmic microscope 16 is integrated, or the camera 36 may be a separate device. Because the collected image data 38 in the digital embodiment is formed from image pixels, the logic block B74 may include associated quantization information that describes the corresponding illumination level of each of the constituent image pixels, including, for example, the intensity of that constituent image pixel.

[0041] As part of logic block B74, image data 38 is transmitted to ECU 50 via a suitable transmission conductor (not shown). Therefore, logic block B74 also includes receiving the collected image data 38 from camera 36 via ECU 50. This is in contrast to the light output data (arrow FB) provided in logic block B72. L In combination, image data 38 enables ECU 50 to estimate the power, intensity, wavelength, and other relevant energy spectral content of the directional light (LL) from light source 32, as well as the distribution of the power, intensity, wavelength, and other relevant energy spectral content of the directional light on retina 25. Method 70 then proceeds to logic block B76.

[0042] At logic block B76, ECU 50 then uses the optical output data from logic block B72 (arrow FB). LThe image data 38 of the logic block B74 is used to estimate or calculate the cumulative energy spectral density of the directional light LL incident on the retina 25. The estimation can be performed solely based on the collected image data 38 (e.g., using a model based on brightness, color, distribution, and other factors present in the image including the collected image data 38). In embodiments using light output data (arrow FB) L More accurate results can be obtained in embodiments that use, for example, the prediction of the power of the light source 32, the diffusion function of the light source 32, the distance between the light source 32 and the retina 25, and the duration of exposure of the retinal tissue to light LL.

[0043] Logic block B76 may include calculating the average or normalized energy spectral density over the entire illuminated retinal surface 25I, or ECU 50 may calculate multiple discrete energy spectral densities in a region-specific manner. When using the latter method (e.g., as...), Figure 3 When the surgeon is aware of any parallax in the concentration of light energy on the surface of the retina 25 (as depicted), the procedure proceeds to logic block B78 once the ECU 50 has calculated the cumulative energy spectral density or the area-specific energy spectral density.

[0044] At logic box B78 Figure 2 ECU 50 then compares one or more cumulative energy spectral densities with corresponding phototoxicity thresholds. When no phototoxicity threshold is exceeded, method 70 repeats logic block B72. Alternatively, when ECU 50 determines that one or more phototoxicity thresholds have been exceeded, method 70 proceeds to logic block B80.

[0045] Logic block B80 relates to executing a control action via ECU 50 in response to the cumulative energy spectral density exceeding a phototoxicity threshold. As described above, the control action indicates the possible presence of phototoxicity and includes activating indicator device 40. As part of logic block B80, ECU 50 may take into account the magnitude of exceeding the given phototoxicity threshold in logic block B78 when determining which of a number of possible control actions ECU 50 should execute in a given situation. That is, the control action may be proportionate to the magnitude of the difference between the exceeded phototoxicity threshold and the cumulative energy spectral density, and ECU 50 may escalate the corresponding alarm as the magnitude increases.

[0046] Illustrative examples include those for Figure 3 The threshold phototoxicity level is established for representative regions Z1 and Z2. During ophthalmic surgery 13, ECU 50 automatically integrates the power delivered over time by the directional light LL in different regions or areas (including regions Z1 and Z2) of the illuminated retinal surface 25I. ECU 50 can be used via... Figure 1Displays 20 and / or 200 Figure 3 The color-coded version of the heatmap 45 allows surgeons to readily identify whether a particular area is overexposed relative to others. In an embodiment, ECU 50 can modify the color of a "hotter" area as the cumulative energy spectral density increases, for example, by gradually changing the color of that area from yellow to red. ECU 50 can activate [something] when a given phototoxicity threshold is crossed for a given area. Figure 2 Indicator device 40 (e.g., light or audible alarm tone).

[0047] Additionally, within the scope of this disclosure, ECU 50 can respond to phototoxicity levels exceeding a given threshold by automatically adjusting the settings of light source 32. This option may be selectable by the surgeon, or in other embodiments, may be selectively skipped or ignored. Representative control actions in such events may include adjusting... Figure 2 The power level of the power supply 37 can be adjusted to reduce the power of the light source 32 and / or change the wavelength and / or intensity of the directional light LL emitted by the light source 32 during ophthalmic surgery 13. The latter control action may cover changing the spectral content of the directional light to reduce the amount of ultraviolet / violet / blue light, thereby making the energy safer for the eyes, although possibly at the cost of less detail.

[0048] By using Figure 1 and Figure 2 ECU 50 Figure 3 Intuitive heatmap 45, and Figure 4 Algorithm 70 shown is used to perform... Figure 2 The surgeon performing ophthalmic surgery 13 illustrated is aware in a more practical and localized way of the phototoxic risks associated with directing incident light LL from the described light source 32 onto the retina 25. Because phototoxicity alarms are not triggered unless and until a given energy spectral density-specific threshold is exceeded, this approach should help reduce the number of false alarms compared to conventional worst-case modeling scenarios.

[0049] Furthermore, reducing the false alarm rate provides surgeons with an increased level of confidence. In other words, an alarm that does sound during ophthalmic surgery 13 is highly likely to be a genuine alarm and therefore unlikely to be ignored or left unattended without action. The implementation can be standalone; that is, the ECU 50 and its accompanying logic can be used with existing ophthalmic microscopes 16, cameras 36, and light sources 32. Alternatively, any or all of the described hardware can be integrated, enabling the ECU 50 to perform… Figure 4 The programming functionality of method 70 is seamlessly integrated.

[0050] The detailed description and accompanying drawings are supportive and descriptive of this disclosure, but the scope of this disclosure is defined only by the claims. While some best modes and other embodiments for implementing the claimed disclosure have been described in detail, various alternative designs and embodiments exist to practice the disclosure as defined in the appended claims. Furthermore, the features of the embodiments shown in the drawings or the various different embodiments mentioned in this specification are not necessarily to be construed as embodiments independent of each other. Rather, each feature described in one of these examples of embodiments may be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings. Therefore, such other embodiments fall within the scope of the appended claims.

Claims

1. A system for quantifying light exposure of a patient's retina during ophthalmic surgery, the system comprising: A light source configured to illuminate the patient's retina with directional light during the ophthalmic surgery to thereby produce an illuminated retinal surface; A camera configured to collect image data of the illuminated retinal surface as collected image data; Indicator device; as well as An electronic control unit (ECU) communicates with the indicator device and the camera, wherein the ECU is configured to: Receive from the camera the collected image data depicting the illuminated retinal surface; The collected image data is used to estimate the cumulative energy spectral density of the directional light incident on the retina during the ophthalmic surgery; The illuminated retinal surface is divided into multiple virtual regions, each of which has a corresponding region-specific phototoxicity threshold. The cumulative energy spectral density is mapped onto the illuminated retinal surface, such that each of the plurality of virtual regions has a corresponding cumulative energy spectral density; The cumulative energy spectral density is determined for each of the plurality of virtual regions based on the cumulative energy spectral density; and In response to the cumulative energy spectral density corresponding to one of the plurality of virtual regions exceeding the corresponding region-specific phototoxicity threshold, a control action indicating possible phototoxicity is performed, including activating the indicator device. The ECU is configured to selectively adjust the control settings of the light source, wherein the control action includes adjusting the wavelength of the directional light in real time during the ophthalmic surgery according to the control settings.

2. The system of claim 1, wherein, The ECU communicates with the light source and is configured to receive light output data from the light source, the light output data describing the intensity and spectral content of the light illuminating the patient's retina.

3. The system as described in claim 1, wherein, The indicator device includes a speaker, and the control action includes issuing an auditory alarm via the speaker.

4. The system as claimed in claim 1, wherein, The indicator device includes a color-coded light, and the control action includes illuminating the color-coded light.

5. The system as claimed in claim 1, wherein, The indicator device includes a display screen, and the control action includes displaying information indicating the cumulative energy spectral density via the display screen.

6. The system of claim 5, wherein, The ECU is configured to display a thermal map of the illuminated retinal surface via the display screen, the thermal map indicating the distribution of the cumulative energy spectral density on the illuminated retinal surface.

7. The system of claim 6, wherein, The digital image data includes a fundus image of the patient's retina, wherein the heatmap is displayed on the fundus image such that the fundus image forms the background of the heatmap.

8. The system of claim 1, wherein, The control action includes adjusting the intensity level of the directional light in real time during the ophthalmic surgery according to the control settings.

9. The system of claim 8, wherein, The light source is a light guide or intraocular illuminator with variable intensity and / or spectral content.

10. An electronic control unit (ECU) for quantifying light exposure of a patient's retina during ophthalmic surgery, the ECU communicating with a light source during the ophthalmic surgery to thereby generate an illuminated retinal surface, the ECU comprising: processor; An input / output (I / O) circuit system that communicates with the processor, the light source, the indicator device, and the camera; as well as A memory on which computer-readable instructions are recorded, wherein execution of the computer-readable instructions by the processor causes the ECU to: Image data collected from the camera during the ophthalmic surgery is received, wherein the collected image data depicts the illuminated retinal surface of the patient's retina; Receive light output data from the light source, the light output data describing the intensity and spectral content of the directional light emitted by the light source when illuminating the patient's retina; Calculate the cumulative energy spectral density of the directional light from the light source that provides illumination to the retinal surface during the ophthalmic surgery; The illuminated retinal surface is divided into multiple virtual regions, each of which has a corresponding region-specific phototoxicity threshold. The cumulative energy spectral density is mapped onto the illuminated retinal surface, such that each of the plurality of virtual regions has a corresponding cumulative energy spectral density; and In response to the cumulative energy spectral density corresponding to one of the plurality of virtual regions exceeding the corresponding region-specific phototoxicity threshold, a control action indicating possible phototoxicity is performed, including activating the indicator device. The ECU is configured to selectively adjust the control settings of the light source, wherein the control action includes adjusting the wavelength of the directional light in real time during the ophthalmic surgery according to the control settings.

Images