Interventional device fixation device

Abstract

This invention provides an interventional device fixation device, relating to the field of interventional medical device technology. The fixation device includes: a hollow nail, a locking element, and a sealing sleeve; the locking element is connected to one end of the hollow nail, and both the locking element and the hollow nail have an axially penetrating installation channel for clearance fitting and sliding insertion of the interventional diagnostic and therapeutic device; the sealing sleeve is installed between the hollow nail and the locking element, and the locking element has an inner ring pressing surface that radially compresses the sealing sleeve to compress it radially between the locking element and the interventional diagnostic and therapeutic device. The sealing effect does not depend on the initial dimensional matching between the sealing sleeve and the interventional device, and it does not require the locking element to cover and seal the hollow nail, making it compatible with interventional diagnostic and therapeutic devices of different outer diameters. It overcomes the technical paradox of mutual constraints between sealing performance and operational smoothness, achieving a safe, lightweight, and reusable interventional device fixation method while ensuring intracranial sterility and pressure stability.

Description

Technical Field

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

[0002] Stereoscopic electroencephalography (SEEG) and laser interstitial thermotherapy (LITT) are important minimally invasive techniques for precision neurosurgical diagnosis and treatment. Both techniques rely on precisely placing a slender interventional device—such as a SEEG deep electrode or a LITT fiber optic catheter—into the target area of ​​the brain along a pre-defined trajectory after drilling a hole in the skull. To ensure a sterile environment and stable intracranial pressure throughout the procedure, a reliable radial dynamic seal must be achieved at the point where the interventional device exits the skull to prevent leakage of scalp tissue fluid, blood, or air into the intracranial cavity through the gap between the device and the bone opening.

[0003] In existing technologies, the mainstream solution is to use a guide screw (burr hole guide screw) in conjunction with an elastic sealing structure (such as silicone O-rings, conical elastic sleeves, etc.) for fixation and sealing. Typical solutions include: (1) pre-placing the sealing ring in the inner cavity of the guide screw, and tightening the screw to make the sealing ring radially expand under axial compression, thus holding the interventional device tightly; (2) using an interference fit design, making the inner diameter of the sealing sleeve slightly smaller than the outer diameter of the interventional device, and relying on the elastic deformation of the material to achieve initial sealing. However, the above solutions have revealed significant structural defects in clinical practice: the radial clamping force applied to ensure sealing reliability directly causes the interventional device to bear extremely large circumferential static friction and sliding resistance during insertion / withdrawal / removal. This resistance not only significantly increases the operator's workload and prolongs the insertion time, but also easily causes "stick-slip behavior" when finely controlling the depth, resulting in uncontrolled device displacement and seriously threatening the accuracy of target positioning; in the case of simultaneous placement of multiple electrodes in SEEG, the superposition of resistance may also cause adjacent electrodes to pull each other, shift, or even break. In addition, repeated insertion and removal exacerbate the wear of the sealing material and accelerate the failure of the seal, making it difficult to meet the clinical needs of LITT procedure, which requires multiple fine adjustments of the fiber position, or SEEG procedure, which requires the placement of multiple electrodes in stages.

[0004] Therefore, there is currently a lack of fixation devices that can seal and fix interventional diagnostic and therapeutic devices (electrodes or fiber optic catheters, etc.) and ensure smooth axial movement, facilitating insertion and position adjustment. Existing technologies either prioritize sealing at the expense of operability or weaken the sealing structure in exchange for smooth and easy operation, failing to establish a sealing and fixation mechanism that can balance both aspects. Summary of the Invention

[0005] The purpose of this invention is to provide an interventional device fixation device to solve the technical problems of existing fixation devices being unable to simultaneously achieve sealing and fixation of interventional diagnostic and therapeutic devices, as well as the laborious operation and easy jamming during insertion, removal and fine adjustment.

[0006] In a first aspect, the interventional device fixing device provided by the present invention includes: a hollow nail, a locking element, and a sealing sleeve; The locking member is connected to one end of the hollow nail. The locking member and the hollow nail are provided with an axially penetrating installation channel. The installation channel is used for clearance fitting and sliding insertion of the interventional diagnostic and therapeutic device. The sealing sleeve is installed between the hollow nail and the locking member. The locking member has an inner ring pressing surface that compresses the sealing sleeve radially to compress the sealing sleeve between the locking member and the interventional diagnostic device.

[0007] In conjunction with the first aspect, the present invention provides a first possible implementation of the first aspect, wherein the radial dimension of the inner ring pressing surface decreases from the end near the hollow nail to the end away from the hollow nail.

[0008] In conjunction with the first possible implementation of the first aspect, the present invention provides a second possible implementation of the first aspect, wherein the hollow nail is provided with a first threaded connection portion, the first threaded connection portion cooperating with the locking member to drive the locking member to move axially relative to the hollow nail, and to press the sealing sleeve through the inner ring pressing surface.

[0009] In conjunction with the second possible implementation of the first aspect, the present invention provides a third possible implementation of the first aspect, wherein the hollow nail has a second threaded connection portion at the end away from the locking member; The pitch of the second threaded connection is greater than the pitch of the first threaded connection.

[0010] In conjunction with the third possible implementation of the first aspect, the present invention provides a fourth possible implementation of the first aspect, wherein the hollow nail is provided with a limiting part, the limiting part being located at one end of the second threaded connection near the locking member.

[0011] In conjunction with the first aspect, the present invention provides a fifth possible implementation of the first aspect, wherein the hollow nail has a shaft end that abuts against the sealing sleeve, the sealing sleeve is located outside the hollow nail, and the shaft end of the sealing sleeve abuts against the shaft end and is axially pressed between the shaft end and the locking member.

[0012] In conjunction with the first aspect, the present invention provides a sixth possible implementation of the first aspect, wherein the hollow nail has a shaft end that abuts against the sealing sleeve, the shaft end of the sealing sleeve abuts against the shaft end, and deforms the sealing sleeve to form a first filling portion surrounding the outside of the hollow nail.

[0013] In conjunction with the sixth possible implementation of the first aspect, the present invention provides a seventh possible implementation of the first aspect, wherein, in the state where the sealing sleeve is axially pressed against the shaft end, the sealing sleeve deforms and forms a second filling portion extending into the inner side of the hollow nail.

[0014] In conjunction with the first aspect, the present invention provides an eighth possible implementation of the first aspect, wherein the mounting channel includes an inner sealing hole disposed in the locking member; The inner sealing hole is located on the side of the sealing sleeve opposite to the hollow nail, and is coaxially arranged with the sealing sleeve.

[0015] In conjunction with the first aspect, the present invention provides a ninth possible implementation of the first aspect, wherein the mounting channel includes a channel extending through the hollow nail along its axial direction; The hollow nail has at least one axial end with a hole-expanding guide portion, which is coaxially connected to the channel and its inner diameter gradually increases from the inside to the outside.

[0016] In conjunction with the first aspect, the present invention provides a tenth possible embodiment of the first aspect, wherein the hollow nail has a first fastening engagement portion for engaging with a fastening tool at its axial center.

[0017] In conjunction with the first aspect, the present invention provides an eleventh possible embodiment of the first aspect, wherein one end of the hollow nail connected to the locking member is provided with a second fastening engagement portion for engaging with a fastening tool.

[0018] The embodiments of this invention bring the following beneficial effects: A locking member is connected to one end of a hollow nail. Both the locking member and the hollow nail have an axially penetrating installation channel for clearance fitting and sliding insertion of the interventional diagnostic and therapeutic device. A sealing sleeve is installed between the hollow nail and the locking member. The locking member has an inner ring pressing surface that radially compresses the sealing sleeve to compress it between the locking member and the interventional diagnostic and therapeutic device. The sealing sleeve does not rely on applying a continuous, high-intensity radial interference clamping force to the interventional device to achieve sealing. Instead, the inner ring pressing surface of the locking member actively and controllably compresses the sealing sleeve body radially, causing it to undergo directional deformation and tightly adhere to the surface of the interventional device. This sealing mechanism is essentially an externally driven, asymmetric compression radial seal, which avoids the high static friction and sliding resistance caused by traditional interference fits and overcomes the problems of uneven sealing and rebound hysteresis caused by simple axial compression of the sealing sleeve. This significantly reduces the axial operating force during instrument insertion / removal and intraoperative fine-tuning, eliminating the "stuck-jump" phenomenon, and is especially suitable for improving SEEG electrode positioning and LITT fiber position control.

[0019] Furthermore, this fixation device exhibits excellent ease of operation and durability. On one hand, the sealing effect is independent of the initial dimensional matching between the sealing sleeve and the interventional device, and it does not require a locking device to cover and seal the hollow nail. It is compatible with interventional diagnostic and therapeutic devices of different outer diameters (SEEG electrodes or LITT optical fibers), and can restore an effective seal by retightening the locking device after multiple insertions and removals. On the other hand, the stress on the sealing sleeve is concentrated in its peripheral area, avoiding overall material shear fatigue and significantly delaying aging and permanent deformation caused by repeated deformation. This meets the stringent requirements of neurosurgical procedures for multi-stage operations of a single device (such as stepwise SEEG placement and fiber retraction and repositioning during LITT hyperthermia). In summary, this solution overcomes the technical paradox of mutually restrictive sealing and operational smoothness, achieving a safe, lightweight, and reusable method for fixing interventional devices while ensuring an intracranial sterile barrier and pressure stability.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1This is a cross-sectional view of the interventional device fixation device provided in an embodiment of the present invention; Figure 2 A schematic diagram of the hollow nail in the interventional device fixation device provided in an embodiment of the present invention; Figure 3 A cross-sectional view of the interventional device fixation device and the interventional diagnostic and therapeutic device provided in the embodiments of the present invention; Figure 4 This is a first partially enlarged schematic diagram of the interventional device fixation device and interventional diagnostic and therapeutic device provided in the embodiments of the present invention, in the state where the sealing sleeve is compressed; Figure 5 This is a second partially enlarged schematic diagram of the interventional device fixation device and interventional diagnostic and therapeutic device provided in the embodiments of the present invention, in the state where the sealing sleeve is compressed; Figure 6 This is a third partially enlarged schematic diagram of the interventional device fixation device and interventional diagnostic and therapeutic device provided in the embodiments of the present invention under the condition that the sealing sleeve is compressed.

[0023] Icons: 100-Hollow nail; 101-Shaft end; 102-First fastening part; 103-Second fastening part; 104-Limiting part; 110-First threaded connection part; 120-Second threaded connection part; 200-Locking element; 210-Inner ring pressing surface; 300-Sealing sleeve; 301-First filling part; 302-Second filling part; 400-Interventional diagnostic and therapeutic device; 500-Installation channel; 510-Inner sealing hole; 520-Channel; 521-Enlarged hole introduction part. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used only to describe differences in name and should not be construed as indicating or implying relative importance. Physical quantities in formulas, unless otherwise specified, should be understood as basic quantities in the International System of Units (SI), or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] like Figure 1 and Figure 3 As shown, an embodiment of the present invention provides an interventional device fixation device comprising: a hollow nail 100, a locking member 200, and a sealing sleeve 300; the locking member 200 is connected to one end of the hollow nail 100, and the locking member 200 and the hollow nail 100 are provided with an axially penetrating installation channel 500 for clearance fitting and sliding insertion of the interventional diagnostic and therapeutic device 400; the sealing sleeve 300 is installed between the hollow nail 100 and the locking member 200, and the locking member 200 has an inner ring pressing surface 210 that radially compresses the sealing sleeve 300 to shrink, so that the sealing sleeve 300 is radially pressed between the locking member 200 and the interventional diagnostic and therapeutic device 400.

[0028] The hollow nail 100 is a hollow cylindrical rigid body made of medical-grade titanium alloy (Ti-6Al-4V ELI), possessing excellent biocompatibility, high strength-to-weight ratio, and fatigue resistance. The hollow nail 100 axially extends to form a main channel, constituting the insertion pathway for interventional diagnostic and therapeutic devices 400 (such as SEEG deep brain electrodes, LITT laser fiber with a cooling sheath, etc.). The locking element 200 is a ring-shaped nut structure, threadedly connected to the proximal end of the hollow nail 100 (i.e., the end facing the operator), together defining an axially extending installation channel 500. The inner diameter of this channel is 0.15–0.30 mm larger than the outer diameter of the interventional diagnostic and therapeutic device 400, forming a clearance fit, allowing the device to slide axially without resistance within the channel. The sealing sleeve 300 is an elastomeric ring, which can be made of silicone, with its Shore hardness optimized to balance deformation response and creep resistance; it is pre-installed in the inner cavity of the locking element 200, forming a clearance fit. When the locking element 200 is connected to the hollow nail 100 and tightened along the axial direction of the hollow nail 100, its inner ring pressing surface 210 applies radial pressure from the outside to the inside to the outer peripheral area of ​​the sealing sleeve 300, and the distal end of the sealing sleeve 300 abuts against the proximal end of the hollow nail 100. The inner ring pressing surface 210 forces the sealing sleeve 300 to undergo controllable compression deformation—its inner edge is radially squeezed towards the circumferential surface of the interventional diagnostic and therapeutic device 400, forming a continuous annular contact sealing band; while the remaining area of ​​the sealing sleeve 300 can remain basically free, free from shear deformation. This mechanism makes the sealing force originate from active compression rather than initial interference, significantly reducing the axial sliding friction coefficient of the interventional diagnostic and therapeutic device 400 and completely eliminating "sticking-jumping". This structure decouples the sealing force source from the sliding resistance: the sealing force is driven by the axial displacement of the locking element 200 and acts on the outer periphery of the sealing sleeve 300; while the interventional diagnostic and therapeutic device 400 only bears the normal contact pressure applied to the inner edge of the sealing sleeve 300 after elastic buffering. Its tangential friction force mainly depends on the normal pressure of the contact surface and the equivalent coefficient of friction, which is far lower than the adhesion-shear composite resistance caused by large material deformation in the traditional interference compression scheme. Therefore, under the same clinical operating torque, the axial pushing force of the locking element 200 on the sealing sleeve 300 is reduced, and the locking operation of the locking element 200 is easier.

[0029] It is important to emphasize that the locking element 200 is provided with an inner ring pressing surface 210. This inner ring pressing surface 210 radially compresses the sealing sleeve 300, causing the sealing sleeve 300 to undergo radial contraction deformation. Its inner circumferential surface tightly adheres to the outer circumferential surface of the interventional diagnostic and therapeutic device 400, while its outer circumferential surface tightly adheres to the inner wall of the locking element 200, thus forming two sealing interfaces. During this process, the sealing sleeve 300 does not need to enter the internal channel of the hollow nail 100, nor does it rely on axial compression to generate radial expansion. This makes it easier to adjust the position and disassemble the interventional diagnostic and therapeutic device 400, significantly reducing the difficulty of intraoperative operation and the risk of instrument damage, and achieving a safe, lightweight, and reusable method of fixing interventional devices.

[0030] In an optional embodiment, the hollow nail 100 adopts a multi-stage stepped shaft structure: except for the unthreaded main body in the middle section as described above, its proximal end (on the locking member 200 side) can be further subdivided into a sealing support section and a threaded adjustment section. Among them, the outer diameter of the sealing support section is slightly larger than that of the threaded adjustment section, forming an annular shoulder facing the locking member 200, which is used to limit and support the starting position of the axial compression stroke of the sealing sleeve 300; the end face of the shoulder is ultra-precision ground to ensure that the initial contact of the sealing sleeve 300 is uniform when it is compressed, and to avoid local stress concentration caused by unilateral load.

[0031] In an optional embodiment, an annular snap-fit ​​groove is formed on the outer periphery of the hollow nail 100 (located between the sealing support section and the limiting part 104) for mounting external micro-sensor modules (such as intracranial pressure probes, temperature feedback loops, and fiber Bragg grating strain monitoring units). The groove has a T-shaped cross-section, is compatible with sensor module snap-fitting of different thicknesses, and does not affect the strength and sterilization compatibility of the hollow nail 100 itself.

[0032] In an optional embodiment, the assembly relationship between the hollow nail 100 and the locking element 200 adopts a detachable precision threaded pair to ensure the accuracy of axial displacement adjustment. This accuracy ensures the controllability and consistency of the radial pressure applied by the inner ring pressing surface 210 to the sealing sleeve 300. The sealing sleeve 300 can adopt a segmented modulus design elastomer: the hardness of the outer peripheral pressure-bearing area is slightly lower than that of the inner edge sealing contact area, and it is locally vulcanized to enhance the extrusion resistance while ensuring deformation compliance and preventing lip roll-up under high compression ratios.

[0033] In an optional embodiment, the sealing sleeve 300 adopts an integrally molded multiphase composite structure: in addition to the previously described low-hardness outer periphery and high-hardness inner edge regions, a transition buffer ring can be provided in its axial center—made of silicone, with a hardness between the inner and outer regions, and a thickness accounting for 15% to 20% of the overall height. This ring undergoes axial compression first during the tightening process of the locking member 200, absorbing the initial impact energy and guiding the stress to be transmitted orderly to the inner and outer regions, significantly improving the synchronicity and repeatability of the overall deformation of the sealing sleeve 300.

[0034] Furthermore, the radial dimension of the inner ring pressing surface 210 decreases from the end near the hollow pin 100 to the end away from the hollow pin 100. As the locking member 200 is fastened relative to the hollow pin 100, the inner ring pressing surface 210 gradually increases the degree of compression on the sealing sleeve 300 along the axial direction. The smooth conical transition formed by the inner ring pressing surface 210 can prevent stress concentration from causing the sealing sleeve 300 to be squeezed and torn.

[0035] Specifically, the inner ring pressing surface 210 is a continuous, smooth conical surface with a cone angle ranging from 3° to 10°, preferably 5°. This angle balances pressing stroke efficiency and stress distribution uniformity: if the angle is too small, a larger axial displacement is required to achieve the target radial compression, affecting the operational response speed; if the angle is too large, stress concentration is likely to form on the outer edge of the sealing sleeve 300, inducing local tearing. The conical surface undergoes a micron-level sandblasting and polishing composite treatment and is coated with a biocompatible silicone oil coating (such as polydimethylsiloxane PDMS) to further reduce the interfacial friction between the locking element 200 and the outer periphery of the sealing sleeve 300 during tightening, preventing circumferential torsion or displacement of the sealing sleeve 300 due to dry friction. The conical structure causes the sealing sleeve 300 to experience gradual radial compression during the tightening process, rather than abrupt extrusion. Combined with the aforementioned segmented modulus design, the deformation path of the sealing sleeve 300 exhibits a three-stage evolution from circumferential contraction on the outer periphery to axial extension on the inner edge and finally fitting the surface of the intervention device. This effectively suppresses the peak value of internal shear strain in the material and extends the fatigue life of the sealing sleeve 300 under repeated compression or release cycles.

[0036] Furthermore, although the inner ring pressing surface 210 is a continuous and smooth conical surface, its surface can be divided into three functional sections along the axial direction: a pre-compression zone, a main compression zone, and a final compression zone. The pre-compression zone is close to the hollow nail 100 and has a slightly higher surface roughness. It is used to initially grip the outer periphery of the sealing sleeve 300 to prevent circumferential slippage during the initial tightening. The main compression zone is in the center, is mirror-polished, and has a PDMS coating area, which undertakes the main radial compression task. The final compression zone is far from the hollow nail 100 and has a micro-annular groove to accommodate the small amount of elastomeric material that overflows after the sealing sleeve 300 is compressed, thus preventing the lip from rolling over or being extruded and failing.

[0037] In one embodiment, see Figure 2 and Figure 4 After the locking member 200 is tightened along the axial direction of the hollow nail 100, the sealing sleeve 300 is pressed and tightly filled between the inner ring pressing surface 210 and the interventional diagnostic and therapeutic device 400. At this time, one end of the sealing sleeve 300 abuts against the shaft end 101 of the hollow nail 100, and the end face of the sealing sleeve 300 in contact with the shaft end 101 only undergoes a small amount of deformation, thereby maintaining the stability of the shape of the sealing sleeve 300.

[0038] In another embodiment, see Figure 5 After the locking member 200 is tightened axially along the hollow nail 100, one end of the sealing sleeve 300 abuts against the shaft end 101, causing the sealing sleeve 300 to deform and form a first filling portion 301 surrounding the outside of the hollow nail 100. The first filling portion 301 is pressed between the internal thread of the locking member 200 and the outer wall of the hollow nail 100 (the second fastening fit portion 103), thereby improving the sealing performance at the connection between the hollow nail 100 and the locking member 200.

[0039] In another preferred embodiment, see Figure 6With the sealing sleeve 300 axially pressed against the shaft end 101, the sealing sleeve 300 deforms and forms a second filling portion 302 extending into the inner side of the hollow nail 100. Given that the shaft end of the hollow nail 100 has a reaming guide portion 521, it is easier for the second filling portion 302 to extend into the reaming guide portion 521. The first filling portion 301 wraps around the outside of the hollow nail 100, and the second filling portion 302 fills the space between the inner wall of the reaming guide portion 521 and the interventional diagnostic device 400.

[0040] Further details can be found in [link to relevant document]. Figure 1 , Figure 4 , Figure 5 After the hollow nail 100, locking element 200, and sealing sleeve 300 are assembled and locked, the sealing sleeve 300 is always located outside the hollow nail 100. That is, the sealing sleeve 300 is not embedded in or extends into the main channel (i.e., channel 520) of the hollow nail 100. Therefore, when it is necessary to remove / adjust the interventional diagnostic and therapeutic device 400, the sealing sleeve 300 will not get stuck in the channel 520, resulting in low friction and easy, quick, and non-destructive removal.

[0041] Further details can be found in [link to relevant document]. Figure 6 The hollow nail 100 has at least one axial end with a reaming guide portion 521, which is coaxially connected to the channel 520, and its inner diameter gradually increases from the inside to the outside. That is, the diameter of the reaming guide portion 521 is larger than the diameter of the channel 520. After the hollow nail 100, the locking member 200, and the sealing sleeve 300 are assembled and locked, the sealing sleeve 300 can partially enter the reaming guide portion 521. Because the diameter of the reaming guide portion 521 is larger, compared with the case where the sealing sleeve 300 directly enters the main channel (channel 520), the friction between the sealing sleeve 300 and the side wall of the reaming guide portion 521 is smaller in this invention. Therefore, when it is necessary to remove or adjust interventional diagnostic and therapeutic devices, the sealing structure of this invention is easier and more convenient to operate.

[0042] It should be noted that the end of the sealing sleeve 300 that abuts against the shaft end 101 can be made of a material that is easily deformable, so that it can form an inner and outer layered deformation during compression, thereby forming a first filling part 301 and a second filling part 302. Alternatively, the end of the sealing sleeve 300 that abuts against the shaft end 101 can be provided with an annular cut, and the shaft end 101 is inserted into the annular cut and the sealing sleeve 300 is compressed axially, so that it tightly fills the space between the inner ring pressing surface 210 and the interventional diagnostic and therapeutic device 400. Furthermore, a second fastening fit part 103 is formed on the outer side of the annular cut, filling the space between the internal thread of the locking member 200 and the outer wall of the hollow nail 100 (the second fastening fit part 103); a second filling part 302 is formed on the inner side of the annular cut, filling the space between the inner wall of the enlarged inlet part 521 and the interventional diagnostic and therapeutic device 400.

[0043] In addition, although the distal reaming guide section 521 and the proximal reaming guide section 521 are both funnel-shaped, their cone angles can be set asymmetrically: the cone angle of the distal reaming guide section 521 is slightly larger to meet the high requirements of the surgeon for initial insertion tolerance when operating outside the skull; the cone angle of the proximal reaming guide section 521 is slightly smaller, which, together with the precise guiding effect of the inner sealing hole 510, enhances the centering stability of the instrument exit side and prevents the SEEG electrode from micro-bending deformation or sheath scraping caused by channel eccentricity during the exit process.

[0044] In an optional embodiment, all exposed surfaces of the sealing sleeve 300 (including the inner sealing contact surface) are plasma-grafted to introduce short-chain polyethylene glycol (PEG) side groups, forming a nanoscale hydrophilic brush-like layer. This modification does not change the bulk elastic properties, but can significantly inhibit protein adsorption and platelet adhesion, reducing the risk of biofilm formation and extending the effective sealing window period under long-term SEEG monitoring (≥7 days) or multiple LITT thermal cycling scenarios.

[0045] like Figure 1 , Figure 2 and Figure 3 As shown, the hollow nail 100 has a first threaded connection portion 110, which cooperates with the locking member 200 to drive the locking member 200 to move axially relative to the hollow nail 100, thereby compressing the sealing sleeve 300 through the inner ring pressing surface 210. The hollow nail 100 and the locking member 200 form a precision helical pair: when the locking member 200 is screwed in, its axial displacement is directly converted into a radial pressing stroke on the sealing sleeve 300. Even under axial vibration or slight traction of the instrument during surgery, the locking member 200 will not accidentally loosen. In addition, the degree of compression on the sealing sleeve 300 can be adjusted by screwing the locking member 200 in or out, thereby adjusting the tightness of the fit between the sealing sleeve 300 and the interventional diagnostic and therapeutic device 400.

[0046] The first threaded connection 110 employs a fine-pitch right-hand trapezoidal thread or a machine thread. The right-hand design prevents the locking element 200 from accidentally loosening during surgery due to axial traction from the interventional diagnostic device 400. The trapezoidal thread offers higher axial load-bearing stiffness and lower rotational resistance compared to ordinary metric threads, facilitating precise one-handed adjustment. This threaded pair not only transmits axial displacement but also constitutes a mechanical self-locking system: when the locking element 200 is tightened to the set position, the high helix angle self-locking characteristic of the trapezoidal thread (equivalent friction angle > helix angle) ensures it remains locked under normal intraoperative vibration and instrument traction loads, eliminating the need for additional anti-loosening structures. Simultaneously, the fine-pitch design reduces the axial displacement corresponding to a unit rotation angle, supporting finer adjustments to the sealing force and meeting the precision requirements for SEEG electrode depth adjustment.

[0047] In an optional implementation, the hollow nail 100 and the locking member 200 are made of different materials. In key mating dimensions (such as the outer diameter of the first threaded connection 110 and the bottom diameter of the internal thread of the locking member 200), a thermally induced gap compensation amount is reserved: based on the difference in the coefficient of linear expansion of the two at a physiological temperature of 37°C, the assembly gap at room temperature approaches zero under body temperature conditions, ensuring that the axial displacement accuracy of the threaded pair does not drift during long-term use during surgery.

[0048] In an optional embodiment, the outer peripheral wall of the locking member 200 is provided with rotation direction indicator marks and torque threshold color mark strips: the rotation direction marks are a group of short lines arranged obliquely along the circumference, pointing to the right-hand tightening direction; the color mark strip is printed with medical-grade thermochromic ink, which is light blue at room temperature. When the tightening torque approaches the recommended upper limit (preset according to the material creep characteristics), the local temperature rises and the ink turns light red, providing the operator with an intuitive visual reminder of impending overload and avoiding plastic deformation of the sealing sleeve 300 due to excessive tightening.

[0049] In addition, a thin axially pre-compression elastic washer (made of fluororubber / PTFE composite film) with a thickness of 0.05–0.1 mm can be added between the locking element 200 and the threaded section of the hollow nail 100. This washer generates a small axial rebound force in the initial stage of screwing in the locking element 200, which offsets the locking response delay caused by the manufacturing tolerance of the thread pair or the assembly clearance, making the pressure establishment of the inner ring pressing surface 210 on the sealing sleeve 300 more linear and controllable. This is especially beneficial for the dynamic maintenance of the sealing force in scenarios where the optical fiber needs to be frequently fine-tuned by ±0.5 mm during LITT procedures.

[0050] Furthermore, the end of the hollow nail 100 furthest from the locking member 200 is provided with a second threaded connection portion 120; the pitch of the second threaded connection portion 120 is greater than the pitch of the first threaded connection portion 110. The distal end of the hollow nail 100 (i.e., the end that protrudes from the skull and needs to be fixed to the skull) is also provided with a second threaded connection portion 120, which is a coarse right-hand thread with a pitch greater than that of the first threaded connection portion 110. This design achieves functional zoning and operational decoupling: the second threaded connection portion 120 is used for rapid, large-stroke screwing into the skull guide ring or bone surface; while the first threaded connection portion 110 is used for fine-tuning the seal, and can simultaneously adjust the axial sliding resistance of the interventional diagnostic and therapeutic device 400.

[0051] The second threaded connection 120 is self-tapping, and the hollow screw 100 has a stepped shaft structure: the middle section of the hollow screw 100 is unthreaded and its diameter is slightly larger than that of the first threaded connection 110 and the second threaded connection 120, forming a natural axial positioning step, which facilitates limiting the travel of the threaded connection. The dual-pitch design optimizes ergonomics: the surgeon first uses a high-torque tool (such as an electric bone drill with a special chuck) to quickly screw into the second threaded connection 120 to complete the skull anchoring, and then switches to a finger-operated or micro-torque wrench to finely adjust the locking element 200 to engage with the first threaded connection 110 to achieve a seal. This process reduces preparation time by an average of 35% compared to traditional single-threaded guide screws, reduces surgeon hand fatigue, and is especially beneficial for high-frequency repetitive operations in multi-electrode SEEG surgery.

[0052] In an optional embodiment, the hollow nail 100 is provided with a limiting part 104, which is located at one end of the second threaded connection 120 near the locking member 200. The limiting part 104 can be configured as a convex ring with a radial dimension larger than that of the second threaded connection 120. After the second threaded connection 120 is screwed into the skull and reaches a preset depth, the limiting part 104 abuts against the outer surface of the skull, thereby preventing excessive screwing and potential brain tissue damage.

[0053] The limiting part 104 is an integrally formed convex ring located at the starting end of the second threaded connection part 120. Its outer edge can be chamfered to avoid scratching the scalp tissue. The end face of the convex ring is mirror-polished to form a low-friction sliding interface when in contact with the outer plate of the skull, preventing a sudden increase in torque due to jamming during the screwing process. The limiting part 104 constitutes a physical depth stop to reduce the depth error of the hollow nail 100 screwing into the skull, avoiding over-penetration (such as mistakenly entering the subdural space) or under-penetration (leading to unstable fixation) caused by reliance on experience.

[0054] In an optional embodiment, the limiting part 104 not only serves as a physical stop for the screw-in depth, but its convex ring structure can also extend into radial positioning grooves—a number of shallow grooves evenly distributed along the circumference, for fitting with the optical marking ring or electromagnetic positioning ring of the surgical navigation system, so as to realize the real-time spatial orientation calibration of the hollow nail 100 on the skull surface; the depth and width of the grooves are matched and designed so as not to affect the overall rigidity of the limiting part 104, nor to weaken its fit and sealing with the outer plate of the skull.

[0055] Furthermore, the hollow nail 100 has a shaft end 101 that abuts against the sealing sleeve 300, and the sealing sleeve 300 is axially pressed between the shaft end 101 and the locking member 200. The shaft end 101 is a flat end face perpendicular to the axis, and it can form surface contact with the end face of the sealing sleeve 300. The sealing sleeve 300 is axially pressed between the shaft end 101 and the locking member 200. As the locking member 200 is tightened, the sealing sleeve 300 is compressed axially, causing it to gradually penetrate into the tapered hole surrounded by the inner ring pressing surface 210.

[0056] In an optional embodiment, the end of the sealing sleeve 300 opposite to the shaft end 101 may be provided with two layers (inner ring layer and outer ring layer). When the shaft end 101 abuts against the sealing sleeve 300, the outer ring layer is squeezed by the shaft end 101 and tightly adheres to the inner wall surface of the locking member 200, and the inner ring layer is squeezed by the shaft end 101 and tightly adheres to the circumferential surface of the interventional diagnostic and therapeutic device 400.

[0057] like Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown, in an optional embodiment, a shallow conical guide recess is provided at the center of the end face of the shaft end 101, which matches the corresponding protrusion preset on the end face of the sealing sleeve 300 to achieve initial positioning during assembly; the end of the sealing sleeve 300 that abuts against the shaft end 101 adopts a double-layer composite structure: the outer layer is high-resilience silicone, and the inner layer is low-modulus thermoplastic polyurethane (TPU), which are integrally molded through a blending and vulcanization process; this structure gives the first filling part 301 strong extrusion resistance and the second filling part 302 excellent axial elongation; the inner wall of the flared mouth of the enlarged hole inlet 521 is provided with a guide groove to guide the second filling part 302 to extend along a predetermined path to avoid disorderly accumulation. The collaborative deformation mechanism constructs a three-dimensional sealing barrier: the first filling part 301 seals the annular gap between the hollow nail 100 and the locking part 200, preventing external contaminants from entering along the thread gap; the second filling part 302 fills the gap between the enlarged hole inlet part 521 and the interventional diagnostic device 400, eliminating the leakage channel caused by device eccentricity in traditional straight channels.

[0058] In an optional embodiment, the guide groove on the inner wall of the flared opening of the enlarged inlet portion 521 can be further evolved into a spiral guide groove, the direction of which is consistent with the direction of the thread of the locking member 200. When the interventional diagnostic and therapeutic device 400 is rotated and inserted (such as when the SEEG electrode is operated with a torque control handle), the spiral groove can guide it to rotate smoothly into the center; at the same time, the groove can also trap and drain a small amount of infiltrated tissue fluid or irrigation fluid, avoiding accumulation at the inlet of the channel to form liquid film resistance.

[0059] like Figure 1 and Figure 3As shown, the installation channel 500 includes an inner sealing hole 510 disposed in the locking member 200; the inner sealing hole 510 is located on the side of the sealing sleeve 300 opposite to the hollow nail 100, and is coaxially disposed with the sealing sleeve 300. The inner wall of the inner sealing hole 510 is mirror polished and can be coated with a hydrophobic PTFE nano-coating, which significantly reduces the viscous resistance between the interventional diagnostic and therapeutic device 400 and the metal hole wall when it is inserted.

[0060] The inner sealing orifice 510 features a nanoscale hydrophobic microtexture on its wall: a periodic array of micropillars is fabricated using femtosecond laser processing and then modified with fluorosilane, significantly reducing the tendency of blood / cerebrospinal fluid to spread on the orifice wall; the conical angle of the enlarged inlet section 521 is 3°–15°; its maximum inner diameter is 1.2 to 2 times larger than that of the channel 520, forming a smooth transition zone and preventing turbulent separation of fluid at the inlet; the inner wall of the channel 520 is electropolished and passivated to eliminate microburrs and reduce instantaneous resistance fluctuations during instrument passage. This dual-channel structure achieves Pareto optimality in insertion resistance and sealing performance: the enlarged inlet section 521 lowers the initial insertion threshold, while the inner sealing orifice 510 provides stable guidance and a low-viscosity interface at the final stage.

[0061] In an optional embodiment, the PTFE nanocoating region of the inner sealing hole 510 pore wall can be staggered with the femtosecond laser microtexture region: the micropillar array covers the lower half of the pore wall, while the PTFE coating covers the upper half. This arrangement is optimized based on the natural flow direction of cerebrospinal fluid or blood during device removal, giving the ascending side stronger hydrophobic and anti-adhesive capabilities, while the descending side enhances interfacial shear dissipation through microtexture, synergistically suppressing the capillary effect of fluid being carried into the cranium by the device.

[0062] Furthermore, the installation channel 500 includes a channel 520 extending axially through the hollow nail 100; at least one axial end of the hollow nail 100 is provided with a reamed hole guide portion 521, which is coaxially connected to the channel 520, and its inner diameter gradually increases from the inside to the outside. The channel 520 is a straight circular hole, and the distal end of the hollow nail 100 (i.e., the end where the second threaded connection portion 120 is located) is provided with a reamed hole guide portion 521, which has a bell-shaped chamfered structure, and the proximal end (the side of the locking member 200) is also provided with a symmetrical reamed hole guide portion 521. This double-sided reamed hole design greatly reduces the initial insertion difficulty of the interventional diagnostic and therapeutic device 400. The operator can lightly touch the edge of the reamed hole with the electrode tip, and rely on the conical surface to automatically guide it into the center of the channel 520.

[0063] See Figure 2 As shown, in an optional embodiment, the hollow nail 100 has a first fastening engagement part 102 at its axial center for engaging with a fastening tool. The first fastening engagement part 102 can be configured as a two-plane structure facing opposite directions along the circumference of the hollow nail 100, for engaging with a wrench for tightening. In addition, the first fastening engagement part 102 can also be configured as a hexagonal prism structure, which can also engage with a fastening tool to achieve tightening or loosening operations.

[0064] In this embodiment, the first fastening mating part 102 adopts a double-plane structure: the two parallel planes can be adapted to surgical wrenches; the second fastening mating part 103 is a quadrilateral cross-section prism, compatible with manual ratchet wrenches, electric bone drill chucks, and magnetic surgical instrument racks; both mating parts are treated with a black ceramic coating (Al2O3-TiN composite coating) to improve wear resistance. The differentiated fastening interface design meets the compatibility of tools in multiple scenarios: during the preoperative preparation stage, an electric bone drill with a star-shaped chuck is used to screw the hollow screw 100 in at high speed; during the intraoperative fine-tuning stage, the first fastening mating part 102 is operated with a finger wrench; during postoperative removal, the device is quickly removed using a magnetic rack. No tool head replacement is required throughout the entire cycle, reducing the number of instrument handovers and lowering the risk of intraoperative contamination.

[0065] Furthermore, one end of the hollow nail 100 connected to the locking member 200 is provided with a second fastening engagement part 103 for cooperating with a fastening tool. The second fastening engagement part 103 can be configured as a polygonal structure such as a quadrangular prism or a hexagonal prism. The center of the inscribed circle of the cross-section of the second fastening engagement part 103 perpendicular to the axis of the hollow nail 100 is located on the axis of the hollow nail 100. The second fastening engagement part 103 can be used with an electric drill, wrench, etc., to realize the tightening operation of the hollow nail 100.

[0066] If 1, Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the interventional device fixation device provided in this application has the following technical advantages: (1) It achieves physical decoupling between sealing performance and axial sliding freedom. The locking member 200 drives the inner ring pressing surface 210 to radially squeeze the outer periphery of the sealing sleeve 300 through axial screwing displacement, so that the sealing force acts on the sealing sleeve 300, and the inner edge of the sealing sleeve 300 elastically fits the surface of the interventional diagnostic and therapeutic device 400; while the interventional diagnostic and therapeutic device 400 itself only bears the normal pressure after the elastic buffering of the sealing sleeve 300. Compared with the traditional interference fit sealing scheme, it can achieve smooth axial sliding and can achieve sealing locking after sliding adjustment; (2) It eliminates the "stuck-jump" phenomenon and ensures the millimeter-level depth control accuracy of the SEEG electrode. It adopts a progressive conical surface compression and segmented modulus design (low hardness of the outer periphery to adapt to deformation, high hardness of the inner edge to resist extrusion). The deformation of the sealing sleeve 300 is a three-stage evolution of outer periphery circumferential contraction, inner edge axial extension and finally fitting the interventional diagnostic and therapeutic device 400, which suppresses the peak value of shear strain.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for fixing interventional devices, characterized in that, include: Hollow nail (100), locking element (200) and sealing sleeve (300); The locking member (200) is connected to one end of the hollow nail (100). The locking member (200) and the hollow nail (100) are provided with an axially penetrating installation channel (500). The installation channel (500) is used for clearance fit and sliding insertion of interventional diagnostic and therapeutic device (400). The sealing sleeve (300) is installed between the hollow nail (100) and the locking member (200), the locking member (200) having an inner ring pressing surface (210) that compresses the sealing sleeve (300) radially to compress the sealing sleeve (300) between the locking member (200) and the interventional diagnostic device (400).

2. The interventional device fixation device according to claim 1, characterized in that, The radial dimension of the inner ring pressing surface (210) decreases from the end near the hollow nail (100) to the end away from the hollow nail (100).

3. The interventional device fixation device according to claim 2, characterized in that, The hollow nail (100) is provided with a first threaded connection part (110), which cooperates with the locking member (200) to drive the locking member (200) to move axially relative to the hollow nail (100) and to squeeze the sealing sleeve (300) through the inner ring pressing surface (210).

4. The interventional device fixation device according to claim 3, characterized in that, The hollow nail (100) has a second threaded connection (120) at the end away from the locking member (200); The pitch of the second threaded connection (120) is greater than the pitch of the first threaded connection (110).

5. The interventional device fixation device according to claim 4, characterized in that, The hollow nail (100) is provided with a limiting part (104), which is located at one end of the second threaded connection part (120) near the locking member (200).

6. The interventional device fixation device according to any one of claims 1 to 5, characterized in that, The hollow nail (100) has a shaft end (101) that abuts against the sealing sleeve (300). The sealing sleeve (300) is located outside the hollow nail (100), and the shaft end of the sealing sleeve (300) abuts against the shaft end (101) and is pressed axially between the shaft end (101) and the locking member (200).

7. The interventional device fixation device according to any one of claims 1 to 5, characterized in that, The hollow nail (100) has a shaft end (101) that abuts against the sealing sleeve (300). The shaft end of the sealing sleeve (300) abuts against the shaft end (101) and deforms the sealing sleeve (300) to form a first filling part (301) surrounding the outside of the hollow nail (100).

8. The interventional device fixation device according to claim 7, characterized in that, With the sealing sleeve (300) axially pressed against the shaft end (101), the sealing sleeve (300) deforms and forms a second filling part (302) extending into the inside of the hollow nail (100).

9. The interventional device fixation device according to claim 1, characterized in that, The mounting channel (500) includes an inner sealing hole (510) disposed in the locking member (200); The inner sealing hole (510) is located on the side of the sealing sleeve (300) away from the hollow nail (100) and is coaxially arranged with the sealing sleeve (300).

10. The interventional device fixation device according to claim 1 or 9, characterized in that, The installation channel (500) includes a channel (520) extending axially through the hollow nail (100). The hollow nail (100) has at least one axial end provided with a hole-expanding guide portion (521), which is coaxially connected with the channel (520) and its inner diameter gradually increases from the inside to the outside.

11. The interventional device fixation device according to claim 1, characterized in that, The hollow nail (100) has a first fastening mating part (102) at its axial center for cooperating with a fastening tool.

12. The interventional device fixation device according to claim 1, characterized in that, The hollow nail (100) is connected to the locking member (200) at one end, which is provided with a second fastening engagement part (103) for cooperating with a fastening tool.

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