Optical fiber balloon catheter

Abstract

The invention discloses an optical fiber balloon catheter, and relates to the technical field of medical instruments. Comprising a catheter, a balloon arranged at the tail end of the catheter, an optical fiber penetrating through the catheter and extending into the balloon, a dodging pipe fitting and a sleeve. The light uniformizing pipe fitting axially extends along the interior of the balloon, is provided with a near end and a far end which are opposite to each other, and is used for scattering light emitted by the optical fiber to realize uniform illumination; the sleeve is connected to the near end of the dodging pipe fitting and sleeved outside the optical fiber, and comprises a central positioning part formed on the through hole of the sleeve; the centering positioning part is used for positioning the optical fiber penetrating through the centering positioning part on the central axis of the dodging pipe fitting; wherein the optical fiber is inserted into the near end of the dodging pipe fitting on the central axis of the dodging pipe fitting after penetrating through the central positioning part of the sleeve, and an optical fiber section located in the dodging pipe fitting is provided with a light emitting part. The optical fiber can be centered and positioned in the dodging pipe fitting, and local overheating of the dodging pipe is prevented.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a fiber optic balloon catheter. Background Technology

[0002] In the field of interventional therapy, integrating optical fibers into balloon catheters for photodynamic therapy or illumination has become an important development direction. To improve the uniformity of light energy distribution, a beam homogenizing tube is sometimes installed inside the balloon. However, in practical applications, the radial position of the optical fiber within the beam homogenizing tube may be off, resulting in a situation where the optical fiber is closer to the tube wall on one side and farther away on the other. This off-center arrangement can cause significant heat accumulation in the closer tube wall area due to continuous high-density light radiation, potentially leading to localized overheating and subsequent melting, carbonization, or even ablation of the tube wall material, affecting the safety and reliability of the device. Summary of the Invention

[0003] This application aims to at least solve one of the technical problems existing in the prior art. To this end, this application proposes a fiber optic balloon guide tube that can achieve centered positioning of the optical fiber within a beam homogenizing tube, thereby preventing local overheating of the beam homogenizing tube.

[0004] The fiber optic balloon catheter provided according to the embodiments of this application includes a catheter, a balloon disposed at the end of the catheter, and an optical fiber passing through the catheter and extending into the balloon;

[0005] The fiber optic balloon catheter also includes:

[0006] A light-diffusing tube extends axially along the interior of the balloon and has opposing proximal and distal ends for scattering the light emitted by the optical fiber to achieve uniform illumination.

[0007] A sleeve, connected to the near end of the light-diffusing tube and sleeved on the outside of the optical fiber, includes a central positioning part formed on the through hole of the sleeve; the central positioning part is used to position the optical fiber passing through it on the central axis of the light-diffusing tube.

[0008] Wherein, after the optical fiber passes through the central positioning part of the sleeve, it is inserted into the near end of the light-diffusing tube on the central axis of the light-diffusing tube, and the optical fiber segment located in the light-diffusing tube has a light-emitting part.

[0009] The fiber optic balloon catheter according to the embodiments of this application has at least the following beneficial effects: by setting a sleeve with a central positioning part, mechanical constraint and stable centering of the radial position of the optical fiber can be achieved in the light-uniform tube, thereby effectively ensuring that the optical fiber is on the central axis of the light-uniform tube section, avoiding local photothermal accumulation in the tube wall due to optical fiber eccentricity, fundamentally preventing local overheating, melting or ablation of the light-uniform tube, and significantly improving the working safety and long-term reliability of the device.

[0010] According to some embodiments of this application, the sleeve further includes a stress-dispersing portion formed on its outer surface, the stress-dispersing portion extending from the optical fiber side to the light-diffusing tube side, the diameter of which gradually increases from the diameter of the optical fiber to the diameter of the light-diffusing tube.

[0011] According to some embodiments of this application, the central positioning part is a through-hole section; at least two target positions of the through-hole section are equal in size to the diameter of the optical fiber, and the central axis of the through-hole at the at least two target positions coincides with the central axis of the light-diffusing tube, so as to support and position the optical fiber on the central axis of the light-diffusing tube and restrict the radial movement of the optical fiber; wherein, the longest axial distance between the target positions is 3 to 100 times the diameter of the optical fiber.

[0012] According to some embodiments of this application, the centering positioning part and the stress dispersion part are respectively formed on the through hole of the first pipe section and the outer surface of the second pipe section; the first pipe section and the second pipe section are two sections connected axially to the casing, and the second pipe section is located between the first pipe section and the light-diffusing fitting, and is connected to the light-diffusing fitting.

[0013] According to some embodiments of this application, the centering positioning portion and the stress dispersing portion are respectively formed on the through hole and the outer surface of the same axial section of the sleeve.

[0014] According to some embodiments of this application, the outer surface of the sleeve is funnel-shaped, and the funnel-shaped outer surface is the stress dispersion part.

[0015] According to some embodiments of this application, the axial cantilever length of the optical fiber on the side of the uniform light tube is less than 100 times the diameter of the optical fiber.

[0016] According to some embodiments of this application, the distal end of the light-diffusing tube is connected to the balloon.

[0017] According to some embodiments of this application, the light-diffusing tube is located on the central axis of the balloon.

[0018] According to some embodiments of this application, the light-diffusing tube segment includes a light-diffusing material filled therein, the optical fiber is inserted into the light-diffusing material, and the end of the optical fiber is located near the end of the light-diffusing tube, the end face of the optical fiber being the light-emitting part.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The present application will be further illustrated below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments illustrated in the following drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application.

[0021] Figure 1 This is one of the structural schematic diagrams of the fiber optic balloon catheter according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the internal structure of the fiber optic balloon according to an embodiment of this application;

[0023] Figure 3 This is a cross-sectional view of the light-diffusing tube segment according to an embodiment of this application;

[0024] Figure 4 This is one of the structural schematic diagrams of the sleeve in the embodiments of this application;

[0025] Figure 5 This is a second schematic diagram of the sleeve structure in an embodiment of this application;

[0026] Figure 6 This is the third schematic diagram of the sleeve structure in the embodiments of this application;

[0027] Figure 7 This is the fourth schematic diagram of the sleeve structure in the embodiments of this application;

[0028] Figure 8 This is the fifth schematic diagram of the sleeve structure in the embodiments of this application;

[0029] Figure 9 This is the sixth schematic diagram of the sleeve structure in the embodiments of this application;

[0030] Figure 10 This is one of the schematic diagrams illustrating the fiber optic cantilever length in an embodiment of this application;

[0031] Figure 11 This is a second schematic diagram of the fiber optic cantilever length in an embodiment of this application;

[0032] Figure 12 This is the second schematic diagram of the fiber optic balloon catheter according to an embodiment of this application;

[0033] Figure 13 This is the third schematic diagram of the fiber optic balloon catheter in the embodiments of this application.

[0034] Figure label:

[0035] 1. Catheter; 2. Balloon; 3. Light-diffusing fitting; 4. Optical fiber; 5. Drug coating; 6. Imaging ring; 7. First guidewire port; 8. Second guidewire port; 9. Third guidewire port; 10. Fourth guidewire port; 11. Fluid filling port;

[0036] 31. Light-diffusing material; 32. Tube wall of uniform light tube section; 33. Positioning section; 121. Central positioning part; 122. Stress dispersion part; 123. First tube section; 124. Second tube section; 311. First step; 312. Second step. Detailed Implementation

[0037] The embodiments of this application are described in detail below with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0038] In the description of this application, it should be understood that the terms "center", "middle", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0039] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0040] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] In the description of this application, the use of terms such as "one embodiment," "some embodiments," "an example," "some instances," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] In some phototherapy or lighting applications, such as balloon catheters coated with drugs for vascular repair, a uniform light field distribution is often required inside the balloon catheter. To achieve this uniform light field, this application incorporates a homogenizing tube within the balloon. This homogenizing tube extends axially inside the balloon. On one hand, it provides uniform axial illumination; on the other hand, its diameter is larger than that of the optical fiber, thus expanding the illumination area to some extent radially within the balloon. The optical fiber is inserted into the homogenizing tube to provide a light source. However, during fiber insertion, deviations can occur, resulting in the fiber not being centered within the tube. This leads to the fiber being closer to one side of the tube wall than the other. This eccentric arrangement can cause excessively high temperatures on the side closer to the fiber, potentially leading to melting, carbonization, or even ablation of the tube wall material at that location, posing a safety hazard.

[0043] This application provides an optical fiber balloon catheter to address the aforementioned problems by setting a centering positioning structure on the light-diffusing tube to ensure the centering of the optical fiber.

[0044] See appendix Figure 1 and attached Figure 2 The fiber optic balloon catheter provided in this embodiment includes a catheter 1, a balloon 2 disposed at the end of the catheter 1, an optical fiber 4 passing through the catheter 1 and extending into the balloon 2, a light-diffusing tube 3, and a sleeve 12 connected to the proximal end of the light-diffusing tube 3 and sleeved outside the optical fiber 4. The light-diffusing tube 3 extends axially along the interior of the balloon 2 and has axially opposite proximal and distal ends, used to scatter the light emitted by the optical fiber 4 to achieve uniform illumination. The sleeve 12 includes a central positioning portion formed on a through-hole of the sleeve 12, used to position the optical fiber 4 passing through it on the central axis of the light-diffusing tube 3. After the optical fiber 4 passes through the central positioning portion of the sleeve 12, it is inserted into the proximal end of the light-diffusing tube 3 on the central axis of the light-diffusing tube 3. It can be understood that the optical fiber segment located within the light-diffusing tube 3 has a light-emitting portion.

[0045] In this embodiment, the optical fiber is centered and positioned by the sleeve and its centering part before entering the light-diffusing tube. Compared with the method of directly inserting the optical fiber into the diffusion material in the light-diffusing tube (the diffusion material plays both the role of light diffusing and fixing), this embodiment can avoid the optical fiber from being biased in the light-diffusing tube, thereby avoiding the danger of the light-diffusing tube being overheated and burned.

[0046] In some embodiments, the central positioning part is a through-hole section; at least two target positions of the through-hole section are equal in size to the diameter of the optical fiber, and the central axis of the through-hole at at least two target positions coincides with the central axis of the light-diffusing tube, so as to support and position the optical fiber on the central axis of the light-diffusing tube and restrict the radial movement of the optical fiber.

[0047] Furthermore, in one example, see Figure 5 In the axial direction of the through hole section 121, there are at least two target positions 13 spaced apart from each other. A hole diameter matching the diameter of the optical fiber 4 is machined at the target position 13, and the central axis of the through hole at the target position coincides with the central axis of the light-diffusing tube 3. In this way, the target position 13 constitutes the central positioning fulcrum for the optical fiber 4.

[0048] This solution employs the geometric principle of "two points determine a straight line." By ensuring the diameter of the through-holes at at least two positioning points and the central axis they define, even if the inner diameter of the tube section between the two points is large (to facilitate fiber insertion, reduce friction, or simplify manufacturing), the direction and exit position of the optical fiber can be precisely constrained. This reduces the stringent requirements for the consistency of the entire centering positioning section's processing, simplifying the manufacturing process, reducing costs, and improving the smoothness of fiber insertion while maintaining final positioning accuracy.

[0049] It should be noted that the term "target" in "target location" used in this article is a descriptive term intended to refer to any location and does not imply any technical limitation or special meaning.

[0050] See another example. Figure 4 The aforementioned through-hole section 121 is a through-hole with a constant inner diameter. This means that any position within this constant inner diameter is the target position. The inner diameter D1 of this section is equal to the outer diameter D2 of the cladding of the selected optical fiber 4, achieving size matching. Here, "equal in size" means that they are essentially equal; D1 can be slightly larger than D2 to ensure smooth insertion, while also ensuring that the geometric axis of this constant-diameter cavity coincides with the geometric axis of the light-diffusing tube 3.

[0051] See Figure 4 In the through-hole section, fiber 4 is completely contained and guided, and any radial displacement tendency is limited by the tube wall. This scheme has a simple structure and direct positioning effect.

[0052] This embodiment requires no external sensors or adjustment mechanisms, relying solely on the inherent properties of the mechanical structure for positioning. It boasts high reliability, strong anti-interference capabilities (unaffected by vibration or bending during use), and enables low-cost, high-volume production.

[0053] In some embodiments, the longest axial distance L between target positions (the portion that actually serves as an effective centering constraint) in the above embodiments is 3 to 100 times the fiber diameter D2.

[0054] It should be noted that the longest axial distance refers to, for example, such as... Figure 5 As shown, the through-hole section includes three target positions spaced a certain distance apart. The "longest axial distance between target positions" refers to the axial distance between the two positions with the greatest axial distance among the three target positions 13. If the above-mentioned through-hole section is a through-hole with a constant diameter, the "longest axial distance between target positions" refers to the axial length of the above-mentioned through-hole section.

[0055] The aforementioned numerical range achieves an optimal balance between positioning stability and operational convenience. If the length is too short (e.g., less than 3d), the guiding constraint is insufficient, and the optical fiber may still deflect or shift at the exit point due to minor disturbances, affecting positioning reliability. If the length is too long (e.g., exceeding 100d), it unnecessarily increases the frictional resistance during fiber insertion, making assembly difficult and increasing unnecessary tube length and material costs. A range of 3d to 100d provides sufficiently stable guiding while maintaining good feasibility in the assembly process. In some embodiments, the aforementioned numerical range is preferably 30d to 80d.

[0056] In some embodiments, the axial cantilever length of the optical fiber 4 on the side of the beam homogenizing tube is less than 100 times the diameter of the optical fiber 4. In other embodiments, the axial cantilever length of the optical fiber 4 on the side of the beam homogenizing tube is less than 200 times the diameter of the optical fiber 4.

[0057] Understandably, see Figure 10 and Figure 11 The aforementioned cantilever length refers to the distance ΔL from the end of the effective centering constraint of the centering position to the end of the optical fiber on one side of the light-diffusing tube after the optical fiber exits from the centering position.

[0058] The aforementioned range of ΔL values ​​balances the positioning stability of the fiber optic emitter within the beam homogenizer with the integrity of the optical field morphology. Specifically, limiting the cantilever length of the fiber prevents it from bending and deviating from the axis during use due to excessive length, which could lead to optical field asymmetry, localized energy concentration, or uneven heating of the beam homogenizer. A cantilever length less than 100 times the fiber diameter achieves better centering.

[0059] Understandably, the cantilever length must ensure that the optical fiber can be inserted into the light-diffusing material of the uniform light tube.

[0060] In some embodiments, the sleeve 12 further includes a stress-dispersing portion 122 formed on its outer surface. Specifically, the stress-dispersing portion 122 has an outer contour whose diameter gradually increases from the optical fiber diameter to the diameter of the beam homogenizing tube from the near end to the far end; strictly speaking, it gradually increases from the optical fiber diameter plus the sleeve wall thickness to the outer diameter of the beam homogenizing tube. Its large-diameter end is connected to the beam homogenizing tube 3, and the optical fiber is inserted from its small-diameter end. This stress-dispersing portion makes the mechanical transition between the optical fiber 4 and the beam homogenizing tube 3 smoother, thereby effectively dispersing the stress concentration caused by tube bending or external loads at the connection point, reducing the risk of local fracture, and improving the reliability and service life of the overall structure.

[0061] It should be noted that in this application, the proximal end refers to the end closer to the operator, and the distal end refers to the end farther away from the operator.

[0062] In some embodiments, the stress-dispersing portion in the above embodiments may be funnel-shaped or horn-shaped. That is, its outer surface is a continuous, outwardly expanding curved or conical surface, similar to the opening shape of a horn.

[0063] The trumpet shape is an ideal geometry for achieving smooth stress transition. Its continuous curvature variation makes the force transmission path most fluid and the stress concentration factor minimal. In addition, this shape is relatively easy to achieve in mold making (such as injection molding and blow molding) or thermal processing (such as glass stretching).

[0064] In some embodiments, such as Figures 4 to 6 As shown, the centering positioning part 121 and the stress dispersing part 122 are respectively formed on the through hole of the first pipe section 123 and the outer surface of the second pipe section 124; the first pipe section 123 and the second pipe section 124 are two sections connected axially in the casing; the second pipe section 124 is located between the first pipe section and the light-diffusing fitting and is connected to the light-diffusing fitting.

[0065] It should be noted that this application's Figure 4 and Figure 5 The illustration of the centering and stress-dispersing parts is merely illustrative and ignores the wall thickness of the sleeve.

[0066] In other embodiments, such as Figure 7 As shown, the centering positioning part 121 and the stress dispersing part 122 are respectively formed on the through hole and the outer surface of the same axial section of the sleeve.

[0067] It should be noted that the diameter of the stress-dispersing part 122 is gradually changing, and there is no constant diameter surface that maintains the fiber diameter at the near end.

[0068] As understood in the above embodiments, the cantilever length cannot be too short (the optical fiber needs to be able to extend into the beam-diffusing tube) nor too long (excessive length can easily cause bending and deviation from the central axis). Therefore, the closer the centering positioning part is to the beam-diffusing tube in the axial direction, the better. However, the stress-dispersing part also needs a certain length in the axial direction to form its stress-dispersing surface; otherwise, the stress-dispersing effect will be poor. Therefore, we need to consider both the axial distance between the centering positioning part and the beam-diffusing tube, and the axial length requirement of the stress-dispersing part. This embodiment integrates the centering positioning part and the stress-dispersing part into the same axial section of the sleeve, allowing the positioning constraint point (centering positioning part) to be set extremely close to the beam-diffusing tube, thereby controlling the cantilever length ΔL within an ideal range. Simultaneously, the stress-dispersing part obtains the necessary axial extension space within this section, ensuring its mechanical properties.

[0069] In some embodiments, see Figure 6 The sleeve 12 is not made of solid tubing, but is made of a continuous metal filament (such as medical stainless steel wire or nickel-titanium wire) or a high-strength polymer monofilament spirally wound.

[0070] This spiral winding structure has several advantages. First, it possesses sufficient rigidity and roundness to constrain the optical fiber and achieve positioning. Second, the winding structure has a certain degree of elasticity, allowing it to better adapt to the optical fiber and providing some resistance to impact and fretting wear.

[0071] It should be noted that the final external dimensions of the spiral wound structure and the internally defined aperture dimensions comply with the description in the foregoing embodiments, that is, the internally defined aperture dimensions may include aperture dimensions for centering positioning, and the outer contour has a gradual transition dimension that can reduce or eliminate stress.

[0072] The spiral winding structure is spirally wound from the near end to the far end. The last turn, which is connected to the light-diffusing tube 3, is no longer located on the same plane, that is, it no longer has the tendency to extend axially. The last turn is circumferentially connected to the outer wall of the light-diffusing tube 3.

[0073] In some embodiments, see Figure 8 and Figure 9 The first segment 123 and the second segment 124 of the sleeve 12 can be stepped rather than continuously gradual. For example, its proximal portion maintains a small outer diameter (first step 311), and at a certain position in the axial direction, the outer diameter suddenly increases to be equal to the outer diameter of the uniform light segment (second step 312), forming a clear stepped connection.

[0074] Stepped transitions are a common method of change in mechanical design, with their biggest advantage being ease of manufacturing. For example, they can be achieved by butt-welding, bonding, or mechanically pressing two sections of pipe with different diameters together. While not as effective as a smooth, gradual transition in terms of stress dispersion, it is reliable enough for many applications with low stress levels. This approach offers more flexible and potentially lower-cost manufacturing options, especially when using specific materials that are difficult to process gradually.

[0075] Furthermore, in some embodiments, the two pipe segments forming the step can be obtained separately by injection molding, and then connected by welding, bonding or mechanical pressing. For details, see [link to documentation]. Figure 8 The two pipe sections can be directly connected at the end face, see [reference]. Figure 9 Alternatively, slots matching the outer diameter of smaller pipe sections can be formed on larger outer diameter pipe sections. The smaller outer diameter pipe sections are inserted into the slots, and then the connection is achieved through welding, bonding, or mechanical pressing. Of course, there are other connection and implementation methods, and this invention does not limit them.

[0076] In some embodiments, the sleeve 12 and the light-diffusing fitting 3 can be two independently manufactured parts. They are made of the same or different materials and are manufactured by processes suitable for their respective structures, such as machining, injection molding, and drawing. Then, they are firmly combined at the interface into a single light-diffusing fitting by precision welding (such as laser welding), bonding (medical-grade UV adhesive or epoxy resin), interference fit, or other methods.

[0077] Separate manufacturing offers greater freedom in design and material selection. For example, the central positioning section can be made of materials such as metal, which are readily available for achieving high dimensional accuracy and wear resistance; while the light-diffusing section can be made of polymers or special glass with excellent optical properties (such as high light transmittance and high diffuse scattering). By manufacturing each section using optimal processes and then connecting them reliably, optimal mechanical and optical properties can be achieved comprehensively.

[0078] In some embodiments, the uniform light distribution tube can be integrally formed from a prefabricated tube (such as a quartz glass tube or a polycarbonate tube) with a uniform initial material and consistent outer diameter through a thermal processing process. Specifically, the tube is locally heated and subjected to axial tension. The heated portion is stretched and thinned to form a centrally positioned tube segment with a smaller outer diameter and a correspondingly reduced inner diameter; the portion that is not stretched or is stretched only slightly retains its original diameter, becoming the uniform light distribution tube segment. The stretching process can control the final shape and size using a die.

[0079] One-piece molding eliminates any mechanical connection interfaces, achieving a seamless transition. This results in maximum structural integrity, completely avoiding potential breakage, leakage, or optical distortion issues at joints. The hot-stretching process produces microchannels with extremely smooth inner walls, significantly reducing friction during fiber insertion. Furthermore, this process is ideally suited for manufacturing minute, intricately structured medical device components.

[0080] In some embodiments, an efficient mass production method is provided for sleeves made of polymer materials. The sleeves can be manufactured using an injection molding process. Using a high-precision mold, tube segments with complex geometries, including their precise inner bores, flared outer contours, and all structural details, are formed in a single injection molding machine.

[0081] Injection molding is a standard and efficient process for the mass production of plastic parts. It can reproduce complex and dimensionally precise parts in large quantities with extremely low unit cost and extremely high production efficiency.

[0082] In some embodiments, the sleeve and the beam-diffusing fitting are made of the exact same material. For example, both are fused silica glass, or both are made of the same medical-grade optical polymer (such as polymethyl methacrylate PMMA, polycarbonate PC, or cyclic olefin copolymer COC).

[0083] Using the same materials ensures that the two parts have completely identical coefficients of thermal expansion. When the temperature changes (such as during sterilization or when there is a temperature difference between the inside and outside of the body), the two expand or contract synchronously, without generating thermal stress at the joint, thus avoiding deformation, cracking, or deterioration of optical performance caused by thermal stress.

[0084] In some embodiments, the optical fiber emits light from its end face (e.g., directly from the fiber end face). We define the axial distance from the emitting end face of the optical fiber to the far-end exit plane of the effective positioning area of ​​the centered positioning tube segment as the working distance ΔL. See also Figure 10 and Figure 11 In this embodiment, ΔL < 100d, where d is the cladding diameter of the optical fiber, and the optical fiber diameter is approximately 0.1 mm. In other embodiments, ΔL < 200d is sufficient.

[0085] The optical fiber is constrained and centered within the central positioning section. Once it leaves this section, the constraint disappears. If the working distance ΔL is too large, the unconstrained fiber segment becomes a free cantilever, which may experience slight bending or vibration under external disturbances, causing its end face (light emission point) to deviate from the theoretical centerline, thus compromising the positioning effect. Limiting the length of the free segment minimizes the uncertainty in the position of the light emission point, ensuring the stability of the optical axis at the entrance of the uniform beam section. Limiting ΔL to within 100 times the diameter yields even better centering results.

[0086] In some embodiments, the tube wall 31 of the light-diffusing tube 3 is a light-transmitting tube wall. For example, the light-transmitting tube wall is made of a transparent material, or it has multiple evenly distributed light-transmitting holes.

[0087] The light-scattering material 32 may comprise a transparent or translucent matrix, such as an epoxy resin adhesive containing light-scattering particles, and the matrix must be substantially transparent to the wavelength spectrum of the light to be emitted. The light-scattering particles may be titanium dioxide particles, etc.

[0088] In some embodiments, the installation method of the uniform light tube 3 is limited in order to improve the stability of the entire light emission system within the flexible spherical cavity.

[0089] Specifically, see Figure 1 The end of the light-diffusing tube 3 furthest from the catheter inlet (i.e., the distal end of the light-diffusing tube segment) is fixedly connected to the inner wall of the balloon. The connection point is usually selected at the distal sealing part of the balloon or on the side wall near the distal end. The connection method can be medical-grade adhesive bonding, thermoforming welding, etc.

[0090] Because balloon 2 may bend during delivery and needs to be inflated during operation, these factors cause dynamic changes in the shape and position of balloon 2. Fixing the distal end of the homogenizing tube 3 is equivalent to establishing a stable optical support inside balloon 2. This ensures that the coaxial relationship between the fiber optic cable and the homogenizing tube 3, established by the homogenizing tube 3, can maintain a preset relative position with balloon 2 as a whole, preventing it from swinging freely. This ensures that regardless of the shape of balloon 2, the illumination area always maintains the expected consistency with the balloon wall, greatly improving the reliability and repeatability of treatment.

[0091] In some embodiments, the beam homogenizing tube 3 is designed and installed on the geometric central axis of the internal space of the balloon 2. This means that not only is the optical fiber 4 centered inside the beam homogenizing tube 3, but the entire beam homogenizing tube 3 itself is also located in the center of the balloon 2.

[0092] This embodiment achieves global coaxiality from the microscopic (optical fiber inside the tube) to the macroscopic (tube inside the balloon). When the homogenizing tube 3 (containing a centrally located optical fiber) is coaxial with the balloon 2, the annular symmetrical light field scattered from the homogenizing tube 3 will radiate uniformly to the entire inner wall of the balloon 2, with the central axis of the balloon 2 as the reference. This provides an ideal geometric basis for achieving completely uniform circumferential illumination or photodynamic therapy after balloon 2 expansion, and is particularly suitable for applications requiring uniform energy distribution across the entire area, such as circumferential plaque irradiation of blood vessels.

[0093] In some embodiments, the light-diffusing tube segment 3 includes a light-diffusing material filling its interior. An optical fiber is inserted into the light-diffusing material, with the end of the optical fiber located near the proximal end of the light-diffusing tube segment 3. The length of the inserted optical fiber segment 3 can be 1-2 mm. The end face of the optical fiber segment 3 emits light, which is the light-emitting part. In other embodiments, the optical fiber inserted into the light-diffusing tube segment 3 can be longer, or it can emit light circumferentially.

[0094] The internal light-diffusing medium of the uniform light tube 3 is an optical gel, silicone or cured resin, and high-refractive-index, chemically stable micro-scattering particles, such as titanium dioxide (TiO2), barium sulfate (BaSO4) or aluminum oxide (Al2O3) nano / micro particles, are uniformly dispersed therein.

[0095] The filled-in homogenization method can achieve near-ideal Lambertian (perfectly diffuse reflector) light emission effects. After entering the filling medium, the light is randomly scattered countless times by scattering particles, and finally radiates uniformly from the outer surface of the homogenizing tube. This method has high homogenization efficiency, uniform brightness of the emission surface, and can provide excellent illumination or therapeutic light field quality. The medium itself can also serve to fix the fiber end, buffer stress, and even assist in heat dissipation.

[0096] In some embodiments, see Figure 1 The outer surface of balloon 2 is coated with a drug coating 5. This drug coating 5 is a drug that requires irradiation with light of a specific wavelength to activate or accelerate its release, thereby exerting a therapeutic effect on target tissues such as the vascular endothelium. An optical fiber is placed inside the catheter, with its distal luminescent portion extending into the balloon. The emitted light can irradiate the inner wall of balloon 2 and act on the drug coating on the outer surface through the balloon wall to achieve photoactivated or photocontrolled drug release therapy.

[0097] In some embodiments, see Figure 2 The light-diffusing tube 3 includes a positioning section 33 at its distal end. The distal end of the positioning section 33 is reliably connected to the inner wall of the balloon 2 (especially at the distal apex or a specific position on the side wall) by means of medical adhesive, thermofusion welding or mechanical fastening.

[0098] In addition, an X-ray-opaque imaging ring 6 can be fitted or embedded on this positioning segment 33. This imaging ring 6 is clearly visible under X-ray fluoroscopy, which facilitates the surgeon to determine the specific position of the distal end of the balloon 2 and the light-diffusing tube 3 in the blood vessel in real time and accurately during the operation, so as to achieve more precise positioning and treatment.

[0099] In some embodiments, the proximal end of the catheter 1 is provided with a liquid filling port 11, through which liquid is injected into the balloon to inflate the balloon.

[0100] In some embodiments, to ensure that the guidewire delivery function does not interfere with the optical treatment environment inside the balloon, a variety of guidewire paths are designed, with the common principle being that the guidewire does not pass through the internal cavity of the balloon.

[0101] Path 1: See Figure 12 This design is suitable for operational scenarios requiring rapid guidewire exchange. The guidewire enters the catheter wall at the fourth guidewire port 10 in the proximal region of the catheter (e.g., the outer tube sidewall near the handle). Subsequently, the guidewire extends distally within the catheter wall, exiting the catheter at the third guidewire port 9 on the catheter sidewall near the proximal region of the balloon, just before reaching but not yet entering the balloon. At this point, the guidewire is outside the catheter. The guidewire adheres to the outer surface of the balloon and continues to extend distally, crossing the balloon. At the second guidewire port 8 on the catheter sidewall on the distal side of the balloon, the guidewire re-enters the catheter wall. Finally, the guidewire exits from the first guidewire port 7 at the distal end of the catheter (typically located at the catheter tip). In this path, the guidewire only adheres to the outside of the balloon for a short distance, without affecting the optical components and light field inside the balloon.

[0102] Path 2: See Figure 13 This design is more concise. The guidewire does not pass through the proximal regions of the catheter and balloon. During the procedure, the guidewire is inserted directly into the guidewire lumen inside the catheter through the second guidewire port 8 on the side wall of the catheter (or tip tube) on the distal side of the balloon, and then immediately exits from the first guidewire port 7 at the distal end of the catheter. This design also achieves the goal of the guidewire not entering the balloon lumen and has the advantage of structural simplicity.

[0103] The aforementioned guidewire path design, through a clever "insertion-exit-external passage-re-insertion" or "direct distal insertion" method, completely avoids the need for the guidewire to pass through the balloon's working chamber. This avoids the risk of physical obstruction, scratching, or collision of the guidewire with the light-monitoring device; it also prevents the guidewire from blocking or scattering the treatment light, ensuring a complete and uniform light field; simultaneously, it maintains the guidewire's supporting and guiding function at the distal end of the catheter, without affecting the overall pushability and tracking performance of the device.

[0104] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

Claims

1. A fiber optic balloon catheter, comprising a catheter, a balloon disposed at the end of the catheter, and an optical fiber passing through the catheter and extending into the balloon, characterized in that, The fiber optic balloon catheter also includes: A light-diffusing tube extends axially along the interior of the balloon and has opposing proximal and distal ends for scattering the light emitted by the optical fiber to achieve uniform illumination. A sleeve, connected to the near end of the light-diffusing tube and sleeved on the outside of the optical fiber, includes a central positioning part formed on the through hole of the sleeve; the central positioning part is used to position the optical fiber passing through it on the central axis of the light-diffusing tube. Wherein, after the optical fiber passes through the central positioning part of the sleeve, it is inserted into the near end of the light-diffusing tube on the central axis of the light-diffusing tube, and the optical fiber segment located in the light-diffusing tube has a light-emitting part.

2. The fiber optic balloon catheter according to claim 1, characterized in that, The sleeve also includes a stress-dispersing portion formed on its outer surface, which extends from the optical fiber side to the light-diffusing tube side, and its diameter gradually increases from the diameter of the optical fiber to the diameter of the light-diffusing tube.

3. The fiber optic balloon catheter according to claim 2, characterized in that, The central positioning part is a through-hole section; at least two target positions of the through-hole section are equal in size to the diameter of the optical fiber, and the central axis of the through-hole at the at least two target positions coincides with the central axis of the light-diffusing tube, so as to support and position the optical fiber on the central axis of the light-diffusing tube and restrict the radial movement of the optical fiber; wherein, the longest axial distance between the target positions is 3 to 100 times the diameter of the optical fiber.

4. The fiber optic balloon catheter according to claim 3, characterized in that, The centering positioning part and the stress dispersion part are respectively formed on the through hole of the first pipe section and the outer surface of the second pipe section; the first pipe section and the second pipe section are two sections connected axially to the casing, and the second pipe section is located between the first pipe section and the light-diffusing fitting, and is connected to the light-diffusing fitting.

5. The fiber optic balloon catheter according to claim 3, characterized in that, The centering positioning part and the stress dispersing part are respectively formed on the through hole and the outer surface of the same axial section of the sleeve.

6. The fiber optic balloon catheter according to any one of claims 2-5, characterized in that, The outer surface of the sleeve is funnel-shaped, and the funnel-shaped outer surface is the stress dispersion part.

7. The fiber optic balloon catheter according to claim 3, characterized in that, The axial cantilever length of the optical fiber on the side of the uniform light tube is less than 100 times the diameter of the optical fiber.

8. The fiber optic balloon catheter according to claim 1, characterized in that, The distal end of the light-diffusing tube is connected to the balloon.

9. The fiber optic balloon catheter according to claim 1, characterized in that, The light-diffusing tube is located on the central axis of the balloon.

10. The fiber optic balloon catheter according to claim 1, characterized in that, The light-diffusing tube segment includes a light-diffusing material filled inside it, the optical fiber is inserted into the light-diffusing material, and the end of the optical fiber is located near the end of the light-diffusing tube segment, the end face of the optical fiber being the light-emitting part.

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