Electrode and puncture kit for dorsal root ganglion (DRG) stimulation

Abstract

The present application relates to an electrode and puncture kit for dorsal root ganglion (DRG) stimulation. The electrode comprises an electrode carrier, wherein an electrode pad is arranged on an electrode segment of the electrode carrier, and barbs are arranged on a barb segment of the electrode carrier. The barbs comprise a main barb and several micro-barbs distributed on an outer side of the main barb, wherein the micro-barbs implement anti-slippage positioning of the main barb by means of increasing a coefficient of friction of a tissue contact surface; and the main barb presents an outwardly protruding arc-shaped contour, and the tail end of the main barb curls inward to form a curled structure. By means of the synergistic design of the electrode carrier and the electrode pad, in combination with the innovative structure of the barb segment, the present invention realizes the integration of mechanical support and stimulation functions, and significantly improves the fixation and long-term stability of the electrode in DRG stimulation.

Description

Electrode and puncture kit for dorsal root ganglion electrical stimulation TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, and particularly relates to an electrode and puncture kit for dorsal root ganglion electrical stimulation. BACKGROUND

[0002] In the prior art, dorsal root ganglion electrical stimulation (DRG stimulation) has become an important means for relieving chronic pain due to its precise targeted treatment characteristics. However, its clinical application still faces significant technical bottlenecks. First, for the treatment scene of patients with lumbar spinal stenosis, the traditional puncture kit has limitations in expanding the vertebral foramen. Due to the narrow anatomical structure of the vertebral foramen and the dense surrounding nerve tissue, the existing technology is difficult to efficiently expand the vertebral foramen in a minimally invasive manner, resulting in difficulty for the electrode to pass through or a high implantation failure rate. Second, the barb structure on the electrode has a problem of slow stress release after implantation. The existing barb relies on the stress relaxation characteristics of the material itself, and the recovery time is relatively long, which easily leads to electrode displacement in the tissue, affecting the stimulation effect and even causing complications. In addition, the existing electrode design usually uses fixed-position barb structures, which cannot be dynamically adjusted according to individual differences of patients (such as vertebral foramen shape, muscle tissue density, etc.), limiting the universality and precision of treatment. Although the existing technology assists implantation through minimally invasive puncture and visualization devices, it still has problems such as complex operation and insufficient postoperative stability due to the limitations of the stress control ability of the electrode barb and the efficiency of vertebral foramen expansion.

[0003] CN222889295U discloses a dorsal root ganglion stimulation electrode with lubricity, which comprises a stimulation part, a protection tube, a connecting part and an inner tube. The inner tube is arranged in the stimulation part, the protection tube and the connecting part. The stimulation electrode is also provided with a first gel body and a second gel body. The first gel body fills the gap between the stimulation part and the inner tube and extends into the partial gap between the protection tube and the inner tube. The second gel body fills the gap between the connecting part and the inner tube and extends into the partial gap between the protection tube and the inner tube. The first gel body and the second gel body enhance the stiffness and structural strength of the stimulation part and the connecting part. The outer peripheral side of the protection tube is provided with a coating prepared from a hydrophilic material. The coating improves the lubrication conditions of the electrode surface and reduces the risk of electrode displacement and fracture. This technical solution cannot solve the technical problems of the present application. Regarding the problem of barb stress release lag, this technical solution does not actively control the stress of the barb structure. In the prior art, the barb relies on the stress relaxation characteristics of the material itself, and the recovery time is relatively long, which easily leads to electrode displacement. The gel body of this technical solution only serves to enhance the structural strength and cannot achieve rapid stress release, so the barb may still fail to be fixed due to slow stress recovery. In addition, in terms of electrode fixation stability, this technical solution relies on the hydrophilic coating to reduce friction, but lacks a dynamic fixation structure.

[0004] To overcome the above defects, it is urgent to provide an improved dorsal root ganglion electrical stimulation puncture kit and its electrode, how to design the electrode barb structure, so that it can quickly release stress after implantation, and avoid electrode displacement caused by slow stress recovery is a technical problem that has not been solved at present.

[0005] The present application hopes to improve the structure of the dorsal root ganglion electrical stimulation puncture kit and its electrode to solve the above problems.

[0006] In addition, on the one hand, there are differences in the understanding of those skilled in the art; on the other hand, a large number of literatures and patents have been studied by the applicant when making this application, but due to the limitation of space, all the details and contents have not been listed in detail, but this is not because this application does not have the characteristics of the prior art, on the contrary, this application has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art in the background art. SUMMARY

[0007] In the field of neural regulation, dorsal root ganglion targeted intervention technology has become an important strategy for chronic pain management due to its precise positioning advantage. However, this technology still faces multiple technical challenges in clinical implementation. For the treatment needs of lumbar spinal stenosis, the current puncture system has obvious limitations in the vertebral foramen expansion process. Limited by the anatomical constraints of the vertebral foramen and the dense distribution of surrounding nerve tissues, traditional minimally invasive instruments are difficult to achieve effective expansion of the vertebral foramen, making it difficult for the guide electrode to pass through, resulting in a low implantation success rate. Notably, the electrode anchoring structure exhibits a gradual stress relaxation phenomenon after surgery, and its stress release mechanism, which relies on the inherent properties of the material, often takes a long time, which can easily cause electrode displacement risk, thereby affecting the treatment effect and possibly inducing adverse reactions. In addition, the existing electrode design uses a rigid fixed barb structure, which lacks dynamic response capability to individualized parameters, including differences in vertebral foramen shape, muscle density distribution, etc., significantly restricting the universality and accuracy of the treatment plan. Although minimally invasive intervention combined with visual navigation system has been widely adopted, limited by the stress control accuracy of the barb and the efficiency of vertebral foramen expansion, there is still room for improvement in the operation convenience and postoperative stability of this technology.

[0008] The present application provides an electrode for dorsal root ganglion electrical stimulation from a first aspect, the electrode includes an electrode carrier, an electrode piece is arranged on an electrode segment of the electrode carrier, and a barb is arranged on a barb segment of the electrode carrier. The barb includes a main barb and a plurality of micro-barbs distributed outside the main barb. The micro-barbs increase the friction coefficient of the tissue contact surface to achieve anti-sliding positioning of the main barb. The main barb presents an outwardly convex arc profile, and the tail end of the main barb is curled inward and forms a curled structure.

[0009] The present application realizes the unity of mechanical support and electrical stimulation function through the synergistic design of electrode carrier and electrode sheet combined with the innovative structure of barb section, and significantly improves the fixation and long-term stability of the electrode in the dorsal root ganglion (DRG) electrical stimulation. The electrode carrier, as the overall support structure, needs to have sufficient mechanical strength and biocompatibility to maintain the electrode shape and reduce tissue reaction; while the electrode sheet is directly responsible for transmitting electrical stimulation signals, and its design needs to ensure uniform distribution of electric field to avoid local current density too high causing tissue damage. The barb section enhances the fixation of the electrode in the vertebral foramen or epidural space through the combined design of main barb and micro barb. The arc-shaped structure of the main barb increases the contact area with the tissue, disperses the stress to reduce the risk of local damage, and the inwardly curled structure at the tail end further improves the pull-out resistance; the micro barb on the outside fills the gap between the main barb and the tissue, disperses the pressure through multi-point contact, reduces single-point stress concentration, and adapts to the surface characteristics of irregular bone or fibrous tissue. This geometric optimization design not only reduces the insertion resistance, but also prevents the electrode from shifting due to patient activity or tissue creep through mechanical balance.

[0010] According to a preferred embodiment, a memory strain ring is provided between the barb and the electrode carrier, in the case of the electrode being removed from the expansion tube body, the pressure on the memory strain ring disappears and restores the original ring-shaped memory shape, pushing the barb to unfold to quickly eliminate stress in a short time.

[0011] During electrode implantation, the memory strain ring is compressed and embedded in the dilation tube body, and is in a compressed state to maintain the folded state of the barb. When the electrode is removed from the dilation tube body, the memory strain ring restores to the original ring-shaped memory state due to the disappearance of external pressure, and the barb is slowly unfolded by the gradual release of its own elastic potential. This process avoids the impact of traditional barbs on the surrounding tissue, disperses the stress concentration when the barb is unfolded, reduces the risk of local tissue damage or inflammation, and precisely regulates the restoring force through the pre-deformation design of the material to ensure that the anchoring force of the barb is moderate, which can not only stably fix the electrode, but also will not excessively press the nerve or blood vessel. The automatic unfolding mechanism of the memory strain ring simplifies the implantation operation process, and only needs to remove the dilation tube body to trigger the unfolding of the barb, thereby reducing the complexity of manual adjustment during the operation, especially suitable for minimally invasive implantation scenes in narrow spaces such as the foramen. The fatigue resistance of the memory strain ring (such as the durability of nickel-titanium alloy) also ensures that the electrode maintains stable mechanical properties during long-term use, dynamically compensates for the displacement risk caused by tissue creep or micro-motion, thereby improving the long-term fixation effect of the electrode. From the perspective of biocompatibility, the material selection of the memory strain ring takes into account the safety and flexibility of medical grade, and the surface can also be passivated or coated with drugs to further reduce foreign body reactions. This design not only solves the stress control problem of traditional barb unfolding, but also significantly improves the reliability and clinical safety of electrode implantation through automatic triggering, minimally invasive adaptability and dynamic mechanical compensation, providing a more precise and stable neural regulation solution for chronic pain treatment such as dorsal root ganglion electrical stimulation.

[0012] According to a preferred embodiment, the memory shape of the memory strain ring between the barb and the electrode carrier is set to be circular, and in the non-compressed state, the natural diameter of the memory strain ring is greater than the maximum diameter of the curled structure of the tail end of the barb, thereby maintaining the stability of the unfolded state of the barb through the self-expanding mechanism; in the case that the main barb is compressed and the tail end contacts the electrode carrier, the memory strain ring is in a deformed state.

[0013] The diameter of the tail end of the main barb is smaller than the diameter of the memory shape of the memory strain ring, and when the electrode is compressed into the dilation tube, the contact between the tail end and the electrode carrier will force the memory strain ring to deform controllably (such as compression or stretching), thereby storing elastic potential energy. This design enables the barb to obtain sufficient restoring force when it is unfolded, while avoiding material failure due to excessive deformation. In addition, the reduction of the tail end diameter also reduces the frictional resistance between the barb and the electrode carrier, making the electrode easier to slide when inserted into the dilation tube, reducing the operation difficulty.

[0014] According to a preferred embodiment, in the case that the electrode is arranged in the dilation tube body of the puncture kit, the memory strain ring is located between the bending memory position and the step in the axial direction, so that the memory strain ring indirectly applies force to the dilation tube body through the main barb.

[0015] Firstly, the position of the memory strain ring enables it to indirectly apply force to the dilation tube body through the main barb, rather than directly acting on the dilation tube wall. This indirect force application mechanism can avoid the local stress concentration or excessive deformation of the dilation tube material caused by direct contact in traditional designs, thereby reducing the risk of rupture or deformation of the dilation tube during electrode removal. Secondly, the positioning relationship between the bending memory position and the step provides a controllable spatial constraint for the deformation and recovery of the memory strain ring: when the electrode is compressed into the dilation tube, the step structure can limit the maximum compression amount of the memory strain ring, preventing material fatigue due to excessive deformation; and the bending memory position serves as a reference point for the recovery of the memory strain ring, ensuring that its deformation path is consistent with the unfolding direction of the main barb, improving the accuracy and stability of the unfolding process. In addition, this design also disperses the recovery force of the memory strain ring evenly to the electrode carrier through the mechanical transmission of the main barb, rather than concentrating it in a local area, thereby reducing the direct impact force on the dilation tube body and avoiding displacement or deflection of the electrode during removal due to reverse force. Finally, the cooperative positioning of the step and the bending memory position also simplifies the assembly process of the electrode in the dilation tube, clearly defines the interaction boundaries of each functional component through structured separation, and further improves the reliability and minimally invasive nature of the implantation operation.

[0016] According to a preferred embodiment, the electrode carrier is provided with a non-uniform phase arrangement of barb arrays in the circumferential direction.

[0017] The present application achieves multi-directional anchoring and stress equalization of the electrode in the ganglion by uniformly distributing the barbs in the circumferential direction of the electrode carrier. The uniformly distributed barbs can provide symmetrical gripping force to the electrode in the axial and radial directions, avoiding electrode deviation, rotation, or local tissue damage caused by uneven stress. At the same time, this design disperses the anchoring force, reduces the local pressure of individual barbs on the neural tissue, reduces the risk of inflammation or fibrosis, and improves long-term fixation stability. In addition, the circumferentially uniform layout simplifies the prediction of the mechanical behavior of the electrode during implantation, facilitating precise control of the electrode position by the surgeon, ultimately ensuring stable transmission of electrical stimulation parameters and improving the reliability of treatment effect.

[0018] According to a preferred embodiment, the barbs are divided into at least two groups, at least one group of barbs as the first layer of barbs and closer to the electrode sheet, the first layer of barbs being equally spaced in the circumferential direction of the electrode carrier; at least one group of barbs as the second layer of barbs and axially spaced from the first layer of barbs and away from the electrode sheet, the second layer of barbs being rotated by a specific angle relative to the first layer of barbs in the circumferential direction to form a staggered distribution, and also forming a staggered puncture depth through a predetermined axial spacing.

[0019] The present application realizes multi-level and multi-direction fixation and stress optimization of the electrode in the ganglion through the non-uniform circumferential distribution and layered design of the barbs. The first layer of barbs is close to the electrode sheet and is distributed at equal intervals, which can preferentially provide uniform initial adhesion force to ensure stable adhesion of the electrode sheet to the surface of the ganglion; the second layer of barbs is away from the electrode sheet and is distributed in axial staggered and circumferential intervals, which disperses the axial tension through the staggered depth and avoids circumferential stress concentration by using the interval layout, thereby improving the overall rotation resistance and displacement resistance of the electrode. This staggered design meets the fast anchoring needs of the electrode in the early stage of implantation, and through the non-uniform distribution, it adapts to different direction mechanical loads (such as multidimensional traction caused by patient activity), reduces the risk of local tissue damage, and at the same time prolongs the stability of long-term fixation of the electrode.

[0020] According to a preferred embodiment, auxiliary barbs are arranged between the barbs distributed circumferentially along the electrode carrier, the auxiliary barbs have a shorter length and a smaller angle compared with the barbs, and the tail end of the auxiliary barbs is not provided with a bending structure, the auxiliary barbs are used for fine adjustment and local stress relief in the case of fixing the electrode by the barbs.

[0021] The present application optimizes the mechanical distribution and tissue compatibility by arranging auxiliary barbs between the main barbs while maintaining the stable fixation of the electrode. The auxiliary barbs are shorter and have a smaller angle, so that the mechanical stimulation of the surrounding tissue is more slight when the electrode is fixed, avoiding local damage or inflammation caused by excessive penetration or excessive angle; at the same time, the tail end of the auxiliary barbs is not provided with a bending structure, which reduces the manufacturing complexity and reduces the potential cutting risk of the tip to the tissue. After the electrode is anchored by the main barbs, the auxiliary barbs can further fill the gap between the main barbs, adapt to the irregular morphology of the ganglion surface by fine adjustment of the adhesion point position, and improve the fixation accuracy. In addition, the short length and small angle design of the auxiliary barbs makes them more likely to deform elastically when stressed, thereby dispersing the concentrated stress borne by the main barbs and reducing the risk of fibrosis or necrosis of the local tissue caused by long-term compression. This main-auxiliary barb cooperative mechanism not only ensures the stability and displacement resistance of the electrode, but also takes into account the minimally invasive and tissue compatibility, providing a safer mechanical environment for long-term neural stimulation treatment.

[0022] According to a preferred embodiment, the micro spikes of the main barbs are distributed in a gradient along the axial direction, and the density of the micro spikes at the tail end is higher than that at the root.

[0023] The application optimizes the fixation stability and tissue adaptability of the electrode through the axial gradient distribution of the main barb microspikes. The high-density microspikes at the tail end can provide stronger local gripping force, ensuring that the electrode is quickly anchored on the surface of the ganglion after implantation, especially in the key area where displacement is prone to occur at the tail end, enhancing the fixation effect. The low-density design at the root reduces mechanical stimulation to the deep tissues, avoiding inflammation or fibrosis caused by excessive compression. In addition, the gradient distribution gradually transitions the stress along the axial direction, reducing the risk of stress concentration at the root due to high-density gripping, while improving the flexibility of the barb as a whole, making it more adaptable to the irregular morphology and dynamic micro-motion of the ganglion surface. This design not only meets the long-term anti-displacement requirements of the electrode, but also reduces local tissue damage through mechanical distribution optimization, improving biocompatibility and clinical safety.

[0024] According to a preferred embodiment, a flexible buffer layer is provided between the memory strain ring and the barb for absorbing the stress mutation generated when the memory alloy framework recovers.

[0025] The application solves the potential damage problem of stress mutation of memory alloy recovery to the electrode structure and surrounding tissues by providing a flexible buffer layer between the memory strain ring and the barb. The flexible buffer layer has excellent energy absorption and stress dispersion capacity, which can effectively buffer the instantaneous high stress generated during the rapid recovery of the memory alloy, avoiding mechanical fatigue failure of the barb or electrode carrier due to stress concentration. In addition, the flexibility of the flexible buffer layer can reduce the direct impact of the barb on the neural tissue, reducing the risk of local inflammation or fibrosis, while prolonging the long-term stability of the electrode through the damping effect of the material itself.

[0026] According to a preferred embodiment, the electrode is used in cooperation with a puncture kit, the puncture kit comprising a sheath tube and a dilating tube, the sheath tube comprising a first connector and a sheath tube body connected thereto, the dilating tube comprising a second connector and a dilating tube body connected thereto, the dilating tube being capable of being sleeved in the sheath tube, and the first connector and the second connector being detachably connected, the dilating tube body being provided with a tapered gradual change section at the dilating tube distal end, the connection between the gradual change section and the dilating tube body being a step with a height difference, and the gradual change section being provided with at least two openings in the axial direction, in the case that the gradual change section of the dilating tube body moves out of the sheath tube distal end of the sheath tube, the gradual change section expands outward along the openings to enlarge the vertebral foramen.

[0027] The tapered design of the tapered gradual change section combined with the height difference of the step allows the dilating tube to gradually enlarge the diameter of the vertebral foramen when it moves out of the sheath tube, avoiding the sudden impact on the bone or nerve tissue caused by one-time expansion, and reducing the risk of tissue damage. The multiple openings of the gradual change section in the axial direction allow the material to elastically deform, allowing the range of vertebral foramen expansion to be controlled by adjusting the number and position of the openings, preventing tissue tearing caused by excessive expansion. The pointed design of the tapered structure reduces the initial puncture resistance, and the step as a mechanical limiting point ensures that the expansion direction is consistent with the axis of the vertebral foramen, improving the positioning accuracy.

[0028] The present application provides a puncture kit for dorsal root ganglion electrical stimulation from a second aspect, which comprises a sheath tube for establishing a channel to the foramen and a dilator tube for expanding the foramen. The sheath tube mounted on the outside of the dilator tube in a sleeved manner comprises a first joint and a sheath tube body connected therewith; the first joint is provided with two pieces of first marking wings protruding radially, and the two pieces of first marking wings together form an indication plane coinciding with a plane formed by the bending of the distal end of the sheath tube. This provides intuitive puncture direction guidance for medical personnel, ensures that the dilator tube accurately enters the foramen along the predetermined bending angle, and thus improves the targeting of electrode implantation. The sheath tube body is a hollow tubular structure, which restricts the extension direction of the dilator tube by mechanical limiting, so that the dilator tube penetrates out of the sheath tube body at the predetermined bending angle of the sheath tube. This makes the dilator tube penetrate out stably at a fixed angle, avoiding the risk of electrode displacement caused by operation deviation.

[0029] In addition, the cooperative design of the sheath tube and the dilator tube simplifies the establishment process of the intervertebral foramen puncture path, not only reduces the operation difficulty, but also reduces the damage to the surrounding tissues, which meets the requirements of minimally invasive surgery for safety and tissue protection. The structured design precisely controls the puncture path, not only improves the success rate of dorsal root ganglion electrical stimulation electrode implantation, but also enhances the stability of postoperative efficacy and effectively reduces the incidence of complications.

[0030] According to a preferred embodiment, the dilator tube comprises a second joint and a dilator tube body connected therewith; the distal end of the second joint is threadedly connected with the first joint; the proximal end of the dilator tube body is adhesively connected with the second joint, and the distal end thereof penetrates out of the hollow axial space of the first joint. This connection mode forms a double fixation structure, which significantly enhances the connection stability between the sheath tube and the dilator tube, effectively avoids the loosening or displacement of the components caused by pulling or operation during the operation, and thus guarantees the positioning reliability of the dorsal root ganglion electrical stimulation electrode in the complex anatomical environment. The dilator tube body is a hollow tube, which ensures that its extension direction strictly matches the predetermined bending angle of the sheath tube, realizes precise guidance of the puncture path, and prevents the electrode from deviating from the target area of the intervertebral foramen or causing tissue damage. The distal end of the dilator tube body is bent by 30 to 45 degrees at the inflection point, which fully matches the anatomical curvature of the intervertebral foramen, so that the electrode can more naturally conform to the morphological distribution of the ganglion, not only improving the adhesion of the electrode to the dorsal root ganglion (reducing the stimulation threshold and reducing energy consumption), but also reducing the risk of postoperative electrode displacement through the anatomical constraint of the intervertebral foramen, which meets the requirements of the “epidural decompression ring” principle for long-term stability of the electrode in dorsal root ganglion electrical stimulation.

[0031] Therefore, through multiple structural optimizations, the present application realizes the cooperative guidance and stable connection of the sheath tube and the dilator tube, significantly improves the success rate of electrode implantation for dorsal root ganglion electrical stimulation and the durability of postoperative efficacy.

[0032] According to a preferred embodiment, the surface of the second joint of the dilating tube is provided with two radially protruding second marker wings, which together form an indication plane coinciding with the plane formed by the bending of the distal end of the dilating tube, providing real-time visual guidance for medical personnel. Medical personnel can determine the spatial orientation of the distal end of the dilating tube in the patient's body by observing the plane formed by the second marker wings outside the patient's body, thereby accurately controlling the spatial position of the dilating tube. This structure does not need to rely on additional imaging equipment for positioning, significantly improving the intuitiveness and response speed of intraoperative operation, especially in complex anatomical conditions (such as intervertebral foramen variation or lack of experience of the operator), which can effectively reduce the risk of misplacement and further ensure the targeting and safety of dorsal root ganglion electrode implantation.

[0033] According to a preferred embodiment, at least part of the internal section of the dilating tube body of the dilating tube is embedded with a memory alloy framework; the memory alloy framework is arranged on the dilating tube body to form an inflection point as a mechanical deformation boundary point, and the section where the distal end of the dilating tube is located relies on the deformation recovery characteristics of the memory alloy framework to achieve controllable bending, thereby simultaneously completing direction correction and spatial positioning during the expansion of the vertebral foramen. This makes the distal end section of the dilating tube rely on its controllable bending ability to achieve local deformation during the expansion of the vertebral foramen, thereby adapting to the anatomical curvature of the intervertebral foramen and correcting the puncture direction. The section from the proximal end of the dilating tube to the inflection point is not provided with a memory alloy framework, so that the section from the proximal end of the dilating tube to the inflection point can maintain a straight shape to ensure the axial advancement stability of the dilating tube body, ensuring the axial stability of the dilating tube during advancement, avoiding the shaking or deviation of the proximal end due to the bending of the distal end. When the dilating tube body is extended from the sheath body of the sheath, the memory alloy framework quickly establishes a matching path with the vertebral foramen based on its preset shape recovery mechanism without additional operation, improving the efficiency and success rate of the operation, and the section where the distal end of the dilating tube is located is automatically reset to the predetermined bending state. This structure realizes the adaptive guidance and mechanical stability collaborative control of the dilating tube in complex anatomical environments through the intelligent deformation characteristics of the memory alloy. According to a preferred embodiment, the dilating tube body of the dilating tube is provided with a limiting ring, which is rotatably sleeved on the outside of the dilating tube body and can trigger different mechanical constraint modes by axial movement; the frustum-shaped gradual transition section of the dilating tube body is provided with at least two through openings along the axial direction, and the openings extend out a part towards the proximal end of the dilating tube, separating the gradual transition section, the step, and part of the dilating tube body into multiple independent arc-shaped pieces in the axial direction; the extension of the openings terminates at a bending memory position, which is located in the coverage area of the limiting ring and is the point where the preset memory alloy framework starts to deform. The arc-shaped piece structure separated by the openings gives the dilating tube body local flexibility and overall stability, allowing it to conform to the anatomical curvature of the vertebral foramen and reduce the pulling injury to the surrounding tissues, meeting the dual requirements of tissue protection and operation precision in minimally invasive spinal surgery.

[0034] In the case that the tapered section of the dilating tube body is moved out of the sheath distal end of the sheath tube, the limiting ring achieves different mechanical constraints through axial movement. Preferably, when the limiting ring abuts against the annular end face of the step, the arc-shaped sheet is forced to close, reducing the diameter of the dilating tube so as to pass through the foramen; when the limiting ring slides towards the dilating tube proximal end, the pressing on the memory bending position is released, and the arc-shaped sheet expands rapidly based on the shape memory alloy deformation recovery characteristics, distracting the foramen space. This design realizes the low profile passability of the dilating tube in the puncture stage and the self-adaptive distraction ability in the expansion stage through the mechanical constraint of the limiting ring and the intelligent response of the shape memory alloy, which not only reduces the foramen puncture resistance, but also ensures the accurate reconstruction of the space in the foramen. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1 is a schematic diagram of the overall structure of the puncture kit for dorsal root ganglion electrical stimulation provided by the present application;

[0036] Fig. 2 is a schematic diagram of the dilating tube structure of the puncture kit for dorsal root ganglion electrical stimulation provided by the present application;

[0037] Fig. 3 is a schematic diagram of the structure of the dilating tube distal end in the closed state provided by the present application;

[0038] Fig. 4 is a cross-sectional view of the dilating tube distal end in the closed state provided by the present application;

[0039] Fig. 5 is a schematic diagram of the structure of the dilating tube distal end in the expansion state from one angle provided by the present application;

[0040] Fig. 6 is a schematic diagram of the structure of the dilating tube distal end in the expansion state from another angle provided by the present application;

[0041] Fig. 7 is a cross-sectional view of the puncture kit for dorsal root ganglion electrical stimulation provided by the present application including electrodes;

[0042] Fig. 8 is a schematic diagram of the structure of the electrode barb in the expanded state provided by the present application;

[0043] Fig. 9 is a schematic diagram of the structure of the non-uniform distribution of barbs provided by the present application;

[0044] Fig. 10 is a schematic diagram of the structure of the barb and auxiliary barb provided by the present application;

[0045] Fig. 11 is a schematic diagram of the structure of the auxiliary barb provided by the present application.

[0046] List of reference numbers 100: sheath; 110: sheath proximal end; 120: sheath distal end; 130: first joint; 131: first flag wing; 140: sheath body; 200: dilator; 210: dilator proximal end; 220: dilator distal end; 230: second joint; 231: second flag wing; 240: dilator body; 250: stop ring; 251: step; 252: gradual transition section; 253: opening; 254: first guide wire; 255: bend memory position; 256: inflection point position; 300: electrode; 310: electrode blade; 320: electrode carrier; 321: electrode section; 322: barb section; 330: barb; 331: main barb; 332: tail end; 333: memory strain ring; 334: microbarb; 335: second guide wire; 340: first layer of barbs; 350: second layer of barbs; 360: auxiliary barb; 370: elastic buffer layer; 380: proximal end section; 390: distal end section. DETAILED DESCRIPTION

[0047] The following detailed description will be made with reference to the accompanying drawings.

[0048] Vertebral foramen: is a channel or opening located in the vertebrae, which is formed by the concave part between the adjacent two vertebrae. The posterior of each vertebral body has a ring-shaped bone structure called the vertebral arch, and the central concave part of the vertebral arch constitutes the vertebral foramen. When multiple vertebrae are connected by intervertebral discs and small joints and stacked together, their vertebral foramina will form a long cylindrical spinal canal in succession.

[0049] Example 1

[0050] In the process of implanting a dorsal root ganglion electrical stimulation device, the electrode needs to be inserted into the human body through a puncture kit and enter through the vertebral foramen. However, the puncture kit has some shortcomings: first, for patients with lumbar spinal stenosis, it is a challenge to enlarge the vertebral foramen and make the electrode pass through smoothly. The traditional dilator is a hollow tube with a tapered tip, and it can only achieve the expansion of the vertebral foramen by replacing the dilator with a larger diameter, which increases the operation time and causes inconvenience. Second, the barbs on the electrode release stress slowly. When the electrode is positioned at the predetermined position, the stress is released slowly, resulting in displacement of the electrode that fails to be fixed in time. Therefore, there is an urgent need to improve the puncture kit and electrode design of the dorsal root ganglion electrical stimulation so that the stress of the barbs on the electrode is quickly released after the electrode is implanted, and the puncture kit can help the thicker electrode to pass through the narrow vertebral foramen, which is a key problem faced in surgery and a technical difficulty that has not been solved by current medical products.

[0051] In view of the deficiencies of the prior art, the present application provides a dorsal root ganglion electrical stimulation puncture kit, as shown in FIG. 1, which comprises a sheath tube 100 for establishing a channel to the foramen and a dilating tube 200 for expanding the foramen. As shown in FIG. 1, the sheath tube 100 mounted on the outside of the dilating tube 200 in a sleeved manner comprises a first joint 130 and a sheath tube body 140 connected thereto, wherein the proximal end of the first joint 130 is a standard external thread luer, used for detachable connection of the sheath tube 100 with the dilating tube 200, and the distal end is provided with a connecting interface such as a clamping groove or a threaded opening, so as to be detachably connected with the sheath tube proximal end 110 of the sheath tube body 140. The sheath tube body 140 is a hollow tubular structure, and the sheath tube distal end 120 is formed into a bend structure through a specific bending angle, which restricts the extension direction of the dilating tube 200 through mechanical limiting, so that the dilating tube 200 is out of the sheath tube body 140 at the predetermined bending angle of the sheath tube 100. The first joint 130 is provided with two radially protruding first marker wings 131, which together constitute an indication plane coinciding with the plane formed by the bending of the sheath tube distal end 120. The medical staff can observe the plane of the first marker wings 131 outside the patient's body during the operation, and simultaneously determine the spatial orientation of the sheath tube distal end 120 inside the patient's body, so as to accurately control the advancing path of the sheath tube 100.

[0052] The dilating tube 200 can be sleeved in the sheath tube body 140 of the sheath tube 100 (see FIG. 1, not shown in FIG. 2), and the first joint 130 and the second joint 230 are detachably connected. As shown in FIG. 2, the dilating tube 200 comprises a second joint 230 and a dilating tube body 240 connected thereto, wherein the distal end of the second joint 230 is a standard internal thread luer, which can be matched and threadedly connected with the standard external thread luer of the first joint 130; the proximal end of the dilating tube body 240 is adhesively connected with the second joint 230, and the distal end is out of the hollow axial space of the first joint 130. In combination with FIG. 2, the dilating tube body 240 is a hollow tube, and the dilating tube distal end 220 is bent by 30 to 45 degrees as a whole at a certain special inflection point position 256. The surface of the second joint 230 is provided with two radially protruding second marker wings 231, which together constitute an indication plane coinciding with the plane formed by the bending of the dilating tube distal end 220. The medical staff can observe the plane constituted by the second marker wings 231 outside the patient's body during the operation, and simultaneously determine the spatial orientation of the bending of the dilating tube distal end 220 inside the patient's body, so as to accurately control the spatial position of the dilating tube 200.

[0053] As shown in FIG. 3, the distal end 220 of the dilating tube is provided with a tapered section 252 in the shape of a truncated cone, one end of which is connected to the dilating tube body 240 via an annular step 251. The step 251 provided around the dilating tube body 240 forms a height difference in the radial direction, so that the diameter of the end face of the tapered section 252 connecting with the step 251 is larger than the diameter of the dilating tube body 240. When the tapered section 252 extends in the axial direction, its diameter gradually decreases from the large-diameter end to the small-diameter end, and finally converges at the distal end 220 of the dilating tube to form an end structure with a diameter smaller than that of the dilating tube body 240. The tapered design of the tapered section 252 forms a smooth guide slope through the geometric transition of the continuous variable diameter, which not only reduces the resistance when puncturing the tissue, but also forms an effective mechanical limiting function, ensuring that the dilating tube 200 can accurately pass through the narrow anatomical structure such as the foramen.

[0054] The dilating tube body 240 is made of a biocompatible flexible material, and at least part of the section is embedded with a memory alloy framework. When the dilating tube body 240 is extended from the sheath body 140 of the sheath tube 100, the memory alloy framework restores the corresponding section to the predetermined bending state based on its preset shape restoration mechanism. The memory alloy framework is arranged on the dilating tube body 240 to form an inflection point position 256 as a mechanical deformation boundary point. The section from the proximal end 210 of the dilating tube to the inflection point position 256 is not provided with the memory alloy framework, so that the section from the proximal end 210 of the dilating tube to the inflection point position 256 can maintain a straight shape to ensure the stability of the axial advancement of the dilating tube body 240, and the section where the distal end 220 of the dilating tube is located realizes controllable bending relying on the deformation restoration characteristics of the memory alloy framework, thereby synchronously completing the direction correction and spatial positioning during the foramen dilation.

[0055] As shown in FIG. 3, the dilating tube body 240 is provided with a limiting ring 250 which is rotatably sleeved outside the dilating tube body 240 and axially abuts against the annular abutting surface of the step 251 (see FIG. 4). The thickness of the limiting ring 250 is equal to the radial height difference of the step 251, and preferably, the height difference is 1-5 mm. Further preferably, the height difference is 3 mm. Correspondingly, the thickness of the limiting ring 250 is also 3 mm. The matching of the thickness of the limiting ring 250 and the radial size of the step 251 makes the two jointly form a continuous and smooth transition surface after being engaged. The equal-thickness design eliminates the radial abrupt interface between the limiting ring 250 and the tapered section 252, avoiding the resistance generated when the dilating tube body 240 moves in the sheath body 140.

[0056] As shown in FIG. 3, the frustum-shaped gradual transition section 252 of the dilating tube body 240 is provided with at least two through openings 253 extending axially and by a certain length towards the dilating tube proximal end 210, which separates the axially connected gradual transition section 252, step 251 and part of the dilating tube body 240 into multiple independent arc-shaped pieces (see FIG. 3). When subjected to external force constraint, these arc-shaped pieces maintain a close state; after the constraint is removed, they separate axially along the openings 253 to dilate (see FIG. 5). The extension of the openings 253 ends at the bending memory position 255, which is located within the coverage area of the limiting ring 250 and is the point where the preset deformation of the memory alloy framework begins. Under no external pressure, the memory alloy framework triggers a self-recovery mechanism, causing the arc-shaped pieces to elastically evert by 30-50 degrees at the bending memory position 255 (see FIGS. 5 and 6), at which time the bending shape of the arc-shaped pieces completely matches the preset deformation state of the memory alloy framework. In the case where the gradual transition section 252 of the dilating tube body 240 is moved out of the sheath tube distal end 120 of the sheath tube 100, the limiting ring 250 achieves different mechanical constraints by moving axially: when it abuts against the annular end face of the step 251, it forces the arc-shaped pieces to close in order to pass through the foramen; when it slides towards the dilating tube proximal end 210, it releases the pressure on the bending memory position 255, causing the arc-shaped pieces to rapidly dilate and distract the foramen space. The axial size of the limiting ring 250 is designed to cover the entire length of the openings 253, ensuring that the same degree of limiting control is formed on the entire section of the arc-shaped pieces from the bending memory position 255 to the end of the gradual transition section 252 in the constrained state.

[0057] As shown in FIGS. 3-6, the limiting ring 250 is connected with the first guide wire 254, and medical personnel can drive the limiting ring 250 to move axially along the dilating tube body 240 by controlling the first guide wire 254 in the extracorporeal part. When the first guide wire 254 is pushed forward, the limiting ring 250 synchronously pushes the gradual transition section 252 to extend into the foramen; conversely, when the first guide wire 254 is pulled backward, the limiting ring 250 displaces towards the dilating tube proximal end 210, releasing the mechanical constraint on the bending memory position 255. At this time, the memory alloy framework triggers deformation recovery, forcing the multiple arc-shaped pieces of the gradual transition section 252 to spread radially from the openings 253, achieving rapid dilation of the foramen space. If the bending memory position 255 is not provided, the dilating tube body 240 dilates the foramen slowly, and the stress is released slowly, so that the larger electrode 300 cannot pass through the foramen quickly, or the electrode 300 needs to pass through the foramen slowly. Preferably, medical personnel can control the moving speed of the limiting ring 250 by controlling the pulling or pushing of the first guide wire 254, thereby controlling the dilation speed of the gradual transition section 252 of the dilating tube body 240.

[0058] The foregoing linkage design enables medical personnel to complete the switching of the foramen expansion state through a single operation: maintaining the closed form to ensure puncture passability, and forming a stable expansion channel at the target position in real time, so that a larger diameter electrode 300 can be smoothly implanted, eliminating the replacement process of traditional multi-stage expansion instruments. If the foramen and the target position are adjacent, the expansion tube body 240 can remain in place to maintain the expansion state, providing continuous channel protection for subsequent electrode implantation.

[0059] Embodiment 2

[0060] This embodiment is a further improvement of Embodiment 1, and the repeated contents will not be described again.

[0061] As shown in FIG. 7, the puncture kit further includes an electrode 300 for transmitting an electrical stimulation signal and being stably fixed to the ganglion target for a long time. The electrode 300 can be used in cooperation with the puncture kit.

[0062] As shown in FIG. 7, the electrode carrier 320 has a columnar structure, and the electrode segment 321 of the electrode carrier 320 is surrounded by the electrode sheet 310 as a direct conductive interface of the dorsal root ganglion. The barb 330 is integrated on the adjacent barb segment 322 for anchoring the electrode carrier 320 to the muscle tissue. The barb 330 is composed of an alloy material with shape memory effect. The barb 330 includes a main barb 331 and a micro-barb 334. The micro-barb 334 is arranged on the outside of the main barb 331. The main barb 331 has an outwardly convex arc-shaped profile, and the tail end 332 of the main barb 331 is curled inwardly and forms a curled structure.

[0063] A memory strain ring 333 is arranged between the barb 330 and the electrode carrier 320. The preset memory shape of the memory strain ring 333 is a circular shape (such as a circular or elliptical shape), and in a non-compressed state, the natural diameter of the memory strain ring 333 is greater than the maximum diameter of the curled structure of the barb tail end 332, thereby maintaining the stability of the unfolded shape of the barb 330 through a self-expanding mechanism.

[0064] As shown in FIG. 8, in the case where the electrode 300 is removed from the expansion tube body 240, the pressure on the memory strain ring 333 disappears and the memory strain ring 333 returns to the original ring-shaped memory shape, pushing the barb 330 to unfold to quickly eliminate stress in a short time. The advantage of such an arrangement is that the memory strain ring 333 can quickly push the barb 330 to unfold, so that the stress of the barb 330 is quickly released, avoiding the displacement risk caused by the slow release of stress of the traditional electrode 300.

[0065] As shown in FIG. 7 and FIG. 8, the barb 330 includes a main barb 331 and a plurality of micro-barbs 334 distributed outside the main barb 331, and the micro-barbs 334 increase the friction coefficient of the tissue contact surface to achieve anti-slip positioning of the main barb 331. The main barb 331 presents an outwardly convex arc-shaped profile, and the tail end 332 is curled inward to form a multi-turn spiral structure, i.e., a curled structure. This design not only guarantees the anchoring strength of the muscle tissue, but also avoids excessive invasion of the soft tissue through the inward retraction characteristics of the curled tip. The natural diameter formed by the curled structure of the tail end 332 is always smaller than the initial memory state diameter of the memory strain ring 333. When the main barb 331 is compressed by external force, the tail end 332 contacts the surface of the electrode carrier 320 to form a rigid support, and at the same time, the memory strain ring 333 is compressed to a flat deformation state. The curled structure becomes an axial bearing assembly of the memory strain ring 333 during the compression process, which not only ensures controllability of deformation, but also prevents plastic deformation of the ring body and loss of shape recovery ability.

[0066] As shown in FIG. 7, when the electrode carrier 320 is placed in the dilating tube body 240, the axial position of the memory strain ring 333 is between the bending memory position 255 and the step 251. At this time, the arc-shaped profile of the main barb 331 tightly abuts the inner wall of the dilating tube body 240, so that the restoring stress of the memory strain ring 333 is converted into a sustained radial expansion force by the main barb 331 and transmitted to the tube wall. This arrangement enables the superimposed stress released by the memory strain ring 333 to significantly accelerate the expansion process when the gradual change section 252 needs to perform foramen expansion, so that the separated arc-shaped pieces achieve rapid external expansion.

[0067] As shown in FIG. 7, the electrode carrier 320 is integrated with a second guide wire 335 extending axially along the inner lumen. Through in-vitro regulation of the second guide wire 335, the operator can finely adjust the implantation depth and angle of the electrode 300, and ensure the spatial positioning accuracy of the stimulation target and the dorsal root ganglion.

[0068] Embodiment 3

[0069] This embodiment is a further improvement of embodiment 2, and the repeated contents will not be described again.

[0070] In view of the physiological characteristics of the dorsal root ganglion, the electrode 300 is further improved in this embodiment.

[0071] As shown in FIG. 8, in the current symmetrical barb structure, the barbs 330 distributed at equal angles along the circumference of the electrode carrier 320 can provide uniform anchoring force, but the high structural rigidity leads to two defects: first, the resistance generated by the barbs simultaneously during the puncture process is easy to cause micro-injury to the tissue; second, multi-point stress concentration may increase the puncture pain and inflammation risk. In addition, the contact between the electrode 300 and the nerve tissue is relatively concentrated, and there is a problem of uneven stimulation. Therefore, in this embodiment, the electrode carrier 320 is provided with a barb array arranged at non-uniform phases along the circumference.

[0072] Preferably, to optimize the implantation performance of the dorsal root ganglion electrode, the barbs 330 are divided into at least two groups in this embodiment: the first layer of barbs 340 closer to the electrode sheet 310 are arranged equidistantly in the circumferential direction of the electrode carrier 320 for basic anchoring point; the second layer of barbs 350 axially spaced from the first layer of barbs 340 are arranged away from the electrode sheet 310, which are rotated at a certain angle relative to the first layer of barbs 340 in the circumferential direction to form a staggered distribution, and at the same time form staggered puncture depths through the preset axial distance. The plurality of barbs 330 are dispersed in different cross sections along the axial direction of the electrode carrier 320 to form a multi-layer anchoring array with staggered axial distribution, and the fixation state with the tissue in the body is optimized through the asymmetric layout. As shown in FIG. 9, the two groups of three barbs 330 respectively form the first layer of barbs 340 with equidistant 120° in the circumferential direction and the second layer of barbs 350 with a rotation offset of 60°. The axial distance between the layers makes the puncture positions of the barbs staggered, which significantly reduces the synchronous puncture resistance.

[0073] For example, when there are six barbs 330, the six barbs 330 are divided into at least two groups. As shown in FIG. 9, the first group includes 3 barbs 330, which are the first layer of barbs 340 and are closer to the electrode sheet 310. The first layer of barbs 340 is distributed equidistantly in the circumferential direction of the electrode carrier 320 by 120°. As shown in FIG. 9, the second group includes 3 barbs 330, which are the second layer of barbs 350. The second layer of barbs 350 is away from the electrode sheet 310. As shown in FIG. 9, the second layer of barbs 350 is staggered in the axial direction from the first layer of barbs 340 by a puncture distance and is distributed with a rotation offset of 60°. Preferably, the offset distance is 0.5-1 mm.

[0074] The plurality of barbs 330 are distributed in multiple cross sections along the axial direction of the electrode 300, staggered and arranged to form a multi-layer distribution.

[0075] In this way, (1) the puncture resistance can be reduced, specifically, the number of single-layer barbs is reduced, the number of barbs in each cross section is limited, the resistance is more uniform, the spatial distribution is smaller, and the tissue damage is reduced. (2) There are multiple layers of staggered barbs in the axial direction, which increase the contact surface with the tissue, increase the fixation force, and avoid stress concentration. (3) The stimulation is more uniform. The staggered distribution of the barbs avoids excessive compression of the electrode on the local nerve tissue, and promotes uniform electrical contact between the electrode and the surface of the ganglion.

[0076] Further preferably, as shown in FIGS. 10 and 11, auxiliary barbs 360 are arranged between the barbs 330 distributed in the circumferential direction of the electrode carrier 320. As shown in FIG. 11, compared with the barbs 330, the auxiliary barbs 360 have a shorter length, a smaller barb angle, and no tail end 332 with a curved structure. The tail end 332 of the auxiliary barb 360 only has a slight curvature and cannot be bent into a "circle".

[0077] In the case of barb 330 fixing electrode 300, auxiliary barb 360 is used for fine adjustment and stress relief.

[0078] In this way, auxiliary barb 360 can share part of the fixing pressure and relieve the penetration pressure of main barb 331 on the local tissue. Auxiliary barb 360 is generally softer and can better adapt to the irregular microstructure of the nerve ganglion surface, improving the fixing comfort. The low-invasion design of auxiliary barb 360 can effectively disperse mechanical stimulation.

[0079] Preferably, the micro spikes 334 of the main barb 331 are distributed in a gradient along the axial direction. As shown in FIG. 10, the density of the micro spikes at the tail end 332 is higher than that at the root. This density distribution can ensure higher fixing strength and stability in the medial region of the foramen, while reducing stimulation to the entrance region of the foramen and avoiding unnecessary damage. The root of the main barb 331 is close to the entrance region of the foramen, and the density of the micro spikes at the root is lower. The density of the micro spikes in the medial region of the foramen is 3-5 per square millimeter. This design takes into account the particularity of the entrance region of the foramen, and the lower density can reduce interference with the surrounding tissue and reduce discomfort during use. The tail end 332 of the main barb 331 extends to the medial region of the foramen. The density of the micro spikes at the tail end 332 is higher. That is, the density of the micro spikes near the entrance region of the foramen is 1-2 per square millimeter. This design can ensure sufficient support in areas where higher fixing strength is needed, enhancing overall stability and reliability.

[0080] Preferably, the micro spikes 334 are designed in a tapered structure, which not only ensures controllable penetration depth, but also adjusts the depth and force of penetration according to the needs of different regions, thereby achieving more precise operation and more efficient function realization. The design of the tapered structure can also reduce the resistance during penetration, improving the convenience and comfort of use.

[0081] Further preferably, as shown in FIG. 10, the main barb 331 is divided into two sections along the axial direction, namely the proximal section 380 and the distal section 390. The proximal section 380 is a part close to the entrance of the foramen and is a rigid structure. The distal section 390 is a part deep into the foramen and is a flexible structure. The material of the rigid structure is, for example, nickel-titanium alloy. The material of the flexible structure is, for example, polyimide. The junction of the proximal section 380 and the distal section 390 is provided with a gradual transition section. A nickel-titanium alloy-polyimide blending layer is provided in the gradual transition section, which is formed by micro-scale mixing or layered stacking to form an interface with gradually changing mechanical properties. Preferably, the gradual transition section adopts a tapered or stepped structure, gradually changing the cross-sectional area of the rigid section and the flexible section to reduce mechanical discontinuity. Alternatively, a groove or corrugated structure is provided in the gradual transition section to increase the contact area of nickel-titanium alloy and polyimide and improve the interface bonding strength (such as through mechanical interlocking).

[0082] Further preferably, the microspikes 334 in the proximal section 380 are sparsely distributed, for example at a density of 1-2 per mm2. The microspikes 334 in the distal section 390 are densely distributed, for example at a density of 3-5 per mm2, and the tips of the microspikes 334 are coated with a hydrophilic coating.

[0083] The rigid microspikes 334 can provide an initial fixation force, and the flexible microspikes 334 can adapt to the dynamic deformation of the neural tissue. The hydrophilic coating can reduce the friction coefficient to below 0.1, reducing the continuous frictional damage to the nerve.

[0084] Preferably, an elastic buffer layer 370 is provided between the memory strain ring 333 and the barb 330, to absorb the stress mutation generated when the memory alloy skeleton recovers. The elastic buffer layer 370 is, for example, a polyurethane film with a thickness of 0.05-0.1 mm.

[0085] The number of turns of the curled tail end 332 is designed to be 2-3 turns, and the diameter is slightly smaller than the recovered diameter of the memory strain ring 333 (1.5-2.0 mm), forming a progressive support.

[0086] The elastic buffer layer 370 can avoid the mechanical impact of the sudden deployment of the barb 330 on the nerve. The optimized number of turns and diameter of the curled tail end 332 balance the fixation force and tissue compatibility.

[0087] It should be noted that the above specific embodiments are exemplary, and those skilled in the art can think of various solutions under the inspiration of the disclosure of the present application, and these solutions also belong to the disclosed scope of the present application and fall within the protection scope of the present application. Those skilled in the art should understand that the present application specification and its drawings are illustrative and do not constitute a limitation on the claims. The protection scope of the present application is defined by the claims and their equivalents. The present application specification contains multiple inventive concepts, such as "preferably", "according to a preferred embodiment" or "optionally", which all indicate that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application according to each inventive concept.

Claims

1. An electrode for dorsal root ganglion electrical stimulation, characterized by, The electrode (300) comprises an electrode carrier (320), an electrode sheet (310) is arranged on an electrode segment (321) of the electrode carrier (320), and barbs (330) are arranged on a barb segment (322) of the electrode carrier (320), The barbs (330) comprise main barbs (331) and a plurality of micro barbs (334) distributed outside the main barbs (331), the micro barbs (334) increase the friction coefficient of the tissue contact surface to achieve anti-slip positioning of the main barbs (331); The main barbs (331) have an outwardly convex arc-shaped profile, and the tail ends (332) of the main barbs (331) are inwardly curled and form curled structures.

2. The electrode of claim 1, wherein A memory strain ring (333) is arranged between the barbs (330) and the electrode carrier (320), In the case that the electrode (300) is removed from the expansion tube body (240), the pressure on the memory strain ring (333) disappears and the memory shape of the memory strain ring (333) returns to the original ring shape, pushing the barbs (330) to expand to quickly eliminate stress in a short time.

3. The electrode according to claim 1 or 2, characterized in that The memory shape of the memory strain ring (333) between the barbs (330) and the electrode carrier (320) is arranged to be a circle, In the non-pressurized state, the natural diameter of the memory strain ring (333) is greater than the maximum diameter of the curled structure of the barb tail end (332), thereby maintaining the stability of the expanded shape of the barbs (330) through a self-expanding mechanism; In the case that the main barbs (331) are pressed and the tail ends (332) contact the electrode carrier (320), the memory strain ring (333) is in a deformed state.

4. The electrode according to any one of claims 1 to 3, characterized in that In the case that the electrode (300) is arranged in the expansion tube body (240) of the puncture kit, in the axial direction, the position of the memory strain ring (333) is between the bending memory position (255) and the step (251), so that the memory strain ring (333) indirectly applies force to the expansion tube body (240) through the main barbs (331).

5. The electrode according to any one of claims 1 to 4, characterized in that The electrode carrier (320) is circumferentially arranged with an array of barbs arranged in a non-uniform phase.

6. The electrode according to any one of claims 1 to 5, characterized in that The barbs (330) are divided into at least two groups, At least one group of barbs (330) is a first layer of barbs (340) and is closer to the electrode sheet (310), The first layer of barbs (340) is distributed at equal intervals along the circumference of the electrode carrier (320); At least one group of barbs (330) is a second layer of barbs (350) and is axially spaced apart from the first layer of barbs (340) and away from the electrode sheet (310), The second layer of barbs (350) is rotated by a certain angle in the circumferential direction relative to the first layer of barbs (340) to form a spaced distribution, and a staggered puncture depth is formed through a preset axial spacing.

7. The electrode according to any one of claims 1 to 6, characterized in that Auxiliary barbs (360) are arranged between the barbs (330) distributed along the circumference of the electrode carrier (320), Compared with the barbs (330), the auxiliary barbs (360) have a shorter length, a smaller barb angle, and no tail end (332) with a curled structure, In the case that the barbs (330) fix the electrode (300), the auxiliary barbs (360) are used for fine adjustment and local stress relief.

8. The electrode according to any one of claims 1 to 7, characterized in that The micro spikes (334) of the main barb (331) are distributed in a gradient along the axial direction, and the density of the micro spikes at the tail end (332) is higher than that at the root.

9. The electrode according to any one of claims 1 to 8, characterized in that An elastic buffer layer (370) is arranged between the memory strain ring (333) and the barb (330) to absorb the stress mutation generated when the memory alloy framework recovers.

10. The electrode according to any one of claims 1 to 9, characterized in that The electrode (300) is used in cooperation with a puncture kit, The puncture kit comprises a sheath tube (100) and a dilating tube (200), The sheath tube (100) comprises a first joint (130) and a sheath tube body (140) connected thereto, The dilating tube (200) comprises a second joint (230) and a dilating tube body (240) connected thereto, The dilating tube (200) can be sleeved in the sheath tube (100), and the first joint (130) and the second joint (230) are detachably connected, A tapered transition section (252) is arranged at the dilating tube distal end (220) of the dilating tube body (240), and the transition section (252) is connected to the dilating tube body (240) at a stepped portion (251) with a height difference, At least two openings (253) are arranged at the transition section (252) along the axial direction, When the transition section (252) of the dilating tube body (240) is moved out of the sheath tube distal end (120) of the sheath tube (100), the transition section (252) expands outward along the openings (253) to enlarge the vertebral foramen.

11. A puncture kit for dorsal root ganglion electrical stimulation, characterized by, The sheath tube (100) for establishing a channel to the vertebral foramen and the dilating tube (200) for enlarging the vertebral foramen are arranged in a sleeved manner outside the dilating tube (200), and the sheath tube (100) comprises a first joint (130) and a sheath tube body (140) connected thereto; Two first marking wings (131) protruding radially are arranged on the first joint (130), and the two first marking wings (131) together form an indication plane coinciding with a plane formed by bending of the sheath tube distal end (120); The sheath tube body (140) is a hollow tubular structure, and the extension direction of the dilating tube (200) is constrained by mechanical limiting, so that the dilating tube (200) passes out of the sheath tube body (140) at a predetermined bending angle of the sheath tube (100).

12. The lancing set of claim 11, wherein, The dilating tube (200) comprises a second joint (230) and a dilating tube body (240) connected thereto; The distal end of the second joint (230) is threadedly connected with the first joint (130); The proximal end of the dilating tube body (240) is adhesively connected with the second joint (230), and the distal end passes out of the hollow axial space of the first joint (130); The dilating tube body (240) is a hollow tube, and the dilating tube distal end (220) is bent by 30 to 45 degrees as a whole at an inflection point position (256).

13. The lancing set according to claim 11 or 12, characterized in that The surface of the second joint (230) of the dilating tube (200) is provided with two second marking wings (231) protruding radially, and the two second marking wings (231) together form an indication plane coinciding with a plane formed by bending of the dilating tube distal end (220). The medical staff can determine the bending direction of the distal end (220) of the expansion tube in the patient's body by observing the plane formed by the second marker wing (231) outside the patient's body, so as to accurately control the spatial position of the expansion tube (200).

14. The lancing set of any one of claims 11 to 13, wherein, The inside of the expansion tube body (240) of the expansion tube (200) is embedded with a memory alloy framework in at least a partial section; The memory alloy framework is arranged on the expansion tube body (240) to form an inflection point position (256) as a mechanical deformation demarcation point. The section where the distal end (220) of the expansion tube is located realizes controllable bending by relying on the deformation recovery characteristics of the memory alloy framework, thereby synchronously completing direction correction and spatial positioning during the expansion of the foramen. The section from the proximal end (210) of the expansion tube to the inflection point position (256) is not provided with a memory alloy framework, so that the section from the proximal end (210) of the expansion tube to the inflection point position (256) can maintain a straight shape to ensure the stability of the axial advancement of the expansion tube body (240). When the expansion tube body (240) is stretched out of the sheath tube body (140) of the sheath tube (100), the memory alloy framework restores the section where the distal end (220) of the expansion tube is located to a predetermined bending state based on its preset shape recovery mechanism.

15. The lancing set of any one of claims 11 to 14, wherein, The expansion tube body (240) of the expansion tube (200) is provided with a limiting ring (250), The limiting ring (250) is rotatably sleeved outside the expansion tube body (240); the frustum-shaped gradual change section (252) of the expansion tube body (240) is axially provided with at least two through openings (253), and the openings (253) extend out a part towards the proximal end (210) of the expansion tube, thereby separating the gradually changing section (252), the step (251) and part of the expansion tube body (240) connected in the axial direction into multiple independent arc-shaped pieces; The extension of the openings (253) terminates at a bending memory position (255), which is located in the coverage area of the limiting ring (250) and is the point where the preset memory alloy framework starts to deform; in the case that the gradual change section (252) of the expansion tube body (240) is moved out of the sheath tube distal end (120) of the sheath tube (100), the limiting ring (250) realizes different mechanical constraints by axial movement; When the limiting ring (250) abuts against the annular end face of the step (251), the arc-shaped pieces are forced to close to pass through the foramen; when the limiting ring (250) slides towards the proximal end (210) of the expansion tube, the pressing on the bending memory position (255) is released, so that the arc-shaped pieces are quickly expanded to distract the foramen space.

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