OCT (Optical Coherence Tomography) imaging catheter

Abstract

The invention discloses an OCT (optical coherence tomography) imaging catheter, and relates to the technical field of medical instruments. The OCT imaging catheter comprises a catheter body, an imaging probe and filling liquid. An inner cavity is formed in the catheter body, and an imaging window and a filling space located in the imaging window are arranged at the far end of the catheter body; the imaging probe is movably inserted into the inner cavity and extends into the filling space at the imaging window; the filling space is filled with the filling liquid, and the filling liquid is used for changing the refraction direction of emergent light of a lens of the imaging probe so as to reduce astigmatism and attenuation during scanning imaging. According to the OCT imaging catheter, the structure of the OCT imaging catheter is improved, the smoothness of rotating and pulling back of the lens is guaranteed, the imaging quality is improved, it is effectively guaranteed that the lens is not damaged, and the convenience of pushing the catheter to a blood vessel is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to an OCT imaging catheter. Background Art

[0002] Since the images collected by OCT (Optical Coherence Tomography) imaging technology are relatively clear and can completely and clearly observe the situation of the target part, it has become a relatively mainstream blood vessel imaging method at present. At present, OCT imaging catheters have been widely used in fields such as coronary blood vessels and intracranial blood vessels.

[0003] However, due to the thinness and complexity of intracranial blood vessels, during intracranial blood vessel imaging, when the OCT imaging catheter shuttles through intracranial blood vessels with multiple bends, thinness and high complexity, the distal end of the optical fiber in the OCT imaging catheter is easily damaged, resulting in poor imaging quality or even imaging failure. Summary of the Invention

[0004] The main purpose of the present invention is to provide an OCT imaging catheter, aiming to improve the imaging quality of the OCT imaging catheter.

[0005] To achieve the above object, the present invention provides an OCT imaging catheter, including: A catheter body, which forms a lumen, and a distal end of the catheter body is provided with an imaging window and a filling space located within the imaging window; An imaging probe, which is movably inserted into the lumen and extends into the filling space at the imaging window; and A filling liquid, which fills the filling space.

[0006] Optionally, the filling liquid is a viscous liquid.

[0007] Optionally, the catheter body includes an outer catheter, a guide wire head and a spring tube. The guide wire head is provided at the distal end of the outer catheter. The spring tube is sleeved on the outer periphery of the imaging probe and is used to drive the imaging probe to perform a rotational retraction movement under the drive of an external force. The filling space is formed by enclosing the outer catheter, the guide wire head and the spring tube.

[0008] Optionally, the spring tube includes an inner layer tube, an outer layer tube and a developing ring. The outer layer tube is provided on the outer periphery of the inner layer tube, and a peeling part is provided on the outer layer tube. The developing ring is provided within the peeling part.

[0009] Optionally, the imaging probe includes an optical fiber, a lens and a light output control member. The lens is provided at the distal end of the optical fiber, and the light output control member is provided on the lens and is used to control the light output direction and protect the lens.

[0010] Optionally, the imaging probe further includes a protective member that covers the outer periphery of the lens and is connected to the spring tube. The protective member is used to protect the lens. A coating layer is applied to the protective member, and the material of the coating layer is polyimide.

[0011] Optionally, the light output control member is sequentially provided with a first material layer, a second material layer, a third material layer, and a fourth material layer from the inside to the outside. The material of the first material layer is high-elastic polyurethane, the material of the second material layer is polyimide nanofibers, the third material layer is a helical winding structure of shape memory alloy wires, and the material of the fourth material layer is a biocompatible material.

[0012] Optionally, the light output control member is a heat-shrinkable tube; and / or The protective member is a RJ45 connector.

[0013] Optionally, the outer sheath includes a proximal outer tube and a distal outer tube connected to the proximal outer tube; and / or The proximal outer tube includes an inner layer, a middle layer, and an outer layer that are sequentially stacked from the inside to the outside. The material of the inner layer is PTFE, the material of the middle layer is 304 stainless steel, and the material of the outer layer is PI; and / or The material of the distal outer tube is Pebax.

[0014] Optionally, the proximal outer tube is provided with a sunk section on the outer surface at its connection with the distal outer tube, and the distal outer tube is provided with a mating section on the inner surface at its connection with the proximal outer tube. The mating section surrounds the sunk section and is fixed by welding or bonding.

[0015] In the technical solution of the present invention, the OCT imaging catheter includes a catheter body, an imaging probe, and a filling liquid. The catheter body forms an inner cavity, and the distal end of the catheter body is provided with an imaging window and a filling space located within the imaging window. The imaging probe is movably inserted into the inner cavity and extends into the filling space at the imaging window. The filling liquid is filled in the filling space, and the filling liquid is used to change the refraction direction of the light emitted by the lens of the imaging probe, so as to reduce astigmatism and attenuation during scanning imaging. It can be understood that the present invention improves the distal structure of the OCT imaging catheter. By arranging the filling liquid in the filling space within the imaging window at the distal end of the catheter body, the lens of the imaging probe performs retracting and rotating movements in the solution, effectively ensuring the smoothness of the lens retracting and rotating, changing the refraction direction of the light emitted by the lens of the imaging probe, being able to reduce astigmatism and attenuation during scanning imaging, and improving the imaging quality.

[0016] In the present invention, the OCT imaging probe is provided with a multi-layer structure, which improves the buffering protection effect on the lens, increases the tensile strength of the lens, has higher structural support stability, reduces stress concentration, and has better biocompatibility with biological tissues. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0018] Figure 1 Schematic structural diagram of an embodiment of the OCT imaging catheter of the present invention; Figure 2 is Figure 1 an enlarged view of a partial area A therein; Figure 3 is Figure 1 an enlarged view of a partial area B therein; Figure 4 Schematic structural diagram of the imaging probe in an embodiment of the OCT imaging catheter of the present invention; Figure 5 Schematic structural diagram of the imaging probe in another embodiment of the OCT imaging catheter of the present invention; Figure 6 Schematic structural diagram of the proximal outer tube in an embodiment of the OCT imaging catheter of the present invention; Figure 7 Schematic connection diagram of the proximal outer tube and the distal outer tube in an embodiment of the OCT imaging catheter of the present invention; Figure 8 Schematic structural diagram of the spring tube and a cross-sectional view of the spring tube at the visualization ring thereon in an embodiment of the OCT imaging catheter of the present invention.

[0019] Explanation of the reference numerals in the drawings: 10. Conduit body; 20. Imaging probe; 10a. Filling space; 101. Outer sheath; 102. Guide wire head; 103. Spring tube; 104. Marking ring for imaging; 201. Optical fiber; 202. Lens; 203. Light output control member; 204. Protective member; 2411. Coating layer; 2421. First material layer; 2422. Second material layer; 2423. Third material layer; 2424. Fourth material layer; 111. Proximal outer tube; 112. Distal outer tube; 1111. Inner layer; 1112. Middle layer; 1113. Outer layer; 1131. Counterbore section; 1132. Fitting section; 30. Protective cover; 40. Connection seat; 50. Stress buffer tube; 60. Connection seat sheath; 71. Pull-back mark; 72. Lens mark; 73. Axial marking tape; 221. Reflective surface; 1121. Imaging window.

[0020] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] It should be noted that all the directional indications (such as up, down, left, right, front, back,...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0023] In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0024] In addition, the descriptions involving "first", "second", etc. in the present invention are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. The meaning of "and / or" appearing throughout the text is that it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or the solution where both A and B are satisfied simultaneously. The technical solutions between various embodiments can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions results in contradictions or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] The present invention provides an OCT imaging catheter, which can be applied to fields such as intracranial blood vessels and coronary blood vessels, and is not limited here.

[0026] Refer to Figures 1 to 5 , in an embodiment of the present invention, the OCT imaging catheter includes a catheter body 10, an imaging probe 20, and a filling liquid (not shown in the figure); the catheter body 10 forms an inner cavity, and a distal end of the catheter body 10 is provided with an imaging window 1121 and a filling space 10a located within the imaging window 1121; the imaging probe 20 is movably inserted into the inner cavity and extends into the filling space 10a at the imaging window 1121; the filling liquid is filled in the filling space 10a, and the filling liquid is used to change the refraction direction of the light emitted by the lens 202 of the imaging probe 20 to reduce astigmatism and attenuation during scanning imaging.

[0027] In this embodiment, the filling liquid is a viscous liquid such as medical silicone oil. Such a solution can not only play the role of changing the refraction direction of the light emitted by the lens 202 of the imaging probe 20, but also has a certain smoothness, which helps to improve the smoothness of the back-and-forth pulling and rotational movements of the imaging probe 20 within the inner cavity. In addition, when the lens 202 moves in the filling liquid for imaging a blood vessel segment, the solution can also protect the imaging components.

[0028] It can be understood that the present invention improves the distal structure of the OCT imaging catheter. By arranging a filling liquid in the filling space 10a within the imaging window 1121 at the distal end of the catheter body 10, the lens 202 of the imaging probe 20 makes back-and-forth pulling and rotational movements in the solution, changing the refraction direction of the light emitted by the lens 202 of the imaging probe 20, which can reduce astigmatism and attenuation during scanning imaging, can eliminate the extra halos outside the imaging probe during catheter scanning imaging due to the absence of a contrast agent, and can reduce the resistance between the high-speed rotation of the catheter core and the inner wall of the distal outer tube 112, thereby improving the image quality, effectively ensuring the smoothness of the rotation and back-and-forth pulling of the lens 202 and improving the imaging quality.

[0029] To further improve the convenience of the rotational retraction movement of the imaging probe 20, mainly referring to Figure 1 and Figure 2 , in one embodiment, the catheter body 10 may include an outer sheath 101, a guide wire head 102, and a spring tube 103. The guide wire head 102 is provided at the distal end of the outer sheath 101. The spring tube 103 is sleeved on the outer periphery of the imaging probe 20 and is used to drive the imaging probe 20 to perform rotational retraction movement under the drive of an external force. The filling space 10a is formed by enclosing the outer sheath 101, the guide wire head 102, and the spring tube 103.

[0030] It should be noted that the imaging window 1121 has light transmissivity and is circumferentially arranged. Its length is the same as the retraction length of the imaging probe 20 and can allow light to pass through. The imaging window 1121 may be a part of the tube segment at the distal end of the outer sheath 101, arranged around the outer periphery of the lens 202, or a light-transmitting sheet embedded on the distal end of the outer sheath 101; of course, the imaging window 1121 may also be a light-transmitting tube connected to the distal end of the outer sheath 101, which is not limited here.

[0031] Further, referring to Figure 8 , the spring tube 103 may include an inner layer tube, an outer layer tube, and a developer ring 104. The outer layer tube is arranged on the outer periphery of the inner layer tube and a peeling part is provided on the outer layer tube. The developer ring 104 is arranged in the peeling part. In this way, by adopting the design of a double-layer spring tube 103 plus a developer ring 104, a part of the outer layer of the spring tube 103 is peeled off. After welding the developer ring 104 at the peeling position, the spring tube 103 has a developer mark under X-ray, and the outer diameter of the spring tube 103 at the welding position is smaller than the outer diameter of the rest of the spring tube 103, which is beneficial to making the outer diameter of the application section of the product smaller.

[0032] In this embodiment, the developer ring 104 may be made of platinum-iridium material, which is not limited here.

[0033] To protect the lens 202 from being squeezed by the lumen and affecting imaging, or even causing damage, mainly referring to Figure 2 , Figure 4 and Figure 5 , in some embodiments, the imaging probe 20 may include an optical fiber 201, a lens 202, and a light output control member 203. The lens 202 is provided at the distal end of the optical fiber 201. The light output control member 203 is provided on the lens 202 and is used to control the light output direction and protect the lens 202. In this way, when the catheter is pushed in a narrow blood vessel, the problem that the lens 202 of the imaging probe 20 is deformed and damaged due to being squeezed by the catheter lumen, resulting in the catheter being unable to image normally, is solved. And when the catheter is retracted in a tortuous blood vessel, the problem that the lens 202 of the imaging probe 20 is broken due to the large pulling force of the proximal optical fiber 201 and the friction of the lumen inner wall, and the catheter is unable to image normally, is solved.

[0034] In this embodiment, the thickness of the bourdon tube 103 can be 0.075 mm, and the diameter of the optical fiber 201 can be 0.15 mm, which is not limited here. The light output control member 203 can be a heat shrinkable tube or the like, the material can be PET, and the thickness can be 0.01 mm, which is not limited here.

[0035] It should be noted that the heat shrinkable tube forms the reflecting surface 221 of the lens 202. During scanning imaging, light is emitted from the optical fiber 201 to the lens 202, hits the heat shrinkable tube, and then is totally reflected and emitted.

[0036] To further improve the protection effect on the lens 202, referring to Figure 4 , in one embodiment, the imaging probe 20 further includes a protection member 204. The protection member 204 covers the outer periphery of the lens 202 and is connected to the bourdon tube 103. Specifically, the protection member 204 is attached to the tip of the optical fiber 201 and the lens 202 to protect the lens 202; a coating layer 2411 is coated on the protection member 204, and the material of the coating layer 2411 can be polyimide or the like.

[0037] In this embodiment, the protection member 204 can be a crystal head or the like, the material can be epoxy resin glue, and the thickness can be 0.15 mm, which is not limited here. The thickness of the polyimide coating layer 2411 can be 0.01 mm, which is not limited here.

[0038] To further improve the protection effect on the lens 202, referring to Figure 5 , in another embodiment, the surface of the light output control member 203 can be sequentially provided with a first material layer 2421, a second material layer 2422, a third material layer 2423, and a fourth material layer 2424 from the inside to the outside. The material of the first material layer 2421 is high elastic polyurethane or the like, the material of the second material layer 2422 is polyimide nanofibers or the like, the third material layer 2423 is a shape memory alloy wire spiral winding structure, and the material of the fourth material layer 2424 is a biocompatible material or the like.

[0039] Preferably, the first material layer 2421 is made of high elastic polyurethane with a thickness of 0.01 mm to provide preliminary buffering; the second material layer 2422 is a nanofiber reinforcement layer made of polyimide nanofibers, and the thickness can be 0.01 mm to improve the tensile strength. The third material layer 2423 can adopt a shape memory alloy wire spiral winding structure with a pitch of 0.5 mm and a thickness of 0.03 mm to provide structural support and stress dispersion. The fourth material layer 2424 can adopt medical grade silicone with a thickness of 0.01 mm to make the lens 202 have better biocompatibility.

[0040] During manufacturing, the multi-layer structure should be layered in sequence, then a lamination process is adopted, and then they are welded together at high temperature.

[0041] Mainly referring to Figure 1And Figure 6 In one embodiment, the outer catheter 101 may include a proximal outer tube 111 and a distal outer tube 112 connected to the proximal outer tube 111. The proximal outer tube 111 includes an inner layer 1111, a middle layer 1112, and an outer layer 1113 that are stacked in sequence from the inside out. The material of the inner layer 1111 may be PTFE or the like, the material of the middle layer 1112 may be 304 stainless steel or the like, and the material of the outer layer 1113 may be PI. The distal outer tube 112 is a single-layer structure, and the material may be Pebax or the like.

[0042] That is to say, the proximal outer tube 111 of this embodiment adopts a three-layer structure design. The inner layer 1111 is made of PTFE material, the middle layer is made of stainless steel braided wire, and the outer layer 1113 is a three-layer outer tube made of PI material. Such a setting can enhance the support strength of the proximal end of the catheter, contribute to further improving the overall pushing performance of the catheter, make the inner cavity more lubricated, and can reduce the resistance between the catheter and the outer tube during high-speed rotation.

[0043] In this embodiment, referring to Figures 1 to 3 , the OCT imaging catheter further includes a protective cap 30, a connection seat 40, a stress buffer tube 50, a pull-back mark 71, a lens mark 72, a connection seat sheath 60, an axis mark band 73, etc. Among them, the protective cap 30 is used to protect the proximal end of the OCT imaging catheter when the OCT imaging catheter is not plugged into the host. The connection seat 40 is similar to a handle for convenient hand operation. The stress buffer tube 50 is used for buffering when the catheter enters the blood vessel and is advanced. The proximal outer tube 111 is the proximal part entering the human body. The distal outer tube 112 is the distal part entering the human body. The guide wire head 102 is used to guide the catheter body 10 to the target position in the blood vessel. The pull-back mark 71 and the lens mark 72 are used to observe the position of the catheter. The spring tube 103 is used to drive the imaging probe 20 to rotate and pull back. The lens 202 is used to emit laser for imaging, and may be composed of the end of the optical fiber 201 or a lens provided on the optical fiber 201. The connection seat sheath 60 is used to protect the connection seat 40. The axis mark band 73 is used to mark the proximal position of the catheter.

[0044] Furthermore, the effective length of the catheter can be set to 1850 ± 50 mm, and the effective length is the length that can enter the body. The length of the hydrophilic coating is the length of entering the blood vessel, which is 1500 ± 50 mm, and the length of the hydrophilic coating is the distance between the axis mark band 73 and the farthest end of the OCT imaging catheter. The length of the imaging window 1121 is the distance of the probe pull-back, which can be set to 100 ± 5 mm, and the outer diameter of the imaging window 1121 (the outer diameter of the outer catheter 101 where the imaging window 1121 is located) can be set to 0.46 ± 0.03 mm. The maximum outer diameter of the catheter insertion part can be set to 0.46 ± 0.03 mm. The distance between the pull-back mark 71 and the lens mark 72 can be 40 ± 3 mm or 60 ± 3 mm. The length from the lens 202 to the farthest end of the catheter can be set to 20 + 0 or -3 mm. The length of the guide wire head 102 can be set to 15 ± 3 mm.

[0045] It should be noted that blood is composed of plasma and blood cells, and plasma accounts for about 55%, and water accounts for 90% of plasma. In order to reduce friction during the operation, in this embodiment, a hydrophilic coating is applied to the outer periphery of the outer catheter 101 of the OCT imaging catheter; the hydrophilic coating can be applied by dip coating with a hyaluronic acid (HA)-based solution and then thermally cured. When physiological saline is continuously applied to the hydrophilic coating during the insertion into the blood vessel, the frictional force between the catheter and the blood is significantly reduced, greatly enhancing the smoothness of the catheter.

[0046] Mainly referring to Figure 7 , in one embodiment, the proximal outer tube 111 is provided with a sunk section 1131 on the outer surface at its connection with the distal outer tube 112, and the distal outer tube 112 is provided with a mating section 1132 on the inner surface at its connection with the proximal outer tube 111, which is adapted to the sunk section 1131. The mating section 1132 is arranged around the sunk section 1131 and fixed by welding or bonding.

[0047] In this embodiment, the proximal outer tube 111 and the distal outer tube 112 adopt a unique welding process. While ensuring the strength of the connection between the two outer tubes, it also ensures that the outer diameter of the welded part does not exceed the outer diameters of the proximal outer tube 111 and the distal outer tube 112. Specifically, mechanical stripping is adopted at the connection of the proximal outer tube 111 and the distal outer tube 112. The outer surface of the tube of the distal part of the proximal outer tube 111 with a length of about 6 - 7 mm is uniformly stripped by about 1 / 2 of the wall thickness to form an outer stepped shape, that is, the above-mentioned sunk section 1131; the inner surface of the tube of the proximal part of the distal outer tube 112 with a length of about 6 - 7 mm is uniformly stripped by about 1 / 2 of the wall thickness to form an inner stepped shape, that is, the above-mentioned mating section 1132. After stripping the outer layer 1113 of the proximal outer tube 111 and the inner layer 1111 of the distal outer tube 112, it is connected by hot melting or gluing. The difference between the stripping thickness of the inner layer 1111 of the distal outer tube 112 and the stripping thickness of the outer layer 1113 of the proximal outer tube 111 is equal to the gluing thickness. At this time, the smoothness of the catheter after gluing the proximal and distal outer tubes 112 can be ensured, and at the same time, the size of the connection part does not become larger. Such a setting can make the outer diameter of the application section of the catheter smaller and the passability better in clinical applications.

[0048] In addition, in some embodiments, the OCT imaging catheter may further include a guiding tube, which is used to guide the catheter body 10 to the target position in the blood vessel. Specifically, the guiding tube can assist the guide wire head 102 at the distal end of the catheter body 10 to smoothly enter other instruments and can provide support for the pushing of the catheter body 10. The material of the guiding tube is PTFE, etc.; the outer diameter can be 1.35 ± 0.05 mm, and the inner diameter can be 0.75 ± 0.05 mm, which is not limited here.

[0049] In summary, in the present invention, by filling the inner cavity of the catheter body 10 with liquid, the smoothness of the rotation and retraction of the lens 202 and the imaging quality are ensured; by providing the lens protection member 204 for the lens 202, the lens 202 is protected from damage; in the present invention, the proximal outer tube 111 is designed with a three-layer structure, ensuring the rigidity of the outer tube and facilitating the pushing into the blood vessel; in the present invention, the proximal outer tube 111 and the distal outer tube 112 adopt welding or bonding technology, which can ensure the passageability of the catheter; in addition, the design of the spring tube 103 and the visualization ring 104 ensures that the diameter of the catheter is small.

[0050] The above are only optional embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. An OCT imaging catheter, characterized in that, Comprising: A catheter body having a lumen formed therein, with an imaging window provided at the distal end of the catheter body and a filling space located within the imaging window; An imaging probe movably inserted into the lumen and extending into the filling space at the imaging window; And A filling liquid filled in the filling space.

2. The OCT imaging catheter according to claim 1, wherein The filling liquid is a viscous liquid.

3. The OCT imaging catheter according to claim 1, wherein The catheter body includes an outer sleeve, a guide wire head, and a spring tube. The guide wire head is provided at the distal end of the outer sleeve. The spring tube is sleeved around the outer periphery of the imaging probe and is used to drive the imaging probe to perform a rotational retraction movement under the drive of an external force. The filling space is formed by surrounding the outer sleeve, the guide wire head, and the spring tube.

4. The OCT imaging catheter according to claim 3, wherein, The spring tube includes an inner layer tube, an outer layer tube, and a developing ring. The outer layer tube is provided on the outer periphery of the inner layer tube, and a peeling portion is provided on the outer layer tube. The developing ring is provided within the peeling portion.

5. The OCT imaging catheter according to claim 3, wherein The imaging probe includes an optical fiber, a lens, and a light output control member. The lens is provided at the distal end of the optical fiber. The light output control member is provided on the lens and is used to control the light output direction and protect the lens.

6. The OCT imaging catheter according to claim 5, wherein, The imaging probe further includes a protective member. The protective member covers the outer periphery of the lens and is connected to the spring tube. The protective member is used to protect the lens. A coating layer is coated on the protective member, and the material of the coating layer is polyimide.

7. The OCT imaging catheter according to claim 5, wherein On the surface of the light output control member, a first material layer, a second material layer, a third material layer, and a fourth material layer are sequentially provided from the inside to the outside. The material of the first material layer is high-elastic polyurethane, the material of the second material layer is polyimide nanofiber, the third material layer is a shape memory alloy wire spiral winding structure, and the material of the fourth material layer is a biocompatible material.

8. The OCT imaging catheter according to claim 6, wherein The light output control member is a heat-shrinkable tube; and / or The protective member is a crystal head.

9. The OCT imaging catheter according to claim 3, wherein The outer sleeve includes a proximal outer tube and a distal outer tube connected to the proximal outer tube; and / or The proximal outer tube includes an inner layer, a middle layer, and an outer layer sequentially stacked from the inside to the outside. The material of the inner layer is PTFE, the material of the middle layer is 304 stainless steel, and the material of the outer layer is PI; and / or The material of the distal outer tube is Pebax.

10. The OCT imaging catheter according to claim 9, characterized in that, A sunk platform section is provided on the outer surface of the proximal outer tube at the connection thereof with the distal outer tube. A mating section adapted to the sunk platform section is provided on the inner surface of the distal outer tube at the connection thereof with the proximal outer tube. The mating section surrounds the sunk platform section and is fixed by welding or bonding.

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