A catheter for intracerebral ultrasound diagnosis

Abstract

This invention discloses a catheter for intravascular ultrasound diagnosis of the brain. The catheter includes a catheter body, a distal ultrasound imaging unit fixedly connected to the distal end of the catheter body, and a proximal connection unit fixedly connected to the proximal end of the catheter body. A signal transmission component is disposed within the lumen of the catheter body. The catheter body adopts a three-layer composite wall structure with a stepped increase in stiffness from distal to proximal. The catheter body has a large-sized internal lumen capable of simultaneously accommodating multiple independently arranged signal transmission cables. The proximal connection unit is equipped with a multi-channel integrated signal interface. This invention provides a catheter for intravascular ultrasound diagnosis of the brain that employs a three-layer composite wall and gradient stiffness design, integrates multi-channel signals into a large-sized internal lumen, and balances mechanical adaptation, transmission stability, and biosafety, achieving precise diagnosis and integrated treatment.

Description

Technical Field

[0001] This invention belongs to the field of neurointerventional medical device technology, specifically, it relates to a catheter for intravascular ultrasound diagnosis of brain blood vessels. Background Technology

[0002] There is a technical contradiction in the field of intracranial vascular ultrasound diagnostic catheters that cannot simultaneously achieve mechanical compatibility, signal integration and transmission capabilities, and clinical biosafety. This contradiction is not a local problem at the level of process improvement, but rather stems from the inherent limitations formed by the failure to fully adapt to the special anatomy and clinical needs of intracranial vessels during the migration of mature coronary catheter design paradigms to intracranial scenarios. This problem has not yet been effectively resolved.

[0003] The design of existing intracranial vascular ultrasound diagnostic catheters is mostly based on the mature technical paradigm of coronary vascular ultrasound catheters, that is, it follows the structural design and performance balance logic applicable to coronary vessels. Coronary vessels have relatively straight courses, thick walls, and large diameters, and their catheter designs can achieve a basic balance between pushability and flexibility through simple composite structures with a single rigidity. However, intracranial vessels have tortuous courses, thin and fragile walls, numerous branches, and small diameters, and the requirements for catheter mechanical performance are significantly different from those in the coronary scenario. The performance balance logic under the traditional design paradigm is difficult to directly adapt to the application needs of intracranial vessels.

[0004] Under the constraints of this design paradigm, adjustments to catheter mechanical properties exhibit a clear trade-off. Reducing overall stiffness to improve catheter passage through tortuous vessels leads to insufficient catheter support and attenuated propulsion force, affecting the catheter's ability to reach distal intracranial target vessels and increasing its susceptibility to bending during propulsion. Conversely, increasing catheter stiffness to enhance support and propulsion force reduces catheter flexibility, causing mechanical irritation to the thin and fragile intracranial vessel walls and increasing the risk of vascular injury. Furthermore, existing catheter designs inherently constrain the relationship between the catheter's outer diameter and lumen size. To accommodate the diameter requirements of small intracranial vessels, the outer diameter must be controlled, thus limiting the lumen space. This limited lumen space results in insufficient space for internal signal transmission lines, making them prone to compression, entanglement, and wear, affecting signal transmission stability. Additionally, the narrow lumen makes it difficult to reserve space for subsequent therapeutic instruments, restricting the realization of integrated diagnostic and therapeutic procedures.

[0005] In addition, due to limitations in catheter outer diameter and structural complexity, existing catheters have deficiencies in surface biocompatibility treatment and signal connection structure design, which can easily lead to problems such as vasospasm and thrombosis, and the signal transmission stability is insufficient, affecting the accuracy of diagnostic results. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a catheter for intravascular ultrasound diagnosis of the brain.

[0007] To achieve the aforementioned objectives, the technical solution adopted by this invention includes: The catheter body has a distal ultrasound imaging unit fixedly connected to its distal end and a proximal connection part fixedly connected to its proximal end. A signal transmission component is disposed within the inner cavity of the catheter body. The catheter body adopts a three-layer composite tube wall structure, and the hardness increases in a stepped manner from the distal end to the proximal end. The catheter body has a large-sized inner cavity that can simultaneously accommodate multiple independently arranged signal transmission cables. The proximal connection part is provided with a multi-channel integrated signal interface, and the multi-channel integrated signal interface is electrically connected to each signal transmission cable in a one-to-one correspondence.

[0008] Preferably, the three-layer composite tube wall consists of an inner lubrication layer, a middle mechanical support layer, and an outer biocompatible layer, from the inside out. The three-layer structure is integrally formed through a hot-pressing composite process, with an interlayer bonding strength ≥50N / cm. In this invention, the structure not only ensures the overall mechanical properties of the tube wall but also achieves the dual functions of inner lubrication and outer wall biocompatibility. The interlayer bonding is firm, eliminating the risk of delamination. The interlayer bonding strength can be selected from 50N / cm, 55N / cm, 60N / cm, 65N / cm, and 70N / cm. 50N / cm meets the basic structural strength requirements of conventional surgery, 55-60N / cm can improve the catheter's resistance to delamination under repeated bending operations, and 65-70N / cm has extremely high structural stability, suitable for long-term interventional operations in complex and tortuous blood vessels.

[0009] Preferably, the catheter body is divided into a distal compliant segment, a middle transition segment, and a proximal support segment along the distal-to-proximal direction, with a length ratio of 5:3:2. The Shore hardness of the distal compliant segment is D20-D25, the Shore hardness of the middle transition segment is D35-D40, and the Shore hardness of the proximal support segment is D50-D55. This invention achieves the design goal of strong proximal support and high distal compliance, solving the problem of the inability to balance delivery and compliance caused by the uniform hardness of traditional catheters. The Shore hardness of the distal compliant segment can be selected from D20, D21, D22, D23, D24, and D25. D20-D22 provides extreme compliance, suitable for the most tortuous distal branch vessels in the intracranial cavity; D23-D25 balances compliance and basic support, suitable for vessels with moderate tortuosity; the Shore hardness of the middle transition segment can be selected from... Using D35, D36, D37, D38, D39, and D40, D35-D37 achieves a smooth transition in hardness, effectively reducing stress concentration, while D38-D40 enhances mid-section support and optimizes the continuous transmission of pushing force. For the near-end support section, Shore hardness can be selected from D50, D51, D52, D53, D54, and D55. D50-D52 balances flexural strength and flexibility, while D53-D55 provides the strongest near-end support, ensuring no significant attenuation of pushing force during long-distance pushing.

[0010] Preferably, the inner diameter of the large-size cavity is 1.0-1.2 mm, with no step transition throughout. The signal transmission component includes an ultrasound signal transmitting cable, an ultrasound signal receiving cable, a data transmission cable, and an operation control cable, all of which are evenly arranged circumferentially within the large-size cavity. In this invention, the large-size cavity provides ample space for integrated signal transmission, avoiding cable compression, tangling, and wear, while also reserving expansion space for integrated diagnostic and therapeutic operations. The inner diameter of the large-size cavity can be selected from 1.0 mm, 1.1 mm, and 1.2 mm. 1.0 mm is suitable for the smallest intracranial blood vessels, meeting the basic multi-line signal transmission requirements; 1.1 mm balances vascular adaptability and device expansion space; and 1.2 mm provides the largest cavity space, compatible with more types of minimally invasive interventional treatment devices.

[0011] Preferably, the distal ultrasound imaging unit is integrally formed with the catheter body, and the imaging protective cover of the distal ultrasound imaging unit is sealed to the distal end of the catheter body. In this invention, the integrally formed structure ensures the smoothness of the distal end of the catheter, and the sealed connection prevents blood from entering the transducer chamber and causing damage, while also avoiding damage to the vascular endothelium.

[0012] Preferably, three radiopaque rings are fixedly connected to the outer wall of the catheter body. These rings are made of radiopaque tantalum metal and are respectively positioned 0.5-1.0 mm from the distal tip of the catheter body and at both ends of the distal ultrasound imaging section. In this invention, the radiopaque rings can clearly display the catheter's delivery position and shape under DSA / X-ray guidance, facilitating precise positioning during surgery. The distance between the radiopaque rings and the distal tip can be selected from 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1.0 mm. 0.5-0.6 mm allows for precise positioning of the distal tip of the catheter, 0.7-0.8 mm considers the overall positioning of the tip and the imaging area, and 0.9-1.0 mm clearly displays the proximal boundary of the imaging area.

[0013] Preferably, the outer biocompatibility layer is coated with a heparin anticoagulant coating with a thickness of 3-5 μm, uniformly covering all surfaces in contact with blood. In this invention, this coating effectively inhibits platelet deposition and thrombus formation, improves catheter biocompatibility, and reduces the risk of thrombosis during surgery. The coating thickness can be selected from 3 μm, 4 μm, and 5 μm. A 3 μm coating is thin and has minimal impact on the catheter's outer diameter, making it suitable for interventional procedures in extremely fine vessels. A 4 μm coating balances anticoagulant effect and coating firmness, making it the preferred clinical option. A 5 μm coating provides the best anticoagulant effect and is suitable for complex cases with longer surgical times.

[0014] Preferably, all signal transmission cables are medical-grade shielded cables, each with an independent insulation layer and shielding layer; a medical-grade silicone buffer layer is filled between the cables, and the buffer layer is fixedly connected to the inner wall of the inner lubrication layer. In this invention, the shielding layer can effectively avoid attenuation and interference during signal transmission, and the buffer layer can further fix the cable position, improving the stability and safety of signal transmission.

[0015] Preferably, the catheter body includes a quick-connect section with a quick-connect opening; the quick-connect opening is a side-hole structure with rounded edges and a removable medical silicone sealing plug inside. In this invention, the quick-connect opening enables integrated diagnosis and treatment without catheter replacement, the rounded edges prevent scratching instruments, and the sealing plug prevents blood from entering the catheter lumen.

[0016] Compared with the prior art, the advantages of the present invention include: (1) The present invention provides a catheter for intravascular ultrasound diagnosis of brain vessels, which achieves the unity of mechanical properties, lubrication properties and biocompatibility properties through a three-layer composite tube wall structure, effectively improving the overall performance of the catheter.

[0017] (2) The present invention provides a catheter for intravascular ultrasound diagnosis of brain vessels. Through a stepped hardness gradient design, it ensures both the passage of the catheter in tortuous blood vessels and the efficient transmission of pushing force.

[0018] (3) The catheter provided by the present invention for intravascular ultrasound diagnosis of cerebral blood vessels has the ability to independently arrange multiple lines through a large-size inner lumen design, while being compatible with the insertion of subsequent minimally invasive interventional devices; the design of heparin anticoagulant coating and low-friction inner lubrication layer reduces the risk of vasospasm and thrombosis; the multi-channel integrated signal interface realizes rapid and accurate signal transmission, ensures high resolution of ultrasound imaging, and improves the accuracy of diagnostic results. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of an overall catheter for intravascular ultrasound diagnosis of brain vessels according to the present invention. Figure 2 This is a schematic diagram of the structure connecting the head in this invention; Figure 3 This is a schematic diagram of the proximal stress buffer tube in this invention; Figure 4 This is a schematic diagram of the signal acquisition section in this invention; Figure 5 This is a schematic diagram of the hardness gradient segmented structure of the catheter body in this invention.

[0021] Figure label: 1. Connector head; 11. Multi-channel integrated signal interface; 12. Housing; 13. Proximal stress buffer tube; 14. Signal collection cable; 2. Catheter body; 21. Proximal connection; 22. Signal acquisition section; 23. Quick junction section; 24. Quick junction port; 25. Imaging ring; 3. Three-layer composite tube wall. Detailed Implementation

[0022] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution, its implementation process, and principles will be further explained below with reference to the accompanying drawings and specific implementation examples in the embodiments of this application.

[0023] It should be noted that the embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, the present invention covers any substitutions, modifications, equivalent methods and solutions made on the spirit, principles and scope of the present invention as defined by the claims. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the description of this application, the terms "first," "second," "third," and similar words do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," and similar words, do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including," and similar words, mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including," and their equivalents, but do not exclude other elements or objects. The terms "connected" or "linked," and similar words, are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0025] In the description of this application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplification, 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. Therefore, they should not be construed as limitations on this application. Furthermore, when using positional terms such as "both sides," "outer side," and "upper and lower," it should be understood that they are used only for ease of understanding and description, taking into account that the structure may be oriented to other positions.

[0026] In the description of this application, unless otherwise expressly specified and limited, the technical or scientific terms used shall have the ordinary meaning understood by a person with ordinary skills in the art to which this application pertains. Terms such as “installation,” “connection,” and “joining” shall be interpreted broadly, for example, as fixed connection, detachable connection, mating connection, or integral connection. For a person skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0027] The present invention aims to introduce and explain the structural composition of a catheter for intravascular ultrasound diagnosis of cerebral blood vessels and the cooperation relationship between the components. Unless otherwise specified, the size, material and manufacturing process of each component in the catheter suitable for intravascular ultrasound diagnosis of cerebral blood vessels in the present invention can be selected according to specific circumstances, and no special limitations or explanations are made here.

[0028] Furthermore, to provide the public with a better understanding of the present invention, certain specific details are described in detail in the following description of the invention. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0029] See Figure 1 As shown in the figure, this embodiment provides a catheter for intravascular ultrasound diagnosis of the brain, including a connecting head 1 and a catheter body 2. The connecting head 1 is fixedly connected to the proximal end of the catheter body 2. The catheter body 2 is a hollow long tubular structure with a total length of 1450~1500mm and an outer diameter of 1.8~2.2mm. It is compatible with existing neurointerventional minimally invasive delivery systems and intracranial IVUS ultrasound diagnostic systems, and can deliver ultrasound imaging components to the target intracranial blood vessel via minimally invasive intervention to complete high-resolution intravascular ultrasound imaging of the brain.

[0030] See Figure 2As shown, the connector head 1 includes a housing 12, which is a cylindrical structure with an outer diameter of 5.0~6.0mm and a length of 20~30mm. A multi-channel integrated signal interface 11 is fixedly connected inside the housing 12. This interface is a multi-channel integrated electrical connection interface with four gold-plated pins, corresponding to four independent pathways: ultrasound signal transmission, reception, data transmission, and operation control. The pins and corresponding cable ends are fixed using a composite method of crimping and soldering. The interface has a foolproof protrusion on the outside to ensure a unique and correct connection with the intracranial IVUS ultrasound diagnostic system, avoiding reversed signal connection or poor contact, achieving fast and accurate signal transmission. The overall signal transmission loss is ≤3% and there is no significant electromagnetic interference. The proximal end of the outer shell 12 is provided with a mechanical connection port, which is machined with an M5×0.5 external thread for detachable connection with the neurointerventional minimally invasive delivery system, ensuring a secure and non-loose connection. An annular sealing groove is formed on the inner wall of the mechanical connection port, into which a sealing gasket is embedded. The sealing gasket is an O-ring structure made of medical-grade silicone, with a thickness of 2-3 mm. When tightened, it tightly abuts against the internal thread end face of the delivery system, achieving radial and axial double sealing to effectively prevent blood and body fluids from entering the catheter lumen. The distal end of the outer shell 12 is fixedly connected to a proximal stress buffer tube 13, which is sleeved on the proximal outer side of the catheter body 2 to alleviate stress concentration at the connection point between the catheter body 2 and the connecting head 1, preventing the catheter from bending and breaking.

[0031] See Figure 3 As shown, the proximal stress buffer tube 13 is a tapered tubular structure made of medical-grade soft polyurethane material with a Shore hardness of D15~D20. Its surface is smooth and seamless. The proximal diameter is the same as the distal diameter of the outer shell 12, and the distal diameter is the same as the outer diameter of the catheter body 2. The proximal end of the proximal stress buffer tube 13 is heat-fused to the distal end of the outer shell 12, and the distal end is heat-fused to the outer wall of the catheter body 2. This achieves a smooth transition between the connecting head 1 and the catheter body 2, effectively dispersing stress concentration at the connection point and preventing the catheter from breaking due to repeated bending during surgical procedures.

[0032] See Figure 4As shown, the catheter body 2 is divided into a proximal connection section 21, a quick-connect section 23, and a signal acquisition section 22 from proximal to distal. The proximal end of the proximal connection section 21 is fixedly connected to the proximal stress buffer tube 13. The quick-connect section 23 has a quick-connect port 24, which is a side hole structure with rounded edges. The rounded edge radius is 0.1 mm, and there are no burrs or sharp edges. It is equipped with a removable medical silicone sealing plug. When the treatment device is not in use, the sealing plug blocks the quick-connect port 24 to prevent blood from entering the catheter lumen. When in use, the sealing plug can be directly removed to insert guide wires, microcatheters, and other minimally invasive interventional treatment devices, meeting the integrated operation requirements of immediate interventional treatment after diagnosis. Three radiopaque rings 25 are fixedly connected to the outer wall of the catheter body 2. The radiopaque rings 25 are made of radiopaque tantalum metal, are annular in structure, and are 0.5~1.0mm wide. They are embedded in the pre-set annular grooves on the outer wall of the catheter body 2 and are flush with the outer wall of the catheter body 2. They are fixedly connected to the outer biocompatible layer by heat fusion process, without protrusions or burrs. They are respectively set at 0.5~1.0mm from the distal end of the catheter body 2 and at both ends of the signal acquisition section 22. The delivery position and shape of the catheter can be clearly displayed under DSA / X-ray guidance, which facilitates precise positioning during surgery.

[0033] The catheter body 2 has a three-layer composite wall 3, consisting of an inner lubrication layer, a middle mechanical support layer, and an outer biocompatible layer, from the inside out. These three layers are integrally formed using a hot-pressing composite process. The inner lubrication layer and the middle mechanical support layer are bonded together using a hot-melt bonding process, while the middle mechanical support layer and the outer biocompatible layer are bonded together using a co-extrusion composite process. This seamless bonding eliminates any air leakage channels formed between the layers, resulting in a bonding strength ≥50 N / cm and eliminating the risk of delamination. The inner lubrication layer is made of medical-grade polytetrafluoroethylene (PTFE) with a thickness of 0.1~0.2 mm, a surface friction coefficient ≤0.05, and a surface roughness Ra ≤0.2 μm. This significantly reduces the frictional resistance between the inner lumen and the signal collection cable 14, preventing cable wear. The middle mechanical support layer is made of medical-grade nickel-titanium shape memory alloy braided mesh, serving as the core mechanical layer of the catheter wall and providing sufficient support and flexural strength. The outer biocompatibility layer is made of medical-grade polyurethane with a thickness of 0.1~0.2mm. The outer wall is coated with a heparin anticoagulant coating with a thickness of 3~5μm. It uniformly covers the entire outer wall of the catheter body 2, the outer wall of the proximal stress buffer tube 13, and the outer wall of the imaging protective cover. All surfaces in contact with blood are fully covered. The coating is firmly bonded and is not easily detached under saline flushing and blood flushing. It can effectively inhibit platelet deposition and thrombus formation and improve the biocompatibility of the catheter.

[0034] See Figure 5As shown, the hardness of the catheter body 2 increases in a stepped manner from distal to proximal, divided into a distal compliant segment, a middle transition segment, and a proximal support segment, with a length ratio of 5:3:2, and the total length matches the catheter body 2. The distal compliant segment corresponds to the signal acquisition segment 22, with a Shore hardness of D20~D25. The outer biocompatible layer is made of PEBAX2533 low-hardness polyurethane modified material, and the middle mechanical support layer has a nickel-titanium shape memory alloy braided mesh with a mesh count of 100 and a braiding density of 85%, ensuring extreme flexibility to adapt to the course of tortuous intracranial blood vessels and avoid damage to the vessel wall. The middle transition segment corresponds to the fast crossing segment 23, with a Shore hardness of D35~D40. The outer biocompatible layer is made of PEBAX3533 medium-hardness polyurethane material, and the middle mechanical support layer has a nickel-titanium shape memory alloy braided mesh with a mesh count of 90 and a braiding density of 88%. The proximal support section corresponds to the proximal connector 21, with a Shore hardness of D50~D55. The outer biocompatible layer is made of PEBAX5533 high-hardness polyurethane material, and the middle mechanical support layer has a nickel-titanium shape memory alloy braided mesh with 80 meshes and a braiding density of 90%, providing sufficient proximal support and bending resistance to ensure efficient transmission of pushing force without significant attenuation or bending risk. At the connection between the distal compliant section and the middle transition section, and between the middle transition section and the proximal support section, the nickel-titanium shape memory alloy braided mesh and density of the middle mechanical support layer adopt a gradual transition of 20mm in length, rather than an abrupt change, to achieve a continuous and stable transition in hardness, ensuring continuous transmission of pushing force while avoiding catheter bending failure caused by stress concentration.

[0035] The distal end of the signal acquisition segment 22 is fixedly connected to a distal ultrasound imaging unit, which is integrally formed with the catheter body 2. The distal end face of the signal acquisition segment 22 is smoothly plasticized, forming a hemispherical transition without sharp edges, which can avoid scratching the thin and fragile intracranial blood vessel wall during delivery. The distal ultrasound imaging unit includes a miniature ultrasound transducer and an imaging protective cover. The miniature ultrasound transducer is fixed to the center of the distal lumen of the signal acquisition segment 22 by encapsulation with medical epoxy resin. It is made of 50MHz high-frequency piezoelectric ceramic material, with an axial resolution ≥50μm, a lateral resolution ≥150μm, and a maximum imaging diameter ≥20mm, which can realize high-resolution layered imaging of the cerebral blood vessel wall. The imaging protective cover is fitted over the outside of the miniature ultrasound transducer. It is made of medical-grade high-sound-transmitting silicone material with a thickness of 0.1~0.2mm and a sound transmittance of ≥95%. The proximal edge of the imaging protective cover is sealed to the distal end face of the catheter body 2 by laser thermofusion welding. The weld is smooth and without protrusions, forming a fully sealed protection for the miniature ultrasound transducer, isolating the blood from direct contact with the transducer and preventing damage to the transducer. At the same time, it avoids direct contact between the transducer and the blood vessel wall, preventing damage to the vascular endothelium. The miniature ultrasonic transducer is electrically connected to the distal end of the signal collection cable 14. The signal collection cable 14 includes an ultrasonic signal transmitting cable, an ultrasonic signal receiving cable, a data transmission cable, and an operation control cable. Each cable is a medical-grade shielded cable with an outer diameter of 0.15~0.2mm. Each cable has an independent polyimide insulation layer and a copper mesh shielding layer. A medical-grade silicone buffer layer is filled between the cables, and the buffer layer is fixedly connected to the inner wall of the inner lubrication layer, uniformly fixing each cable circumferentially within the large-sized inner cavity of the catheter body 2, effectively preventing the cables from being squeezed, tangled, or axially displaced during catheter advancement. The two ends of the cable are electrically connected to the miniature ultrasonic transducer and the multi-channel integrated signal interface 11, respectively, to realize the transmission and reception of ultrasonic signals and bidirectional data transmission. At the same time, the imaging parameters of the miniature ultrasonic transducer can be adjusted through the operation control cable. The inner lumen of the catheter body 2 is a large-sized lumen with an inner diameter of 1.0~1.2mm, which is more than 50% larger than that of traditional catheters. The large-sized lumen has no step transition throughout, extending from the multi-channel integrated signal interface 11 of the proximal connection part 21 to the miniature ultrasound transducer of the distal ultrasound imaging part. The inner wall of the lumen and the inner lubrication layer are integrally formed, which can accommodate multiple cables to be arranged independently at the same time without compression or entanglement. At the same time, it provides sufficient expansion space to be compatible with the insertion of various minimally invasive interventional treatment devices.

[0036] The working process of this embodiment is as follows: During the preoperative preparation stage, the multi-channel integrated signal interface 11 is aligned with and inserted into the corresponding interface of the intracranial IVUS ultrasound diagnostic system through the anti-foolproof protrusion. The mechanical connection port connecting the head 1 is threaded to the neurointerventional minimally invasive delivery system. After tightening, the sealing gasket is tightly abutted against the end face of the delivery system to achieve internal cavity sealing. The quick-connect port 24 is pre-installed with a medical silicone sealing plug to complete the preoperative instrument connection preparation.

[0037] During the procedure, the catheter body 2 is advanced into the intracranial blood vessel via the femoral or radial artery using a neurointerventional minimally invasive delivery system. During catheter advancement, the proximal support segment provides sufficient support and anti-bending properties, ensuring efficient transmission of the pushing force to the distal end of the catheter; the middle transition segment achieves a smooth transition in rigidity, preventing bending at abrupt changes in rigidity; the distal compliant segment conforms to the tortuous course of the intracranial blood vessel, naturally bending with the vessel's shape, avoiding mechanical damage to the thin and fragile vessel wall, thus solving the problem of the inability to simultaneously achieve both advancement and compliance caused by the uniform rigidity of traditional catheters. The heparin anticoagulant coating on the outer wall of the catheter continuously inhibits platelet adhesion and deposition on the catheter surface, reducing the risk of thrombosis and vascular embolism; the low-friction characteristics of the inner lubricating layer effectively reduce frictional loss between the signal collection cable 14 and the inner wall, extending the cable's lifespan. During the procedure, the position and shape of the catheter are observed in real time under DSA / X-ray guidance through the contrast ring 25, allowing for adjustments to the pushing force and direction, and precise delivery of the signal acquisition segment 22 to the target vascular lesion location.

[0038] The intracranial IVUS ultrasound diagnostic system is activated. An electrical signal is transmitted to a miniature ultrasound transducer via an ultrasound signal transmission cable. The miniature transducer converts the electrical signal into ultrasound waves and emits them towards the surrounding blood vessel walls. After penetrating the blood, the ultrasound waves are reflected by the intima, media, adventitia, and plaque tissue. The reflected waves are received by the miniature ultrasound transducer and converted back into electrical signals. These electrical signals are transmitted via a shielded ultrasound signal receiving cable to a multi-channel integrated signal interface 11, and then to the intracranial IVUS ultrasound diagnostic system. After processing by the system, a layered, high-resolution ultrasound image of the cerebral blood vessel walls is generated, solving the problem of insufficient imaging resolution caused by signal attenuation and interference in traditional catheters. During imaging, the operator can remotely adjust parameters such as the imaging frequency and scanning range of the miniature ultrasound transducer via a control cable to obtain clear images of lesion details, providing accurate evidence for disease diagnosis.

[0039] If minimally invasive interventional treatment is required immediately after diagnosis, the medical silicone sealing plug inside the quick-connect port 24 can be removed. Guidewires, microcatheters, balloons, or stents can then be inserted through the quick-connect port 24. The large-diameter, stepless design ensures smooth passage of various treatment devices without the need for catheter replacement. Diagnostic and treatment procedures can be completed directly through the same pathway, solving the problem of traditional catheters having narrow lumens that cannot accommodate treatment devices. After the procedure, the intracranial IVUS ultrasound diagnostic system is turned off, and the catheter is slowly and steadily withdrawn. The procedure is concluded once it is confirmed that the catheter has been completely removed without any parts remaining in the patient's body.

[0040] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A catheter for intravascular ultrasound diagnosis of the brain, comprising a catheter body (2), wherein a distal ultrasound imaging unit is fixedly connected to the distal end of the catheter body (2), a proximal connecting part (21) is fixedly connected to the proximal end of the catheter body (2), and a signal transmission component is disposed within the lumen of the catheter body (2), characterized in that: The catheter body (2) adopts a three-layer composite tube wall (3) structure, and the hardness increases in a stepwise manner from the distal end to the proximal end; the catheter body (2) has a large-sized inner cavity inside, which can simultaneously accommodate multiple independently arranged signal transmission cables; the proximal connection part (21) is provided with a multi-channel integrated signal interface (11), and the multi-channel integrated signal interface (11) is electrically connected to each signal transmission cable one by one.

2. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 1, characterized in that: The three-layer composite pipe wall (3) consists of an inner lubricating layer, a middle mechanical support layer and an outer biocompatible layer from the inside to the outside. The three-layer structure is integrally formed by hot pressing composite process, and the interlayer bonding strength is ≥50N / cm.

3. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 1, characterized in that: The catheter body (2) is divided into a distal compliant segment, a middle transition segment and a proximal support segment along the distal to proximal direction, with the length ratio of the three segments being 5:3:2; the Shore hardness of the distal compliant segment is D20~D25, the Shore hardness of the middle transition segment is D35~D40, and the Shore hardness of the proximal support segment is D50~D55.

4. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 1, characterized in that: The large-size inner cavity has an inner diameter of 1.0-1.2mm and a stepless transition throughout; the signal transmission component includes an ultrasonic signal transmitting cable, an ultrasonic signal receiving cable, a data transmission cable, and an operation control cable, with each cable evenly arranged circumferentially within the large-size inner cavity.

5. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 1, characterized in that: The distal ultrasound imaging unit is integrally formed with the catheter body (2), and the imaging protective cover of the distal ultrasound imaging unit is sealed to the distal end of the catheter body (2).

6. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 1, characterized in that: Three imaging rings (25) are fixedly connected to the catheter body (2). The imaging rings (25) are made of non-transparent tantalum metal and are respectively located at the distal end of the catheter body (2) at 0.5-1.0 mm and at both ends of the distal ultrasound imaging part.

7. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 2, characterized in that: The outer biocompatible layer is coated with a heparin anticoagulant coating with a thickness of 3-5 μm, which uniformly covers all surfaces in contact with blood.

8. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 4, characterized in that: All signal transmission cables are medical-grade shielded cables, each with an independent insulation layer and shielding layer; medical-grade silicone buffer layer is filled between the cables, and the buffer layer is fixedly connected to the inner wall of the inner lubrication layer.

9. The catheter for intravascular ultrasound diagnosis of cerebral blood vessels according to claim 1, characterized in that: The catheter body (2) includes a quick-connect section (23), on which a quick-connect port (24) is provided; the quick-connect port (24) is a side hole structure with rounded edges and a removable medical silicone sealing plug inside.

Images