Fundus blood vessel imaging system and method for intraoperative real-time navigation
By embedding FFA and ICGA dual-modality imaging technology into the microscope system, the problems of insufficient real-time and intelligence in existing technologies have been solved, real-time dynamic vascular observation and intelligent early warning under the microscope have been achieved, and the accuracy and popularity of surgery have been improved.
Patent Information
- Application Number
- CN202510878633.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-09-12
AI Technical Summary
Existing intraocular angiography technology cannot track blood flow changes in real time during surgery. The separation of equipment makes the operation cumbersome. Spectral crosstalk and timing conflicts limit the imaging frame rate. There is a lack of intelligent decision-making support and it relies on the subjective experience of the surgeon, which affects the accuracy and popularity of the surgery.
It uses time-sharing multiplexing technology combined with FFA and ICGA excitation light sources, realizes dual-modal imaging through invisible beam splitting prisms and high-speed CMOS cameras, and is embedded in the microscope system to provide real-time dynamic images and intelligent warnings, and support touch annotation and playback.
It enables real-time and clear dynamic observation of blood vessels under a microscope, reduces light loss and timing errors, provides precise blood vessel registration and intelligent analysis, and improves surgical safety and standardization.
Smart Images
Figure CN120616433A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of ophthalmic surgical equipment, and in particular to a fundus vascular imaging system and method for real-time navigation during surgery. Background Art
[0002] Intraocular angiography is a key tool for diagnosing and guiding the treatment of fundus diseases. Dual-modality imaging using fluorescein angiography (FFA) and indocyanine green angiography (ICGA) is particularly important. FFA clearly reveals retinal blood flow, while ICGA excels at visualizing choroidal vasculature. The combination of these two techniques can effectively diagnose a variety of fundus diseases, including age-related macular degeneration, polypoidal choroidal vasculopathy, diabetic retinopathy, and retinal vascular occlusion.
[0003] However, current traditional angiography technology faces significant technical bottlenecks, making it difficult to meet the practical needs of clinical surgery. In terms of real-time performance, traditional FFA and ICGA devices are limited to static imaging before or after surgery and are unable to dynamically track blood flow changes, such as leakage and blockage, during surgery. Surgeons are forced to rely on delayed, static imaging data, significantly increasing the risk of surgical errors.
[0004] From a device usage perspective, existing FFA / ICGA systems are physically separate from surgical microscopes. For example, the Heidelberg Spectralis HRA, as an outpatient diagnostic device, is non-portable and requires a complex sterilization process. It only provides static image reports and cannot be integrated with the surgical microscope's field of view. While the Zeiss Rescan700 is integrated into the surgical microscope, it only provides real-time OCT imaging and cannot obtain hemodynamic information or reveal areas of vascular leakage or ischemia. This separation of devices results in cumbersome intraoperative switching operations, severely impacting surgical continuity and efficiency.
[0005] In terms of dual-modality imaging technology, FFA operates in the visible light band, while ICGA operates in the near-infrared band. There are spectral crosstalk and timing conflicts between the two during the excitation and acquisition process. The existing time-sharing alternating imaging scheme limits the imaging frame rate to ≤5fps, making it difficult to capture rapid changes in blood flow. At the same time, due to the physical separation of the two devices, complex registration algorithms are required to integrate the images. However, the distance difference between the devices affects the measurement accuracy, and the devices are too large to be integrated into the surgical microscope, resulting in a registration error of ≥10μm for the dual-modality images, making it impossible to accurately present the spatial relationship between the retinal and choroidal blood vessels.
[0006] Furthermore, existing technologies lack intelligent decision-making support. Intraoperative assessments of vascular abnormalities, such as neovascular leakage, ischemia, and hyperplasia, rely primarily on the surgeon's subjective judgment and experience, lacking real-time quantitative analysis and risk warning mechanisms. This results in low levels of standardization and intelligentization. Many complex fundus disease surgeries rely heavily on highly skilled surgeons, hindering widespread adoption and severely restricting the development and promotion of surgical treatments for fundus diseases.
[0007] To this end, the present invention provides a fundus vascular imaging system and method for real-time navigation during surgery. Summary of the Invention
[0008] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.
[0009] The technical solution adopted by the present invention to solve the technical problem is: a fundus vascular imaging system for intraoperative real-time navigation according to the present invention, the imaging system comprises:
[0010] The excitation light source module includes an FFA excitation light source and an ICGA excitation light source. The FFA excitation light source and the ICGA excitation light source are connected through the same optical fiber coupler and use time-division multiplexing technology to alternately output excitation light.
[0011] The dichroic mirror is placed in the microscope illumination light path to reflect the laser excitation light emitted by the excitation light source module toward the objective lens while transmitting white light to maintain normal illumination.
[0012] An invisible beam splitter prism is placed in the main light path between the objective lens and the eyepiece to split the light collected by the objective lens;
[0013] An imaging module includes a dual-channel filter wheel and a high-speed CMOS camera. The dual-channel filter wheel includes a 500-530nm bandpass filter for the FFA channel and an 820-850nm bandpass filter for the ICGA channel. The high-speed CMOS camera is located at the end of the reflective light path of the beam splitter prism and is used for time-sharing synchronous acquisition of light filtered by the dual-channel filter wheel.
[0014] The eyepiece AR display module receives image data collected by a high-speed CMOS camera and superimposes the angiographic image onto the surgical field of view at 5% brightness through a micro LCoS projector. It also displays the outline of new blood vessels, leakage areas, and the core marker layer of ischemic areas. A red pulse border is automatically displayed when the instrument is less than 0.5 mm from the marked blood vessel.
[0015] The external 4K display module receives image data acquired by a high-speed CMOS camera, displays FFA / ICGA fusion images, updates arteriovenous circulation time in real time, and provides touch annotation and angiography playback.
[0016] Preferably, the FFA excitation light source is a 488 nm blue laser with a power of ≤ 5 mW;
[0017] The ICGA excitation light source is an 805 nm near-infrared laser with a power of ≤10 mW.
[0018] Preferably, the invisible beam splitter prism makes the light loss rate of the eyepiece field of view ≤3%, and the working distance of the microscope objective lens remains ≥150mm after the transformation.
[0019] Preferably, the end-to-end delay from acquisition by the high-speed CMOS camera to projection by the eyepiece AR display module is ≤33ms, and the timing error is <1ms in the FFA / ICGA alternating imaging mode.
[0020] An imaging method for a fundus vascular imaging system with real-time navigation during surgery, the imaging method comprising the following steps:
[0021] S1, the FFA excitation light source or ICGA excitation light source in the excitation light source module emits laser excitation light of corresponding wavelength, which is reflected by the dichroic mirror toward the objective lens to excite the fundus blood vessels;
[0022] S2. The fluorescence signal generated by the excited blood vessels in the fundus is collected by the objective lens and transmitted to the invisible beam splitter prism through the main optical path. The invisible beam splitter prism splits the light into 95% and transmits it to the eyepiece for observation by the operator, and 5% is reflected to the imaging module.
[0023] S3: The light reflected to the imaging module is filtered by the bandpass filter of the corresponding channel in the dual-channel filter wheel, and then captured by the high-speed CMOS camera in a time-sharing synchronous manner;
[0024] The image data collected by S4 and the high-speed CMOS camera are transmitted to the eyepiece AR display module and the external 4K display module respectively. The eyepiece AR display module superimposes the angiography image on the surgical field at 5% brightness and displays the core marker layer and warning prompts;
[0025] S5, the external 4K display module displays FFA / ICGA fusion images, refreshes arteriovenous circulation time in real time, and provides touch annotation and angiography playback functions.
[0026] The beneficial effects of the present invention are as follows:
[0027] 1. The fundus vascular imaging system and method for intraoperative real-time navigation described in the present invention utilizes a 95:5 high-ratio spectroscopic design using an invisible beam splitter prism (BS1). The measured light loss rate in the eyepiece field of view is controlled at ≤3%, far below the threshold of brightness changes perceptible to the surgeon (<5%). This allows conventional white light illumination to remain largely unaffected during surgery, allowing the surgeon to continuously obtain a bright, clear surgical field of view, avoiding operational errors caused by insufficient light and significantly improving surgical safety. After modifying the microscope optical path, the objective lens working distance remains at ≥150mm, fully complying with the working distance range of 125-175mm for standard ophthalmic microscopes. This ensures that the operating space for surgical instruments is unrestricted, allowing doctors to perform surgical operations flexibly. This system is particularly suitable for complex and delicate fundus surgeries, effectively ensuring the smooth progress of the operation.
[0028] 2. The present invention describes a fundus vascular imaging system and method for intraoperative real-time navigation. The system achieves an end-to-end delay of ≤33ms from high-speed CMOS camera acquisition to eyepiece AR projection. This delay is far below the human visual perception threshold (≈50ms), enabling the surgeon to smoothly and in real time observe dynamic changes in fundus vascularization, such as blood leakage and blockage, during surgery, providing a reliable basis for timely adjustment of surgical strategies. Through time-division multiplexing (TDM) technology, FFA and ICGA excitation light are alternately output, and the timing error is less than 1ms in the alternating imaging mode. Combined with the high frame rate acquisition of 30fps (FFA) / 15fps (ICGA) by the high-speed CMOS camera, the time misalignment problem in dual-modal imaging is avoided, ensuring the precise registration of retinal and choroidal vascular images. The registration error is significantly reduced, and the spatial relationship between the two can be accurately displayed, providing doctors with more accurate diagnostic information.
[0029] 3. The present invention describes a system and method for intraoperative fundus vascular imaging with real-time navigation. This system deeply embeds the FFA / ICGA excitation and imaging optical paths into the surgical microscope system, transforming the traditional reliance on static preoperative imaging data. During surgery, the surgeon can directly obtain dynamic, real-time angiographic images of the fundus vessels, eliminating the need to subjectively judge the surgical scope by comparing preoperative static angiographic images. This allows for timely adjustments to the surgical procedure based on the actual lesion location, significantly improving surgical precision and effectiveness while reducing the risk of postoperative complications. The eyepiece AR display module uses pseudo-color to mark core lesion information, such as new vessels, leakage areas, and ischemic areas, and features an instrument proximity warning function (a red pulsing border is triggered when the instrument is less than 0.5 mm from the marked vessel). The external 4K display module updates key parameters such as arteriovenous circulation time (ART) in real time and supports interactive features such as touch-sensitive annotation and angiographic playback. These intelligent features provide surgeons with real-time quantitative analysis and risk warnings, reducing reliance on surgeon experience. This effectively promotes the standardization of fundus surgery, enabling more surgeons to perform complex fundus disease surgeries and increasing the accessibility and popularity of the procedure. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The present invention will be further described below with reference to the accompanying drawings.
[0031] Figure 1 It is a flow chart of the system method in the present invention. DETAILED DESCRIPTION
[0032] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific implementation methods.
[0033] like Figure 1 As shown, an intraoperative real-time navigation fundus vascular imaging system according to an embodiment of the present invention includes:
[0034] The excitation light source module includes an FFA excitation light source and an ICGA excitation light source. The FFA excitation light source and the ICGA excitation light source are connected through the same optical fiber coupler and use time-division multiplexing technology to alternately output excitation light.
[0035] The dichroic mirror is placed in the microscope illumination light path to reflect the laser excitation light (488 / 805nm) emitted by the excitation light source module toward the objective lens, while transmitting white light (400-700nm) to maintain conventional illumination.
[0036] The invisible beam splitter prism is set in the main optical path between the objective lens and the eyepiece. It has a splitting ratio of 95:5 and is used to split the light collected by the objective lens. 95% of the light is transmitted to the eyepiece for observation by the operator, and 5% of the light is reflected to the imaging module.
[0037] The imaging module includes a dual-channel filter wheel and a high-speed CMOS camera. The dual-channel filter wheel contains a 500-530nm bandpass filter for the FFA channel and an 820-850nm bandpass filter for the ICGA channel. The high-speed CMOS camera is located at the end of the reflective light path of the beam splitter prism. It has a resolution of 3840×2160 and a frame rate of 30fps (FFA) / 15fps (ICGA). It is used for time-sharing synchronous acquisition of light after filtering by the dual-channel filter wheel.
[0038] The eyepiece AR display module receives image data collected by a high-speed CMOS camera and superimposes the angiographic image onto the surgical field of view at 5% brightness through a micro LCoS projector. It also displays the outline of new blood vessels, leakage areas, and the core marker layer of ischemic areas. A red pulse border is automatically displayed when the instrument is less than 0.5 mm from the marked blood vessel.
[0039] The external 4K display module receives image data acquired by a high-speed CMOS camera, displays FFA / ICGA fusion images, updates arteriovenous circulation time in real time, and provides touch annotation and angiography playback.
[0040] The FFA excitation light source is a 488nm blue laser with a power of ≤5mW, which complies with the IEC60825-1 Class 1 safety standard;
[0041] The ICGA excitation light source is an 805 nm near-infrared laser with a power of ≤10 mW.
[0042] The invisible beam splitter prism makes the light loss rate of the eyepiece field of view ≤3%, and the working distance of the microscope objective lens remains ≥150mm after the transformation.
[0043] The end-to-end delay from acquisition by the high-speed CMOS camera to projection on the eyepiece AR display module is ≤33ms, and in the FFA / ICGA alternating imaging mode, the timing error is <1ms.
[0044] An imaging method for a fundus vascular imaging system with real-time navigation during surgery, the imaging method comprising the following steps:
[0045] S1, the FFA excitation light source or ICGA excitation light source in the excitation light source module emits laser excitation light of corresponding wavelength, which is reflected by the dichroic mirror toward the objective lens to excite the fundus blood vessels;
[0046] S2. The fluorescence signal generated by the excited blood vessels in the fundus is collected by the objective lens and transmitted to the invisible beam splitter prism through the main optical path. The invisible beam splitter prism splits the light into 95% and transmits it to the eyepiece for observation by the operator, and 5% is reflected to the imaging module.
[0047] S3: The light reflected to the imaging module is filtered by the bandpass filter of the corresponding channel in the dual-channel filter wheel, and then captured by the high-speed CMOS camera in a time-sharing synchronous manner;
[0048] The image data collected by S4 and the high-speed CMOS camera are transmitted to the eyepiece AR display module and the external 4K display module respectively. The eyepiece AR display module superimposes the angiography image on the surgical field at 5% brightness and displays the core marker layer and warning prompts;
[0049] S5, the external 4K display module displays FFA / ICGA fusion images, refreshes arteriovenous circulation time in real time, and provides touch annotation and angiography playback functions.
[0050] Specifically,
[0051] (1) Ensuring the integrity of vision
[0052] Low light loss design: The invisible beam splitter prism (BS1) adopts a 95:5 splitting ratio. The measured light loss rate of the eyepiece field of view is ≤3%, which is far below the surgeon's perception threshold (<5%), ensuring that the brightness of the surgical field of view is not significantly affected.
[0053] Unobstructed operating space: After the modification, the working distance of the microscope objective lens remains ≥150mm, which is in line with the working distance range of 125-175mm of the standard ophthalmic microscope. The operating space of the instrument is not restricted, ensuring the smooth progress of the operation.
[0054] (2) Real-time verification
[0055] Ultra-low latency imaging: The end-to-end latency from high-speed CMOS camera acquisition to eyepiece AR projection is ≤33ms, which is lower than the human visual perception threshold (≈50ms). The operator can observe without any lag, achieving true real-time imaging.
[0056] High-precision time-sharing synchronization: In FFA / ICGA alternating imaging mode, the timing error is less than 1ms, effectively avoiding the time misalignment of dual-modality imaging and ensuring accurate registration of retinal and choroidal vascular images.
[0057] (3) Filling the instrument gap: Embedding the FFA / ICGA excitation and imaging optical path into the microscope system to achieve dynamic real-time angiography during surgery. This allows the surgeon to directly obtain the real-time lesion location without having to compare static angiography images to subjectively judge the surgical scope, significantly improving the accuracy and safety of the surgery.
[0058] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.
Claims
1. A fundus vascular imaging system for real-time navigation during surgery, characterized in that: The imaging system includes: An excitation light source module, comprising an FFA excitation light source and an ICGA excitation light source, wherein the FFA excitation light source and the ICGA excitation light source alternately output excitation light through the same optical fiber coupler using time-division multiplexing technology; A dichroic mirror is provided in the microscope illumination light path, and is used to reflect the laser excitation light emitted by the excitation light source module toward the objective lens, while transmitting white light to maintain conventional illumination; An invisible beam splitter prism is placed in the main light path between the objective lens and the eyepiece to split the light collected by the objective lens; An imaging module comprising a dual-channel filter wheel containing a 500-530nm bandpass filter for the FFA channel and an 820-850nm bandpass filter for the ICGA channel, and a high-speed CMOS camera located at the end of the reflective light path of the beam splitter prism for time-sharing synchronous acquisition of light filtered by the dual-channel filter wheel. The eyepiece AR display module is used to receive the image data collected by the high-speed CMOS camera, superimpose the angiographic image on the surgical field at 5% brightness through a micro LCoS projector, and display the core marker layer of the new blood vessel outline, leakage area, and ischemic area. When the instrument is less than 0.5 mm away from the marked blood vessel, a red pulse frame is automatically displayed; The external 4K display module is used to receive image data collected by the high-speed CMOS camera, display FFA / ICGA fusion images, refresh arteriovenous circulation time in real time, and provide touch annotation and angiography playback.
2. The fundus vascular imaging system for intraoperative real-time navigation according to claim 1, characterized in that: The FFA excitation light source is a 488nm blue laser with a power of ≤5mW; The ICGA excitation light source is an 805nm near-infrared laser with a power of ≤10mW.
3. The intraoperative real-time navigation fundus vascular imaging system according to claim 1, characterized in that: The invisible beam splitter prism makes the light loss rate of the eyepiece field of view ≤3%, and the working distance of the microscope objective lens is maintained at ≥150mm after the transformation.
4. The fundus vascular imaging system for intraoperative real-time navigation according to claim 1, characterized in that: The end-to-end delay from the acquisition by the high-speed CMOS camera to the projection by the eyepiece AR display module is ≤33ms, and the timing error is <1ms in the FFA / ICGA alternating imaging mode.
5. An imaging method for a fundus vascular imaging system with real-time navigation during surgery, characterized in that: It is used in an intraoperative real-time navigation fundus vascular imaging system as described in any one of claims 1 to 4, and the imaging method comprises the following steps: S1, the FFA excitation light source or ICGA excitation light source in the excitation light source module emits laser excitation light of corresponding wavelength, which is reflected by the dichroic mirror toward the objective lens to excite the fundus blood vessels; S2. The fluorescence signal generated by the excited blood vessels in the fundus is collected by the objective lens and transmitted to the invisible beam splitter prism through the main optical path. The invisible beam splitter prism splits the light into 95% and transmits it to the eyepiece for observation by the operator, and 5% is reflected to the imaging module. S3: The light reflected to the imaging module is filtered by the bandpass filter of the corresponding channel in the dual-channel filter wheel, and then captured by the high-speed CMOS camera in a time-sharing synchronous manner; The image data collected by S4 and the high-speed CMOS camera are transmitted to the eyepiece AR display module and the external 4K display module respectively. The eyepiece AR display module superimposes the angiography image on the surgical field at 5% brightness and displays the core marker layer and warning prompts; S5, the external 4K display module displays FFA / ICGA fusion images, refreshes arteriovenous circulation time in real time, and provides touch annotation and angiography playback functions.