Obtaining ophthalmic information using polychromatic endoscopic illumination with hyperspectral imaging

Abstract

In a particular embodiment, a system for acquiring ophthalmic information includes an illumination device having an optical fiber, a hyperspectral illumination source, a controller, a modulation device, and an imaging device. The modulation device is configured to receive a first source light generated from the hyperspectral illumination source. The first source light includes a plurality of wavelengths. The modulation device is also configured to modulate each of the wavelengths at a different frequency to generate a second source light having a plurality of frequency-modulated wavelengths, and transmit the second source light to an optical fiber that emits the second source light to contact the ocular tissue. The imaging device selects a first frequency associated with the first frequency-modulated wavelength, and captures light returning from the ocular tissue as a result of the first frequency-modulated wavelength contacting the ocular tissue. The controller determines a parameter of the ocular tissue based on the returned light.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to obtaining ophthalmic information, and more particularly, to systems, devices, and methods for obtaining ophthalmic information about an eye using polychromatic endoocular illumination with hyperspectral imaging. [Background technology]

[0002] Many microsurgical procedures require precise cutting and / or ablation of various body tissues. For example, vitreoretinal procedures such as retinotomy, retinectomy, retinal autotransplantation, and vitreous surgery typically require cutting, ablation, peeling, delaminating, coagulating, or otherwise manipulating intraocular tissues such as the retina, vitreous humor, traction zones, and membranes.

[0003] Many of these intraocular tissues play a vital role in enabling vision. For example, the retina, or the innermost layer lining the posterior wall of the eyeball, is responsible for receiving, modulating, and transmitting visual stimuli from the external environment to the optic nerve and ultimately to the visual cortex of the brain. Structurally, the retina is a complex and delicate tissue with many types of cells arranged in multiple cell layers. Due to the role of the retina in vision and its fragility, damage to the retina can result in severe loss of vision or even permanent blindness. Therefore, cutting, resection, or other manipulation of the retina must be performed with great care to avoid unnecessary trauma to the retina. Summary of the Invention [Problem to be solved by the invention]

[0004] However, at present, intraoperative visualization and data acquisition are still somewhat limited. For example, existing imaging systems lack the capability to provide the surgeon with in situ measured information related to spectral parameters of ocular tissues / structures and / or treatment outcomes that may enable real-time adjustments during the use of instruments (e.g., forceps, lasers, probes, etc.) used to manipulate ocular tissues / structures during surgery. One exemplary imaging system can generate optical coherence tomography (OCT) images based on scanning data from an ophthalmic scanning device. However, identifying ocular sites, structures, and / or tissues from OCT images poses various challenges due to certain inherent characteristics of OCT images. For example, OCT images may suffer from speckle noise, low signal-to-noise ratio (SNR), and / or other image interferences that may increase the difficulty in identifying and determining parameters (e.g., thickness, roughness, etc.) of different structures or tissues of the eye.

[0005] Therefore, it would be beneficial to have improved systems, devices, and methods for acquiring ophthalmic information associated with various ocular tissues / structures during an ophthalmic procedure. [Means for solving the problem]

[0006] In a particular embodiment, a system is provided. The system includes an illumination device including an optical fiber, a hyperspectral illumination source, a controller, and a modulation device coupled to each of the illumination device, the hyperspectral illumination source, and the controller. The modulation device is configured to receive a first source light generated from the hyperspectral illumination source. The first source light includes a plurality of wavelengths. The modulation device is also configured to modulate each of the plurality of wavelengths of the first source light at a different frequency to generate a second source light having a plurality of frequency-modulated wavelengths. The modulation device is further configured to transmit the second source light to the optical fiber. The optical fiber is configured to emit the second source light in the optical fiber from the illumination device to illuminate an ocular tissue. The first imaging device is configured to select at least a first frequency associated with a first frequency-modulated wavelength of the plurality of frequency-modulated wavelengths of the second source light. The first imaging device is also configured to capture a first light returning from the ocular tissue as a result of the first frequency-modulated wavelength of the second source light contacting the ocular tissue. The controller is configured to determine one or more parameters of the ocular tissue based on the first returned light.

[0007] In a particular embodiment, a method is provided. The method includes receiving a first source light generated from a hyperspectral illumination source. The first source light includes a plurality of wavelengths. The method also includes modulating each of the plurality of wavelengths of the first source light at a different frequency to generate a second source light having a plurality of frequency-modulated wavelengths. The method also includes transmitting the second source light to an optical fiber of an illumination device, such that the second source light in the optical fiber is emitted to illuminate an ocular tissue. The method also includes selecting, with a first imaging device, at least a first frequency associated with a first frequency-modulated wavelength of the plurality of frequency-modulated wavelengths of the second source light. The method also includes capturing, with the first imaging device, first light returned from the ocular tissue as a result of the first frequency-modulated wavelength of the second source light contacting the ocular tissue. The method further includes determining one or more parameters of the ocular tissue based on the first returned light.

[0008] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly summarized above can be had by reference to embodiments, some of which are illustrated in the accompanying drawings, It should be noted, however, that the accompanying drawings depict only exemplary embodiments and therefore should not be considered as limiting the scope of the invention, as other equally effective embodiments are possible. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an example of a system for acquiring ophthalmic information, in accordance with certain embodiments. [Diagram 2] FIG. 2 is a flowchart of a method for obtaining ophthalmic information, according to a particular embodiment. [Diagram 3] FIG. 3 illustrates an example of absorption of different illumination wavelengths in ocular tissue, according to certain embodiments. [Figure 4] FIG. 4 illustrates an example timeline of the operation of an imaging camera, according to a particular embodiment. [Figure 5A]FIG. 5A illustrates an example of a sequence for obtaining ophthalmic information, according to certain embodiments. [Figure 5B] FIG. 5B illustrates an example of a sequence for obtaining ophthalmic information, according to certain embodiments. [Figure 5C] FIG. 5C illustrates an example of a sequence for obtaining ophthalmic information, according to certain embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] To facilitate understanding, wherever possible, like reference numerals have been used to designate like elements common to the figures, and it is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further reference.

[0011] The embodiments described herein provide optical systems, devices, and techniques for obtaining ophthalmic information about a patient's eye during intra-operative ophthalmic procedures using polychromatic endophthalmic illumination with hyperspectral imaging. The ophthalmic information may include, but is not limited to, parameters of ocular tissues / structures related to treatments, parameters of ocular tissues / structures related to disease states, topographical maps of various ocular tissues / structures, and the like. As used herein, the terms "information" and "data" may be used interchangeably to refer to qualitative observations and / or quantitative data.

[0012] Exemplary optical systems described herein can include an illumination source and one or more imaging devices. An illumination device coupled to an illumination source, such as an intraocular illuminator, can be inserted into a chamber (e.g., the fundus) of an eye to illuminate a particular region or site of the eye within the chamber. For example, the illumination device can project illumination light (also referred to herein as "source light") onto a desired location / surface of the retina during a surgical procedure.

[0013] The imaging device can be configured to receive light returning from ocular tissues / structures as a result of the illumination light being projected onto the desired location / surface of the eye during a surgical procedure (also referred to herein as "return light" or "backward light"). For example, a first imaging device (e.g., a microscope) can facilitate visualization of the desired location / surface of the eye. Additionally, a second imaging device (e.g., a camera device such as a hyperspectral (imaging) camera) can capture an image of the desired location / surface of the eye through a field-of-view (FOV) of the first imaging device.

[0014] In certain embodiments, the illumination device can project illumination light at a variety of different frequencies across a range of wavelengths, for example, the optical system can modulate each wavelength of illumination light at a different frequency, such that the illumination light projected onto the desired location / surface of the eye includes multiple different wavelengths at different frequencies.

[0015] In certain embodiments, the second imaging device can capture images of the target location / surface of the eye illuminated with multiple wavelengths of illumination light. For example, the second imaging device can lock into different modulation frequencies of the illumination light to capture images of the target location / surface of the eye at wavelengths of the illumination light associated with each modulation frequency. Targeting specific modulation frequencies of the illumination light in this manner can improve the SNR of the target location / surface of the eye in the captured images.

[0016] In certain embodiments, the optical system can control the focal position (e.g., focal length) of the first imaging device based on the different modulation frequencies targeted by the second imaging device. Controlling the focal position of the first imaging device in this manner can reduce (or eliminate) chromatic aberrations caused by multiple radiation wavelengths.

[0017] In certain embodiments, the optical system can determine ophthalmic information associated with various ocular tissues / structures based on images captured using the techniques described herein. In some cases, the ophthalmic information can be related to one or more parameters of the ocular tissues / structures used in disease diagnosis and / or stage assessment, thereby providing additional data points to improve diagnostic accuracy. By way of reference, the optical system described herein can provide parameters (e.g., thickness) that can be indicative of the amount of wear, tear, etc., of various ocular tissues / structures that can be indicative of disease and / or stage of disease.

[0018] In some cases, the ophthalmic information can be related to one or more parameters of the ocular tissue / structure, thereby providing the surgeon with additional information regarding the ocular tissue / structure, which can enhance the safety and / or efficacy of the surgical procedure. By way of reference, certain ophthalmic surgical procedures, such as internal limiting membrane (ILM) resection and epiretinal membrane (ERM) resection, may require the surgeon using forceps to grasp and separate (or peel) a first ocular tissue from a second ocular tissue without causing trauma to at least one of the tissues. In these surgical procedures, the optical system described herein can provide the surgeon with precise information regarding the location, thickness and / or roughness of the ocular tissue. In certain embodiments, such information can be provided in the form of a topographical map of the ocular tissue. For example, the optical system can overlay multiple images of the ocular tissue / structure at multiple wavelengths to generate a topographical map.

[0019] It should be noted that while many of the following embodiments use thickness and roughness as reference examples of ocular tissue parameters that may be determined using the optical systems described herein, the embodiments are not limited to such parameters and may include parameters of other types of ocular tissues / structures. Additionally, as used herein, the term "return light" may include reflection, scattering, fluorescence, autofluorescence, Raman spectra, or combinations thereof.

[0020] 1 illustrates a system 100 for acquiring ophthalmic information associated with a patient's eye, according to one embodiment. The system 100 includes an optical system 130 and an illumination device 108 (also referred to as a probe) coupled to the optical system 130. The optical system 130 includes one or more light sources 104, a modulation device 114, a controller 106, an imaging device 142, and an imaging device 144.

[0021] The light source 104 can generate a laser beam and / or an illumination beam that can be used during an ophthalmic procedure. For example, the light source 104 can generate a laser beam and an illumination beam alternately, sequentially, or simultaneously. A user, such as a surgeon or a surgical staff member, can control the optical system 130 (e.g., via a foot switch, voice command, etc.) to emit a laser beam and / or an illumination beam during an ophthalmic procedure, such as vitreoretinal surgery. In one particular embodiment, the optical system 130 includes a port and a laser beam and / or an illumination beam that can be emitted from the light source 104, through the port, and into an optical fiber 152-2 that is partially housed inside the illumination device 108.

[0022] The optical system 130 delivers the laser light and / or illumination light from the port to the illumination device 108 via the optical fiber 152-2. As shown, the illumination device 108 includes a hand piece, or probe body 110. The illumination device 108 also includes a tip 140 coupled to a distal end of the hand piece 110. Note that, as used herein, the distal end of a component refers to the end closer to the patient's body or where the laser light and / or illumination light is emitted from the illumination device. On the other hand, the proximal end of a component refers to the end that faces away from the patient's body or, for example, closer to the light source. The tip 140 includes a tube 112 that extends the entire length of the tip 140. In one particular embodiment, the tube 112 is a cylindrical hollow tube. Although not shown herein, the optical fiber 152-2 extends the entire length of the tube 112 to transmit the laser light and / or illumination light to the distal end of the tube 112.

[0023] During surgery, the surgeon uses the handpiece 110 to guide the tube 112 into the patient's eye 120. The tube 112 is only partially inserted into the eye 120 such that a proximal end of the tube 112 is located outside the eye 120. The light source 104 generates a light beam 150, which is directed (or projected) by the tube 112 to a desired location / surface of the eye 120, such as the retinal surface 122. In one particular embodiment, the illumination device 108 is an intraocular illumination device.

[0024] The light source 104 may include a laser source (coherent light source) and / or an illumination source (incoherent light source). In certain embodiments, the illumination source includes an LED-based illuminator. In certain embodiments, the illumination source includes a broadband light source or a hyperspectral light source. Hyperspectral light may refer to light beyond the visible spectrum, including, for example, infrared and ultraviolet light. In certain embodiments, the light source 104 is integrated with a console (not shown). In some other embodiments, the light source 104 is a stand-alone light source.

[0025] The modulation device 114 is generally configured to perform frequency modulation of the illumination light received from the light source 104. In the embodiment shown in FIG. 1, the modulation device 114 is optically coupled to the light source 104 via optical fiber 152-1 and to the illumination device 108 via optical fiber 152-2. In certain other embodiments, the modulation device 114 and the light source 104 can be coupled together through other configurations. In certain embodiments, the modulation device 114 modulates each wavelength of the illumination light emitted from the light source 104 at a different frequency. That is, the modulation device 114 receives one or more wavelengths of illumination light via optical fiber 152-1 and outputs one or more frequency-modulated wavelengths of illumination light via optical fiber 152-2. In certain such embodiments, the light beam 150 directed from the tip 140 onto the retinal surface 122 can include one or more frequency-modulated wavelengths of illumination light via optical fiber 152-2.

[0026] Both optical fibers 152-1, 151-2 can transmit laser light and / or illumination light from the light source 104 to the illumination device 108. In certain embodiments, certain portions of the optical fiber 152 can be disposed inside the cable. For example, a portion of the optical fiber 152-2 that is external to the illumination device 108 can be disposed within an outer sleeve, while only the fiber without the outer sleeve is disposed inside the illumination device 108. In certain embodiments, the modulation device 114 is an electro-optic modulator. The operation of the modulation device 114 can be controlled via the controller 106, as will be described in more detail below.

[0027] The system 100 uses an optical fiber 152 to transmit the source light and an empty space to transmit the return light. For example, the light beam 150 is directed from the tip 140 onto the tissue / structure inside the eye (e.g., the retinal surface 122), and the return light (e.g., at least a portion of the light reflected from the tissue / structure inside the eye) is collected by the imaging device 142 and the imaging device 144. The imaging device 142 (e.g., a microscope) is generally configured to allow a close-up view of the tissue / structure inside the eye. For example, the imaging device 142 can generate a magnified image (e.g., a digital image) of the tissue / structure inside the eye, allowing an observer (e.g., a surgeon) to view the tissue / structure closer. In a particular embodiment, the focal position (e.g., focal length) of the imaging device 142 is compensated based on one or more of the modulation frequencies of the emission wavelength of the illumination light. For example, the focal position can be adjusted (eg, by controller 106) to reduce (or eliminate) chromatic aberration caused by multiple wavelengths of the reflected illumination light.

[0028] The imaging device 144 (e.g., a hyperspectral camera) is generally configured to generate (e.g., capture) an image of a target tissue / structure within the eye (e.g., retinal surface 122) based on the returned light. In a particular embodiment, the imaging device 144 is configured to select a particular modulation frequency of the emitted wavelength of the illumination light (e.g., light beam 150) and lock on to the selected modulation frequency. After locking on to the selected modulation frequency, the imaging device 144 can capture an image of the target tissue / structure at the wavelength of the illumination light associated with the selected modulation frequency. Input to the imaging device 144 is provided by the imaging device 142.

[0029] In certain embodiments, the operation of imaging device 144 and the operation of imaging device 142 may be synchronized (e.g., via controller 106). For example, controller 106 may trigger imaging device 142 to adjust its focus position to a focal length associated with the modulation frequency locked on by imaging device 142. Once the focus position has been adjusted, controller 106 may trigger imaging device 144 to capture an image of a target tissue / structure within the eye through the FOV of imaging device 142.

[0030] In certain embodiments, imaging device 142 and imaging device 144 can perform a time-based spectral sweep across different modulation frequencies of one or more different wavelengths. In these embodiments, the spectral sweep can be based on the shutter frequency of imaging device 144.

[0031] It should be noted that FIG. 1 illustrates a reference example of the optical system 130, and that in other embodiments, the optical system 130 may have a different configuration. For example, while FIG. 1 illustrates the imaging devices 142, 144 and the light source 104 within the optical system 130, in some embodiments, the imaging devices 142, 144 and / or the light source 104 may be separate from the optical system 130. As a reference, the light source 104 may be included within a surgical console, and the imaging devices 142, 144 may be part of a digital microscope. Furthermore, it should be noted that while FIG. 1 illustrates the imaging devices 142, 144 as separate devices, in some embodiments, the operations of the imaging devices 142, 144 may be implemented by a single device (depicted as the optical receiver 132 in FIG. 1). For example, in one particular embodiment, the optical receiver 132 is a digital microscope that includes optical components (e.g., an objective lens) and a digital camera that outputs an image.

[0032] The display 136 is coupled to the controller 106 and the imaging devices 144 and 142. The display 136 is capable of displaying ophthalmic information associated with the eye 120 to the surgeon, including ophthalmic information acquired using the illumination device 108 and the imaging devices 142, 144. In the illustrated embodiment, the display 136 is separate from the imaging device 144 and the optical system 130. In some other embodiments, the display 136 is integrated with the imaging device 144 or the optical system 130. In certain embodiments, the display 136 includes an augmented reality display. In certain embodiments, the display 136 includes a virtual reality display. In certain embodiments, the display 136 includes a three-dimensional display that provides depth information to the surgeon. In certain embodiments, the display 136 receives an image captured by the imaging device 144 and presents the image for viewing. In certain embodiments, the display 136 receives information from the controller 106 and presents the information for viewing. Such information may include, for example, topographical information generated by controller 106 based on images captured by imaging device 144 .

[0033] The controller 106, such as a programmable computer, is generally configured to perform one or more operations described herein to generate (or acquire) and display ophthalmic information associated with the eye 120. The controller 106 is coupled to one or more of the light source 104, the imaging devices 142, 144, the modulation device 114, and the display 136. For example, the controller 106 may directly control the light source 104, the imaging devices 142, 144, the modulation device 114, and / or the display 136, or indirectly control other controllers associated therewith to control the operation of the optical system 130. During operation, the controller 106 may enable data acquisition and feedback from the respective components to adjust the operation of the optical system 130.

[0034] The controller 106 includes a programmable central processing unit (CPU) 170, which is operable with memory 172 (e.g., non-volatile memory) and support circuits 174. The support circuits 174 typically include cache, clock circuits, input / output subsystems, power supplies, and the like, and combinations thereof, coupled to the CPU 170 and coupled to various components of the optical system 130.

[0035] In some embodiments, CPU 170 is one of any type of general-purpose computer processor used in industrial settings, such as a programmable logic controller (PLC) for controlling various monitoring system components and sub-processors. Memory 172 is coupled to CPU 170 and is typically one or more of readily available memories including volatile or non-volatile memory. For example, memory 172 can be random access memory (RAM), read only memory (ROM), a floppy disk drive, a hard disk, or any other form of local or remote digital storage.

[0036] As used herein, the memory 172 stores instructions that, when executed by the CPU 170, facilitate the operation of the optical system 130. The instructions in the memory 172 are in the form of a program product (e.g., a middleware application, an apparatus software application, etc.), such as a program that implements the methods of the present disclosure. In certain embodiments, the optical system disclosed herein can determine ophthalmic information (e.g., parameters associated with ocular tissue / structure, such as thickness, roughness, etc.). In certain embodiments, the optical system disclosed herein can generate ophthalmic information (e.g., topographical information) based on images captured using one or more components of the optical system (e.g., imaging devices 142, 144). It should be noted that the methods disclosed herein can be performed using one or more of the embodiments of the optical system provided, and thus the optical system 130 is described in the following examples for illustrative purposes only.

[0037] 2 is a flowchart of a method 200 for acquiring ophthalmic information, according to one embodiment. Method 200 may be performed by one or more components of a system (e.g., system 100).

[0038] Method 200 begins at block 202, where the system generates a first light beam having a plurality of wavelengths. For example, light source 104 may generate and output a first light beam (e.g., illumination light) having a plurality of different wavelengths. As mentioned, in certain embodiments, light source 104 is a broadband light source. In certain embodiments, light source 104 is a hyperspectral light source. In these embodiments, the first light beam may include wavelengths within the visible light spectrum (e.g., approximately 380 to 750 nanometers (nm)), the near infrared spectrum (e.g., approximately 800 to 2,500 nm), and / or the mid infrared spectrum (e.g., approximately 0.8 to 1000 nm).

[0039] In certain embodiments, the wavelength of the first light beam can be based on the ocular tissue / structure being observed and / or interacted with. For example, different wavelengths of illumination light may have different penetration (or absorption) into ocular tissue / structure depending on the particular wavelength. For example, a wavelength between approximately 400 and 500 nm may be able to observe the superficial layers of the retina, the nerve fiber layer and the internal limiting membrane, as well as fluorescent retinal components (e.g., carotenoids, a photoreceptor pigment that acts as a yellowish filter in the macula, and lipofuscin, which accumulates in the outer segment and concentrates in the retinal pigment epithelium (RPE)). A wavelength between approximately 500 and 700 nm may be able to observe the retinal vascular layer and distinguish between arteries and veins (oxygenated and deoxygenated blood). Here, hemoglobin spectral signatures can provide both qualitative and quantitative oxygen saturation maps. This data can be used to monitor retinal ischemia due to either systemic disease such as diabetes, or due to localized retinal arterial and vascular occlusion. Wavelengths greater than approximately 600 nm may allow observation of melanin, the primary retinal pigment. Images at these wavelengths may enhance visualization of retinal structures that contain this pigment, such as the underlying RPE. Wavelengths between approximately 732 and 865 nm may provide information on oxygenation of the innermost retina and superficial choroidal vasculature (CV). Wavelengths between approximately 955 and 1213 nm may allow observation of the choroid and sclera, congenital hypertrophy of the RPE, choroidal rupture, and melanoma. In some cases, lipids (or components of drusen) may exhibit absorption peaks in the near-infrared spectrum that exceed that of water, and therefore images taken at longer wavelengths may be appropriate for age-related macular degeneration studies. Additionally or alternatively, in certain embodiments, the wavelength of the first light may be based on the spectral sensitivity of the imaging device 144 (e.g., a hyperspectral camera). For example, assuming that the imaging device 144 is capable of detecting wavelengths (λ) between λ1 and λ2, where λ2>λ1, the wavelength of the first light beam may be between λ1 and λ2.

[0040] In block 204, the system modulates each wavelength of the first light beam with a different frequency to generate a second light beam having multiple frequency-modulated wavelengths. For example, the modulation device 114 can receive the first light beam output from the light source 104 and output a second light beam having multiple frequency-modulated wavelengths. Each wavelength λ of the first light beam is modulated at a different frequency to generate a second light beam having multiple frequency-modulated wavelengths. n are different modulation frequencies f n so that the system knows which wavelengths are being illuminated, which in turn allows the imaging device 144 to target specific wavelengths of interest, thereby improving the SNR of the target ocular tissue / structure in the captured image.

[0041] In certain embodiments, the frequency settings used to modulate the different wavelengths can be based on one or more parameters of the imaging device 144 (e.g., a hyperspectral camera). For example, the frequency settings can be selected based on the shutter speed (or exposure time) of the imaging device 144. In an exemplary embodiment, the illumination modulation frequency can be greater than the frame rate of the imaging device 144, whose frame rate is based on the shutter time. In some embodiments, the turn-on time of the light source 104 can be less than the frame time of the imaging device 144.

[0042] In block 206, the system projects a second light beam (having multiple frequency-modulated wavelengths) onto a target site (e.g., retinal surface 122) of the eye (e.g., eye 120) via an optical fiber (e.g., optical fiber 152) coupled to an illumination device (e.g., illumination device 108) inserted into the eye. In certain embodiments, the illumination device can be an intraocular illuminator that projects multiple frequency-modulated wavelengths of the second light beam simultaneously. In certain embodiments, the illumination device can be an intraocular illuminator that projects multiple frequency-modulated wavelengths sequentially (e.g., one wavelength for each instance of time).

[0043] After block 206, operations at blocks 208, 210, 212, and 214 are performed for each modulation frequency. In block 208, the system selects a modulation frequency using a first imaging device (e.g., imaging device 144) and locks onto this frequency. In certain embodiments, the selection of the frequency can be based on the aperture of the imaging device 144 (e.g., the aperture of the imaging device 144 is inversely proportional to the shutter speed of the imaging device 144, and vice versa). In certain embodiments, the selection of the frequency can be based on the spectral parameters of the target ocular tissue / structure. For example, as mentioned above, different wavelengths may have different levels of penetration into certain ocular tissues / structures.

[0044] As shown in FIG. 3, for example, frequency-modulated wavelengths of light of different wavelengths may be absorbed in and reflected from tissue 320, which includes a plurality of layers, example 1-7. In a particular embodiment, assuming that tissue 320 is a visual (or ocular) tissue, such as the retina, example layer 1 may include the nerve layer and blood vessels of the eye, example layer 2 may include the photoreceptors of the eye, example layer 3 may include the RPE, example layer 4 may include Bruch's membrane, example layer 5 may include the collagen layer of the outer retina, example layer 6 may include the choroid, and example layer 7 may include the sclera. The inner retinal region of the eye may include layers, example 1 and 2, and the outer retinal region of the eye may include layers, example 3-7. Here, in particular, λ1 (f1) of the illumination light (e.g., "blue" illumination light) has a relatively short wavelength and is absorbed in the inner retinal region and reflected from the inner retinal region as "R1". Meanwhile, λ1 (f2) of the illumination light (e.g., "red" illumination light) may be absorbed in the inner retinal region and reflected from the inner retinal region as "R1". n (f n ) has a relatively long wavelength and is absorbed in the outer retinal region, and is separated from the outer retinal region by "R N ". Thus, by locking onto a known modulation frequency, the system can be selected to observe a specific reflective layer of a target ocular tissue / structure.

[0045] In certain embodiments, the first imaging device can lock onto a selected (or specified) frequency-modulated wavelength of illumination by locking onto a shutter frequency associated with the modulation frequency. For example, each modulation frequency used to modulate a different wavelength of illumination can have a corresponding (or associated) shutter frequency. In these embodiments, the first imaging device can lock onto different modulation frequencies of interest by locking onto their respective shutter frequencies to perform a time sequence-based spectral sweep.

[0046] For example, as shown in timeline 400 of FIG. 4, during a first amount of shutter time (e.g., i seconds of shutter time, or X frames), a first imaging device may capture images at a shutter frequency (f s1 ), the first imaging device can lock onto a modulation frequency (f1) associated with a first wavelength (λ1) of illumination, and during a subsequent second amount of shutter time, the first imaging device can lock onto a modulation frequency (f s2 ), the first imaging device can lock onto a modulation frequency (f2) associated with a second wavelength (λ2) of illumination, and during a subsequent third amount of shutter time, the first imaging device can lock onto a modulation frequency (f s3 ), one can lock onto a modulation frequency (f3) associated with a third wavelength (λ3) of illumination, and so on.

[0047] 2, in block 210, the system adjusts the focal length of an objective lens of a second imaging device (e.g., imaging device 142) based on the modulation frequency. In a particular embodiment, the second imaging device can be configured to sweep across multiple different focal lengths, each focal length associated with a different modulation frequency. The second imaging device can adjust the focal length of the objective lens to reduce chromatic aberrations that may arise due to multiple wavelengths of the illumination light.

[0048] In block 212, the system captures (e.g., using imaging device 144) a second light beam reflected from the target site. The captured reflected second light beam includes wavelengths associated with the modulation frequency and may not include wavelengths associated with other modulation frequencies. In block 214, the system generates an image of the target site based on the captured second light beam (e.g., using imaging device 144).

[0049] After an image is captured for each frequency-modulated wavelength of illumination, the system determines ophthalmic information based on the images (block 216). In certain embodiments, the ophthalmic information may include one or more parameters of the target site. For example, the system may determine the thickness and / or roughness of the target site (e.g., epiretinal membrane). In certain embodiments, assuming that the imaging device 142 sweeps across two focal lengths FL(λ1) and FL(λ2), the thickness (TT) of the ocular tissue / structure may be approximately equal to A*(FL(λ1)-FL(λ2)), where FL is the focal length of the imaging device 142 and A is a conversion factor. In some cases, λ1 may be the wavelength of lowest interest and λ2 may be the wavelength of highest interest. In certain embodiments, the ophthalmic information may enable disease detection based on spectral absorption images.

[0050] In certain embodiments, the system can generate topographical information (e.g., a topographical map) of the target area based on the images. For example, the system (e.g., via the controller 106) can overlay the images (corresponding to different wavelengths) to generate an image overlay having multiple wavelengths. This generated image overlay can be used as a topographical map of the target area within the eye.

[0051] In block 218, the system communicates the ophthalmic information. For example, the ophthalmic information may be communicated to a display (e.g., display 136) for viewing in real time by a surgeon performing the ophthalmic procedure. Thereafter, method 200 may end.

[0052] 5A-5C illustrate an example of a sequence for obtaining ophthalmic information, according to one embodiment. As shown in FIG. 5A, illumination light is projected onto tissue 510 within the eye 120 via illumination device 108. Tissue 510 may be similar to tissue 320 shown in FIG. 3. Here, the illumination light is projected onto tissue 510 at two frequency modulated wavelengths, λ1 (f1) and λ n (f2) In other words, λ1 of the illumination light is modulated with f1, and λ2 of the illumination light is modulated with f2.

[0053] As shown in FIG. 5B, the projected illumination light is reflected off of tissue 510 through the open space and captured by imaging devices 142, 144. Here, imaging device 144 can sweep across modulation frequencies f1 and f2 to capture respective images of tissue 510 with wavelengths (λ1, λ2) associated with the respective modulation frequencies. At the same time, imaging device 142 can sweep across different focal lengths (Z2(λ2(f2)) and Z1(λ n (f2)) and can adjust the focal length of its objective based on the modulation frequency targeted by the imaging device 144.

[0054] As shown in FIG. 5C, captured images 546-1 and 546-n of tissue 510 can be overlaid to generate an image overlay displaying topographical information of tissue 510.

[0055] In summary, embodiments of the present disclosure enable the acquisition of ophthalmic information during ophthalmic procedures using optical systems based on intraocular illumination using hyperspectral imaging. The optical systems and / or methods described herein are particularly advantageous for enhancing the safety and / or effectiveness of surgical procedures and / or providing additional data points to increase diagnostic accuracy.

[0056] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. By way of 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 with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or a, b, and c in any other order).

[0057] The foregoing description is provided to enable those skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the full scope consistent with the language of the claims.

[0058] Reference to an element in the claims in the singular is intended to mean "one or more" and not "one and only one" unless specifically stated otherwise. The term "some" refers to one or more, unless specifically stated otherwise. All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later become known to those of skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended as a dedication to the public, regardless of whether such disclosure is expressly recited in the claims. No element of a claim is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited with the phrase "means for" or, in the case of a method claim, the element is recited with the phrase "step for." The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other aspects.

Claims

1. 1. A system comprising: an illumination device including an optical fiber; A hyperspectral illumination source; A controller; a modulation device coupled to each of the illumination device, the hyperspectral illumination source, and the controller, configured to receive a first source light generated from the hyperspectral illumination source, the first source light including a plurality of wavelengths; configured to modulate each of the plurality of wavelengths of the first source light at a different frequency to generate a second source light having a plurality of frequency modulated wavelengths; and the modulation device configured to transmit the second light source light to the optical fiber configured to emit the second light source light in the optical fiber from the illumination device to illuminate ocular tissue; and A first imaging device, configured to select at least a first frequency associated with a first frequency modulation wavelength of the plurality of frequency modulation wavelengths of the second light source light; and a first imaging device configured to capture first return light from the ocular tissue as a result of the first frequency-modulated wavelength of the second source light contacting the ocular tissue; and and wherein the controller is configured to determine one or more parameters of the ocular tissue based on the first returned light.

2. 2. The system of claim 1, a second imaging device including an objective lens, configured to adjust a focal length of the objective lens based on the first frequency associated with the first frequency modulation wavelength; and The system further includes the second imaging device configured to generate a magnified image of the ocular tissue based on the first return light passing through the objective lens having the adjusted focal length.

3. 3. The system of claim 2, wherein the first imaging device is configured to capture the first returning light after the first returning light passes through the second imaging device.

4. 2. The system of claim 1 , wherein the first frequency associated with the first frequency-modulated wavelength is selected based on at least one of: (i) one or more parameters of the first imaging device, (ii) a target reflective layer of the ocular tissue, or (iii) a wavelength associated with the first frequency-modulated wavelength.

5. 5. The system of claim 4, wherein the one or more parameters of the first imaging device include at least one of: (i) a shutter frequency; (ii) a frame time; or (iii) an aperture.

6. 2. The system of claim 1, wherein the first imaging device is further configured to lock on to the selected first frequency associated with the first frequency-modulated wavelength prior to capturing the first return light.

7. 7. The system of claim 6, wherein the first imaging device is configured to lock onto the selected first frequency associated with the first frequency by locking onto a shutter frequency associated with the selected first frequency.

8. 2. The system of claim 1, wherein the one or more parameters of the ocular tissue include at least one of: (i) thickness; or (ii) roughness.

9. 2. The system of claim 1, wherein the first imaging device comprises: further configured to select at least a second frequency associated with a second frequency modulation wavelength of the plurality of frequency modulation wavelengths of the second source light; and The system further configured to capture second return light from the ocular tissue as a result of the second frequency-modulated wavelength of the second source light contacting the ocular tissue.

10. 10. The system of claim 9, wherein the first imaging device comprises: further configured to generate a first image of the ocular tissue based on the first returned light; and The system further configured to generate a second image of the ocular tissue based on the second returned light.

11. 11. The system of claim 10, wherein the controller is configured to generate topographical information associated with the ocular tissue based on the first image and the second image.

12. The system of claim 11 , wherein the topographical information comprises an image overlay of the first image and the second image.

13. The system of claim 1 , wherein the first imaging device is a hyperspectral imaging camera.

14. 1. A method of operating an optical system, comprising the steps of: receiving a first source light generated from a hyperspectral illumination source, the first source light including a plurality of wavelengths; modulating each of the plurality of wavelengths of the first source light at a different frequency to generate a second source light having a plurality of frequency modulated wavelengths; transmitting the second light source light to an optical fiber of an illumination device, whereby the second light source light in the optical fiber is emitted to illuminate ocular tissue; selecting, with a first imaging device, at least a first frequency associated with a first frequency modulation wavelength of the plurality of frequency modulation wavelengths of the second source light; capturing, with the first imaging device, first return light from the ocular tissue as a result of the first frequency-modulated wavelength of the second source light contacting the ocular tissue; determining one or more parameters of the ocular tissue based on the first returned light; and The method includes:

15. 15. The method of claim 14, adjusting a focal length of an objective lens of a second imaging device based on the first frequency associated with the first frequency modulation wavelength; generating, with the second imaging device, a magnified image of the ocular tissue based on the first return light passing through the objective lens having the adjusted focal length; The method further comprises:

16. 16. The method of claim 15, wherein the first return light from the ocular tissue is captured with the first imaging device after the first return light passes through the second imaging device.

17. 15. The method of claim 14, wherein the first frequency associated with the first frequency-modulated wavelength is selected based on at least one of: (i) one or more parameters of the first imaging device, (ii) a target reflective layer of the ocular tissue, or (iii) a wavelength associated with the first frequency-modulated wavelength.

18. 20. The method of claim 17, The one or more parameters of the first imaging device are: The method includes at least one of: (i) shutter frequency; (ii) frame time; or (iii) aperture.

19. 15. The method of claim 14, further comprising locking onto the selected first frequency associated with the first frequency modulation wavelength prior to capturing the first return light with the first imaging device.

20. 20. The method of claim 19, wherein locking on to the selected first frequency associated with the first frequency comprises locking on to a shutter frequency associated with the selected first frequency.

Images