Implantable stimulation lead and stimulation system

Abstract

The invention provides an implantable stimulation lead and a stimulation system, and the stimulation lead comprises a flat contact section which is provided with a semi-exposed stimulation contact embedded on the surface and is internally provided with a bunching lead connected with the stimulation contact; the transition section is connected with the contact section, is gradually narrowed and is internally provided with a reinforcing part, and the reinforcing part is conductively connected with the bunching wire; the extension section is connected with the transition section and is internally provided with an extension wire, and the extension wire is conductively connected with the reinforcing part; the reinforcing part is composed of a plurality of first bending units and a plurality of second bending units, the bending direction of the first bending units is transversely and spirally crossed with the extension direction of the extension section, and each second bending unit is composed of the first bending units and is bent in the extension direction of the extension section. According to the invention, the lead structure in the transition section is redesigned, so that the lead structure has elastic margins in the transverse direction and the longitudinal direction, and the disconnection problem caused by stress concentration and metal fatigue in the bending process of the transition section is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to an implantable stimulation lead and stimulation system. Background Technology

[0002] Neuromuscular stimulation electrodes used for nystagmus can transmit electrical stimulation to the extraocular muscles, inhibiting or regulating abnormal muscle activity through specific electrical signal waveforms, thereby suppressing the nystagmus condition. Compared with traditional extraocular muscle shortening surgery, this method is safe and reversible, and has broad application prospects.

[0003] An implantable neurostimulator consists of a pulse generator and a stimulation lead (including an extension lead and a stimulation electrode). One end of the stimulation lead is fixedly connected to the pulse generator, and the other end (the stimulation electrode) is fixed to the extraocular muscle. It serves to transmit stimulation signals and apply electrical stimulation. It needs to maintain stable mechanical and electrical properties during long-term implantation (usually several to several decades).

[0004] Unlike other neuromodulation devices such as deep stimulators, vagus nerve stimulators, spinal cord stimulators, and peripheral nerve stimulators, which are relatively fixed in position, the neuromuscular stimulation electrodes used for nystagmus are fixed to the extraocular muscles and undergo a great deal of daily activity. The stimulation leads are stretched, compressed, bent, and twisted in conjunction with eye movements, which places stringent demands on their mechanical properties. Summary of the Invention

[0005] To reduce the occurrence of wire breakage in the transition section and thus extend the actual service life of the implantable stimulation lead, in a first aspect of the present invention, an implantable stimulation lead is provided, comprising: a contact section, the contact section being flat and having a semi-exposed stimulation contact embedded on its surface and a bundle conductor connected to the stimulation contact; a transition section, the transition section being connected to the contact section and gradually narrowing and having a reinforcing portion inside, the reinforcing portion being electrically connected to the bundle conductor; and an extension section, the extension section being connected to the transition section and having an extension conductor inside, the extension conductor being electrically connected to the reinforcing portion; wherein, the reinforcing portion is composed of a plurality of first bending units and a plurality of second bending units, the bending direction of the plurality of first bending units being laterally spirally intersecting the extension direction of the extension section, and each second bending unit being composed of a plurality of first bending units and bending along the extension direction of the extension section.

[0006] In one or more embodiments, the first bending unit is a first spiral bending unit.

[0007] In one or more embodiments, the second bending unit includes: an S-shaped bending unit or a second spiral bending unit.

[0008] In one or more embodiments, the outer diameter of the first bending unit is smaller than the outer diameter or width of the second bending unit.

[0009] In one or more embodiments, the bundle conductor is an S-shaped conductor or a spiral conductor.

[0010] In one or more embodiments, the implantable stimulation lead further includes: a cannula, embedded in the transition section, and sleeved around the periphery of the reinforcement portion and extending to the connection point between the reinforcement portion and the extension lead and the bundle lead.

[0011] In one or more embodiments, the inner diameter of the sleeve is greater than the bending width or the outer diameter of the helix of the reinforcement.

[0012] In one or more embodiments, the bundled wire, the reinforcing portion, and the extension wire are corresponding spatial structures formed by bending different parts of the same wire.

[0013] In one or more embodiments, the extension conductor includes an S-shaped conductor or a spiral conductor.

[0014] In a second aspect of the invention, a stimulation system is provided, comprising: an electrical stimulation source; and a stimulation lead according to any of the above embodiments, wherein a distal end of the stimulation lead relative to a contact segment is connected to the electrical stimulation source.

[0015] The beneficial effects of the present invention include: by redesigning the conductor structure within the transition section, the present invention provides elasticity in both the horizontal and vertical directions, thereby reducing the problem of disconnection caused by stress concentration and metal fatigue during bending of the transition section. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the implantable stimulation lead according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the connection structure of the reinforcing part in an embodiment of the present invention; Figure 3 This is a schematic diagram of the stimulation system according to an embodiment of the present invention.

[0018] The meanings of the reference numerals in the above figures are as follows: Contact section 10, stimulation contact point 11, bundled wire 12, suture hole 13, transition section 20, reinforcement section 21, first bending unit 22, second bending unit 23, extension section 30, extension wire 31, suture section 32, sleeve 40, electrical stimulation source 100. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0020] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0021] To reduce the risk of electrode wire breakage due to stretching, bending, and torsion caused by eye movements within the transition section of the stimulation lead, and to extend the actual lifespan of the implantable stimulation lead, this invention improves the structure of traditional implantable stimulation leads and proposes a new type of implantable stimulation lead. For example... Figure 1 As shown, it includes: a contact section 10, which is flat and has semi-exposed stimulation contacts 11 embedded on its surface, and a bundle conductor 12 connected to the stimulation contacts 11; a transition section 20, which connects to the contact section 10 and gradually narrows, and has a reinforcing part 21 inside, the reinforcing part 21 being electrically connected to the bundle conductor 12; and an extension section 30, which connects to the transition section 20 and has an extension conductor 31 inside, the extension conductor 31 being electrically connected to the reinforcing part 21; wherein, as... Figure 2 As shown, the reinforcing part 21 is composed of multiple first bending units 22 and second bending units 23. The bending direction of the multiple first bending units 22 is spirally intersected with the extension direction of the extension section 30. The second bending unit 23 is composed of multiple first bending units 22 and bends along the extension direction of the extension section 30.

[0022] Specifically, the first bending unit 22 is designed with a spiral bend along the radial direction of the electrode wire, which can resist or buffer the bending force / torque and part of the torque on the electrode wire. The second bending unit 23 is composed of multiple first bending units 22 connected smoothly in sequence, and its extension direction is the same as the axial direction of the electrode wire. It not only has the mechanical properties of the first bending unit 22, but also resists or buffers the tensile force, bending torque and a large part of the torque on the electrode wire. The special overall structural design of the reinforcing part 21 not only gives it excellent resistance to tension, pressure, bending moment and torque, but also, combined with the flexible material of the electrode wire and the medical flexible silicone material on the outer periphery of the wire, can more fully resist or buffer the tensile force, bending torque and torsional torque on the electrode wire, effectively preventing the electrode wire from breaking due to the stretching, bending and torsion caused by eye movement in the transition section.

[0023] Furthermore, the unique structural design of the reinforcing part 21, embedded within the transition section 20 of the electrode wire, and through a rational dimensional design, further enhances the toughness of the transition section 20, particularly strengthening its resistance to bending and torsion. The effective combination of the reinforcing part 21 and the electrode wire transition section 20 achieves an unexpected effect greater than the sum of its parts: The unique structural design of the first bending unit 22 and the second bending unit 23 ensures that when external forces, bending, and torques are transmitted to the transition section 20 and further to the first bending unit 22 and the second bending unit 23, the disordered forces and bending and torques in various directions are effectively resisted and absorbed due to the perpendicular or transverse bending direction structure of the first bending unit 22 and the second bending unit 23. This significantly weakens the impact of bending and torque on the transition section 20 and extends its service life. Simultaneously, the coverage of the reinforcing part 21 by the transition section 20 provides a stable carrier for the perpendicular or transverse spiral (planar or spatial) bending direction structure of the first bending unit 22 and the second bending unit 23. The unique structure of the first bending unit 22 and the second bending unit 23 acts like a large spatial net implanted within the transition section 20, expanding the number of effective contact points and the effective contact area between the first bending unit 22 and the second bending unit 23 and the transition section 20 at multiple spatial positions and angles on the three-dimensional surface. This greatly improves the toughness of the transition section 20, further enhancing its ability to resist external deformation.

[0024] The special structural combination of the first bending unit 22 and the second bending unit 23 significantly improves the mechanical properties of the reinforcing part 21 and the transition section 20 of the electrode wire. Bending and torsional fatigue tests have verified that the fatigue test count of this structure design is 2-3 orders of magnitude higher than the original structure. Furthermore, in this embodiment, the bundled wire 12, the reinforcing part 21, and the extension wire 31 are formed by bending different parts of the same wire. To improve the tensile strength of the wire within the transition section—that is, the reinforcing part 21—the invention improves the spatial structure of the reinforcing part 21, allowing for expansion and contraction in multiple tensile directions. This results in more elastic stretching rather than extended stretching, effectively reducing metal fatigue. Optionally, the stimulation contact 11 can be a thin metal electrode sheet, such as a platinum-iridium alloy sheet; alternatively, a non-metallic electrode, such as a flexible porous conductive rubber dry electrode, can be selected.

[0025] In one embodiment, the first bending unit 22 includes a first helical bending unit. In this embodiment, since the helical bending direction of the first bending unit 22 helically intersects the extension direction of the extension segment 30, the first bending unit 22 can provide a certain lateral expansion and contraction allowance when the transition segment 20 is laterally stretched, thereby improving the tensile strength of the reinforcing part 21. Furthermore, the helical design also helps to avoid stress concentration, thereby further strengthening its tensile strength. Figure 2 As shown, the first bending unit 22 adopts a small spiral structure, which not only has lateral expansion and contraction margin, but also has a certain resistance to compression and impact, and can perform deformation buffering when subjected to radial pressure.

[0026] In one embodiment, the second bending unit 23 includes an S-shaped bending unit or a second spiral bending unit. In this embodiment, the second bending unit 23 is formed by connecting multiple first bending units 22 in an S-shaped or spiral manner. The second bending unit 23 is in the same direction as the extension wire 31, and the second bending allows the spiral bending direction of the first bending unit 22 to have more angles relative to the extension direction of the extension wire 31, thereby providing a higher degree of freedom.

[0027] In one embodiment, the outer diameter of the first bending unit is smaller than the outer diameter or width of the second bending unit. The width refers to the distance between two adjacent peaks or troughs when the second bending unit employs an S-shaped bending element.

[0028] In one embodiment, the bundled conductor is an S-shaped conductor or a spiral conductor. Specifically, the stimulation lead in this invention has multiple conductive cores, the number of which is the same as the number of electrode contacts. In the extension and transition sections, the multiple conductor cores are completely bundled together, while in the contact section, some conductor cores are bundled together to form the bundled conductor 12, and the lead-out ends of the bundled conductor 12 are separated for welding to different electrode contacts respectively.

[0029] In one embodiment, the implantable stimulation lead of the present invention further includes a sheath 40, which is embedded within the transition section 20 and sleeved around the periphery of the reinforcing part 21, extending to the connection point between the reinforcing part 21 and the extension lead 31 and the bundle lead 12. Specifically, the inner diameter of the sheath 40 is larger than the bending width or spiral outer diameter of the reinforcing part 21 to form a space for lead movement, allowing the connection points between the reinforcing part 21 and the bundle lead 12, and between the reinforcing part 21 and the extension lead 31, to freely and elastically expand and contract, reducing stress concentration in the bundle lead 12 when subjected to bending forces and moments at the connection points.

[0030] In one embodiment, the bundle conductor 12, the reinforcing part 21, and the extension conductor 31 are different parts of the same conductor and have corresponding spatial structures. Specifically, the bundle conductor 12, the reinforcing part 21, and the extension conductor 31 in this invention are a single conductor, but due to their different locations, the methods of reinforcement are also different. In particular, since the transition section is a stress concentration point, the reinforcement design in the transition section of this invention is more complex. By designing a second-order helical bending structure, the probability of breakage in the transition section is reduced, thereby extending the service life of the stimulation lead.

[0031] In one embodiment, the contact segment 10, transition segment 20, and extension segment 30 are all made of a biocompatible elastic material. Specifically, the contact segment 10, transition segment 20, and extension segment 30 are all made of a biocompatible silicone material. Optionally, suture holes 13 are provided on both sides of the contact segment for fixation. Optionally, a suture portion 32 is provided near the transition segment of the extension segment for fixation.

[0032] In one embodiment, the extension conductor includes an S-shaped conductor or a spiral conductor.

[0033] In one embodiment, the first spiral bending unit and the second spiral bending unit of the present invention are made by winding a self-designed spiral winding bar. The diameter of the thin end of the winding bar is 0.200-0.270mm, and the diameter of the thick end is 0.7mm (the thick end is not affected by tension). The diameter of the platinum-iridium alloy wire used for conduction is 0.025mm. After winding, the diameter of the spiral structure is 0.225mm-0.295mm. After the wire is wound around the winding bar, the spiral will increase by 0.005mm. The thickness of the silicone is 0.500mm, so that the thickness of the silicone on both sides is at least 0.1mm. If the diameter of the wound wire (the diameter of the helical structure) is less than 0.2 mm, the rigidity of the helical structure will increase, affecting eye movement and causing discomfort. This discomfort manifests in the following ways: First, the eyeball is a very soft, delicate, and vascularized tissue. Eye movement requires precise coordination of six extraocular muscles, with large and frequent movements. If the electrode wire is too stiff, it cannot bend and move synchronously and smoothly when the eyeball attempts to move. Second, there is a mechanical mismatch. Ideally, a bio-implant should have similar mechanical properties (such as softness and elastic modulus) to the surrounding tissue. A severe "mechanical mismatch" exists between an overly stiff electrode wire and the soft eye tissue, leading to continuous friction, pressure, and even cutting of the surrounding tissue, causing chronic inflammation and fibrosis. However, the diameter of the wound wire (the diameter of the helical structure) should not be too large, such as greater than 0.3 mm, as this would directly cause the conductive wire to easily puncture the silicone layer during bending.

[0034] In a second aspect of the invention, a stimulation system is proposed, such as Figure 3 As shown, it includes: an electrical stimulation source 100; and a stimulation lead according to any of the above embodiments, the distal end of the stimulation lead relative to the contact segment being connected to the electrical stimulation source 100. Optionally, the stimulation source 100 includes a receiving coil and a rectifier circuit, wherein the receiving coil is used to receive wireless power.

[0035] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. The embodiment numbers disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0036] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. An implantable stimulation lead, characterized in that, include: The contact section is flat and has semi-exposed stimulation contacts embedded on its surface, as well as a bundle wire connected to the stimulation contacts. The transition section is connected to the contact section and gradually narrows, and has a reinforcing part inside, which is electrically connected to the bundled wires; An extension section is connected to the transition section and has an extension wire inside it, the extension wire being electrically connected to the reinforcing part; The reinforcing part is composed of multiple first bending units and multiple second bending units. The bending direction of the multiple first bending units is spirally intersecting the extension direction of the extension segment. Each second bending unit is composed of multiple first bending units and bends along the extension direction of the extension segment.

2. The implantable stimulation lead according to claim 1, characterized in that, The first bending unit is a first spiral bending unit.

3. The implantable stimulation lead according to claim 2, characterized in that, The second bending unit includes: an S-shaped bending unit or a second spiral bending unit.

4. The implantable stimulation lead according to claim 1, characterized in that, The outer diameter of the first bending unit is smaller than the outer diameter or width of the second bending unit.

5. The implantable stimulation lead according to claim 1, characterized in that, The bundle conductor is an S-shaped conductor or a spiral conductor.

6. The implantable stimulation lead according to claim 1, characterized in that, Also includes: The sleeve is embedded in the transition section and is fitted around the periphery of the reinforcement and extends to the connection between the reinforcement and the extension wire and the bundled wire.

7. The implantable stimulation lead according to claim 6, characterized in that, The inner diameter of the sleeve is greater than the bending width of the reinforcing part or the outer diameter of the spiral.

8. The implantable stimulation lead according to claim 1, characterized in that, The bundled conductor, the reinforcing section, and the extension conductor are different parts of the same conductor.

9. The implantable stimulation lead according to claim 1, characterized in that, The extension conductor includes: an S-shaped conductor or a spiral conductor.

10. A stimulation system, characterized in that, include: Electrical stimulation source; as well as According to any one of claims 1-9, the stimulation lead is connected to the electrical stimulation source at its distal end relative to the contact segment.

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