Stimulating lead and stimulating system comprising the same

Abstract

A stimulation lead and a stimulation system comprising the stimulation lead are provided. The stimulation lead is used to direct electrical stimulation to a stimulation site. The stimulation lead comprises an insulating housing extending in a longitudinal direction from a distal end to a proximal end, an electrode contact arranged at the distal end of the insulating housing and at least partially exposed outside the insulating housing, and an inner conductor connecting the electrode contact to an electrical stimulation source and extending at least partially inside the insulating housing in the longitudinal direction. The inner conductor is configured to be extendable to be able to change a length of the inner conductor in the longitudinal direction. The electrode contact of the stimulation lead can be stably positioned at a specific location.

Description

Technical Field

[0001] The present invention relates to a stimulation lead and a stimulation system comprising such a stimulation lead, which is particularly suitable for stimulating extraocular muscles. Background Technology

[0002] Nystagmus is an involuntary, rhythmic, and reciprocating movement or jerking of the eyeballs. Clinically, it presents with complex symptoms and is often accompanied by visual impairment in both eyes. Based on the underlying disease causing nystagmus, it is classified into ocular nystagmus, vestibular nystagmus, central nystagmus, and nystagmus of unknown cause.

[0003] Ocular nystagmus is closely related to ophthalmological clinical practice, and is mainly congenital nystagmus (CN). It commonly occurs at birth or within the first four months of life, with a prevalence of 1 / 1000 to 1 / 1500 in children, affecting millions worldwide. Congenital nystagmus is classified according to its etiology into sensory defect nystagmus (SDN) and congenital idiopathic nystagmus (CIN).

[0004] Motor deficit nystagmus is a congenital defect in the efferent mechanism of nystagmus, with a normal afferent mechanism and no associated ocular abnormalities. It often manifests as impulsive nystagmus. The main harm of motor deficit nystagmus is that it leads to amblyopia. According to statistics, among these patients, amblyopia cases account for 86.7%, moderate to severe amblyopia accounts for 20.2%, and moderate amblyopia accounts for 52.3%. Therefore, the impact of motor deficit nystagmus on vision is widespread.

[0005] Because the specific pathogenesis of motor deficit nystagmus is unclear and there is a lack of effective treatments in clinical practice, this disease has always been a difficult and important issue for ophthalmology.

[0006] Chinese Patent Publication CN106861041A describes an implantable extraocular muscle neuromuscular stimulator for treating motor nystagmus and its parameter setting method. It detects the contraction of the extraocular muscles and stimulation signals, and provides corresponding stimulation to the extraocular muscles to balance nerve stimulation and counteract contraction, so as to keep the eyeball fixed and prevent nystagmus.

[0007] A muscle or nerve stimulator includes an electrical stimulation source and a stimulation lead with electrode contacts thereon. The electrical stimulation source generates a stimulation signal, and the stimulation lead transmits the stimulation signal from the electrical stimulation source to a specific site to be stimulated. There is a need for a stimulation lead that can stably and accurately transmit the stimulation signal from the electrical stimulation source to a site to be stimulated, such as the extraocular muscles. Summary of the Invention

[0008] At least one embodiment of this disclosure provides a stimulation lead for directing electrical stimulation to a site to be stimulated. The stimulation lead includes: an insulating housing extending from a distal end to a proximal end in a longitudinal direction; electrode contacts disposed at the distal end of the insulating housing and at least partially exposed outside the insulating housing; and an inner conductor connecting the electrode contacts to an electrical stimulation source and extending at least partially within the insulating housing in the longitudinal direction. The inner conductor is configured to be stretchable, allowing its length to be varied in the longitudinal direction.

[0009] Because the inner conductor is configured to be stretchable so that its length can be changed in the longitudinal direction, the inner conductor can change its length as the eye moves, thereby allowing the electrode contacts connected to its inner conductor to be positioned more stably in a specific location.

[0010] For example, in some embodiments, the inner conductor includes a helical segment that extends in a helical or zigzag manner along the longitudinal direction of the stimulation lead.

[0011] For example, in some embodiments, the spiral section is located inside the insulating housing.

[0012] For example, in some embodiments, the insulating housing is elastic to allow the length of the insulating housing to be changed in the longitudinal direction.

[0013] Therefore, the insulating shell can change its length along with the internal conductors so that the electrode contacts can be more stably positioned in a specific location.

[0014] For example, in some embodiments, the insulating housing is made of silicone.

[0015] For example, in some embodiments, the insulating housing includes a stimulation segment located at a distal end and a connecting segment extending proximally from the stimulation segment along the longitudinal direction, the electrode contacts being fixed to the stimulation segment, the stimulation segment being flat in shape.

[0016] The flat-shaped stimulation segment can be more stably fitted and placed on the site to be stimulated.

[0017] For example, in some embodiments, the stimulation segment includes a thickness and a width, the ratio of which is in the range of 1 / 4 to 1 / 2.

[0018] For example, in some embodiments, the connecting segment is cylindrical, and the insulating housing further includes a transition segment disposed between the connecting segment and the stimulation segment.

[0019] For example, in some embodiments, the stimulation lead further includes at least one fixing portion disposed on the insulating housing for fixing the stimulation lead.

[0020] The fixed portion helps ensure that the position of the stimulation lead, especially the distal part of the stimulation lead, remains unchanged relative to the site to be stimulated.

[0021] For example, in some embodiments, the at least one fixing portion is provided with a fixing hole for the fixing wire to pass through.

[0022] For example, in some embodiments, the diameter of the fixing hole is in the range of 0.1-0.2 mm.

[0023] For example, in some embodiments, the stimulation lead further includes at least one fixing portion disposed on the insulating housing for fixing the stimulation lead. The at least one fixing portion includes a plurality of first fixing portions disposed at the stimulation segment of the insulating housing, which are respectively disposed on both sides of the electrode contact along the longitudinal direction.

[0024] For example, in some embodiments, the at least one fixing portion further includes a second fixing portion near the proximal end of the stimulation lead relative to the first fixing portion, the distance between the second fixing portion and the first fixing portion along the longitudinal direction being greater than the distance between the plurality of first fixing segments along the longitudinal direction.

[0025] The second fixing part helps to isolate the effect of proximal forces on the electrode contacts at the distal end of the stimulation lead.

[0026] For example, in some embodiments, the distance between the plurality of first fixing portions is in the range of 1-5 mm, and the distance between the second fixing portion and the first fixing portion is in the range of 1-30 mm.

[0027] For example, in some embodiments, the stimulation lead further includes at least one fixing portion disposed on the insulating housing for securing the stimulation lead. The at least one fixing portion includes a plurality of first fixing portions disposed at the stimulation section of the insulating housing and a second fixing portion disposed at the transition section of the insulating housing.

[0028] For example, in some embodiments, the internal conductor is soldered to the electrode contacts.

[0029] For example, in some embodiments, the distal end of the stimulation lead is configured to be placed on the extraocular muscle, and the length of the stimulation lead is in the range of 15-21 cm.

[0030] This length is particularly suitable for stimulation leads used to stimulate extraocular muscles.

[0031] At least one embodiment of this disclosure provides a stimulation system including an electrical stimulation source and a stimulation lead as described above, the proximal end of the stimulation lead being connected to the electrical stimulation source. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation on the scope of protection. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic top view of a stimulation lead according to an embodiment of the present disclosure is shown;

[0034] Figure 2 It shows Figure 1 An enlarged view of the portion containing the middle electrode contact;

[0035] Figure 3 for Figure 1 A schematic side view of the central stimulation lead;

[0036] Figure 4 A schematic top view of a stimulation lead and an electrical stimulation source according to another embodiment of the present disclosure is shown;

[0037] Figure 5 It shows Figure 4 A magnified view of the circled area;

[0038] Figure 6 A schematic diagram is shown of a stimulation system, including an electrical stimulation source and stimulation leads according to an embodiment of the present disclosure, placed inside a human body;

[0039] Figure 7 Another schematic diagram of a stimulation system including stimulation leads according to an embodiment of the present disclosure is shown. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0041] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positioning; when the absolute positioning of the described object changes, the relative positioning may also change accordingly.

[0042] Figure 1 A schematic top view of a stimulation lead according to an embodiment of the present disclosure is shown. Figure 2 It shows Figure 1 An enlarged view of the area where the middle electrode contact is located. Figure 3 It shows Figure 1 A schematic side view of the stimulation lead. Figure 6 A schematic diagram is shown of a stimulation system comprising a stimulation lead according to an embodiment of the present disclosure and placed within a human body. The stimulation lead is included in a stimulation system, and the stimulation system further includes the electrical stimulation source 150, such as a pulse generator. The stimulation lead can be used to direct stimulation signals generated by the electrical stimulation source 150 to stimulation sites such as extraocular muscles. However, the stimulation lead according to the present disclosure is not limited to such ophthalmic applications. The stimulation lead according to the present disclosure can also be applied to other stimulation systems, such as stimulation leads included in spinal cord stimulation systems with their distal ends configured for placement near the spinal cord, stimulation leads included in cochlear implants with their distal ends configured for placement within the ear, etc.

[0043] like Figures 1-3 As shown, the stimulation lead is strip-shaped, extending in a longitudinal direction, and has a proximal end for connection to an electrical stimulation source 150 and a distal end for placement at a site of stimulation, such as the extraocular muscles. The stimulation lead includes electrode contacts 110, an inner conductor 120, and an insulating housing 130.

[0044] One or more electrode contacts 110 are located at the distal end of the stimulation lead. Preferably, there are multiple electrode contacts 110. Therefore, if one or more electrode contacts 110 fail, other electrode contacts 110 can be used for stimulation. Furthermore, because the impedance and nerve distribution differ at various specific locations on the extraocular muscles, the effect of applying electrical stimulation at each electrode contact 110 at its location varies. Multiple electrode contacts 110 allow for the selection of a more suitable electrode contact 110 based on the stimulation effect to achieve a better therapeutic effect.

[0045] In this example, there are four electrode contacts 110, arranged in pairs along the longitudinal direction in a 2×2 array. These four electrode contacts 110 are the stimulation electrodes. Additionally, feedback electrodes can be placed near the electrical stimulation source 150 or near the proximal end of the stimulation lead, but the location of the feedback electrodes is not limited to these. The main function of the feedback electrodes is to provide feedback on the electrical stimulation signal. For example, if the stimulation signal is emitted by the front stimulation electrode, the feedback electrode receives the electrical signal emitted by the front stimulation electrode, forming a loop to confirm whether the emitted electrical stimulation signal is indeed the electrical stimulation signal emitted by the stimulator.

[0046] Electrode contacts 110 may include metals such as platinum, iridium, and gold, and are preferably made of a platinum-iridium alloy.

[0047] The internal conductor 120 extends longitudinally along the stimulation lead, and is electrically connected at its proximal end to the electrical stimulation source 150 to receive stimulation signals, and at its distal end to the electrode contact 110 to transmit the received stimulation signals to the electrode contact 110. The internal conductor 120 may be electrically connected to the electrode contact 110 by soldering. Figure 2 A branch of the internal conductor 120 is shown as a solder joint 121 to an electrode contact 110.

[0048] exist Figure 1 Only one internal conductor 120 is shown, which is simultaneously connected to multiple electrode contacts 110 at the distal end of the stimulation lead. However, this disclosure is not limited thereto. The stimulation lead may also include multiple internal conductors 120, each connected to a different electrode contact 110, to independently transmit stimulation signals to the different electrode contacts 110.

[0049] For example, Figure 4 A schematic top view of a stimulation lead and an electrical stimulation source 150 according to another embodiment of the present disclosure is shown. Figure 5 It shows Figure 4 A magnified view of the circled area. (See image.) Figure 4 and Figure 5 As shown, the stimulation lead includes four internal conductors 120, which are respectively connected to four different electrode contacts 110 via solder points 121.

[0050] The internal conductor 120 may include metals such as platinum, iridium, and gold, and is preferably made of a platinum-iridium alloy.

[0051] Return to reference Figures 1-3An insulating housing 130 extends longitudinally along the stimulation lead, covering at least a portion of the length of the inner conductor 120 and fixing the electrode contacts 110. The insulating housing 130 at least partially exposes the electrode contacts 110 so that the electrode contacts 110 contact the site to be stimulated to apply a stimulation signal. Preferably, the electrode contacts 110 are fully exposed on one side of the insulating housing 130 to ensure that the stimulation signal is applied to the extraocular muscles, rather than other nerve or muscle sites.

[0052] When stimulation leads are placed on sites of stimulation such as extraocular muscles, they are prone to displacement (e.g., when the eye moves), which can result in the inability to apply a suitable stimulation signal at the appropriate site. Stimulation leads according to embodiments of this disclosure are more likely to maintain their position stably for the application of a stable stimulation signal.

[0053] In some embodiments, the insulating housing 130 of the stimulation lead may include a distal stimulation segment 132, a connecting segment 131 extending proximally from the stimulation segment 132, and a transition segment 133 located between the connecting segment 131 and the stimulation segment 132, to which the electrode contact 110 is fixed. The stimulation segment 132 may be designed as a flat shape rather than a cylindrical shape to allow for more stable contact and placement with the stimulation site, such as the extraocular muscle. The stimulation segment 132 may include a height and a width. For example, the ratio of the thickness to the width is in the range of 1 / 4 to 1 / 2. For example, while keeping the stimulation segment 132 flat, the thickness may be in the range of 0.1-2 mm, and the width may be in the range of 1-12 mm. Furthermore, the connecting segment 131 may be designed as a cylindrical shape to facilitate processing and placement of the internal conductor 120.

[0054] For example, when the eye moves, the electrode contact 110 on the stimulation segment 132 may not be able to follow the movement of the extraocular muscle due to the pulling or pushing force of the connecting segment 131, thus failing to maintain its specific position relative to the extraocular muscle. In some embodiments, the inner conductor 120 of the stimulation lead includes a helical segment that extends in a helical or zigzag manner along the longitudinal direction of the stimulation lead to allow for variation in the length of the inner conductor 120 in the longitudinal direction. This variation in length of the inner conductor 120 in the longitudinal direction under the action of pulling or pushing forces prevents eye movement from causing a change in the position of the distal portion of the stimulation lead (particularly the electrode contact 110) relative to the extraocular muscle, and, for example, prevents a change in the position of the proximal portion of the stimulation lead and the electrical stimulation source 150 connected to the proximal portion relative to the implantation site. Therefore, the stimulation lead exhibits good tensile and compressive strength. In some examples, the inner conductor 120 may extend substantially along its entire length in a helical or zigzag manner.

[0055] In this embodiment, the helical segment is located inside the insulating housing 130. The insulating housing 130 of the stimulation lead is designed to be flexible and also elastic. Because the insulating housing 130 is elastic, it can change its length in the longitudinal direction together with the inner conductor 120, thereby ensuring the stability of the position of the distal and proximal portions of the stimulation lead. For example, the insulating housing 130 can be made of silicone, and the silicone is implantable silicone with long-term biocompatibility. For example, the insulating housing 130 is formed around the inner conductor 120 by overmolding.

[0056] In some embodiments, the stimulation lead may further include at least one fixing portion having a fixing hole for passing a fixing suture to secure the stimulation lead to the site of stimulation. The size of the fixing hole may be determined based on the size of the surgical suture. In some examples, the diameter of the fixing hole is in the range of 0.1-0.2 mm. The fixing portion helps to ensure that the position of the stimulation lead, especially the distal portion of the stimulation lead, remains unchanged.

[0057] At least one fixing portion may include a first fixing portion 141 and a second fixing portion 142. The first fixing portion 141 is disposed at the stimulation segment 132. Furthermore, there may be multiple first fixing portions 141, which are respectively disposed on both sides of the electrode contact 110 along the longitudinal direction and located at the edge of the stimulation segment 132. The second fixing portion 142 may be configured such that its distance from the first fixing portion 141 is greater than the distance between the multiple first fixing portions 141, to further stabilize the position of the stimulation segment 132 and isolate the stimulation segment 132 from the influence of forces at the connecting segment 131 caused by eye movement. For example, the second fixing portion 142 may be disposed in the transition segment 133. For example, there may be two second fixing portions 142, which are protrusions extending from both sides of the insulating housing 130, respectively. The design of the second fixing portions 142 as protrusions extending from both sides of the insulating housing 130 facilitates the surgeon's operation. Due to the arrangement of the first fixing portion 141 and the second fixing portion 142, the stimulation lead is placed more stably.

[0058] For example, the distance between the first fixing parts 141 can be in the range of 1-5mm, and the distance between the first fixing parts 141 and the second fixing parts 142 can be in the range of 1-30mm.

[0059] In this embodiment, the stimulation lead is applied to an extraocular muscle neuromuscular stimulator. In addition to the stimulation lead, the extraocular muscle neuromuscular stimulator also includes an electrical stimulation source 150, such as a pulse generator, for generating extraocular muscle stimulation signals. The proximal end of the stimulation lead is directly connected to the electrical stimulation source 150, while the distal end is placed on the extraocular muscle. The electrical stimulation source 150 can be placed in a bone groove located in the mastoid region behind the ear. To suit such an application, the total length of the stimulation lead is designed to be in the range of 15-21 cm, with a redundancy of approximately 5 cm from the implantation site of the electrical stimulation source 150 to the site to be stimulated. When the electrical stimulation source 150 is placed in the bone groove, a feedback electrode can also be placed in the bone groove simultaneously to protect the feedback electrode and ensure its reliability.

[0060] The following describes in detail the surgical procedure of implanting the electrical stimulation source 150 and the stimulation lead into the human body.

[0061] The surgical procedure includes:

[0062] S1, the patient is under general anesthesia, the surgical area is disinfected and draped, and the eyelids are opened;

[0063] S2, make a Parkes conjunctival incision in the infratemporal region;

[0064] S3, the strabismus hook grabs the lateral rectus muscle, separates the fascia and control ligaments, and fully exposes the lateral rectus muscle;

[0065] S4, make a 1cm long lateral canthal incision to expose the orbit at the lateral canthus, grind a 0.5*0.5cm notch with a bone drill, and make a puncture incision from the lateral canthus to the Parks incision at the fornix;

[0066] S5, make a postauricular incision to expose the cortical bone of the mastoid region, and use an electric drill to create a bone bed on the surface of the skull above and behind the mastoid process for placing an electrical stimulation source;

[0067] S6, using a tube to make a subcutaneous tunnel from the bone bed to the outer canthus, and then exiting through the outer canthus incision;

[0068] S3, place the electrical stimulation source into the bone bed and fix it, then advance the distal end of the stimulation lead along the trachea to the lateral canthus incision and remove the trachea;

[0069] S7, insert the distal end of the stimulation lead into the subconjunctival space at the Parks incision site through the lateral canthus notch and puncture site;

[0070] S8, hook out the lateral rectus muscle with a strabismus hook, and fix the fixed part of the stimulation line to both sides of the muscle belly with sutures.

[0071] S9, after disinfection, suture the surgical incision; reposition the conjunctival flap.

[0072] The distal end of the stimulation lead is implanted on the medial side of the extraocular muscle, passes through the conjunctival incision and the lateral canthal notch and is guided into the subcutaneous tunnel, thereby allowing the proximal end of the stimulation lead to be guided through the subcutaneous tunnel to the electrical stimulation source 150 placed in the bone bed of the mastoid region behind the ear and connected to the electrical stimulation source 150.

[0073] Those skilled in the art will understand that the stimulation leads can also be placed in other ways. For example, the stimulation leads can be guided directly to the outside of the human body and connected to an electrical stimulation source 150 located outside the human body. Figure 6 As shown, the electrical stimulation source 150 can be placed inside the human body, for example, in the bone bed of the mastoid region behind the ear. Figure 7 Another schematic diagram of a stimulation system including stimulation leads according to embodiments of the present disclosure is shown. Figure 7 As shown, the electrical stimulation source 150 is placed outside the human body and is connected to stimulation leads that are at least partially placed inside the human body.

[0074] The scope of this disclosure is not limited by the embodiments described above, but by the appended claims and their equivalents.

Claims

1. A stimulation lead for guiding electrical stimulation to a site to be stimulated, the stimulation lead comprising: An insulating housing extending from a distal end in a longitudinal direction toward a proximal end, the insulating housing including a stimulation segment located at the distal end and a connecting segment extending from the stimulation segment in the longitudinal direction toward the proximal end; Electrode contacts are disposed at the distal end of the insulating housing and are at least partially exposed outside the insulating housing; An inner conductor that connects the electrode contacts to an electrical stimulation source and extends at least partially within the insulating housing along the longitudinal direction, wherein the inner conductor is configured to be stretchable to change its length in the longitudinal direction; At least one fixing part is provided on the insulating shell, which includes a plurality of first fixing parts and second fixing parts. The plurality of first fixing parts are respectively provided on both sides of the electrode contact. The second fixing part is provided at the transition section of the insulating shell. The transition section is provided between the connecting section and the stimulation section, thereby isolating the influence of the force at the connecting section caused by eye movement on the stimulation section.

2. The stimulation lead according to claim 1, wherein, The inner conductor includes a helical section that extends along the longitudinal direction of the stimulation lead in a helical or zigzag manner.

3. The stimulation lead according to claim 2, wherein, The spiral section is located inside the insulating shell.

4. The stimulation lead according to claim 2, wherein, The insulating shell is elastic, allowing its length to be changed in the longitudinal direction.

5. The stimulation lead according to claim 4, wherein, The insulating shell is made of silicone.

6. The stimulation lead according to claim 1, wherein, The insulating housing includes a stimulation segment located at the distal end and a connecting segment extending from the stimulation segment towards the proximal end along the longitudinal direction. The electrode contacts are fixed to the stimulation segment, which is flat in shape.

7. The stimulation lead according to claim 6, wherein, The stimulation segment includes a thickness and a width, the ratio of which is in the range of 1 / 4 to 1 / 2.

8. The stimulation lead according to claim 6, wherein, The connecting section is cylindrical in shape.

9. The stimulation lead according to claim 1, wherein, The at least one fixing part is provided with a fixing hole for the fixing wire to pass through.

10. The stimulation lead according to claim 9, wherein, The diameter of the fixing hole is in the range of 0.1-0.2 mm.

11. The stimulation lead according to claim 6, further comprising: Multiple first fixing parts are respectively disposed on both sides of the electrode contact along the longitudinal direction.

12. The stimulation lead according to claim 1, wherein, The distance between the plurality of first fixing parts is in the range of 1-5mm, and the distance between the second fixing part and the first fixing part is in the range of 1-30mm.

13. The stimulation lead according to claim 1, further comprising: The at least one fixing portion includes a plurality of first fixing portions disposed at the stimulation segment of the insulating housing.

14. The stimulation lead according to claim 1, wherein, The internal conductor is welded to the electrode contacts.

15. The stimulation lead according to claim 1, wherein, The distal end of the stimulation lead is configured to be placed on the extraocular muscle, and the length of the stimulation lead is in the range of 15-21 cm.

16. A stimulation system comprising: Electrical stimulation source; And a stimulation lead according to any one of claims 1-15, wherein the proximal end of the stimulation lead is connected to the electrical stimulation source.

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