CN115568827A

CN115568827A - OCT-based fluorescence imaging catheter and system

Info

Publication number: CN115568827A
Application number: CN202211260097.0A
Authority: CN
Inventors: 胡洵; 李怡; 庄晓东; 刘岗; 赵静静; 张绍钊
Original assignee: First Affiliated Hospital of Sun Yat Sen University
Current assignee: First Affiliated Hospital of Sun Yat Sen University
Priority date: 2022-10-14
Filing date: 2022-10-14
Publication date: 2023-01-06

Abstract

The invention is suitable for the technical field of imaging, and provides a fluorescence imaging catheter and a fluorescence imaging system based on OCT (optical coherence tomography). The fluorescence imaging catheter based on the OCT comprises a first optical fiber bundle, wherein the first optical fiber bundle comprises a first multimode optical fiber and a first single-mode optical fiber, and light emitting ends of the first multimode optical fiber and the first single-mode optical fiber are respectively provided with an obliquely-arranged reflecting surface; the first multimode optical fiber is used for receiving, transmitting and outputting the fluorescence excitation light beam and is also used for receiving, transmitting and outputting a fluorescence detection signal formed after the fluorescence excitation light beam carries out fluorescence excitation on the tissue; the first single mode fiber is used for receiving, transmitting and outputting the OCT excitation beam and is also used for receiving, transmitting and outputting an OCT detection signal formed after the OCT excitation beam is reflected by tissues. The fluorescence imaging catheter and the fluorescence imaging system based on the OCT can realize the simultaneous detection of the OCT imaging system and the fluorescence imaging system.

Description

OCT-based fluorescence imaging catheter and system

Technical Field

The invention belongs to the technical field of imaging, and particularly relates to a fluorescence imaging catheter and a fluorescence imaging system based on OCT (optical coherence tomography).

Background

Optical Coherence Tomography (OCT) is a biomedical Optical imaging technique, and OCT has extremely high resolution, axial resolution of about 10 μm, and tissue discrimination capability, i.e., the OCT image can be used to basically understand the main components and histological features of plaque, and different plaque components, such as fibrous plaque, lipid plaque, and calcified plaque, which are common in coronary artery, show different signal characteristics under the OCT image, so that a clinician with abundant image reading experience can identify the type of plaque according to different signal characteristics on the image, and has important significance in diagnosing and selecting a treatment scheme for coronary heart disease. However, there are limitations to OCT, which cannot identify intravascular dilation hemorrhage (IPH), which is one of the features of high risk atherosclerotic plaques and plays a key role in the treatment of atherosclerotic disease. Current studies indicate that near-infrared fluorescence (NIRF) of tissue can detect IPH. However, intravascular fluorescence often lacks depth information and fails to distinguish and localize lipids, which are one of the most critical features of plaque. Therefore, the OCT system and the fluorescence system can be combined for complementation, and the detection effect is better.

In the process of implementing the invention, the inventor finds that when the OCT system and the fluorescence system are combined, in order to ensure that a complete lumen signal is acquired and an acquired lumen image is more accurate, the OCT excitation beam and the fluorescence excitation beam need to be simultaneously transmitted to intravascular tissue, but at present, the OCT system and the fluorescence system respectively adopt independent catheters, and when the tissue is detected, the OCT system and the fluorescence system need to be inserted into a human body twice, and cannot acquire an OCT signal and a fluorescence detection signal simultaneously.

Disclosure of Invention

The invention aims to provide an OCT-based fluorescence imaging catheter and a system, and aims to solve the technical problem that an OCT signal and a fluorescence detection signal cannot be acquired simultaneously in the prior art.

The invention is realized in such a way, and in a first aspect, an OCT-based fluorescence imaging catheter is provided, which includes a first optical fiber bundle, where the first optical fiber bundle includes a first multimode optical fiber and a first single-mode optical fiber, and light emitting ends of the first multimode optical fiber and the first single-mode optical fiber are both provided with a reflecting surface arranged obliquely;

the first multimode fiber is used for receiving, transmitting and outputting a fluorescence excitation beam and is also used for receiving, transmitting and outputting a fluorescence detection signal formed after the fluorescence excitation beam carries out fluorescence excitation on a tissue;

the first single-mode fiber is used for receiving, transmitting and outputting an OCT excitation beam and is also used for receiving, transmitting and outputting an OCT detection signal formed after the OCT excitation beam is reflected by tissues.

In one embodiment, there is one first multimode optical fiber and one first single-mode optical fiber, and the light emitting directions of the first multimode optical fiber and the first single-mode optical fiber form an included angle.

In one embodiment, the first multimode optical fiber is provided with a plurality of single mode optical fibers and is arranged around the first single mode optical fiber, the length of the first single mode optical fiber is larger than that of the first multimode optical fiber, and the first single mode optical fiber can rotate relative to the first multimode optical fiber;

or the first single-mode fiber is provided with a plurality of single-mode fibers and surrounds the first multimode fiber, the length of the first multimode fiber is greater than that of the first single-mode fiber, and the first multimode fiber can rotate relative to the first single-mode fiber.

In one embodiment, when the first multimode fibers are located at the periphery, the inclination angle of the reflecting surface of each first multimode fiber is the same;

when the first single mode fibers are located on the periphery, the inclined angles of the reflecting surfaces of the first single mode fibers are the same.

In one embodiment, the end faces of the light-emitting ends of the first single-mode optical fiber and the first multimode optical fiber are both inclined planes;

the fluorescence imaging catheter based on the OCT also comprises a light-tight heat-shrinkable part, wherein the heat-shrinkable part is positioned in the extension direction of the first optical fiber bundle and is connected with the light-emitting end of the first optical fiber bundle, the shape of one surface of the heat-shrinkable part, which is used for being connected with the first optical fiber bundle, is matched with the shape of the end surface of the light-emitting end of the first optical fiber bundle, the heat-shrinkable part and the first optical fiber bundle are jointed to form a combined surface, and the combined surface is the reflecting surface.

In a second aspect, an OCT-based fluorescence imaging system is provided, comprising a fluorescence imaging system and an OCT imaging system;

the fluorescence imaging system comprises a fluorescence imaging light source, an optical fiber assembly, a photoelectric detector and a control display device which are sequentially arranged along a first path;

the OCT imaging system comprises a detection branch and a detection branch, wherein the detection branch comprises a coherence tomography light source, a first coupler, a first circulator and the optical fiber assembly which are sequentially arranged along a second path, the detection branch comprises the optical fiber assembly, the first circulator, a second coupler, a photoelectric converter and the control display device which are sequentially arranged along a third path, and the OCT imaging system also comprises a second circulator and a reflecting piece which are sequentially arranged along a fourth path, wherein a light inlet of the second circulator is communicated with one of light outlets of the first coupler through a light path, and a light outlet of the second circulator is communicated with one of light inlets of the second coupler through a light path;

the optical fiber assembly comprises a second optical fiber bundle and the first optical fiber bundle provided by each of the above embodiments, the second optical fiber bundle comprises a second multimode optical fiber and a second single mode optical fiber, the second multimode optical fiber is communicated with the first multimode optical fiber through an optical path, and the second single mode optical fiber is communicated with the first single mode optical fiber through an optical path.

In one embodiment, one of the second multimode optical fiber and the second single mode optical fiber is provided in plurality and disposed around the other.

In one embodiment, the second single-mode fiber is provided with a plurality of second single-mode fibers, the detection branch further comprises a beam splitter located between the first circulator and the fiber assembly, the beam splitter is used for splitting the OCT excitation beam transmitted by the first circulator into a plurality of first split beams with the number consistent with that of the second single-mode fibers, and conducting the plurality of first split beams into the corresponding first single-mode fibers in a one-to-one correspondence manner, and is also used for combining a plurality of OCT detection signals conducted through the plurality of first single-mode fibers into one signal to be conducted to the first circulator;

or the second multimode fibers are provided in plurality, the fluorescence imaging system further comprises a beam splitter located between the fluorescence imaging light source and the fiber assembly, and the beam splitter is used for splitting the fluorescence excitation light beam into a plurality of second split light beams with the number consistent with that of the second multimode fibers and conducting the plurality of second split light beams into the corresponding first multimode fibers in a one-to-one correspondence manner.

In one embodiment, the second optical fiber bundle further comprises a reinforcing optical fiber, when the second multimode optical fiber is positioned at the outer periphery, the reinforcing optical fiber is a multimode optical fiber, has a diameter smaller than that of the second multimode optical fiber, and is positioned in a concave area formed by two adjacent second multimode optical fibers; when second single mode fiber is located the periphery, the reinforcement optic fibre is single mode fiber, and the diameter is less than second single mode fiber's diameter is located adjacent two in the depressed area that second single mode fiber formed.

In one embodiment, the detection branch further includes a light intensity detector, the light intensity detector is respectively connected to the second coupler and the photoelectric converter through a light path, and is also electrically connected to the control display device, and the control display device is configured to receive a light intensity signal output by the light intensity detector, and enhance an OCT detection signal whose light intensity signal is lower than a preset light intensity.

Compared with the prior art, the technical effects of the first aspect of the invention are as follows: the fluorescence imaging catheter based on the OCT provided by the embodiment of the invention comprises a first optical fiber bundle, wherein the first optical fiber bundle comprises a first multimode optical fiber and a first single mode optical fiber, and the first multimode optical fiber is used for receiving, conducting and outputting a fluorescence excitation beam and is also used for receiving, conducting and outputting a fluorescence detection signal formed after the fluorescence excitation of the fluorescence excitation beam on a tissue; the OCT-based fluorescence imaging catheter provided by the embodiment of the invention can realize simultaneous detection of the OCT imaging system and the fluorescence imaging system, so that the OCT excitation beam and the fluorescence excitation beam can be simultaneously transmitted to the inner wall of a tissue to simultaneously acquire signals in the tissue, and the OCT-based fluorescence imaging catheter is rotated to ensure that complete lumen section information is acquired, the accuracy of a detection result is ensured, and the optical signal transmission efficiency is higher.

It is understood that the beneficial effects of the second aspect can be referred to the related description of the first aspect, and are not described herein again.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention or in the description of the prior art will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an OCT-based fluorescence imaging catheter provided by an embodiment of the invention;

FIG. 2 is a schematic diagram of a first optical fiber bundle used in an embodiment of the present invention;

FIG. 3 is a schematic diagram of a first optical fiber bundle used in another embodiment of the present invention;

FIG. 4 is a schematic diagram of a frame line structure of an OCT-based fluorescence imaging system according to an embodiment of the present invention;

FIG. 5 is a schematic optical path diagram of the first circulator of FIG. 4;

FIG. 6 is a schematic view of a rotary drive apparatus used in an embodiment of the present invention;

FIG. 7 is a schematic diagram of a second optical fiber bundle used in accordance with an embodiment of the present invention;

FIG. 8 is a schematic diagram of a second optical fiber bundle used in another embodiment of the present invention;

FIG. 9 is a schematic diagram of a wire structure of an OCT-based fluorescence imaging system according to another embodiment of the invention;

FIG. 10 is a schematic diagram of a frame line structure of an OCT-based fluorescence imaging system according to another embodiment of the invention.

Description of reference numerals:

100. OCT-based fluorescence imaging catheters; 110. a first optical fiber bundle; 111. a first multimode optical fiber; 112. a first single mode optical fiber; 113. a reflective surface; 120. a first housing; 121. a connecting portion; 122. a probe section; 130. a heat shrinkable member; 200. a fluorescence imaging system; 210. a fluorescence imaging light source; 220. a photodetector; 300. an OCT imaging system; 310. a coherence tomography light source; 320. a first coupler; 330. a first circulator; 340. a second coupler; 350. a photoelectric converter; 360. a second circulator; 370. a mirror; 380. a beam splitter; 390. a light intensity detector; 400. controlling a display device; 500. an optical fiber assembly; 510. a second optical fiber bundle; 511. a second multimode optical fiber; 512. a second single mode optical fiber; 513. reinforcing the optical fiber; 600. a rotation driving device; 610. a motor; 620. a first channel; 630. a second channel.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as being permanently connected, detachably connected, or integral; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments.

In an embodiment of the present invention, an OCT-based fluorescence imaging catheter is provided, which is suitable for an OCT-based fluorescence imaging system formed by combining an OCT imaging system and a fluorescence imaging system, and can be applied to cardiovascular operation and post-operation examination, and can also be applied to detection of other tissues such as nasal cavity and throat. The fluorescence imaging system based on the OCT comprises an OCT imaging system and a fluorescence imaging system, wherein a coherence tomography light source is arranged in the OCT imaging system and can provide OCT exciting light beams for the fluorescence imaging catheter based on the OCT, and a fluorescence imaging light source is arranged in the fluorescence imaging system and can provide fluorescence exciting light beams for the fluorescence imaging catheter based on the OCT.

Referring to fig. 1 and 2, an OCT-based fluorescence imaging catheter 100 includes a first fiber bundle 110, where the first fiber bundle 110 includes a first multimode fiber 111 and a first single mode fiber 112, and light-emitting ends of the first multimode fiber 111 and the first single mode fiber 112 are both provided with a reflective surface 113 disposed in an inclined manner. It should be noted that, because the tissue to be detected is generally a tubular structure, and the fluorescence imaging catheter 100 based on OCT is a long-strip-shaped structure, after being inserted into the tissue lumen, if the information of the inner wall of the tissue lumen is to be acquired, light needs to be emitted from one side of the fluorescence imaging catheter 100 based on OCT, so that the light emitted from the fluorescence imaging catheter 100 based on OCT can be irradiated onto the inner wall of the tissue lumen, and thus the reflective surface 113 must be set in an inclined manner, but the inclination angle can be set according to the detection requirement, and the inclination angles of the reflective surfaces 113 of the optical fibers can be the same or different.

The first multimode fiber 111 is configured to receive, conduct, and output the fluorescence excitation beam, and is further configured to receive, conduct, and output a fluorescence detection signal formed after the fluorescence excitation beam excites a tissue.

The first single mode fiber 112 is used for receiving, transmitting and outputting the OCT excitation beam, and is also used for receiving, transmitting and outputting an OCT detection signal formed after the OCT excitation beam is reflected by a tissue.

As shown in fig. 1, in addition to the first optical fiber bundle 110, the OCT-based fluorescence imaging catheter 100 generally includes a first housing 120, the first housing 120 includes a connection portion 121 for connecting with a main system, and a probe portion 122 for extending into a human body, the probe portion 122 and the connection portion 121 are both hollow structures and are communicated with each other to form a mounting cavity, and the first optical fiber bundle 110 is mounted in the mounting cavity.

The operation principle of the OCT-based fluorescence imaging catheter 100 provided by the embodiment of the present invention is as follows:

the fluorescence imaging catheter 100 based on OCT provided in the embodiment of the present invention is applied to a fluorescence imaging system based on OCT formed by combining an OCT imaging system and a fluorescence imaging system, wherein the first single-mode fiber 112 is connected to the OCT imaging system, and the first multi-mode fiber 111 is connected to the fluorescence imaging system.

When the OCT imaging system is used, the OCT imaging system emits an OCT excitation beam and a reference beam, wherein the OCT excitation beam enters the first single-mode fiber 112, then is transmitted and irradiated onto the reflecting surface 113 through the first single-mode fiber 112, then is emitted and irradiated onto a tissue to be detected after being reflected by the reflecting surface 113, then the OCT excitation beam is reflected by the tissue to be detected to form an OCT detection signal, the OCT detection signal returns to the OCT imaging system through the first single-mode fiber 112 and forms a coherent beam with the reference beam, and then corresponding equipment in the OCT imaging system analyzes the coherent beam to obtain a corresponding image.

Meanwhile, the fluorescence imaging system emits a fluorescence excitation beam, the fluorescence excitation beam enters the first multimode fiber 111, then is transmitted and irradiated to the reflecting surface 113 through the first multimode fiber 111, is reflected by the reflecting surface 113 and then is emitted and irradiated to the tissue to be detected, then the fluorescence excitation beam carries out fluorescence laser on the tissue to be detected to form a fluorescence detection signal, the fluorescence detection signal is received by the first multimode fiber 111 and returns to the fluorescence imaging system, and then a corresponding image is obtained through analyzing coherent light beams through corresponding equipment in the fluorescence imaging system.

Since the tissue to be detected is generally a tubular structure, in order to obtain information of the entire inner wall of the tissue lumen, in the above operation process, the OCT-based fluorescence imaging catheter 100 generally needs to be rotated, or only at least one optical fiber of the first optical fiber bundle 110 needs to be rotated.

The OCT-based fluorescence imaging catheter 100 provided in the embodiment of the present invention includes a first fiber bundle 110, where the first fiber bundle 110 includes a first multimode fiber 111 and a first single-mode fiber 112, where the first multimode fiber 111 is configured to receive, conduct, and output a fluorescence excitation beam, and is further configured to receive, conduct, and output a fluorescence detection signal formed after the fluorescence excitation of a tissue by the fluorescence excitation beam; the first single-mode fiber 112 is used for receiving, conducting and outputting an OCT excitation beam, and is also used for receiving, conducting and outputting an OCT detection signal formed after the OCT excitation beam is reflected by a tissue, that is, two different types of fibers are used to transmit the two OCT excitation beams, and with the aid of the fluorescent imaging catheter 100 based on OCT provided in the embodiments of the present invention, simultaneous detection of the OCT imaging system and the fluorescent imaging system can be achieved, so that the OCT excitation beam and the fluorescent excitation beam can be transmitted to the inner wall of the tissue simultaneously, signals in the tissue can be acquired simultaneously, and the fluorescent imaging catheter 100 based on OCT can be rotated, thereby ensuring acquisition of complete lumen segment information, ensuring accuracy of a detection result, and having high optical signal transmission efficiency.

The first multimode fiber and the first single mode fiber may have various configurations, and for the convenience of understanding, the following examples are given:

example one

As shown in fig. 2, there is one first multimode fiber 111 and one first single mode fiber 112, and the light emitting directions of the two fibers form an included angle. Specifically, the light emitting directions of the first multimode fiber 111 and the first single mode fiber 112 in this embodiment may be opposite to each other, or may form other non-zero included angles. By adopting the structure, when tissues such as blood vessels and the like are tested, the full-circle detection of the OCT excitation light beam and the fluorescence excitation light beam on the inner wall of the tissue can be realized by rotating the first optical fiber bundle 110, and the whole first optical fiber bundle 110 has a simple structure and is convenient to assemble.

Example two

As shown in fig. 3, the first multimode fiber 111 is provided in plurality and disposed around the first single mode fiber 112, a length of the first single mode fiber 112 is greater than a length of the first multimode fiber 111, and the first single mode fiber 112 is capable of rotating relative to the first multimode fiber 111. In this embodiment, the diameters of the first multimode fibers 111 are generally the same, and may also have a slight difference, which may be specifically set according to the use requirement, and is not limited herein. All optical fibers in this embodiment are used flush with the main body connection end (i.e., the light entrance end) of the fluorescence imaging system 200 and the OCT imaging system 300. Therefore, the length of the first single mode fiber 112 on the center line is large, and the light emitting end can be located outside the space surrounded by the plurality of first multimode fibers 111, so that the light transmitted in the first single mode fiber can be emitted without being blocked by the first multimode fibers 111 located at the periphery, and can be smoothly irradiated to the tissue to be detected.

By adopting the structure, when tissues such as blood vessels and the like are tested, the full-circle detection of the OCT excitation light beam and the fluorescence excitation light beam on the inner wall of the tissue can be realized by only rotating the first single-mode fiber 112, and the whole first fiber bundle 110 is simple in structure and convenient to assemble.

In addition, in the embodiment, the inclination angles of the reflecting surfaces 113 of the first multimode fibers 111 are the same, which facilitates processing and assembly.

EXAMPLE III

The first multimode optical fiber is provided with a plurality of first multimode optical fibers which are arranged around the first multimode optical fiber, the length of the first multimode optical fiber is larger than that of the first single mode optical fiber, and the first multimode optical fiber can rotate relative to the first single mode optical fiber. In this embodiment, the diameters of the first single-mode fibers are generally the same, and may also have a slight difference, which may be specifically set according to the use requirement, and is not limited herein. All optical fibers in this embodiment are used flush with the body connection end (i.e., the light entrance end) of the fluorescence imaging system and the OCT imaging system. Therefore, the first multimode optical fiber on the central line has a large length, and the light outlet end of the first multimode optical fiber can be positioned outside a space surrounded by the first single-mode optical fibers, so that light transmitted in the first multimode optical fiber can be smoothly irradiated to the tissue to be detected without being blocked by the first single-mode optical fibers positioned on the periphery after being emitted.

By adopting the structure, when the tissues such as blood vessels and the like are tested, the full-circle detection of the OCT excitation light beam and the fluorescence excitation light beam on the inner wall of the tissue can be realized by only rotating the first multimode fiber, and the whole first fiber bundle has a simple structure and is convenient to assemble.

In addition, in this embodiment, the inclination angles of the reflection surfaces of the first single-mode fibers are the same, which is convenient for processing and assembling.

By adopting the second embodiment and the third embodiment, the optical fibers positioned on the periphery are arranged in the circumferential direction, so that the whole circumferential information in the tissue can be acquired simultaneously, and the rotation of the fluorescence imaging catheter based on the OCT is not influenced.

On the basis of the second or third embodiment, as shown in fig. 3, in order to further reduce the diameter of the first optical fiber bundle 110, the optical fibers located at the periphery are connected by grinding to reduce the gap between two adjacent optical fibers, thereby reducing the diameter and volume of the whole first optical fiber bundle 110 and the main body of the OCT-based fluorescence imaging catheter 100.

In each of the above embodiments, the reflecting surface may be implemented by plating a reflecting layer on end surfaces of light emitting ends of the first multimode optical fiber and the first single mode optical fiber, attaching a reflecting film, and the like. As shown in fig. 2 and 3, in an alternative embodiment, the end faces of the light-exiting ends of the first single-mode fiber 112 and the first multimode fiber 111 are both inclined. Specifically, during the preparation, the end faces of the light-emitting ends of the first single-mode fiber 112 and the first multimode fiber 111 may be made into inclined planes with a desired inclination angle by grinding, cutting, or the like, where the inclination angles of the inclined planes and the reflecting surface 113 are the same or have a difference within a certain error value.

OCT-based fluorescence imaging catheter 100 also includes a light-tight heat shrink 130. The heat shrinking member 130 is located in the extending direction of the first optical fiber bundle 110 and connected to the light emitting end of the first optical fiber bundle 110, the shape of the surface of the heat shrinking member 130 connected to the first optical fiber bundle 110 is matched with the shape of the end surface of the light emitting end of the first optical fiber bundle 110, and the two are bonded to form a combined surface, which is the reflecting surface 113.

Specifically, the heat shrinkable member 130 in this embodiment may be one or more heat shrinkable tubes having the above structure, or may be a closed heat shrinkable member having a hollow structure. The heat shrinkable member 130 may be bonded to the end face of the light exit end of the first optical fiber bundle 110 by an adhesive, such as when the first optical fiber bundle 110 includes a first single-mode optical fiber 112 and a first multimode optical fiber 111. When the first optical fiber bundle 110 includes a plurality of first single-mode fibers 112 or a plurality of first multimode fibers 111, at this time, because the light emitting ends of the first single-mode fibers 112 and the first multimode fibers 111 are not flush, at this time, the heat shrinkable member 130 may be formed by a plurality of split bodies, one split body may be used for all fibers located at the periphery, one split body may be used for fibers located at the central area (i.e., on the central line), and one split body may also be provided for each fiber, which may be specifically selected according to the use requirement, and is not limited uniquely here.

As mentioned above, in order to obtain the information of the inner wall of the tissue lumen, the OCT excitation beam needs to be emitted from one side of the optical fiber, so that the end surfaces of the light-emitting ends of the first single-mode optical fiber 112 and the first multimode optical fiber 111 must be made into inclined surfaces, so that the end surface of the light-emitting end of the first optical fiber 110 has at least one tip, and if the tip is exposed, the tip is directly inserted into the human body, which is likely to cause tissue scratch. In this embodiment, the heat shrinkable member 130 connected to the light emitting end of the first optical fiber bundle 110 is additionally disposed at the light emitting end of the first optical fiber bundle 110, so that the tip is hidden, the end of the heat shrinkable member 130 away from the first optical fiber bundle 110 becomes an insertion end for inserting into a tissue, and the heat shrinkable member 130 can be changed into a high elastic state after being heated, thereby providing convenience for inserting the OCT-based fluorescence imaging catheter 100 into a tissue lumen, and reducing the risk of tissue damage when detecting the tissue through the OCT-based fluorescence imaging catheter 100.

Referring to fig. 4, in another embodiment of the present invention, an OCT-based fluorescence imaging system is provided, which includes a fluorescence imaging system 200 and an OCT imaging system 300.

The fluorescence imaging system 200 includes a fluorescence imaging light source 210, a fiber optic assembly 500, a photodetector 220, and a control display device 400 arranged in sequence along a first path. The first path is the path of the tissue detected by the fluorescence excitation beam emitted by the fluorescence imaging light source 210. The fluorescence imaging light source 210, the optical fiber assembly 500, and the photodetector 220 are communicated with each other via optical cables, optical fibers, hollow tubes, optical transmission members, etc., or no other devices are provided between the fluorescence imaging light source 210, the optical fiber assembly 500, and the photodetector 220, as long as the communication between the two is achieved. The photodetector 220 and the control display device 400 may be connected by a cable or may be connected wirelessly.

The fluorescence imaging light source 210 in this embodiment is generally a near infrared light source, and the wavelength of the output near infrared light is between 700 nm and 1600 nm. The control display apparatus 400 may be a device having both a control function and a display function, such as a single computer, a computer cluster, a display apparatus having a control function, and the like; it is also possible to include two devices, one of which is a control device for controlling system functions and processing relevant data information, and the other of which is a display device for displaying the processed data information and performing imaging.

OCT imaging system 300 includes a probe branch and a detection branch. The detection branch comprises a coherence tomography light source 310, a first coupler 320, a first circulator 330 and a fiber assembly 500 shared with the fluorescence imaging system 200, which are arranged in sequence along a second path. The second path here refers to an exit path of the OCT excitation beam from the coherence tomography light source 310. Specifically, the dry tomography light source in this embodiment is a low coherence swept-frequency light source. The coherence tomography light source 310, the first coupler 320, the first circulator 330, and the optical fiber assembly 500 shared by the fluorescence imaging system 200 may be in optical path communication via an optical cable, an optical fiber, a hollow tube, or other optical transmission elements, or no other device may be provided between two adjacent devices, as long as the optical path communication between the two devices is achieved.

The detection branch comprises an optical fiber assembly 500, a first circulator 330, a second coupler 340, a photoelectric converter 350 and a control display device 400 which are sequentially arranged along a third path, and further comprises a second circulator 360 and a reflecting piece which are sequentially arranged along a fourth path, wherein a light inlet of the second circulator 360 is communicated with one of light outlets of the first coupler 320 through a light path, and a light outlet of the second circulator 360 is communicated with one of light inlets of the second coupler 340 through a light path. The third path is a propagation path of an OCT probe signal formed by reflecting an OCT excitation beam by a tissue, and the fourth path is a propagation path of reference light into which a beam emitted from the coherence tomography light source 310 is split. The optical fiber assembly 500, the first circulator 330, the second coupler 340, and the photoelectric converter 350 may be in optical path communication through an optical cable, an optical fiber, a hollow tube, or another optical transmission element, or no other device may be provided between two adjacent devices, as long as the optical path communication between the two devices is achieved. The photoelectric converter 350 and the control display device 400 may be connected by a cable or may be wirelessly connected. The first coupler 320, the second circulator 360 and the second coupler 340 may be in optical path communication through an optical cable, an optical fiber, a hollow tube or other optical transmission elements, or no other device may be provided between two adjacent devices, as long as the optical path communication between the two devices is achieved.

Specifically, the first coupler 320 has three ports, one of which is a light inlet for receiving the light beam emitted from the coherence tomography light source 310, and the other two of which are light outlets, one of which is used for outputting the OCT excitation light beam to the first circulator 330, and the other is used for outputting the reference light to the second circulator 360.

The optical fiber assembly 500 includes a second optical fiber bundle including a second multimode optical fiber and a second single mode optical fiber, the second multimode optical fiber is in optical path communication with the first multimode optical fiber 111, and the second single mode optical fiber is in optical path communication with the first single mode optical fiber 112, as well as the first optical fiber bundle 110 provided in the above embodiments. In addition, since the first fiber bundle 110 needs to rotate when in use, the OCT-based fluorescence imaging system generally further includes a rotation driving device for driving all or part of the fibers in the first fiber bundle 110 to rotate.

Specifically, in this embodiment, the second optical fiber bundle and the first optical fiber bundle 110 may be connected through a multi-channel optical fiber slip ring or other optical connectors that can realize the rotational connection between the first optical fiber bundle 110 and the second optical fiber bundle, so as to realize the optical path communication between the corresponding optical fibers. The rotation driving device in this embodiment may adopt a motor 610, a manipulator, etc., as long as the rotation driving device can drive the first optical fiber bundle 110 to rotate without affecting the light transmission between the corresponding optical fibers of the first optical fiber bundle 110 and the second optical fiber bundle.

In addition, the fluorescence imaging system based on OCT generally further includes a second housing, and the fluorescence imaging light source 210, the coherence tomography light source 310, the first coupler 320, the first circulator 330, the second coupler 340, and the light intensity detector 390 may all be disposed in the second housing, or other devices except the fluorescence imaging catheter 100 based on OCT may all be disposed in the second housing, or most devices except the fluorescence imaging catheter 100 based on OCT may be disposed in the second housing, and a few devices (such as the control display device 400) may be disposed outside the second housing as needed. When in use, the first single-mode fiber 112 and the second single-mode fiber can be butted by connecting the first housing 120 and the second housing, the first multimode fiber 111 and the second multimode fiber can be butted, and the relative positions of the fluorescence imaging catheter 100 based on OCT and other devices in the fluorescence imaging system 200 and the OCT imaging system 300 can be fixed, which is the prior art and will not be described herein again.

As shown in fig. 5, the first circulator 330 in this embodiment has three ports, wherein one port (e.g., a port in the figure) is used for receiving the OCT excitation beam, another port (e.g., B port in the figure) is used for outputting the OCT excitation beam and for receiving the OCT detection signal, and the last port (e.g., C port in the figure) is used for outputting the OCT detection signal received by the B port.

The working principle of the fluorescence imaging system based on the OCT provided by the embodiment of the invention is as follows:

when the fluorescence imaging system is used, the fluorescence imaging light source 210 emits fluorescence excitation light beams, the fluorescence excitation light beams are emitted through the optical fiber assembly 500 and irradiate on tissues, the tissues are subjected to fluorescence excitation to form fluorescence detection signals, the fluorescence detection signals are received by the fluorescence imaging system 200 through the optical fiber assembly 500, then are transmitted to the photoelectric detector 220 through the optical fiber assembly 500, are transmitted to the control display device 400 after signal conversion, and then are displayed by the control display device 400 to form corresponding images.

Meanwhile, the coherent tomography light source 310 emits detection laser light, the detection laser light is then divided into OCT excitation light beams and reference light beams by the first coupler 320, the OCT excitation light beams are sequentially transmitted by the first circulator 330 and the optical fiber assembly 500 shared by the fluorescence imaging system 200 and emitted onto a tissue, and then reflected by the tissue to form OCT detection signals, the OCT detection signals are received by the OCT imaging system 300 through the optical fiber assembly 500, and then transmitted to the second coupler 340 through the first circulator 330 by the optical fiber assembly 500, and are coherently coupled with the reference light beams transmitted through the reference arm optical path formed by the second circulator 360 and the reflector 370 at the position of the second coupler 340 to form interference light of the OCT imaging system 300, and then the interference light is emitted into the photoelectric converter 350 by the second coupler 340 to perform conversion between optical signals and electrical signals, and the electrical signals are sent to the control display device 400 to be displayed.

The display device 400 may be controlled to store the image obtained by the OCT imaging system 300 and the image obtained by the fluorescence imaging system 200, and then perform frame-by-frame registration on the two images by using techniques such as guide wire recognition, and perform fusion display on the registration result.

In the above process, the first coupler 320 divides the detection laser into the OCT excitation beam and the reference beam according to a certain splitting ratio, which may be 90:10, other ratios may be used as desired, such as 50:50, and is not intended to be limiting.

Through testing, when an OCT-based fluorescence imaging system is adopted to detect intravascular tissues, intravascular bleeding, common plaques and the like can be accurately identified.

The fluorescence imaging system based on OCT provided by the embodiments of the present invention employs the fluorescence imaging catheter 100 based on OCT provided by the above embodiments, and is provided with the second optical fiber bundle and other devices, so that the combination of the fluorescence imaging system 200 and the fluorescence imaging system 300 is realized, the simultaneous detection of the fluorescence imaging system 300 and the fluorescence imaging system 200 can be realized, the OCT excitation beam and the fluorescence excitation beam can be simultaneously transmitted to the inner wall of the tissue, the signal in the tissue can be simultaneously acquired, and the fluorescence imaging catheter 100 based on OCT is rotated, so that the detection result is not greatly affected, the accuracy of the detection result is ensured, and the optical signal transmission efficiency is high.

In an alternative embodiment, the fluorescence excitation beam is a laser beam with a wavelength of 633nm and the OCT excitation beam is a laser beam with a wavelength of 1310 nm. And the wavelength of the fluorescence excitation beam, the wavelength of the OCT excitation beam and the wavelength of the fluorescence detection signal are different, so that the identification and analysis of the fluorescence detection signal and the OCT detection signal are facilitated.

As shown in fig. 6, in an alternative embodiment, the rotation driving device 600 includes a motor 610, a first channel 620 penetrating through the motor 610 along an axial direction is provided on a central axis of the motor 610, and a second channel 630 is provided on one side of the first channel 620, the second channel 630 is parallel to the first channel 620, and the number of the second channel 630 is the same as the number of the optical fibers located on the outer periphery in the first optical fiber bundle, that is, as shown in fig. 2 and 3, when only one first single-mode optical fiber 112 and one first multimode optical fiber 111 are provided in the first optical fiber bundle 110, only one second channel 630 is provided, when a plurality of first single-mode optical fibers 112 are provided in the first optical fiber bundle 110, the number of the second channel 630 is the same as the number of the first multimode optical fibers 112, and when a plurality of first multimode optical fibers 111 are provided in the first optical fiber bundle 110, the number of the second channel 630 is the same as the number of the first multimode optical fibers 111. In use, the centrally located optical fiber of the first optical fiber bundle 110 is connected to the corresponding optical fiber of the second optical fiber bundle 510 through the first passage 620, and the peripherally located optical fiber of the first optical fiber bundle 110 is connected to the corresponding optical fiber of the second optical fiber bundle 510 through the second passage 630. After the motor 610 is started, the first channel 620 and the second channel 630 can both rotate around the central axis, and then each optical fiber in the first optical fiber bundle 110 is driven to rotate around the central axis, so that circumferential detection of the tissue lumen by the fluorescence imaging system based on the OCT and rotational retraction of the fluorescence imaging catheter 100 based on the OCT are realized.

In an alternative embodiment, one of the second multimode optical fiber and the second single mode optical fiber is provided in plurality and disposed around the other optical fiber.

The embodiment comprises a plurality of setting modes:

first, as shown in fig. 3 and 7, the first multimode fiber 111 has a plurality of second multimode fibers 511, which are disposed around the first single mode fiber 112 and have the same number as the first multimode fiber 111, and are disposed around the second single mode fiber 512, and meanwhile, the diameter of the first single mode fiber 112 is matched with that of the second single mode fiber 512, and the diameter of the first multimode fiber 111 is matched with that of the second multimode fiber 511. The said adaptation means that the two have equal diameters or have a small difference, and the stable transmission of optical signals can be realized in the butt joint state. With this configuration, the first multimode optical fiber 111 may not rotate and only the first single mode optical fiber 112 may be controlled to rotate when detecting tissue.

Secondly, the first single-mode fiber is provided with a plurality of surrounding first multimode fibers, the number of the second single-mode fibers is consistent with that of the first single-mode fibers and the second single-mode fibers are arranged in a surrounding mode, the diameter of the first multimode fibers is matched with that of the second multimode fibers, and the diameter of the first single-mode fibers is matched with that of the second single-mode fibers. When the scheme is adopted, the first single-mode fiber can not rotate when the tissue is detected, and only the first multimode fiber can be controlled to rotate.

And thirdly, the first single-mode fiber and the first multimode fiber are both provided with one, the second single-mode fiber is provided with a plurality of second single-mode fibers and arranged around the second multimode fiber, the diameter of the first multimode fiber is matched with that of the second multimode fiber, and the diameter of the first single-mode fiber is matched with that of the second single-mode fiber.

Fourthly, as shown in fig. 2 and 7, there is one first single mode fiber 112 and one first multimode fiber 111, there are a plurality of second multimode fibers 511 disposed around the second single mode fiber 512, and the diameter of the first multimode fiber 111 is adapted to the diameter of the second multimode fiber 511, and the diameter of the first single mode fiber 112 is adapted to the diameter of the second single mode fiber 512.

No matter which setting mode is adopted, a plurality of optical fibers exist in the second optical fiber bundle 510, that is, the multichannel transmission of the corresponding OCT excitation beam is realized, and further, the detection precision of the corresponding OCT excitation beam can be improved.

As shown in fig. 9, in an alternative embodiment, the second single-mode fiber 512 is provided with a plurality of single-mode fibers, the detection branch further includes a beam splitter 380 located between the first circulator 330 and the fiber assembly 500, the beam splitter 380 is configured to split the OCT excitation beam transmitted by the first circulator 330 into a plurality of first split beams, the number of the first split beams is equal to the number of the second single-mode fibers 512, and the plurality of first split beams are transmitted to the corresponding first single-mode fibers 112 in a one-to-one correspondence, and is further configured to combine a plurality of OCT detection signals transmitted through the plurality of first single-mode fibers 112 into one signal to be transmitted to the first circulator 330.

The beam splitter 380 in this embodiment is a bidirectional beam splitter 380 having a timing switch, and can split one OCT excitation beam into a plurality of groups of first split beams according to a preset timing and enter the plurality of second single-mode fibers 512 and the plurality of first single-mode fibers 112, and meanwhile, the beam splitter 380 can also couple OCT detection signals transmitted by the plurality of first single-mode fibers 112 and the plurality of second single-mode fibers 512 to form one beam of detection light. Therefore, the beam splitter 380 in this embodiment is configured to match the circumferentially arranged multi-channel second single-mode fibers 512, so that the OCT excitation light beam can uniformly enter each second single-mode fiber 512, and the detection effect is ensured.

In an alternative embodiment, as shown in fig. 10, the second multimode optical fiber 511 is provided in plurality, and the fluorescence imaging system 200 further includes a beam splitter 380 located between the fluorescence imaging light source 210 and the optical fiber assembly 500, wherein the beam splitter 380 is configured to split the fluorescence excitation light beam into a plurality of second split beams corresponding to the number of the second multimode optical fibers 511, and transmit the plurality of second split beams into the corresponding first multimode optical fibers 111 in a one-to-one correspondence.

The beam splitter 380 in this embodiment is a unidirectional optical path beam splitter 380 with a sequential switch. The beam splitter 380 may be in optical path communication with the fluorescence imaging light source 210 or the optical fiber assembly 500 through an optical cable, an optical fiber, a hollow tube, or other optical transmission element, or may not be provided with other devices between the fluorescence imaging light source 210 or the optical fiber assembly 500, as long as the optical path communication between the beam splitter 380 and the fluorescence imaging light source 210 and the optical fiber assembly 500 can be achieved. When the OCT-based fluorescence imaging system provided in this embodiment is used, the fluorescence imaging light source 210 emits a fluorescence excitation light beam, the fluorescence excitation light beam enters the beam splitter 380 to split the optical path into a plurality of second split light beams, the plurality of second split light beams further enter the plurality of second multimode fibers 511, are transmitted to the first multimode fibers 111 through the second multimode fibers 511, are emitted and irradiated onto the tissue through the first multimode fibers 111, perform fluorescence excitation on the tissue to obtain an intracavity fluorescence detection signal, then return to the fluorescence detection system through the first multimode fibers 111 and the second multimode fibers 511, and are converted into an electrical signal by the photodetector to be sent to the control display device 400. Therefore, in the embodiment, the beam splitter 380 is arranged to match the multi-channel second multimode fibers 511 arranged in the circumferential direction, so that the OCT excitation beam can uniformly enter each second multimode fiber 511, and the detection effect is ensured.

In order to stabilize the signal obtained by the OCT-based fluorescence imaging system and obtain a complete tissue lumen image, as shown in fig. 8, in an alternative embodiment, the second optical fiber bundle 510 further includes a reinforcing optical fiber 513, and when the second multimode optical fiber 511 is located at the outer periphery, the reinforcing optical fiber 513 is a multimode optical fiber, has a smaller diameter than that of the second multimode optical fiber 511, and is located in a concave region formed by two adjacent second multimode optical fibers 511; when the second single mode fiber 512 is located at the periphery, the reinforcing fiber 513 is a single mode fiber, has a diameter smaller than that of the second single mode fiber 512, and is located in a recessed area formed by two adjacent second single mode fibers 512. Specifically, one or more reinforcing fibers 513 may be provided in the present embodiment, and when a plurality of reinforcing fibers are provided, the number of the reinforcing fibers may be the same as or less than the number of the fibers located on the outer periphery in the second single-mode fiber 512 and the second multimode fiber 511, and may be specifically set according to the detection requirement. The placement of the reinforcing fiber 513 may enhance the signal to improve the stability of the signal acquired by the OCT-based fluorescence imaging system.

In practical use, the fluorescence imaging catheter based on OCT needs to rotate, and the light intensity of the light signal transmitted through the fluorescence imaging catheter based on OCT during the rotation process has deviations such as peaks and valleys, so that the detection result at different times has little deviation, as shown in fig. 9 and 10, in an optional embodiment, the detection branch further includes a light intensity detector 390, the light intensity detector 390 is respectively connected to the second coupler 340 and the photoelectric converter 350 through a light path, and is also electrically connected to the control display device 400, and the control display device 400 is configured to receive the light intensity signal output by the light intensity detector 390 and enhance the OCT detection signal whose light intensity signal is lower than the preset light intensity.

Because the light intensity of the optical signal transmitted through the OCT-based fluorescence imaging catheter 100 during rotation deviates, the light intensity detector 390 monitors the light intensity information in real time during use, and transmits the monitoring data to the control display device 400 in real time, the control display device 400 compares the data with the pre-stored preset light intensity data therein, and when the data is lower than the preset light intensity value, the electrical signal of the OCT detection signal corresponding to the optical signal is enhanced by an algorithm, and then analyzed to obtain a corresponding image, so as to ensure that the displayed image is more accurate, and further ensure that the detection result is more accurate.

More specifically, according to the structure of the fluorescence imaging catheter 100 based on OCT, there is a large amount of loss in transmission during OCT imaging or fluorescence imaging, and the light intensity detection device selects the imaging information with the highest light intensity as the standard image information, because the loss of the image information with the highest light intensity is the smallest, it is most accurate to include the intracavity information. Meanwhile, in the process of one scanning rotation of the fluorescence imaging catheter 100 based on the OCT, five hundred information images can be acquired by the fluorescence imaging catheter 100 based on the OCT; selecting a standard information image from five hundred images, and perfecting the rest nonstandard information images in a fitting mode to form a frame of intracavity image; after all the intracavity images are continuously acquired, the acquired intracavity images and another acquired modal image (namely, a fluorescence modal image) are identified through a guide wire, frame-by-frame registration is carried out, and the registration result is fused and displayed.

The foregoing is considered as illustrative only of the preferred embodiments of the invention and is not to be construed in any way as limiting the scope of the invention. Any modifications, equivalents and improvements made within the spirit and principles of the invention and other embodiments of the invention without the creative effort of those skilled in the art are included in the protection scope of the invention based on the explanation here.

Claims

1. An OCT-based fluorescence imaging catheter is characterized by comprising a first optical fiber bundle, wherein the first optical fiber bundle comprises a first multimode optical fiber and a first single-mode optical fiber, and the light emitting ends of the first multimode optical fiber and the first single-mode optical fiber are provided with reflecting surfaces;

the first single-mode fiber is used for receiving, transmitting and outputting an OCT (optical coherence tomography) excitation beam and is also used for receiving, transmitting and outputting an OCT detection signal formed after the OCT excitation beam is reflected by tissues.

2. The OCT-based fluorescence imaging catheter of claim 1, wherein the first multimode optical fiber and the first single mode optical fiber are disposed one by one, and the light emitting directions of the first multimode optical fiber and the first single mode optical fiber are disposed at an angle.

3. The OCT-based fluorescence imaging catheter of claim 1, wherein the first multimode optical fiber is provided in plurality and disposed around the first single mode optical fiber, wherein the first single mode optical fiber has a length greater than a length of the first multimode optical fiber, and wherein the first single mode optical fiber is rotatable with respect to the first multimode optical fiber;

4. The OCT-based fluorescence imaging catheter of claim 3, wherein the angle of inclination of the reflective surface of each of the first multimode optical fibers is the same when the first multimode optical fibers are located at the outer circumference;

5. The OCT-based fluorescence imaging catheter of any one of claims 1-4, wherein the end faces of the light exit ends of the first single-mode fiber and the first multimode fiber are both beveled;

the OCT-based fluorescence imaging catheter further comprises a light-tight heat-shrinkable piece, wherein the heat-shrinkable piece is located in the extending direction of the first optical fiber bundle and connected with the light-emitting end of the first optical fiber bundle, the shape of one surface, connected with the first optical fiber bundle, of the heat-shrinkable piece is matched with the shape of the end surface of the light-emitting end of the first optical fiber bundle, the heat-shrinkable piece and the first optical fiber bundle are attached to form a combined surface, and the combined surface is the reflecting surface.

6. An OCT-based fluorescence imaging system is characterized by comprising a fluorescence imaging system and an OCT imaging system;

the OCT imaging system comprises a detection branch and a detection branch, wherein the detection branch comprises a coherence tomography light source, a first coupler, a first circulator and an optical fiber assembly which are sequentially arranged along a second path, the detection branch comprises the optical fiber assembly, the first circulator, a second coupler, a photoelectric converter and the control display device which are sequentially arranged along a third path, and the detection branch further comprises a second circulator and a reflecting piece which are sequentially arranged along a fourth path, an optical inlet of the second circulator is communicated with one of optical outlets of the first coupler through an optical path, and an optical outlet of the second circulator is communicated with one of optical inlets of the second coupler through an optical path;

the fiber optic assembly comprises a first bundle of optical fibers according to any of claims 1-5 and a second bundle of optical fibers comprising a second multimode optical fiber in optical communication with the first multimode optical fiber and a second single mode optical fiber in optical communication with the first single mode optical fiber.

7. The OCT-based fluorescence imaging system of claim 6, wherein one of the second multimode optical fiber and the second single mode optical fiber is provided in plurality and around the other.

8. The OCT-based fluorescence imaging system of claim 7, wherein the second single-mode fiber is provided in plurality, the detection branch further comprises a beam splitter located between the first circulator and the fiber assembly, the beam splitter is configured to split the OCT excitation beam transmitted by the first circulator into a plurality of first split beams corresponding to the second single-mode fiber in number, and to transmit the plurality of first split beams into the corresponding first single-mode fibers in a one-to-one correspondence, and further configured to combine the plurality of OCT detection signals transmitted through the plurality of first single-mode fibers into one signal and transmit the signal to the first circulator;

or, the second multimode optical fiber is provided with a plurality of second multimode optical fibers, the fluorescence imaging system further comprises a beam splitter located between the fluorescence imaging light source and the optical fiber assembly, and the beam splitter is used for splitting the fluorescence excitation light beam into a plurality of second split light beams with the number consistent with that of the second multimode optical fibers and transmitting the plurality of second split light beams into the corresponding first multimode optical fibers in a one-to-one correspondence manner.

9. The OCT-based fluorescence imaging system of claim 8, wherein the second fiber bundle further comprises a reinforcing fiber, wherein when the second multimode fiber is located at the outer periphery, the reinforcing fiber is a multimode fiber, has a smaller diameter than the second multimode fiber, and is located in a concave region formed by two adjacent second multimode fibers; when the second single mode fiber is located at the periphery, the reinforcing fiber is a single mode fiber, the diameter of the reinforcing fiber is smaller than that of the second single mode fiber, and the reinforcing fiber is located in the concave area formed by the two adjacent single mode fibers.

10. The OCT-based fluorescence imaging system of any one of claims 7-9, wherein the detection branch further comprises a light intensity detector, the light intensity detector is respectively connected to the second coupler and the photoelectric converter via a light path, and is electrically connected to the control and display device, and the control and display device is configured to receive the light intensity signal output by the light intensity detector and perform enhancement processing on the OCT detection signal with the light intensity signal lower than a preset light intensity.