Interventional medical device

Abstract

The utility model provides an intrusive medical instrument. The intrusive medical instrument comprises a catheter, a head end electrode, a support, an insulating sleeve, an insulating sheet and a function module. The stent plug is arranged at the far end of the catheter; the stent comprises a tubular part and a supporting part; the tubular part extends into the catheter from the far end opening of the catheter to the near end along the axis of the catheter; the supporting part extends outwards from the tubular part; the head end electrode is connected to the far end side of the supporting part; the functional module is arranged in the guide pipe and is in a barrel shape extending along the axis of the guide pipe; the far end of the functional module is in insulated connection with the supporting part through the insulating sheet, and the inner wall of the functional module is in insulated connection with the tubular part through the insulating sleeve; the functional module comprises a magnetic positioning sensor, the magnetic positioning sensor comprises a metal-core-free hollow coil, and the metal-core-free hollow coil is circumferentially arranged around the axis of the conduit.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to an interventional medical device. Background Technology

[0002] Interventional surgery is a minimally invasive surgical procedure primarily performed using interventional catheters, reducing incisions for patients. Traditional interventional catheters are typically guided by DSA (digital subtraction angiography) and controlled by a drive handle located proximal to the outside of the body. This control is generally achieved by pulling a traction wire. This results in radiation exposure for both the operator and the patient. Furthermore, in situations requiring more complex maneuvers, multiple traction wires must be used with the interventional catheter, increasing its diameter and reducing its maneuverability and flexibility.

[0003] The 3D mapping system uses magnetic positioning sensors embedded near the tip of the interventional catheter to determine its position and orientation, as well as the surrounding environment. This allows for intracardiac modeling and catheter localization, significantly reducing surgical time and greatly improving positioning accuracy. The application of the 3D mapping system also effectively reduces radiation exposure for both the operator and the patient.

[0004] An external drive system is a system that uses an external field to guide interventional medical devices (such as catheters or guidewires) along a pre-defined path and change direction. For example, a magnetic drive device uses rotating magnets on both sides to change the direction of the magnetic field, guiding the magnetically charged interventional medical device along the pre-defined direction and automatically and precisely locating it at the predetermined lesion site. The external drive system changes the previous method of control via a drive handle, allowing for computer-controlled remote operation of interventional medical devices. This shortens treatment time and improves control precision. Furthermore, the external drive system overcomes the operational difficulties posed by the complex anatomy of the heart, enabling interventional medical devices to smoothly reach the target site, thereby simplifying complex surgical procedures.

[0005] However, since the external drive system needs to drive the interventional medical device through an external field, the field strength is relatively high (including but not limited to magnetic field, electric field, etc.). Under such field strength, conventional magnetic positioning sensors are difficult to work properly, which limits the ability to build a heart chamber model on the matching three-dimensional mapping system, thus making it difficult to realize computer remote control.

[0006] Furthermore, since the tip of an interventional catheter is usually equipped with functional modules such as temperature sensors, positioning sensors, pressure sensors, and electrodes, there are high requirements for the insulation performance of the tip. Poor insulation performance can cause the discharge current to interfere with other functional structures and affect the normal use of the catheter.

[0007] Especially for interventional catheters that require external drive systems, their tips are typically designed with a special permanent magnet structure to sense the magnetic field of the magnetic drive device and thus control the catheter's movement. Since permanent magnets are generally conductors or semiconductors, this poses a significant challenge to the insulation performance of the catheter tip. If the insulation between the tip electrode and the functional module is poor, the current may interfere with the accuracy and stability of the functional module, or even the signal from the tip electrode. Utility Model Content

[0008] The purpose of this invention is to provide an interventional medical device that solves at least one of the problems of existing interventional medical devices, namely, that the magnetic positioning sensor cannot be adapted to application scenarios with high external field strength and that the insulation performance of the catheter tip is difficult to guarantee.

[0009] To solve the above-mentioned technical problems, this utility model provides an interventional medical device, which includes: a catheter, a tip electrode, a stent, an insulating sleeve, an insulating sheet, and a functional module;

[0010] The stent is positioned at the distal end of the catheter; the stent includes a tubular portion and a support portion; the tubular portion extends into the catheter from the distal opening to the proximal end along the axis of the catheter; the support portion extends outward from the tubular portion; the tip electrode is connected to the distal side of the support portion.

[0011] The functional module is disposed inside the conduit and is cylindrical in shape extending along the axis of the conduit; the distal end of the functional module is insulated from the support portion through the insulating sheet, and the inner wall of the functional module is insulated from the tubular portion through the insulating sleeve.

[0012] The functional module includes a magnetic positioning sensor, which includes a metal-free hollow coil arranged circumferentially around the axis of the conduit.

[0013] Optionally, the interventional medical device is an ablation catheter, the tip electrode has a blind cavity with an opening towards the proximal end, and the support portion is connected to the side wall of the tip electrode and closes the blind cavity.

[0014] Optionally, the tip electrode has multiple infusion holes that connect the blind cavity to the outside, and the blind cavity is connected to the inner cavity of the catheter through the inner cavity of the tubular part.

[0015] Optionally, the interventional medical device is a high-density mapping catheter, and the tip electrode includes multiple electrode branches, the proximal ends of which converge and connect to the support portion; the electrode connecting lines of all the electrode branches extend proximally through the lumen of the tubular portion.

[0016] Optionally, the magnetic positioning sensor further includes an inner liner tube and an outer casing tube, with the metal-free hollow coil wound around the inner liner tube and the outer casing tube wrapped around the metal-free hollow coil.

[0017] Optionally, at least one of the inner liner and the outer casing is a PI tube; and / or, adhesive is injected and cured between the inner liner and the outer casing.

[0018] Optionally, the outer diameter of the magnetic positioning sensor is 1.0mm to 3.0mm; the axial length of the magnetic positioning sensor along the conduit is 3mm to 9mm.

[0019] Optionally, the resistance of the metal-free hollow coil is 200Ω~460Ω; the inductance of the metal-free hollow coil is 0.26mH~0.54mH.

[0020] Optionally, the outer diameter of the insulating sheet is 1.8mm~2.7mm, the inner diameter of the insulating sheet is 1.0mm~1.5mm, and the axial thickness of the insulating sheet along the conduit is 0.2mm~3.0mm.

[0021] Optionally, the outer diameter of the insulating tube is 1.0mm~1.5mm, the inner diameter of the insulating tube is 0.9mm~1.4mm, and the axial length of the insulating tube along the conduit is 1.5mm~4.0mm.

[0022] In summary, the interventional medical device provided by this utility model includes: a catheter, a tip electrode, a stent, an insulating sleeve, an insulating sheet, and a functional module; the stent is disposed at the distal end of the catheter; the stent includes a tubular portion and a supporting portion; the tubular portion extends into the catheter from the distal opening to the proximal end along the axis of the catheter; the supporting portion extends outward from the tubular portion; the tip electrode is connected to the distal side of the supporting portion; the functional module is disposed within the catheter and is cylindrical in shape extending along the axis of the catheter; the distal end of the functional module is insulated from the supporting portion through the insulating sheet, and the inner wall of the functional module is insulated from the tubular portion through the insulating sleeve; the functional module includes a magnetic positioning sensor, the magnetic positioning sensor including a metal-free hollow coil, the metal-free hollow coil being circumferentially arranged around the axis of the catheter.

[0023] This configuration serves two purposes. First, the insulating sleeves and insulating sheets isolate the head electrode and functional module, ensuring they do not interfere with each other. Second, because the magnetic positioning sensor contains a hollow coil without a metal core, it is unaffected by external magnetic fields and can operate normally. This allows the entire interventional medical device to function under external magnetic fields. Furthermore, the magnetic positioning sensor can operate normally in conjunction with a 3D mapping system, reducing radiation exposure for both the operator and patient, and enabling computer-controlled remote control based on the 3D mapping system. Attached Figure Description

[0024] Those skilled in the art will understand that the accompanying drawings are provided to better understand the present invention and do not constitute any limitation on the scope of the present invention.

[0025] Figure 1 This is a partial schematic diagram of the tip of the ablation catheter according to an embodiment of the present invention.

[0026] Figure 2 This is an axial cross-sectional schematic diagram of the magnetic positioning sensor according to an embodiment of the present invention.

[0027] Figure 3 This is a cross-sectional schematic diagram of the magnetic positioning sensor according to an embodiment of the present invention.

[0028] Figure 4 This is a partial schematic diagram of the tip of the high-density mapping catheter according to an embodiment of the present invention.

[0029] In the attached figures: 1-conduit; 14-infusion channel; 2-head electrode; 20-blind cavity; 21-infusion hole; 22-head permanent magnet; 23-electrode branch; 24-ring electrode; 25-electrode connection wire; 3-support; 31-tubular part; 32-support part; 33-head support tube; 41-insulating sleeve; 42-insulating sheet; 5-functional module; 51-magnetic positioning sensor; 511-hollow coil without metal liner; 512-inner liner tube; 513-outer tube; 514-welding point; 515-wire; 52-first permanent magnet; 53-second permanent magnet; 54-flexible gasket ring; 55-third permanent magnet. Detailed Implementation

[0030] To make the objectives, advantages, and features of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the objectives of the embodiments of this utility model. Furthermore, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may emphasize different aspects and sometimes use different scales.

[0031] As used in this invention, the singular forms “a,” “an,” “one,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature; “one end” and “the other end,” and “proximal end” and “distal end” generally refer to two corresponding parts, which include not only endpoints. Furthermore, the terms "installed," "connected," and "attached," as used in this utility model, and the term "set" on one element from another, should be interpreted broadly. They generally only indicate a connection, coupling, cooperation, or transmission relationship between the two elements, which can be direct or indirect through an intermediate element. They should not be construed as indicating or implying a spatial positional relationship between the two elements, meaning one element can be located inside, outside, above, below, or to one side of the other element, unless otherwise explicitly stated. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances. Additionally, directional terms such as above, below, up, down, upward, downward, left, and right are used relative to exemplary embodiments as shown in the figures, with upward or up direction pointing towards the top of the corresponding figure, and downward or down direction pointing towards the bottom of the corresponding figure.

[0032] The purpose of this invention is to provide an interventional medical device that addresses at least one of the following problems: the magnetic positioning sensor in existing interventional medical devices cannot be adapted to application scenarios with high external field strength, and the insulation performance of the catheter tip is difficult to guarantee. The following description refers to the accompanying drawings.

[0033] Please refer to Figures 1 to 4 This utility model embodiment provides an interventional medical device, which includes: a catheter 1, a tip electrode 2, a stent 3, an insulating sleeve 41, an insulating sheet 42, and a functional module 5; the stent 3 is disposed at the distal end of the catheter 1 ( Figure 1(Left end); the support 3 includes a tubular portion 31 and a support portion 32; the tubular portion 31 extends into the conduit 1 from the distal opening to the proximal end along the axis of the conduit 1; the support portion 32 extends outward from the tubular portion 31; the head electrode 2 is connected to the distal end of the support portion 32; the functional module 5 is disposed in the conduit 1 and is cylindrical in shape extending along the axis of the conduit 1; the distal end of the functional module 5 is insulatedly connected to the support portion 32 through the insulating sheet 42, and the inner wall of the functional module 5 is insulatedly connected to the tubular portion 31 through the insulating sleeve 41; the functional module 5 includes a magnetic positioning sensor 51, the magnetic positioning sensor 51 includes a metal-free hollow coil 511, the metal-free hollow coil 511 is circumferentially arranged around the axis of the conduit 1.

[0034] The inventors discovered that existing magnetic positioning sensors often include a metal core and a coil wound around it. Taking magnetic drive as an example, the purpose of the metal core is to concentrate the magnetic flux inside the coil, increasing the magnetic flux within the coil and improving sensitivity. However, in applications with high magnetic field strength, such as magnetic navigation systems (where the magnetic field strength is much higher than that used for ordinary mapping due to the need for external magnetic fields to drive the inserted device), the metal core of such a magnetic positioning sensor will be interfered with under high magnetic field strength, causing unpredictable changes in the magnetic flux through the coil and preventing it from functioning properly. Optionally, the interventional medical device provided in this embodiment is suitable for external magnetic field strengths of 0.05T to 0.15T, for example, 0.08T or 0.1T. This design is also applicable to external drive systems other than magnetic navigation systems, such as electric fields, magnetic fields with added electric fields, or other drive scenarios, which will not be listed here.

[0035] Based on the above research, the magnetic positioning sensor 51 in the interventional medical device provided in this embodiment includes a metal-free hollow coil 511. Its interior is hollow and does not contain a metal core that generates feedback to external fields, thus it can function normally without interference from external fields. Furthermore, the inner cavity of the metal-free hollow coil 511 allows other components to pass through, making the magnetic positioning sensor 51 highly applicable in interventional medical devices. The inner cavity of the magnetic positioning sensor 51 can accommodate various components such as guidewires, wires, and infusion tubes, helping to reduce the size of the interventional medical device.

[0036] However, the hollow coil 511 without a metal core is more susceptible to interference due to the lack of shielding provided by the metal core. For example, when used in scenarios such as ablation catheters or mapping catheters, it is easily affected by the current interference from the ablation electrodes or mapping electrodes. Furthermore, to adapt to the magnetic drive of the external drive system, the tip of the interventional medical device also needs to include several permanent magnets (such as a first magnet, a second magnet, etc.) to sense the magnetic field of the external drive device and thus be driven. Permanent magnets are generally conductors or semiconductors, and their placement may serve as a conduction path for current interference between the magnetic positioning sensor 51 and the ablation electrodes or mapping electrodes. Therefore, the interventional medical device of this embodiment uses the insulating sleeve 41 and the insulating sheet 42 to form an insulating isolation between the tip electrode 2 and the functional module 5, ensuring that the functional module 5 and the tip electrode 2 do not interfere with each other. This allows the entire interventional medical device to be used in an external magnetic field. For example, it can be magnetically driven by the external magnetic field of the external drive system, while the magnetic positioning sensor can work normally and be used in conjunction with the three-dimensional mapping system. This reduces the radiation exposure of the operator and the patient, and also meets the requirements of computer remote control based on the three-dimensional mapping system.

[0037] The catheter 1 is the main body of the interventional medical device and is generally made of medical-grade polymer materials. To allow for bending and twisting during intervention, the catheter 1 is typically flexible. The stent 3 serves as the mechanical support carrier for the tip of the interventional medical device and is preferably made of a metallic material, such as platinum-iridium, gold, or other precious metals. The insulating sleeve 41 and the insulating sheet 42 are preferably made of polyimide, but can also be other polymer materials with good insulation, thermal insulation properties, high mechanical strength, and good thermal stability.

[0038] In one embodiment, the tubular portion 31 is a cylindrical tube, and the support portion 32 is an annular sheet-like piece. The support portion 32 is sleeved outside the tubular portion 31 and is located at the distal end of the tubular portion 31. In some embodiments, the tubular portion 31 and the support portion 32 can be integrally formed.

[0039] The support portion 32 is used to seal the distal opening of the catheter 1. In some embodiments, the outer circumferential dimensions of the support portion 32 can be adapted to the size of the distal opening of the catheter 1, thereby forming a seal on the distal opening of the catheter 1. In other embodiments, the support portion 32 can also be connected in conjunction with the tip electrode 2 to form a seal on the distal opening of the catheter 1, such as... Figure 1 As shown.

[0040] Optionally, the outer diameter of the insulating tube 41 is 1.0mm~1.5mm, the inner diameter of the insulating tube 41 is 0.9mm~1.4mm, and the axial length of the insulating tube 41 along the conduit 1 is 1.5mm~4.0mm. The outer diameter of the insulating sheet 42 is 1.8mm~2.7mm, the inner diameter of the insulating sheet 42 is 1.0mm~1.5mm, and the axial thickness of the insulating sheet 42 along the conduit 1 is 0.2mm~3.0mm.

[0041] The aforementioned dimensional configuration of the insulating tube 41 and the insulating sheet 42 avoids corona discharge caused by the small gap between the functional module 5 and the support 3, thus ensuring insulation. Furthermore, epoxy adhesive can be injected between the insulating tube 41 and the tubular portion 31, and epoxy adhesive can also be injected between the insulating sheet 42 and the support portion 32 to further improve the firmness of the insulating tube 41 and the insulating sheet 42, as well as their insulation performance on the support 3.

[0042] Functional module 5 may contain different components depending on the application scenario of the interventional medical device. For example, it may include a magnetic positioning sensor 51 and other sensors. Understandably, since interventional medical devices need to bend along with blood vessels during application, in order to minimize the length of the rigid segment and improve bending performance, functional module 5 needs to be as close as possible to the stent 3 and the tip electrode 2. The metal stent 3 can easily introduce current interference conduction paths between functional module 5 and tip electrode 2. Therefore, the insulating sleeve 41 and insulating sheet 42 can insulate and isolate tip electrode 2 from functional module 5, ensuring that functional module 5 and tip electrode 2 do not interfere with each other.

[0043] In order to adapt to the magnetic drive of the external drive system, in one embodiment, the functional module 5 also includes a first permanent magnet 52 and a second permanent magnet 53. The first permanent magnet 52 and the second permanent magnet 53 are preferably hollow cylindrical in shape, and their inner cavities are used for the wires of the head electrode 2, the wires of the magnetic positioning sensor 51, etc. to pass through, and can also be used for the passage of the injection fluid.

[0044] The first permanent magnet 52 is coaxially arranged on the distal side of the second permanent magnet 53. Preferably, the inner diameters of the first permanent magnet 52 and the second permanent magnet 53 are the same, while the outer diameter of the first permanent magnet 52 is larger than the outer diameter of the second permanent magnet 53. The magnetic positioning sensor 51 is sleeved outside the second permanent magnet 53. Preferably, the outer diameter of the first permanent magnet 52 matches the inner diameter of the conduit 1, the outer diameter of the second permanent magnet 53 matches the inner diameter of the magnetic positioning sensor 51, and the outer diameter of the magnetic positioning sensor 51 matches the inner diameter of the conduit 1. All three components—the magnetic positioning sensor 51, the first permanent magnet 52, and the second permanent magnet 53—are housed within the inner cavity of the conduit 1.

[0045] The distal end of the first permanent magnet 52, which is also the distal end of the entire functional module 5, abuts against the insulating sheet 42. The inner wall of the first permanent magnet 52 abuts against the outer periphery of the insulating sleeve 41. This allows the first permanent magnet 52 to be reliably and insulatedly fixed to the bracket 3.

[0046] Optionally, the first permanent magnet 52 and the second permanent magnet 53 can be separated by a flexible washer 54 (such as a silicone washer or a washer made of other elastic materials). This gives the first permanent magnet 52 and the second permanent magnet 53 a certain degree of flexibility, so that the entire functional module 5 can pass smoothly through the bending part.

[0047] Optionally, the first permanent magnet 52 and the second permanent magnet 53 can be made of neodymium iron boron. Preferably, the first permanent magnet 52 and the second permanent magnet 53 are magnetized along the axial direction of the conduit 1, and their magnetic pole directions are consistent. The first permanent magnet 52 and the second permanent magnet 53 can be driven by the magnetic field control of an external driving system, i.e., they act as driven bodies. The second permanent magnet 53 does not play a positive or negative role when the metal-free hollow coil 511 of the magnetic positioning sensor 51 is used as a magnetic sensor. Optionally, the magnetic positioning sensor 51 extends entirely along the axial direction of the conduit 1 within the axial extension range of the second permanent magnet 53, i.e., the magnetic positioning sensor 51 does not exceed the range of the second permanent magnet 53 along the axial direction of the conduit 1. This allows the second permanent magnet 53 to provide some support and protection for the magnetic positioning sensor 51.

[0048] Please refer to Figure 2 and Figure 3 Optionally, the magnetic positioning sensor 51 further includes an inner liner tube 512 and an outer sheath tube 513, with the metal-free hollow coil 511 wound around the inner liner tube 512 and the outer sheath tube 513 wrapped around the metal-free hollow coil 511. Preferably, at least one of the inner liner tube 512 and the outer sheath tube 513 is a PI tube.

[0049] In one embodiment, the inner liner tube 512 serves as the winding carrier for the metal-free hollow coil 511, and also provides a certain load-bearing strength to maintain the stability of the metal-free hollow coil 511. The inner liner tube 512 is preferably a polymer tube or an inorganic non-metallic tube, such as a PI tube (polyimide tube). Of course, other materials with good insulation and mechanical strength can also be used for the inner liner tube 512. After the metal-free hollow coil 511 is wound on the inner liner tube 512, its two ends are welded to the conductors 515, forming two welding points 514. The outer sheath tube 513 wraps around the metal-free hollow coil 511 and preferably covers the two welding points 514. The outer sheath tube 513 is also preferably a polymer tube or an inorganic non-metallic tube, such as a PI tube. Furthermore, adhesive is injected and cured between the inner liner tube 512 and the outer sheath tube 513. This provides further protection for the non-metallic hollow coil 511 and the solder joint 514.

[0050] Optionally, the parameters of the magnetic positioning sensor 51 satisfy at least one of the following:

[0051] The outer diameter of the magnetic positioning sensor 51 is 1.0mm~3.0mm;

[0052] The magnetic positioning sensor 51 has an axial length of 3mm to 9mm along the conduit 1;

[0053] The resistance of the metal-free hollow coil 511 is 200Ω~460Ω;

[0054] The inductance of the metal-free hollow coil 511 is 0.26mH to 0.54mH.

[0055] The external parameters of the magnetic positioning sensor 51 include the outer diameter OD, the inner diameter ID, and the axial length L. These external parameters can be adapted and adjusted according to the specific type of interventional medical device and the specific application scenario. In one example, based on commonly used electrophysiological catheters and their accessories, the outer diameter OD of the magnetic positioning sensor 51 is preferably 2.1mm~2.7mm, for example, 2.4mm; the outer diameter ID is preferably 1.7mm~2.1mm, for example, 1.9mm; and the axial length L is 6mm.

[0056] The electrical parameters of the magnetic positioning sensor 51 include the resistance and inductance of the metal-free hollow coil 511. These electrical parameters can be adjusted to suit the positioning accuracy of the magnetic positioning sensor 51. In an example of an electrophysiological catheter, the resistance of the metal-free hollow coil 511 is 300Ω~360Ω, and the corresponding inductance ranges from 0.36mH to 0.44mH. The metal-free hollow coil 511 is preferably wound with copper wire, and its resistance and inductance can be adjusted by the thickness and number of turns of the copper wire.

[0057] Based on the above parameters, the magnetic positioning sensor 51 can be used in interventional medical devices under external driving systems or other similar external magnetic fields. When used with a three-dimensional mapping system, the position of the magnetic positioning sensor 51 can be displayed in real time and the heart chamber model can be reconstructed.

[0058] The following examples illustrate several interventional medical devices.

[0059] Please refer to the reference. Figure 1 The illustrated interventional medical device is an ablation catheter. The tip electrode 2 has a blind lumen 20 opening towards the proximal end. The support portion 32 is connected to the sidewall of the tip electrode 2 and seals the blind lumen 20. The tip electrode 2 is used to contact tissue to perform ablation discharge or mapping, and it is connected to the proximal ablation device via electrode leads. The tip electrode 2 can be made of platinum-iridium alloy or stainless steel, etc.

[0060] Optionally, the tip electrode 2 has multiple infusion holes 21 connecting the blind cavity to the outside. The blind cavity 20 communicates with the inner cavity of the catheter 1 through the inner cavity of the tubular portion 31. The infusion holes 21 and the inner cavity of the catheter 1 connected through the blind cavity 20 form an infusion channel for infusing saline or other infusion solutions to cool the tip electrode 2 and the ablation site. The structure and principle of other components of this ablation catheter can be referred to in the existing technology of ablation catheters, and will not be described in detail in this embodiment.

[0061] Optionally, to further improve the magnetic drive effect, the ablation catheter also includes a tip permanent magnet 22, which is disposed inside the tip electrode 2. In one embodiment, the support 3 also includes a tip support tube 33 extending distally from the support portion 32, the tip support tube 33 being disposed through the tubular portion 31, and the tip permanent magnet 22 being cylindrically sleeved outside the tip support tube 33 and preferably fixedly connected.

[0062] The tip permanent magnet 22 is preferably magnetized along the axial direction of the catheter 1, with its magnetic poles aligned with those of the first permanent magnet 52 and the second permanent magnet 53, serving as a driven body controlled by the magnetic field of an external drive system. Furthermore, the ablation catheter also includes a safety wire, one end of which is welded or otherwise fixed to the support 3, and the other end extends proximally. The safety wire provides safety for the support 3 and the tip electrode 2 mounted on the support 3, preventing the tip components from falling off during use.

[0063] Optionally, the ablation catheter also includes a third permanent magnet 55. To further increase the magnet volume, the ablation catheter can additionally provide a third permanent magnet 55 near the proximal end of the second permanent magnet 53. The outer diameter, inner diameter, and magnetization direction of the third permanent magnet 55 are the same as those of the first permanent magnet 52. Thus, the arrangement of the first permanent magnet 52, the second permanent magnet 53, and the third permanent magnet 55 effectively forms a concave annular groove in the area of ​​the second permanent magnet 53. The magnetic positioning sensor 51 can then be positioned within this concave annular groove region. The placement of the first permanent magnet 52 and the third permanent magnet 55 also provides axial limitation and protection for the metal-free hollow coil 511 of the magnetic positioning sensor 51, preventing easy damage to the metal-free hollow coil 511.

[0064] In addition to applications in magnetically guided or magnetically driven ablation catheters, the magnetic positioning sensor structure of this embodiment can also be applied to high-density mapping catheters. Please refer to [reference needed]. Figure 4 It shows an axial cross-section of the tip portion of a high-density mapping catheter suitable for an external drive system. The tip electrode 2 of the high-density mapping catheter includes a plurality of electrode branches 23, the proximal ends of which converge and connect to the support portion 32; the electrode connecting lines 25 of all the electrode branches 23 extend proximally through the lumen of the tubular portion 31.

[0065] The catheter 1 is the main body of the high-density mapping catheter. A stent 3 is attached to the distal end of the catheter 1. Multiple electrode branches 23 are connected to the stent 3, and these branches can be arranged in various shapes, such as claw, star, flat, or mesh. Each electrode branch 23 has several ring electrodes 24, and each ring electrode 24 is connected to the proximal end via a ring electrode connecting wire 25. The catheter 1 may optionally have an infusion channel 14 inside, allowing saline infusion during use to reduce or prevent thrombosis at the base of the electrode branches 23.

[0066] To achieve magnetic actuation, a magnet of a certain volume needs to be placed in the distal region of conduit 1, and... Figure 1 Similar to the illustrated example, the high-density mapping conduit can also be equipped with a first permanent magnet 52, a second permanent magnet 53, and a third permanent magnet 55. The first permanent magnet 52, the second permanent magnet 53, and the third permanent magnet 55 can be arranged adjacent to each other or spaced apart, for example, separated by flexible gaskets 54. In other embodiments, adjacent pairs of the first permanent magnet 52, the second permanent magnet 53, and the third permanent magnet 55 can also be fixed together or integrally formed.

[0067] The tip of the ablation catheter and the high-density mapping catheter, both incorporating a magnetic positioning sensor 51, are placed within a three-dimensional mapping system that works in conjunction with the magnetic positioning sensor 51. The magnetic positioning sensor 51 operates normally under the external magnetic field of the external drive system and is not interfered with by the external magnetic field. Under the control of the external magnetic field, the catheter tip can move within the heart chambers, reaching complex intracardiac locations. The synchronous position of the tip is displayed in real-time on the three-dimensional mapping system via signals from the magnetic positioning sensor 51. The trajectories of these positions can then be used to reconstruct the intracardiac model. Simultaneously, specific locations can be marked and positioned within the established intracardiac model.

[0068] In summary, the interventional medical device provided by this utility model includes: a catheter, a tip electrode, a stent, an insulating sleeve, an insulating sheet, and a functional module; the stent is disposed at the distal end of the catheter; the stent includes a tubular portion and a supporting portion; the tubular portion extends into the catheter from its distal opening to its proximal end along the axis of the catheter; the supporting portion extends outward from the tubular portion; the tip electrode is connected to the distal side of the supporting portion; the functional module is disposed within the catheter and is cylindrical, extending along the axis of the catheter; the distal end of the functional module is insulated from the supporting portion by the insulating sheet, and the inner wall of the functional module is insulated from the tubular portion by the insulating sleeve; the functional module includes a magnetic positioning sensor, which includes a metal-free hollow coil, and the metal-free hollow coil is circumferentially arranged around the axis of the catheter. This configuration, on the one hand, through the insulating sleeve and insulating sheet, forms an insulating isolation between the tip electrode and the functional module, ensuring that the functional module and the tip electrode do not interfere with each other. On the other hand, since the magnetic positioning sensor contains a hollow coil without a metal liner, and its interior is hollow and does not contain a metal liner that generates feedback to the external magnetic field, it will not be disturbed under the external magnetic field and can work normally. This allows the entire interventional medical device to meet the application requirements under the external magnetic field. At the same time, the magnetic positioning sensor can work normally and be used in conjunction with the three-dimensional mapping system, which reduces the radiation exposure of the operator and the patient, and can also meet the requirements of computer remote control based on the three-dimensional mapping system.

[0069] It should be noted that the above embodiments can be combined with each other. The above description is only a description of preferred embodiments of the present utility model and is not intended to limit the scope of the present utility model in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the present utility model.

Claims

1. An interventional medical instrument, characterized by It includes: A catheter, a head-end electrode, a stent, an insulating sleeve, an insulating sheet and a functional module; The stent is arranged at the distal end of the catheter; the stent includes a tubular part and a support part; the tubular part extends into the catheter along the axis of the catheter from the distal end opening of the catheter to the proximal end; the support part extends outward from the tubular part; the head-end electrode is connected to the distal end side of the support part; The functional module is arranged in the catheter and has a cylindrical shape extending along the axis of the catheter; the distal end of the functional module is insulatedly connected to the support part through the insulating sheet, and the inner wall of the functional module is insulatedly connected to the tubular part through the insulating sleeve; The functional module includes a magnetic positioning sensor, and the magnetic positioning sensor includes a non-metallic core hollow coil which is arranged circumferentially around the axis of the catheter.

2. The interventional medical instrument of claim 1, wherein, The interventional medical instrument is an ablation catheter, the head-end electrode has a blind cavity facing the proximal end opening, and the support part is connected to the side wall of the head-end electrode and closes the blind cavity.

3. The interventional medical instrument of claim 2, wherein, A plurality of perfusion holes are formed in the head-end electrode and communicate with the blind cavity and the outside, and the blind cavity communicates with the inner cavity of the catheter through the inner cavity of the tubular part.

4. The interventional medical instrument of claim 1, wherein, The interventional medical instrument is a high-density mapping catheter, the head-end electrode includes a plurality of electrode branches, and the proximal ends of the plurality of electrode branches are connected to the support part; and the electrode connecting lines of all the electrode branches extend to the proximal end through the inner cavity of the tubular part.

5. The interventional medical instrument of claim 1, wherein, The magnetic positioning sensor further includes an inner liner tube and an outer wrapping tube, the non-metallic core hollow coil is wrapped outside the inner liner tube, and the outer wrapping tube is wrapped outside the non-metallic core hollow coil.

6. The interventional medical instrument of claim 5, wherein, At least one of the inner liner tube and the outer wrapping tube is a PI tube; and / or, glue is injected and solidified between the inner liner tube and the outer wrapping tube.

7. The interventional medical instrument of claim 1, wherein, The outer diameter of the magnetic positioning sensor is 1.0mm-3.0mm, and the axial length of the magnetic positioning sensor along the catheter is 3mm-9mm.

8. The interventional medical instrument of claim 1, wherein, The resistance value of the non-metallic core hollow coil is 200Ω-460Ω, and the inductance of the non-metallic core hollow coil is 0.26mH-0.54mH.

9. The interventional medical instrument of claim 1, wherein, The outer diameter of the insulating sheet is 1.8mm-2.7mm, the inner diameter of the insulating sheet is 1.0mm-1.5mm, and the axial thickness of the insulating sheet along the catheter is 0.2mm-3.0mm.

10. The interventional medical instrument of claim 1, wherein, The outer diameter of the insulating sleeve is 1.0mm-1.5mm, the inner diameter of the insulating sleeve is 0.9mm-1.4mm, and the axial length of the insulating sleeve along the catheter is 1.5mm-4.0mm.

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