An electrode implantation tool

Abstract

The application discloses an electrode implantation tool, wherein the distal end of the electrode is provided with a fixing component, the implantation tool comprises an outer sheath and an inner sheath, the inner sheath comprises an inner sheath tube and a first handle, the outer sheath comprises an outer sheath tube and a second handle, the inner sheath tube can be inserted into the outer sheath tube, the first handle is fixed in the second handle, the inner diameter of the inner sheath tube is smaller than the outer diameter of the fixing component, the inner diameter of the outer sheath tube is larger than the outer diameter of the fixing component, and the other part of the electrode except the fixing component can be inserted into the inner sheath tube. The implantation tool provided by the application has a very small diameter and is suitable for conveying a full-implant peripheral electrode or a percutaneous implant electrode for peripheral nerve stimulation treatment with a small diameter, and is matched with the fixing structure at the distal end of the electrode, so that the electrode can be conveyed into the body and firmly combined and fixed with the human body tissue.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, and more particularly to an electrode implantation tool. BACKGROUND

[0002] It is known that many diseases can be treated by electrical stimulation of nerves. For example, acute and chronic pain can be treated by electrical stimulation for a long time, and pain nerve stimulation systems include implanted spinal nerve stimulators, non-implanted skin stimulation, and peripheral nerve treatment by percutaneous implantation of electrodes and external electrical stimulators; sacral nerve stimulation can treat incontinence patients; patients with Parkinson's disease can be treated by stimulating the thalamus with electrodes to treat muscle stiffness and restore mobility. Although these devices can reduce pain and improve the quality of life for patients, these stimulation systems have various defects and deficiencies, and the anatomical differences between patients, insufficient electrical stimulation energy, and the fact that the electrode fixation mechanism is unreliable and ineffective, or the fixation mechanism has not yet been fully integrated with the muscle tissue, causing electrode displacement. Another more important reason is that the implantation tool is problematic, which makes it difficult to ensure that the surgeon implants the electrode into the desired location and fixes the electrode. Doctors need to rely on experience and skill to get lucky to achieve the exact implantation point.

[0003] The existing electrode implantation tool is developed from the implantation tool for spinal pain stimulation electrodes and is applied in percutaneous nerve stimulation. Doctors often use spinal implant electrodes for percutaneous peripheral pain treatment, but since it is off-label use, the electrode and implantation tool do not fully meet the needs of percutaneous implantation. The implantation tool is usually a 14G puncture needle with a large outer diameter.

[0004] The advantages of these implantation tools are that they have been used in spinal and nerve electrical stimulation treatment for more than 20 years worldwide, especially in the United States, and are safe, but in the current development of percutaneous peripheral nerve electrical stimulation treatment, the effectiveness is relatively poor. Because the diameter of the percutaneous stimulation electrode (0.5-1.0mm) is required to be smaller than that of the spinal stimulation electrode (1.3mm or so) to minimize trauma to the patient at the percutaneous site and reduce the risk of infection. Therefore, the small diameter of the percutaneous electrode is inseparable from the implantation tool for delivering the electrode, and this requirement has become one of the industry's pain points.

[0005] Patent CN108472484A discloses that the mutual axial movement of the outer sheath and the inner sheath of the implanted electrode during delivery can partially expose the distal electrode near the human tissue nerve, and the stimulator forms a loop by connecting one end of the outer sheath and the other end of the inner sheath to conduct electrical information, so as to stimulate the point tissue and evaluate whether the expected effect is achieved. The problems of this patent are: (1) The design of the electrode distal end can only be sent out by the delivery sheath for a small part. If the proximal end of the distal hook is also delivered out of the bottom of the outer sheath knife tip, the head end electrode will be released into the tissue and cannot be retrieved once it is released. The electrode can only stay at this point, and if the electrical requirements of this point cannot meet the stimulation treatment requirements, the implanted electrode needs to be replaced with a new electrode, causing waste. It is quite difficult to control the movement of the inner sheath in the outer sheath in this way, which is extremely difficult to achieve in actual products; (2) The patent discloses an opening at the proximal end of the inner sheath opening, which tries to place the distal hook electrode inside. The result may be that the distal electrode hook part is stuck in the opening and cannot be released. Moreover, the original purpose of this design is to reduce the diameter of the implanted tool, but since the distal inner sheath wall thickness still exists, the actual diameter of the electrode and the inner sheath assembly cannot be reduced, and the inner diameter of the outer sheath that needs to accommodate the inner sheath assembly of the delivered electrode cannot be reduced, so the purpose of the opening cannot be achieved; (3) Similarly, the axial slot provided cannot achieve the effect of reducing the diameter of the outer sheath; (4) The patent also discloses that the center of the electrode inner sheath delivery assembly can be embedded with a guide steel wire (stylet). According to the detailed description of the patent (paragraph 165), the outer diameter is 0.7-1.0mm, and the inner diameter is 0.5-0.9mm. The example is an inner diameter of 0.61. At present, the guide wire for medical heart pacemaker is about 0.35mm, and because the diameter is too small to have any rigidity, the 0.61mm inner diameter needs to be occupied by the diameter of the electrode, which indicates that the guide wire has little effect on pushing the electrode in this patent; (5) Since the implantation tool of the peripheral nerve electrode directly affects the puncture trauma of the patient, the design of the peripheral nerve electrode not only considers the small diameter of the electrode, but also considers the small diameter of the implantation tool, so as to effectively reduce the risk of infection and reduce the trauma of the patient. The smallest peripheral implantation tool on the market is 17G (1.47mm), and if the patient has less muscle and fat, a thinner implantation tool is more suitable. In summary, transcutaneous peripheral electrode implantation is a relatively new field at home and abroad, and there are many defects and deficiencies in the existing technology, and there is room for optimization.

[0006] The prior art implantable electrode distal end has a useful helix structure, such as the patent US2005251240A1 describes the principle of the design of the distal end helix structure for endocardial fixation, mainly the cardiac rhythm management electrode according to the needs of endocardial fixation, the helix cannot be exposed during the implantation process, the helix is hidden in the distal end of the tube cover, and when the electrode distal end is transported to the expected position of the endocardium, the proximal end connecting needle (through the helical wire of the electrode body) is connected to the rotation (or the whole rotation electrode) to release the distal end helix hooking on the endocardium, such as a screw into wood, which works to fix the cardiac rhythm pacing electrode on the myocardium, and the connecting needle serves as an implantation tool to release the distal end fixation mechanism. But this invention and principle is based on the diameter of the cardiac rhythm electrode in the size of 7F-8F (2.33mm-2.66mm), which can accommodate a helix structure and a proximal end connecting needle, and an implantation tool and a guide wire, the guide wire provides support, so that the proximal end rotation drives the distal end to release the fixation. The natural conditions of such size space are not available in the environment of percutaneous implantable electrodes, so the design structure of the distal end of the percutaneous implantable electrode must be combined with the structure design of the implantation tool to work together to achieve the fixation of the distal end of the implantable electrode on the tissue muscle of the human body.

[0007] Patent CN108136175A discloses a kind of epicardial defibrillation lead with side spiral fixing device and its placement, and specifically discloses (see specification paragraphs

[0064] -

[0073] ): fixed mechanism 30 can be located at the distal end of lead 18 to attach lead 18 to epicardial tissue;Side spiral member 30 is configured so that it extends radially outward from the electrode lead a short distance, and then spirally winds around at least a portion of the longitudinal axis along the circumference of the lead body;The position of the spiral fixing member 30 is based on the specific application and the intended cardiac anatomy, for small anatomical structures such as pediatric patients, the spiral position can be in the range of about 3 cm to about 6 cm from the distal tip, to allow positioning of a defibrillation electrode about 2 cm to about 5 cm long;Side spiral member 30 includes a major outer diameter (OD) about equal to the outer diameter of the lead body to 1.5F (French) (=0.5mm) larger than it (the outer diameter of the fixed component is larger than the outer diameter of the electrode body). And the patent features although the structure is somewhat similar, but the working mechanism is different from the percutaneous electrode delivery and fixation conditions. Because (1) this is a cardiac rhythm electrode, the diameter can be as thick as 2.33mm-2.66mm and rigid, easy to push and operate it fixed, second, it can accommodate guide wire to support and rotate during implantation;(2) its spiral structure is larger than the mechanism of the electrode body is to rotate the electrode under the support of guide wire and its own rigidity, push the side spiral member greater than 1.5F defibrillation electrode body equivalent to hang a screw, hook the tissue of nearby blood vessel wall and fixed, which is completely different from the working mechanism of percutaneous electrode fixation and delivery in the environment without guide wire support and electrode extremely small without rigid operating force, can not be pushed and rotated.

[0008] The electrodes in the neural therapy system are very thin, and the percutaneous implant electrode needs to be even thinner (0.5mm-1.0mm) because the percutaneous electrode needs to be implanted in the body half and half exposed to the outside of the human body from the tissue, and the exposed point needs the electrode to be as small as possible, because the larger the diameter, the more likely it is to be infected and need to be removed and treated, and the treatment is stopped. Therefore, the diameter of the percutaneous electrode is smaller than that of other implant electrodes, such as the diameter of the spinal cord stimulation electrode is about 1.3mm, and the diameter of the cardiac rhythm management electrode is 2.33mm-2.67mm. In the delivery and positioning release of the distal electrode, the internal space is too small to accommodate the supporting guide wire (stylet) due to the small radial diameter of the electrode, and the center of the spinal cord and cardiac rhythm electrode can be designed to accommodate a guide wire (stylet) with a space of 0.35mm. Therefore, in the delivery of the spinal cord nerve electrode and the cardiac rhythm management therapy electrode, the delivery tool contains and needs the support of the guide wire (stylet) to achieve the expected implantation point of the operator. However, the implantable percutaneous electrode cannot use the guide wire (stylet) during delivery, and the distal end of the electrode must be firmly fixed with the tissue, which is a technical difficulty in the implantation and fixation of the percutaneous electrode compared to other electrode implantation and fixation. Not only does it need to design a special fixation structure at the distal end of the electrode, but the structure of the distal end and the whole electrode also needs to be combined with the delivery tool to work together. Therefore, it is necessary to provide an electrode implantation tool suitable for delivering a percutaneously implantable electrode with a smaller diameter. SUMMARY

[0009] The technical problem to be solved by the present application is to provide an electrode implantation tool suitable for delivering an implantable electrode with a smaller diameter for peripheral nerve stimulation therapy.

[0010] To solve the above technical problems, the present application provides an electrode implantation tool, wherein the distal end of the electrode is provided with a fixing component, and the implantation tool comprises an outer sheath and an inner sheath, the inner sheath comprises an inner sheath tube and a first handle, the outer sheath comprises an outer sheath tube and a second handle, the inner sheath tube can be inserted into the outer sheath tube, the first handle is fixed in the second handle, the inner diameter of the inner sheath tube is smaller than the outer diameter of the fixing component, the inner diameter of the outer sheath tube is larger than the outer diameter of the fixing component, and the other part of the electrode except the fixing component can be inserted into the inner sheath tube.

[0011] Preferably, the inner diameter of the inner sheath tube is 0.5mm-0.7mm, and the outer diameter of the outer sheath tube is 1.07mm-1.27mm.

[0012] Preferably, the fixing component is a spiral structure, the inner diameter of the inner sheath tube is smaller than the outer diameter of the spiral structure, and the inner diameter of the outer sheath tube is larger than the outer diameter of the spiral structure.

[0013] Preferably, the distal end of the inner sheath has a second cutting edge.

[0014] Preferably, further comprising a test needle, the test needle comprising a needle body and a third handle, the needle body being insertable into the outer sheath and the distal end of the test needle being exposed outside the outer sheath, the distal end of the test needle having a third cutting edge, a locking mechanism being provided on the second handle and the third handle, the locking mechanism fixing the third handle on the second handle.

[0015] Preferably, the locking mechanism comprises two L-shaped locking grooves symmetrically provided on the proximal end of the second handle, a locking shaft provided on the third handle, and a locking buckle provided at both ends of the locking shaft, the locking shaft being inserted into the locking grooves, the locking buckle having a size greater than the width of the locking grooves.

[0016] Preferably, the length of the inner sheath in the axial direction is equal to the length of the needle body in the axial direction, and the structure of the first handle is the same as the structure of the third handle.

[0017] Preferably, the outer surface of the outer sheath is provided with a first mark, and the distal end surface of the test needle exposed to the outer sheath is provided with a second mark.

[0018] Preferably, the test needle is a solid needle.

[0019] Preferably, the third cutting edge has a first cutting edge and a second cutting edge in the axial direction from the distal end to the proximal end, the first cutting edge and the second cutting edge are formed with an angle, the second cutting edge is a beveled plane, and the first cutting edge is a beveled arc surface.

[0020] Preferably, the distal end of the outer sheath has a first cutting edge, or the distal end of the outer sheath is flat, and the edge of the distal end of the outer sheath is chamfered in the circumferential direction.

[0021] Preferably, two push plates extending in the radial direction are symmetrically provided on the proximal end of the second handle.

[0022] Compared with the prior art, the present invention has the following beneficial effects: 1. The electrode implantation tool provided by the present invention adopts an inner and outer sheath that matches the distal fixation mechanism of the implanted electrode. The implanted electrode works together with the implantation tool. During the delivery process, the distal electrode is delivered and fixed in the expected position by cooperating with the distal fixation component, which solves the technical difficulty of permanently fixing the implanted electrode in human tissue; 2. The present invention, through the force cooperation between the outer sheath, the inner sheath for delivering the electrode, and the distal fixation structure of the electrode, enables the electrode to be delivered into the body and firmly combined and fixed with human tissue, solving the problem of delivery and fixation of the implanted electrode without a guide wire; 3. Percutaneous implantation of electrodes not only requires the electrode itself to have a small diameter, but the diameter of the implantation tool should also be as small as possible, because a large diameter results in a large trauma. Doctors and patients both hope for minimal trauma and no infection. The diameter of the percutaneous implantation tool should be as small as 17G-18G (1.27mm-1.47mm), which is another challenge in this technical field. The implantation tool provided by this invention can achieve a size of 19G-18G (1.07mm-1.27mm diameter), breaking through the minimum size of 17G for existing implantation tools, and is much smaller than the 14G (2.11mm diameter) implantation tool for spinal stimulation electrodes. 4. The implantation point for electrical stimulation therapy needs to be tested to be successful. Sometimes this test requires multiple repositionings to succeed. How to keep the successful test point consistent with the final implantation point is another challenge in the design of the implantation tool during the implantation process. This invention uses an outer sheath and a test needle assembly to allow the surgeon to puncture near the expected nerve. If the test result is not ideal, the surgeon can withdraw the outer sheath and test needle assembly and puncture a new position. After a successful test, this invention, by leaving the outer sheath in the body and keeping the axial length of the inner sheath and the test needle body consistent, can deliver the electrode to the test point, maximizing the consistency between the test point and the electrode implantation point, thus solving this difficulty. Attached Figure Description

[0023] Figure 1a This is a schematic diagram of the overall structure of the implantation tool equipped with percutaneous implantation electrode leads in an embodiment of the present invention. Figure 1b A partially enlarged schematic diagram of the distal end of an implantation tool containing percutaneous implantable electrode leads;

[0024] Figure 2a This is a schematic diagram of the overall structure of the outer sheath and test needle combined in an embodiment of the present invention. Figure 2b for Figure 2a A magnified view of a portion of the proximal handle. Figure 2c for Figure 2a A magnified view of the combined mid-to-distal outer sheath and test needle;

[0025] Figure 3 This is a schematic diagram of the overall structure of the outer sheath in the first embodiment of the present invention;

[0026] Figure 4(a)、 Figure 4 (b)、 Figure 4 (c) is a partial enlarged view of the distal end of the outer sheath tube in the first embodiment of the present application;

[0027] Figure 5a is a schematic view of the overall structure of the outer sheath in the second embodiment of the present application, Figure 5b is a partial enlarged view of the distal end of the outer sheath tube in the second embodiment of the present application;

[0028] Figure 6 is a schematic view of the overall structure of the test needle in the embodiment of the present application;

[0029] Figure 7 (a)- Figure 7 (e) is an enlarged schematic view of the third cutting edge with different shapes at the distal end of the test needle in the embodiment of the present application;

[0030] Figure 8 is a schematic view of the overall structure of the inner sheath in the embodiment of the present application;

[0031] Figure 9a is a schematic view of the inner sheath with a percutaneous implant electrode lead in the embodiment of the present application, Figure 9b 、 Figure 9c and Figure 9d is a partial enlarged side view of the cooperation between the second cutting edge at the distal end of the inner sheath and the helical fixing part at the distal end of the electrode;

[0032] Figure 10 (a)- Figure 10 (e) is a side view of five different cutting edges at the distal end of the inner sheath tube in the embodiment of the present application;

[0033] Figure 11 (a)- Figure 11 (e) is a front view of five different cutting edges at the distal end of the inner sheath tube in the embodiment of the present application;

[0034] Figure 12a 、 Figure 12b is a schematic view of the parameter variables of the cutting edge in the embodiment of the present application;

[0035] Figure 13 (a)- Figure 13 (d) is a schematic view of the design parameters of five different cutting edges in the embodiment of the present application;

[0036] Figure 14a is a schematic view of the test connection state of the test needle in the embodiment of the present application; Figure 14b is a schematic view of the test connection state of the electrode after implantation of the electrode.

[0037] In the figure:

[0038] 100-implantation tool, 1-outer sheath, 2-inner sheath, 3-test needle, 4-adapter, 5-stimulator, 6-electrode, 10-fixing part, 11-outer sheath tube, 12-second handle, 13-push plate, 14-lock slot, 15-first blade, 16-first mark, 21-inner sheath tube, 22-first handle, 23-first lock buckle, 24-first lock shaft, 25-second blade, 31-needle body, 32-third handle, 33-third blade, 34-second lock buckle, 35-second lock shaft, 36-second mark, 37-cable, 51-first blade, 52-second blade. DETAILED DESCRIPTION

[0039] The application will be further described below with reference to the accompanying drawings and examples.

[0040] In order to more clearly describe the structural features of the application, the application uses "proximal end", "distal end" and "axial direction" as directional words, wherein "proximal end" refers to the end close to the operator, "distal end" refers to the end away from the operator, and "axial direction" refers to the direction of the center axis of the inner sheath tube or the outer sheath tube or the direction parallel to the center axis of the inner sheath tube or the outer sheath tube. The term "or" is generally used in the sense of including "and / or", unless the context clearly indicates otherwise.

[0041] The application provides an electrode implantation tool for delivering a fully implanted peripheral electrode or a percutaneous implanted electrode. The "electrode" referred to in the present embodiment mainly refers to a fully implanted peripheral electrode or a percutaneous implanted electrode, which is used in a peripheral nerve stimulation system. The application cooperates with the electrode and the special fixing structure at the distal end of the electrode (for details, see the invention patent application No. CN202111154697.4) by using the cooperation design of the outer sheath and the inner sheath, to deliver the small electrode (0.6-0.7mm in diameter) to the intended implantation point without the support of a guide wire, and to release the electrode and firmly fix the distal electrode to the human tissue, thereby reducing or even completely removing the clinical adverse events of electrode dislocation. In addition, percutaneous implanted electrical stimulation therapy often needs to find the stimulation point multiple times to achieve the effect of inhibiting pain, and the electrode is implanted near the test point after the test is successful. If the test point and the implantation point are not punctured at one time, it is difficult or impossible to keep the tested point consistent. The application can keep the test point and the implantation point coincident to the greatest extent by using the design and cooperation of the implantation tool and the components, so that the implantation tool is left in the human tissue, the test point and the implantation point are coincident, the electrode is released and fixed in the human tissue by the cooperation of the inner sheath and the fixing part at the distal end of the electrode, and the implantation point and the tested successful position are consistent. In addition, the distal electrode can be firmly fixed to the tissue, thereby reducing or even completely removing the clinical adverse events of electrode dislocation.

[0042] Figure 1a Fig. 1 is a schematic view of the overall structure of an implantation tool with a percutaneous implantation electrode lead, Figure 1b Fig. 2 is a schematic view of a partial enlargement of the distal end of the implantation tool with a percutaneous implantation electrode lead.

[0043] Fig. 3 is a schematic view of the overall structure of an implantation tool with a percutaneous implantation electrode lead, Figure 1a Fig. 4 is a schematic view of a partial enlargement of the distal end of the implantation tool with a percutaneous implantation electrode lead. Figure 1b The present application provides an electrode implantation tool, the distal end of the electrode 6 is provided with a fixing member 10, the implantation tool 100 comprises an outer sheath 1 and an inner sheath 2, the inner sheath 2 comprises an inner sheath tube 21 and a first handle 22, the outer sheath comprises an outer sheath tube 11 and a second handle 12, the inner sheath tube 21 can be inserted into the outer sheath tube 11, the first handle 22 is fixed in the second handle 12, the inner diameter of the inner sheath tube 21 is slightly smaller than the outer diameter of the fixing member 10, the inner diameter of the outer sheath tube 11 is slightly larger than the outer diameter of the fixing member 10, so that the electrode 6 passes through the inner sheath tube 21 and the fixing member 10 stays at the opening of the second cutting edge 25 of the inner sheath tube 21, and at the same time, the inner sheath tube 21 and the outer sheath tube 11 can be combined to be implanted into the patient's body. Further, the fixing member 10 is a spiral structure, as shown in Figure 1b Fig. 5, at this time, the inner diameter of the inner sheath tube 21 is smaller than the outer diameter of the spiral structure, the inner diameter of the outer sheath tube 11 is larger than the outer diameter of the spiral structure, and the other part of the electrode 6 except the fixing member 10 can be inserted into the inner sheath tube 21.

[0044] Figure 2a Fig. 6 is a schematic view of the overall structure of the outer sheath and the test needle combined, Figure 2b Fig. 7 is a schematic view of a partial enlargement of the proximal end handle, Figure 2a Fig. 8 is a schematic view of a partial enlargement of the distal end of the outer sheath tube and the test needle combined. Figure 2c Figure 2a Fig. 9 is a schematic view of the overall structure of the outer sheath and the test needle combined, Fig. 10 is a schematic view of a partial enlargement of the proximal end handle,

[0045] Fig. 11 is a schematic view of a partial enlargement of the distal end of the outer sheath tube and the test needle combined. Figures 2a-2cThe implantation tool 100 further comprises a test needle 3, which comprises a needle body 31 and a third handle 32. The needle body 31 can be inserted into the outer sheath 11, and the distal end of the test needle 3 is exposed outside the outer sheath 11. The distal end of the needle body 31 protrudes 9-11 mm beyond the outer sheath 11. The exposed length should be consistent with the length of the implanted electrode stimulation. In the present embodiment, the length of the implanted stimulation electrode is 10 mm. The purpose is to provide the stimulation information output from the stimulator to the intended test target point by using the surface area of the exposed test needle 3. If the test is unsuccessful, the surgeon can move forward and backward, or withdraw the outer sheath 1 and the test needle 3 assembly to re-puncture and position. Figure 3 、 Figure 4 (a)- Figure 4 (c) shown; or can not be provided with the first blade 15, as shown in Figure 5a and Figure 5b Please continue to see Figure 3 In a specific embodiment, the distal end of the outer sheath 11 is provided with the first blade 15. At this time, the first blade 15 on the outer sheath 1 is the second blade that penetrates the skin and enters the muscle. It is easier to cut the skin than the flat head structure without blades on the outer sheath 1, especially for the skin and muscle of the elderly.

[0046] Further, please continue to see Figure 3 The surface of the outer sheath 11 is provided with a length mark, i.e. the first mark 16, which is subjected to sanding treatment, so that the surgeon can see the depth of the implantation tool 100 into the human body under ultrasound.

[0047] Further, please continue to see Figure 4 (a)- Figure 4 (c), the first blade 15 provided on the distal end of the outer sheath 11 can be provided with blades of different lengths and shapes according to the needs of the human implantation target point.

[0048] The inner diameter of the outer sheath 11 needs to accommodate the test needle 3, the inner sheath 2 with the implanted electrode 6 assembly, i.e. the inner diameter of the outer sheath 11 needs to accommodate the implanted electrode distal end fixed part 10 which is larger than the spiral structure of the electrode body, or other structure of the electrode distal end fixed part 10, and make the needle body 31 of the test needle 3 or the inner sheath 21 with the implanted electrode 6 assembly move smoothly.

[0049] Further, the proximal second handle 12 of the outer sheath 1 needs to be arranged to facilitate the operator to operate with one hand, please refer to Figure 2b , the proximal end of the second handle 12 is provided with a radially extending push plate 13, the push plate 13 is symmetrically arranged on the proximal end of the second handle 12 like two leaves, which can be held by the operator's index finger and middle finger to operate with one hand.

[0050] The second handle 12 of the outer sheath 1 is provided with a locking mechanism to limit the axial movement of the test needle 3, in a specific embodiment, please refer to Figure 2b 、 Figure 3 and Figure 6 , the locking mechanism includes two L-shaped lock grooves 14 symmetrically arranged on the proximal end of the second handle 12, and a lock shaft 35 arranged on the third handle 32 and a lock catch 34 arranged at both ends of the lock shaft 35, the lock shaft 35 is inserted into the lock groove 14, the size of the lock catch 34 is larger than the width of the lock groove 14, the L-shaped lock groove 14 includes an axial slot and a circumferential slot connected in communication, the lock shaft 35 is inserted along the axial slot of the lock groove 14 and then turned into the circumferential slot, the upper and lower housings of the circumferential slot limit the axial movement of the lock shaft 35, and the lock catch 34 at both ends of the lock shaft 35 limits the radial movement of the lock shaft 35, thereby fixing the third handle 32 on the second handle 12, thereby fixing the outer sheath 1 and the test needle 3, facilitating the operator to puncture the outer sheath 1 and the test needle 3 assembly into the human body.

[0051] The outer sheath tube 11 can be made of 304 stainless steel, or other medical alloy materials such as 316L; the periphery of the outer sheath tube 11 that may contact the test needle needs to be insulated, PTFE (polytetrafluoroethylene) material, ETFE material (ethylene-tetrafluoroethylene copolymer) or parylene coating can be applied to the surface of the outer sheath tube 11 that needs to be insulated, so that only the exposed part of the distal end of the test needle 3 is electrically conductive during testing, rather than the entire outer sheath 1 and test needle 3 assembly discharging, which can more realistically simulate the treatment effect of the distal end of the electrode emitting electrical stimulation signals in the body. This insulation effect can also be achieved by insulating the outer surface of the test needle 3 except for the distal discharge part, and keeping the test needle 3 from having an electrical connection with the outer sheath 1. The second handle 12 can be made of relatively strong plastic, such as ABS plastic (a ternary copolymer of three monomers: acrylonitrile (A), butadiene (B), and styrene (S)), PC plastic (polycarbonate), etc. Because the smaller the outer diameter of the implantation tool 100, the better, which is beneficial to reduce the puncture wound, the outer diameter and wall thickness of the outer sheath tube 11 should be designed to be small enough, considering that the outer sheath tube 11 also needs to bear and remain in the human tissue, the implantation tool 100 provided by the present application can be made to be 18G outer diameter 1.27mm, which is much smaller than the outer diameter of the existing implantation tool.

[0052] Referring to Figure 5a and Figure 5b In another embodiment, the distal end of the outer sheath tube 11 is a flat head structure without a cutting edge. Further, a chamfer is provided at the edge of the distal end of the outer sheath tube 11 to facilitate penetration into the human body. Similarly, the surface of the outer sheath tube 11 that can come into contact with the test needle 3 is provided with an insulating layer, or the outer layer of the test needle 3 is insulated except for the exposed portion at the distal end, so that the assembly of the outer sheath 1 and the test needle 3 can form a single electrical circuit for stimulation testing of the intended treatment target of the patient.

[0053] Figure 6 Fig. 4 is a schematic diagram of the overall structure of the test needle. Figure 7 (a)- Figure 7 (e) is a partial enlarged view of the third cutting edge of different shapes at the distal end of the test needle.

[0054] Referring to Figure 6 The needle body 31 of the test needle 3 can be a solid steel needle or a hollow needle. The advantage of a solid needle is that it can strengthen the puncture strength because the percutaneous electrode implantation requires a smaller puncture diameter. The outer diameter of the needle body 31 of the test needle 3 should be designed to be contained in the gap of the outer sheath tube 11 and can smoothly move in the outer sheath tube 11. Further, the distal end of the needle body 31 exposed to the surface of the outer sheath tube 11 is provided with a position mark with sanding treatment, i.e., the second mark 36. The third cutting edge 33 at the distal end can adopt various common cutting edges available, such as Figure 7 (a)- Figure 7 (e) shown. The material of the needle body 31 can be 304 stainless steel or other medical alloy materials such as 316L. The cable 37 is electrically connected to the test needle 3 at the third handle 32 of the test needle 3. The other end of the extension line of the cable 37 is a male-female connector paired with the stimulator.

[0055] Figure 8 Fig. 8 is a schematic diagram of the overall structure of the inner sheath. Figure 9a Fig. 9 is a schematic diagram of the combination of the implanted electrode and the inner sheath, Figure 9b 、 Figure 9c and Figure 9d are side views of the distal end of the inner sheath tube and the helical fixing part of the distal end of the electrode.

[0056] Referring to Figure 8 、 Figure 9a and 9b, the inner sheath 2 which transports the electrode 6 is the key part of the whole implanting tool to push the electrode distal end to the fixed position of the tissue, the electrode 6 implanted from proximal end to distal end includes electrode body, stimulating electrode and fixed part 10, the inner diameter of the inner sheath tube 21 is specially designed based on the outer diameter of the electrode body, stimulating electrode and the fixed part 10 with gradually increasing spiral structure at the distal end of the electrode, which can be 0.5mm-0.7mm, the purpose is to accommodate the electrode body and stimulating electrode in the gap, the electrode body and stimulating electrode can smoothly move in the inner sheath tube 21, and the fixed part 10 with gradually increasing spiral structure at the distal end of the electrode is clamped at the distal end opening of the inner sheath 2 and cannot enter the inner sheath tube 21, if the proximal end pulling force of the electrode 6 and the action of the muscle tissue, the bending angle of the fixed part 10 with gradually increasing spiral structure at the distal end will be larger, as shown in Figure 9c and Figure 9d When the electrode 6 is transported to the vicinity of the nerve or other treatment target by the inner sheath 2, the equal outer diameter of the fixed part 10 with gradually increasing spiral structure at the distal end of the electrode is prevented from continuing to move to the inside of the inner sheath tube 21, and extrusion is generated between the pushing force of the inner sheath tube 21 and the equal outer diameter of the fixed part 10 with gradually increasing spiral structure at the distal end of the electrode, and as a result, the muscle tissue enters the spiral gap of the fixed part 10 to fix the distal end of the electrode, which plays a role in fixing the electrode to the human body, therefore, the design is beneficial to the electrode distal end to set the spiral structure to hook the human tissue to be fixed.

[0057] The inner sheath 2 assembly with the electrode 6 also needs to be smoothly inserted from the proximal end of the outer sheath 1 and freely pushed forward until the distal end of the electrode 6 is exposed to the outer sheath tube 11 by a predetermined distance, similar to the test needle 3, the first handle 22 of the inner sheath 2 and the second handle 12 of the outer sheath 1 are axially locked by setting the locking mechanism, in a specific embodiment, the locking mechanism includes the L-shaped lock slot 14 provided on the second handle 12, the first lock shaft 24 and the first lock buckle 23 provided on the first handle 22, the first lock shaft 24 and the first lock buckle 23 are similar to the second lock shaft 35 and the second lock buckle 34 on the third handle 32, the cooperation and locking process of the first handle 22, the third handle 32 and the second handle 12 is the same, which will not be repeated. The axial length of the inner sheath tube 21 is consistent with the axial length of the needle body 31, which ensures that the distal end of the stimulating electrode is consistent with the position of the part of the test needle that emits electric signals at the distal end, so that the test point is consistent with the implantation target, which ensures the treatment effect.

[0058] After the above implanting steps are completed, the handles of the outer sheath 1 and the inner sheath 2 are locked, and the outer sheath 1 and the inner sheath 2 are withdrawn from the body together, since the fixed part 10 with gradually increasing spiral structure at the distal end of the electrode is fixed firmly with the human muscle, the inner sheath 2 and the electrode 6 are designed to have a loose gap fit, so that when the outer sheath 1 and the inner sheath 2 are pulled out together, the stimulating electrode and the electrode body are left in the position requiring treatment, thus realizing that the electrode implantation target is consistent with the doctor's expectation, which ensures the treatment effect.

[0059] The distal end of the inner sheath 2 can be selected from various blade shapes according to the anatomy of the human body where the implant is intended, such as Figure 10 (a)-10(e) and Figure 11 (a)-11(e) shows the second blade 25 including two blade edges in the axial direction, and a corner is formed between the two blade edges.

[0060] The first blade 15, the second blade 25 and the third blade 33 mentioned in this embodiment are similar in structure, and hereinafter the first blade 15, the second blade 25 and the third blade 33 are collectively referred to as the blade 50, please refer to Figure 12a and Figure 12b Preferably, the blade 50 includes a first blade edge 51 and a second blade edge 52, the first blade edge 51 and the second blade edge 52 form a corner, the total length of the blade 50 in the axial direction is a, the length of the second blade edge 52 in the axial direction is b, further, the second blade edge 52 is a beveled plane, the included angle between the beveled plane and the axis is α, the first blade edge 51 is a beveled arc surface, the tangent line of the beveled arc surface and the axis forms an included angle β, Figure 13 The included angles α of the blades shown in (a)-13(d) are 7°, 11°, 17° and 20° respectively, the total lengths a are 6.77 mm, 4.28 mm, 2.73 mm and 2.3 mm respectively, and the lengths b are 3.66 mm, 2.32 mm, 1.47 mm and 1.1 mm respectively; the puncture blade used in this embodiment has an included angle α of 17° and an included angle β of 33°, as shown in Figure 13 (c), which is suitable for most of the outer peripheral parts. The parameters of the blades can be reasonably selected and adjusted according to the patient's constitution / implantation site, such as Figure 10 (e), 11(e) is a new design of the present application, the included angle α is close to 90°, the angle β is 20°, a is 1.93 mm, and b is only 0.28 mm. This structure can make the angle of the spiral fixation member 10 at the distal end of the electrode 6 smaller, so that the spiral fixation member 10 is subjected to smaller radial force, and is kept as straight as possible in the axial direction, while providing certain support force for the spiral fixation member 10 during implantation, so that it will not be deformed too much; it is suitable for muscle dense parts.

[0061] Figure 14a Figure 1 is a schematic diagram of a needle test connection state; Figure 14b Figure 2 is a schematic diagram of an electrode test connection state after electrode implantation.

[0062] This invention utilizes the combination of an outer sheath 1 and an inner sheath 2 to deliver the electrical stimulation signal of the stimulator 5 to the surgeon's intended stimulation point for testing. After the surgeon and patient agree that pain or other neurological disorders have been suppressed, the surgeon uses the implantation tool 100 provided by this invention to release and fix the electrode 6 to the human tissue with the special fixation component 10 at the distal end of the electrode. This ensures that the implantation point is consistent with the successful test location and allows for firm fixation of the distal stimulation electrode to the human tissue, reducing or even completely eliminating the clinical adverse event of electrode dislocation. The specific steps for delivering the electrode 6 using the implantation tool 100 provided by this invention are as follows:

[0063] 1) The surgeon diagnoses the nerve site that the patient needs to treat and locates the expected implantation point under ultrasound guidance;

[0064] 2) such as Figure 2a As shown, the test needle 3 is inserted into the outer sheath 1 for assembly and locking, and then punctured into the vicinity of the expected nerve implantation point in the human body. Because the test needle 3 is about 10mm longer than the outer sheath 11 in the axial direction, the area where the patient is stimulated and treated is the 10mm part of the test needle 3 exposed outside the outer sheath 11.

[0065] 3) Connect the test needle 3 to the stimulator 5 via cable 37, and attach the surface electrode or extended surface electrode of the stimulator 5 to the human body or under the stimulator 5 to form an electrical circuit for testing. Figure 14a As shown. The evaluation test assesses whether the stimulation waves emitted by stimulator 5 can meet the requirements of electrical stimulation and achieve therapeutic effects;

[0066] 4) If the treatment effect is not achieved, move the position of test needle 3 or withdraw test needle 3 and re-puncture, and test again; until the test meets the treatment needs of the operator and the patient.

[0067] 5) The operator withdraws the test needle 3 and leaves the outer sheath 11 in the human tissue. The purpose is to preserve the target point of the test needle 3. Then, the inner sheath 2 assembly containing the electrode 6 is inserted into the proximal end of the outer sheath 1 and pushed forward until it can no longer go forward. When the distal end of the electrode 6 is pushed out of the distal end of the outer sheath 1, the distal end fixing component 10 of the electrode 6 will bend and combine with the human tissue after being squeezed by the human tissue and fixed.

[0068] 6) Lock the inner sheath 2 and outer sheath 1 using the locking mechanism on the handle; connect the proximal end of electrode 6 to adapter 4 via the cable assembly, and connect adapter 4 to stimulator 5 via the cable assembly, as follows. Figure 14b As shown, this confirms once again whether the stimulation therapy is effective.

[0069] 7) After confirming that the stimulation is effective, confirm that the outer sheath 1 and the inner sheath 2 are locked at the handle, and pull out the outer sheath 1 and the inner sheath 2 together from the body; because the electrode distal end has been fixed to the human tissue by the fixing part 10 in the above step 5), and the inner sheath 2 has a relatively loose gap fit with the electrode 6, when the inner sheath 2 and the outer sheath 1 are pulled out together, the electrode 6 will be left in the human tissue, ending the implantation.

[0070] In summary, the present application solves the following technical problems in the technical field:

[0071] 1. The fixation of the implanted electrode in the tissue is a permanent difficulty for active implanted electrode products, and different products have different requirements for electrode fixation due to different treatment and intended implantation sites of human anatomy, and the technology cannot be borrowed from each other. Because the fixation of the electrode not only requires the structural design of the distal electrode, but also requires the electrode to work with the implantation tool, the distal electrode is delivered and fixed at the intended position through the distal fixation structure design during the delivery process, the present application solves this difficult problem and can be implemented in the product.

[0072] 2. The electrodes in the neural therapy system are very small, among which the percutaneous implanted electrode needs to be smaller, with a diameter size (0.5mm-1.0mm), because the percutaneous electrode needs to be implanted in the body for half of the time, and the other half is exposed to the outside of the body from the human tissue through the skin, and the smaller the diameter of the electrode at this exposed point, the better, because a larger diameter is more likely to cause infection and require the electrode and the therapy system to be removed, stopping the treatment. Therefore, the diameter of the percutaneous electrode is smaller than that of other implanted electrodes, such as the diameter of the spinal cord stimulation electrode is about 1.3mm, and the diameter of the cardiac rhythm management electrode (2.33mm-2.67mm), during the delivery and positioning release of the distal electrode, due to the small internal space of the small radial diameter of the electrode, the center of the spinal cord and cardiac rhythm electrode can be designed to accommodate a 0.35mm space for a guide wire (stylet), therefore, in the delivery of the spinal cord nerve electrode and the cardiac rhythm management therapy delivery electrode, the delivery tool contains and requires the support of the guide wire (stylet), in order to achieve the intended implantation point of the operator. However, the implanted percutaneous electrode cannot use the guide wire (stylet) during delivery, and the distal electrode must be firmly combined and fixed with the human tissue, which is a technical difficulty in the implantation and fixation of the percutaneous electrode compared to other electrode implantation and fixation. The present application solves the technical problem of electrode delivery and fixation without a guide wire by the force matching of the outer sheath and the inner sheath of the delivery electrode and the fixing structure of the electrode distal end, and can be implemented in the product.

[0073] 3. The percutaneous implantation electrode not only requires the electrode itself to be thin in diameter, the diameter of the implantation tool is also required to be as small as possible, because the larger the diameter, the greater the trauma, and both the doctor and the patient hope to have small trauma and no infection. The implantation tool for spinal stimulation electrode is 14G (2.11mm in diameter), but the diameter of the percutaneous implantation tool is as small as 17G-18G (1.27mm-1.47mm), which is another difficulty. The implantation tool provided by the present application can be 18G (1.27mm in diameter), or even smaller (19G, 1.07mm in diameter), which solves this difficulty and is the implantation tool with the smallest diameter at present.

[0074] 4. The implantation point of the electrical stimulation treatment needs to be tested to be successful, and sometimes this test needs to be shifted multiple times before it is successful. How to keep the test successful point consistent with the final implantation point is another difficulty in the implantation process. The present application cooperates the outer sheath with the test needle assembly to enable the operator to puncture into the vicinity of the expected nerve. If the test result is not ideal, the operator can withdraw the outer sheath and the test needle assembly to puncture a new position. After the test is successful, the present application keeps the test point consistent with the electrode implantation point to the greatest extent by leaving the outer sheath in the body, setting the axial length of the inner sheath shaft of the electrode delivery device to be consistent with the axial length of the needle body of the test needle, and delivering the stimulation electrode to the test point, thereby solving this difficulty.

[0075] Although the present application has been disclosed with the above preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present application, therefore the protection scope of the present application shall be subject to the scope defined by the claims.

Claims

1. An electrode implantation tool, wherein a fixing component is provided at the distal end of the electrode, characterized in that, The implantation tool includes an outer sheath, a test needle, and an inner sheath. The inner sheath includes an inner sheath tube and a first handle. The outer sheath includes an outer sheath tube and a second handle. The inner sheath tube can be inserted into the outer sheath tube. The first handle is fixed inside the second handle. The fixing component is a spiral structure. The inner diameter of the inner sheath tube is smaller than the outer diameter of the spiral structure, and the inner diameter of the outer sheath tube is larger than the outer diameter of the spiral structure. Other parts of the electrode, except for the fixing component, can be inserted into the inner sheath tube. The inner sheath assembly containing the electrode can be inserted from the proximal end of the outer sheath and advanced forward until the distal end of the electrode is exposed outside the outer sheath tube. The test needle includes a needle body and a third handle. The needle body can be inserted into the outer sheath tube, and the distal end of the test needle is exposed outside the outer sheath tube. The distal end of the test needle has a third blade. The second handle and the third handle are provided with a locking mechanism. The locking mechanism fixes the third handle to the second handle. The axial length of the inner sheath tube is equal to the axial length of the needle body. The structure of the first handle and the structure of the third handle are the same. The implantation process is as follows: The test needle is inserted into the outer sheath for assembly and locking, and then punctured into the vicinity of the intended nerve implantation point in the human body. Assess whether the stimulation waves emitted by the test stimulator are sufficient for electrical stimulation and to achieve the therapeutic effect; if the therapeutic effect is not achieved, move the test needle or withdraw the test needle and re-puncture, and test again; until the test meets the treatment needs of the operator and the patient. Remove the test needle, leave the outer sheath in the human tissue, then insert the inner sheath assembly containing the electrode into the proximal end of the outer sheath, and push it forward until it can no longer go forward. When the distal end of the electrode is pushed out of the distal end of the outer sheath, the distal end fixing component of the electrode will bend and combine with the human tissue after being squeezed by the human tissue and thus be fixed. Lock the inner and outer sheaths together using the locking mechanism on the handle; once the stimulation is confirmed to be effective, remove the outer and inner sheaths together from the body; the electrode remains in the human tissue, and the implantation is complete.

2. The implantation tool as described in claim 1, characterized in that, The inner diameter of the inner sheath is 0.5mm-0.7mm, and the outer diameter of the outer sheath is 1.07mm-1.27mm.

3. The implantation tool as described in claim 1, characterized in that, The distal end of the inner sheath has a second cutting edge.

4. The implantation tool as described in claim 1, characterized in that, The locking mechanism includes two L-shaped locking slots symmetrically arranged on the proximal end of the second handle, a locking shaft arranged on the third handle, and locking buckles arranged at both ends of the locking shaft. The locking shaft is inserted into the locking slot, and the size of the locking buckle is larger than the width of the locking slot.

5. The implantation tool as described in claim 1, characterized in that, A first mark is provided on the outer surface of the outer sheath, and a second mark is provided on the distal surface of the test needle exposed in the outer sheath.

6. The implantation tool as described in claim 1, characterized in that, The test needle is a solid needle.

7. The implantation tool as described in claim 1, characterized in that, The third cutting edge has a first cutting edge and a second cutting edge in the axial direction from the distal end to the proximal end. The first cutting edge and the second cutting edge form an angle. The second cutting edge is a beveled plane, and the first cutting edge is a beveled arc surface.

8. The implantation tool as described in claim 1, characterized in that, The distal end of the outer sheath has a first cutting edge, or the distal end of the outer sheath is flat-headed, and the distal edge of the outer sheath is chamfered circumferentially.

9. The implantation tool as described in claim 1, characterized in that, Two radially extending push plates are symmetrically arranged on the proximal end of the second handle.

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