Systems and methods for implanting electrodes in the brain

Abstract

Provided herein are lead and stylet systems and methods of implanting a lead into the brain using a stylet. The lead may be used for deep brain stimulation (DBS) and may be connected to a skull-mounted implantable pulse generator (IPG) of a deep brain stimulation system. The lead may include a lumen configured to removably receive a stylet to assist in implanting an electrode disposed on the lead into the brain. The lead and stylet systems described herein may allow for a minimum of excess lead length between an implantation site of the lead in the brain and an implantable pulse generator (e.g., implanted in the skull).

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to U.S. Provisional Patent Application No. 63 / 509236, filed June 20, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to leads and cores, and more specifically to leads and cores for implanting electrodes into the brain during deep brain stimulation (DBS) implantation surgery. Background Technology

[0004] Deep brain stimulation (DBS) is a neurostimulation therapy used to treat neurodegenerative diseases such as epilepsy and Parkinson's disease (PD). In DBS, artificial electrical currents are delivered to specific parts of the brain to stimulate neurons, which in turn alleviates symptoms experienced under different brain conditions. For example, in patients with Parkinson's disease, high-frequency stimulation is delivered to areas of the basal ganglia (e.g., the subthalamic nucleus (STN) or the globus pallidus (GPi)) to correct the excitation-inhibition imbalance in the basal ganglia circuits. Deep brain stimulation can alleviate motor symptoms in patients with Parkinson's disease and reduce the need for drug therapy.

[0005] Deep brain stimulation (DBS) systems typically include one or more leads (e.g., including electrodes) implanted in the brain and a pulse generator (e.g., a stimulator battery) implanted in the patient's upper chest. One or more small incisions are made in the patient's scalp, followed by one or more small openings in the skull, allowing the leads to be implanted into the brain. A stereotactic frame can be used to precisely align the leads in the skull and implant the electrodes in the target brain region. In some cases, a cannula can be used to maintain an open channel through which the leads can be guided to the target when the leads are inserted into the brain. The stereotactic frame guides and can engage with the stylet to implant a flexible lead, including electrodes, into the brain. The lead can be a stimulating lead, a sensing lead, or a combination of leads (e.g., a sensing and stimulating lead). A depth stop positioned on the body of the stylet allows for appropriate depth of lead implantation into the brain. Once the depth stop engages with, for example, the stereotactic frame and / or a cannula, the depth stop indicates the appropriate depth.

[0006] In addition to implanting the lead into the brain, a small incision is made in the upper chest to create a soft tissue pocket for the pulse generator. The lead is connected to the pulse generator, for example, using an extension wire in a tunnel under the skin between the lead extending from the skull and the pulse generator in the upper chest. However, these extension wires may shift, causing pain and discomfort to the patient. Furthermore, the extension wires may loosen, detach from the pulse generator, or break, each of which requires subsequent surgery to fix, reconnect, or replace the wire. Additional surgery may increase the risk of intraoperative and / or postoperative complications such as infection, bleeding, swelling, and in more serious cases, coma, sepsis, and stroke. Moreover, implanting the lead and pulse generator requires preparation of at least two surgical sites (e.g., one or more sites in the upper chest and skull), and each procedure is typically performed individually in a separate appointment, a source of inefficiency in the operating room, which is accompanied by an increased risk of surgical complications (i.e., due to the number of procedures). Summary of the Invention

[0007] This article describes a lead and stylet system and a method for implanting a lead into the brain using a stylet during procedures such as deep brain stimulation (DBS) implantation. The lead can be designed such that it extends from an appropriate implantation site of the electrode in the brain to an implantation site on the skull surface suitable for a pulse generator (e.g., a craniotomy implantable pulse generator or IPG), with minimal excess lead length between these sites. The lead may include a lumen along its length, the lumen being configured to removably accommodate a stylet body for facilitating the implantation of the lead, including the electrode, into the brain. A distal portion of the stylet body may be accommodated within the lead, and a proximal portion of the stylet body may be removably attached to a depth stop. Thus, when implanting a lead using a stylet with a depth stop attached to the stylet, the depth stop can contact a stereotactic frame mounted on the skull and / or a cannula inserted into the brain to indicate the appropriate depth of the lead in the brain.

[0008] In some embodiments, a system for implanting electrodes in the brain is provided, comprising: a lead including a lumen and one or more electrodes disposed on the lead; and a stylet body including a distal portion and a proximal portion, wherein the distal portion is configured to be removably received within the lumen such that the length of the lead extends from an end of the distal portion of the stylet body to a midpoint within the distal portion of the stylet body, and the proximal portion of the stylet body is configured to be removably attached to a depth stop.

[0009] In some embodiments, the position of the depth stop, which is attached along the length of the proximal portion of the core needle body, corresponds to a predetermined depth in the brain into which the wire is to be inserted.

[0010] In some embodiments, the predetermined depth in the brain causes 40% to 80% of the length of the wire to be positioned outside the skull.

[0011] In some embodiments, the system includes a depth stop.

[0012] In some embodiments, the depth stop is configured to contact the proximal surface of the retainer of the stereotactic frame to stop the insertion of the wire into the brain at the predetermined depth.

[0013] In some embodiments, the depth stop is configured to contact the proximal end of a cannula inserted into the brain to stop the insertion of the wire into the brain at the predetermined depth.

[0014] In some embodiments, the proximal portion of the mandrel body includes a first diameter, and the distal portion of the mandrel body includes a second diameter different from the first diameter.

[0015] In some embodiments, the first diameter is less than or equal to the diameter of the depth stop, such that the depth stop can be removably secured to the proximal portion of the mandrel body.

[0016] In some embodiments, the second diameter is less than or equal to the diameter of the inner cavity, such that the distal portion of the mandrel body can be removably inserted into the inner cavity.

[0017] In some embodiments, the mandrel body comprises a length between 10 cm and 50 cm.

[0018] In some embodiments, the length of the conductor is less than the length of the mandrel body, such that the conductor is not engaged with the proximal end of the mandrel body.

[0019] In some embodiments, the cross-section of the proximal portion of the mandrel body and / or the cross-section of the distal portion of the mandrel body is a square, a circle, an ellipse, a rectangle, a triangle, or a curved triangle.

[0020] In some embodiments, the cross-section of the proximal portion includes a first geometry, and the cross-section of the distal portion includes a second geometry different from the first geometry.

[0021] In some embodiments, the core needle body comprises one or more biocompatible materials.

[0022] In some embodiments, the proximal portion of the needle body includes a first biocompatible material, and the distal portion of the needle body includes a second biocompatible material different from the first biocompatible material.

[0023] In some embodiments, the one or more biocompatible materials include polypropylene, polyethylene, polyetheretherketone (PEEK), polycarbonate (PC), polyphenylene sulfone (PPSU), polyethylene terephthalate (PET), medical-grade stainless steel, titanium, mixtures of polymers, or mixtures of medical-grade metals.

[0024] In some embodiments, the stylet body is sterilizable, making the stylet body reusable.

[0025] In some embodiments, a deep brain stimulation system is provided, comprising: a system according to any one of the foregoing embodiments; and a pulse generator configured to be implanted in or on the skull and coupled to the lead wire.

[0026] In some embodiments, a method for implanting electrodes into the brain includes: attaching a depth stop to a proximal portion of a stylet body; inserting a distal portion of the stylet body, removably housed in a lumen of a lead wire, into the brain, wherein the length of the lead wire extends from an end of the distal portion of the stylet body to a midpoint within the distal portion of the stylet body, and wherein a portion of the lead wire includes one or more electrodes; and removing the distal portion of the stylet body from the lumen of the lead wire inserted into the brain, thereby leaving at least a portion of the lead wire including the one or more electrodes in the brain.

[0027] In some embodiments, attaching the depth stop to the proximal portion of the mandrel body includes attaching the depth stop along the length of the proximal portion to a location corresponding to a predetermined depth to which the lead is inserted into the brain.

[0028] In some embodiments, the method includes mounting a stereotactic frame onto the skull before inserting the distal portion of the core needle body into the brain, such that the retainer of the stereotactic frame is aligned with the implantation site in the skull.

[0029] In some embodiments, the distal portion of the core needle body is inserted through the retainer of the stereotactic frame and into the brain until the depth stop contacts the proximal surface of the retainer.

[0030] In some embodiments, removing the distal portion of the mandrel body from the lumen of the wire includes removing the mandrel body from the retainer of the stereotactic frame.

[0031] In some embodiments, the method includes removing the stereotactic frame from the skull after removing the core needle body from the lumen of the wire and the retainer of the stereotactic frame.

[0032] In some embodiments, the method includes inserting a cannula into the brain to a predetermined depth before inserting the distal portion of the stylet body into the brain.

[0033] In some embodiments, the distal portion of the core needle body is inserted through the cannula and into the brain until the depth stop contacts the proximal end of the cannula inserted into the brain.

[0034] In some embodiments, the method includes removing the cannula from the brain after removing the core needle body from the lumen of the lead wire.

[0035] In some embodiments, the method includes securing the wire to the outer surface of the skull before removing the mandrel body from the lumen of the wire.

[0036] In some embodiments, the wire is fixed to the outer surface of the skull at a location near a drill hole in the skull, and the wire passes through the drill hole.

[0037] In some embodiments, the method includes inserting the distal portion of the core needle body into the lumen of the lead wire before inserting the distal portion of the core needle body into the brain.

[0038] In some embodiments, the method includes positioning the depth stop on the proximal portion of the stylet body such that when the distal portion of the stylet body is inserted to a predetermined depth in the brain, 40% to 80% of the length of the lead wire is positioned outside the skull.

[0039] In some embodiments, the length of the conductor is less than the length of the mandrel body, such that the conductor is not engaged with the proximal end of the mandrel body.

[0040] In some embodiments, the method includes generating a resection area in a skull configured to receive an implantable pulse generator (IPG) and implanting the implantable pulse generator into the resection area.

[0041] In some embodiments, the method includes connecting the implantable pulse generator to one or more electrical contacts disposed on the proximal portion of the wire after the wire has been inserted into the brain. Attached Figure Description

[0042] Various aspects of the disclosed systems and methods are set forth in the appended claims. A better understanding of the features and advantages of the disclosed systems and methods will be obtained by referring to the detailed description of the illustrative embodiments and the accompanying drawings.

[0043] Figure 1A A perspective view of a wire and core needle system according to some embodiments is shown.

[0044] Figure 1B Another perspective view of a wire and core needle system according to some embodiments is shown.

[0045] Figure 1C A partial close-up view of a wire according to some embodiments is shown.

[0046] Figure 1D A partial cross-sectional view of a wire according to some embodiments is shown.

[0047] Figure 2A A perspective view of a depth stop according to some embodiments is shown.

[0048] Figure 2B Another perspective view of a depth stop according to some embodiments is shown.

[0049] Figure 3 A perspective view of an assembly including a wire, a mandrel, and a depth stop, according to some embodiments, is shown.

[0050] Figure 4A A perspective view of a wire and mandrel system with a stereotactic frame according to some embodiments is shown.

[0051] Figure 4B Detailed views of a wire and mandrel system with a stereotactic frame according to some embodiments are shown. Detailed Implementation

[0052] This document describes a lead and stylet system and a method for implanting a lead using a stylet. The stylet body and lead can be used during deep brain stimulation (DBS) implantation surgery to implant a lead into the brain of a length suitable for a craniotomy-mounted pulse generator (e.g., an implantable pulse generator or IPG). As discussed herein, the lead length can be shorter than that used in DBS systems (which include IPGs implanted in the chest). The stylet of the lead and stylet system described herein facilitates the correct implantation of shorter leads into the brain by positioning the distal portion of the stylet body within the lumen of the lead. Furthermore, the proximal portion of the stylet body can be attached to a depth stop that engages with a stereotactic frame and / or cannula inserted into the brain to indicate the appropriate insertion depth of the electrode in the brain.

[0053] The DBS system discussed in this article may include a craniotomy-mounted IPG instead of an IPG implanted in the patient's chest, thus eliminating the need for long leads and / or extensions that create a tunnel between the skull and chest. A craniotomy-mounted IPG also reduces the number of surgical sites required for DBS system implantation, which in turn reduces the amount of time spent during DBS implantation surgery. Attempting to use these long leads with a craniotomy-mounted IPG (e.g., by bundling excess lead length at the implantation site within a pouch in the scalp) can lead to scalp erosion, thus requiring a system with shorter electrode lead lengths. Shorter lead lengths can also result in more efficient power delivery during deep brain stimulation compared to the longer leads used in DBS systems with chest-mounted IPGs. However, shorter lead lengths leave a minimum length of lead outside the skull that does not extend into the stereotactic frame for proper alignment and placement. Therefore, the stylet provided in this article can be delivered into the lumen of the lead at the distal portion of the stylet body and attached to a depth stop contacting the stereotactic frame for proper alignment and placement of the lead.

[0054] Figures 1A to 1B A system 100 for implanting electrodes in the brain is shown. The system 100 includes a lead 102 and a stylet body 104. The lead 102 may include a lumen 108 and one or more electrodes 106 disposed on the lead. The lead 102 may be a stimulating lead, a sensing lead, or a combination lead (e.g., a lead that can both sense and stimulate). The stylet body 104 may include a distal portion 110 and a proximal portion 112, the distal portion 110 being configured to be removably received within the lumen 108. For example, the length of the lead 102 may extend from the end of the distal portion 110 of the stylet body 104 to a midpoint within the distal portion 110. The proximal portion 112 may be configured to be removably attached to a depth stop (e.g., at least at...). Figures 2A to 2B(Deep stop 200 shown). Each of the mandrel body 104 and the lead wire 102 is described in more detail below.

[0055] die needle body

[0056] At least as Figures 1A to 1B As shown, the mandrel body 104 may include a proximal portion 112 and a distal portion 110, the proximal portion 112 including a first diameter and the distal portion 110 including a second diameter. The first diameter and the second diameter may be substantially the same, or the first diameter and the second diameter may be different (as shown). In some embodiments, the cross-sectional shapes of the proximal portion 112 and the distal portion 110 of the mandrel body 104 may be different, rather than having different diameter measurements. For example, the cross-sectional shape of one or more portions of the mandrel body 104 may be a square, a circle, an ellipse, a rectangle, a triangle, a curved triangle, or other polygonal shapes.

[0057] In some embodiments, the first diameter of the proximal portion 112 of the mandrel body 104 may be less than or equal to 3 mm, 2.75 mm, 2.5 mm, 2.25 mm, 2 mm, 1.75 mm, or 1.5 mm. In some embodiments, the first diameter of the proximal portion 112 of the mandrel body 104 may be greater than or equal to 0.5 mm, 0.75 mm, 1 mm, 1.25 mm, 1.5 mm, 1.75 mm, or 2 mm. The first diameter of the proximal portion 112 may be less than or equal to the diameter of the depth stop (e.g., the diameter of the receiving portion 202 of the depth stop 200, at least within...). Figures 2A to 2B (As shown in the image).

[0058] In some embodiments, the second diameter of the distal portion 110 of the needle body 104 may be less than or equal to 1.5 mm, 1.25 mm, 1.0 mm, 0.75 mm, or 0.5 mm. In some embodiments, the second diameter of the distal portion 110 of the needle body 104 may be greater than or equal to 0.1 mm, 0.25 mm, 0.5 mm, or 0.75 mm. The second diameter of the distal portion 110 of the needle body 104 may be less than or equal to the diameter of the wire cavity 108, such that the distal portion 110 can be removably inserted into the cavity 108.

[0059] In some embodiments, the length of the stylet body 104 may be less than or equal to 5 cm, 10 cm, 20 cm, 25 cm, 30 cm, 40 cm, 50 cm, or 60 cm. In some embodiments, the length of the stylet body 104 may be greater than or equal to 5 cm, 10 cm, 20 cm, 25 cm, 30 cm, 40 cm, 50 cm, or 60 cm. In some embodiments, the stylet body 104 may be selected such that the length of the distal portion 110 is greater than or equal to the length of the selected lead 102 for a given patient.

[0060] In some embodiments, the distal portion 110 may include approximately half the length of the needle body 104, and the proximal portion 112 may include the other half the length of the needle body 104. For example, the distal portion 110 may include approximately 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or more of the length of the needle body 104, while the proximal portion 112 may include the remaining approximately 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% of the length of the needle body 104.

[0061] In some embodiments, the needle body 104 may be made of one or more biocompatible materials. For example, the needle body 104 may include one or more biocompatible materials, including but not limited to polypropylene, polyethylene, polyetheretherketone (PEEK), polycarbonate (PC), polyphenylene sulfone (PPSU), polyethylene terephthalate (PET), medical-grade stainless steel, titanium (e.g., nickel-titanium), mixtures of polymers, mixtures of medical-grade metals, or mixtures of polymers and medical-grade metals. In some embodiments, the distal portion 110 may include a first material mixture (e.g., one or more materials), and the proximal portion 112 may include a second material mixture (e.g., one or more materials) different from the first material mixture. For example, the distal portion 110 may include one or more medical-grade metals (e.g., stainless steel, titanium, etc.), and the proximal portion 112 may include one or more polymers (e.g., PC, PEEK, PPSU, PET, etc.). In another example, the distal portion 110 may include a mixture of medical-grade metals and polymers, such as one or more medical-grade metals coated with one or more polymers.

[0062] In some embodiments, the material of the stylet body 104 may be selected such that the stylet body 104 is sterilizable and reusable for multi-lead stimulation implantation procedures. For example, the stylet body 104 may be sterilized using moist heat (steam), dry heat, radiation, ethylene oxide gas, evaporated hydrogen peroxide, and / or other sterilization methods (e.g., chlorine dioxide gas, evaporated peracetic acid, nitrogen dioxide, etc.).

[0063] wire

[0064] The lead 102 can be configured to deliver artificial current to a region of the brain via one or more electrodes 106 disposed on the lead. For example, the lead 102 may include an array of electrodes 106 disposed at least at the distal end of the lead 102. In some embodiments, the plurality of electrodes may be arranged along at least a portion of the length of the lead. The electrodes 106 may include segmented electrodes configured to direct current to a specific location and / or in a specific direction. Segmented electrodes may introduce advantages over, for example, solid ring electrodes that are axially symmetric in geometry and treatment.

[0065] At least as Figures 1A to 1D As shown, the lead wire 102 may additionally include one or more electrical contacts 109. The electrical contacts 109 may be configured to be electrically coupled to an implantable pulse generator (IPG) in the skull to be implanted. For example, the IPG may include a receiving portion configured to receive and connect to the electrical contacts 109. Thus, upon implantation, the IPG may generate stimulation pulses that can be provided to the electrical contacts 109, and the stimulation pulses may travel within the lead wire 102 (e.g., via one or more extensions electrically connecting the electrical contacts 109 and the electrode 106) to the electrode 106. The electrode 106 may then stimulate the brain region in which the electrode 106 is implanted using the stimulation pulses.

[0066] As mentioned above and at least in Figure 1D As shown, the lead wire 102 may include a lumen 108 configured to removably receive a distal portion 110 of a mandrel body 104. The lumen 108 may be a through-hole extending through at least a portion of the length of the lead wire 102. For example, the lumen 108 may extend from a proximal end of the lead wire 102 toward its distal end. The proximal end may be configured to initially receive the mandrel body 104. The lumen 108 may not extend through the distal end of the lead wire 102, such that when the distal portion 110 of the mandrel body 104 is inserted into the lead wire 102, it can be inserted until a midpoint is reached within the lead wire 102, at which point the lumen 108 terminates. In some embodiments, the lumen 108 may comprise approximately 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99% of the length of the lead wire 102.

[0067] The cross-sectional shape of the inner cavity 108 can be substantially the same as the cross-sectional shape of the distal portion 110 of the mandrel body 104. For example, when the cross-sectional shape of the inner cavity 108 is circular, the diameter of the inner cavity 108 can be less than or equal to 1.5 mm, 1.25 mm, 1.0 mm, 0.75 mm, or 0.5 mm. In some embodiments, the diameter of the inner cavity 108 can be greater than or equal to 0.25 mm, 0.5 mm, 0.75 mm, or 1 mm.

[0068] The length of lead 102 can extend from the electrode implantation site in the brain to the IPG implantation site in the skull with minimal excess lead length. Therefore, the length can be shorter than that of a deep brain stimulation (DBS) system including a pulse generator implanted in the chest. For example, the length of lead 102 can be less than or equal to 50 cm, 40 cm, 30 cm, 20 cm, 15 cm, 10 cm, 5 cm, or 1 cm. In some embodiments, the length of lead 102 can be greater than or equal to 0.5 cm, 1 cm, 5 cm, 10 cm, 15 cm, or 20 cm. Lead 102 can be selected such that the lead length corresponds to one or more measurements of the patient. Therefore, different lengths of lead 102 can be used for different patients. The length of lead 102 can be less than the length of the stylet body 104, such that lead 102 does not engage with the proximal end of the stylet body 104. For example, as discussed herein, the lead wire 102 can extend from the end of the distal portion 112 of the mandrel body 104 to the midpoint within the distal portion 112 of the mandrel body 104. Figure 3 The assembly 300 is shown, wherein the mandrel body 104 is removably inserted into the cavity 108 of the lead wire 102.

[0069] The lead 102 may include one or more biocompatible materials to allow the lead to be safely implanted in a patient's brain. The technical features and materials of the lead 102 are not intended to be limited to the disclosure provided herein, but may encompass any or more features of leads known to those skilled in the art.

[0070] Electrode leads, core pins and depth stop assemblies

[0071] As discussed herein, the die body 104 may be configured to be removably attached to a depth stop. For example, the die body 104 may be directly attached to the depth stop (e.g., rather than to a wire). In some embodiments, the die body 104 may be indirectly attached to the depth stop (e.g., a wire may be attached to the depth stop). Figures 2A to 2BAn exemplary depth stop 200 configured to be removably attached to a mandrel body 104 is shown. As illustrated, the depth stop 200 may include a receiving portion 202 (e.g., a through-hole) configured to receive at least a proximal portion 112 of the mandrel body 104. For example, Figure 3 The assembly 300 is shown, wherein the depth stop 200 is attached to the proximal portion 112 of the mandrel body 104.

[0072] The depth stop 200 may include an opening that allows a user to removably insert the mandrel body 104 into the receiving portion 202 of the depth stop 200. For example, the depth stop 200 may include a semi-annular body, and the opening within the annular shape may be sized such that the mandrel body 104 can be removably inserted through the opening.

[0073] like Figure 2B As shown, the depth stop 200 may include a fastener 204 that engages with the mandrel body 104 when the mandrel body 104 is inserted into the receiving portion 202 of the depth stop 200 to maintain the position of the depth stop 200 on the mandrel body 104. A user can rotate, turn, push, and / or pull a knob 206 connected to the fastener 204 to translate the fastener 204 into / out of the receiving portion 202. For example, the fastener 204 may include threads that allow fine-tuning of the fastener 204 by rotating the knob 206. In some embodiments, the fastener 204 can be translated between two or more positions (e.g., a locked position and an unlocked position), and a user can engage the knob 206 (e.g., by rotating, pushing, pulling, and / or turning the knob 206) to translate the fastener 204 between two or more positions.

[0074] In some embodiments, the depth stop 200 may be configured to clamp onto the mandrel thread instead of the mandrel body 104.

[0075] In some embodiments, the lead and stylet system 100 as described herein may be provided as a component of a deep brain stimulation (DBS) system. For example, a DBS system may include at least the lead 102 and stylet body 104 as discussed herein, and a pulse generator configured for implantation in the skull and coupled to the lead 102. In some embodiments, a depth stop 200 may be included in the DBS system. Nevertheless, those skilled in the art will understand that the lead and stylet system described herein is not limited to deep brain stimulation (DBS) systems with craniotomy-mounted pulse generators, and may be used and / or adapted for use in other systems, including but not limited to other DBS systems in which the IPG can be implanted in other locations on the human body (other than the skull).

[0076] Method using lead wire and core system

[0077] As discussed herein, the lead and stylet system 100 can be used to implant electrodes (e.g., electrode 106) into the brain. For example, electrode 106 can be implanted to perform deep brain stimulation. A method for implanting electrode 106 into the brain may include attaching a depth stop 200 to a proximal portion 112 of stylet body 104. For example, depth stop 200 may be attached to stylet body 104 at a location along the length of proximal portion 112 that corresponds to a predetermined depth in the brain into which lead 102 is inserted.

[0078] In some embodiments, the method may include inserting a distal portion 110 of a mandrel body 104 into a lumen 108 of a lead wire 102. In some embodiments, the lead wire 102 and the mandrel body 104 may be provided to a user as an assembly, such as... Figure 3 As shown in component 300. The length of the lead wire 102 can extend from the end of the distal portion 110 of the mandrel body 104 to the midpoint within the distal portion 110 of the mandrel body 104.

[0079] In some embodiments, the method may include making a cut (e.g., drilling) at a predetermined location on the surface of the skull corresponding to the intended electrode implantation site in the brain.

[0080] In some embodiments, the method may include mounting a stereotactic frame onto the skull. For example, Figures 4A to 4B An exemplary stereotactic frame 400 that can be mounted on the skull is shown. Mounting the stereotactic frame 400 may include adjusting the position of the frame on one or more axes (e.g., X, Y, and Z marked on the stereotactic frame 400 shown in FIG. 4). In some embodiments, the stereotactic frame 400 may already be mounted on the skull, such that the method may not require mounting the frame to the skull.

[0081] The stereotactic frame 400 may include a retainer 402 configured to receive the stylet body 104 and hold the stylet body 104 (inserted within the stylet 102) in position when the stylet 102 is inserted into the brain. For example, as Figure 4B As shown, the retainer 402 may include a receiving portion 404 (e.g., a through hole) configured to receive the mandrel body 104.

[0082] The stereotactic frame 400 (e.g., one or more movable components of the stereotactic frame 400) can be positioned such that the retainer 402 can be aligned with the implantation site in the skull. For example, the retainer 402 can be positioned above the implantation site in the skull at a distance from the implantation site. The position of the retainer 402 can be modified in one or more planes relative to the stereotactic frame 400. As shown in Figure 4, the position of the retainer 402 can be adjusted in one or more directions indicated by arrows 406, 408, and / or 410 in Figure 4.

[0083] In some embodiments, the method may include inserting a cannula to a predetermined depth in the brain. For example, the cannula may be inserted into the brain through a drill hole created in the surface of the skull. The cannula may be used to create an opening in the brain to facilitate wire implantation. One or more of the exemplary stereotactic frame systems discussed herein may be used in conjunction with a cannula.

[0084] The method may include inserting a distal portion 110 of a mandrel body 104, removably housed in the lumen 108 of a lead 102, into the brain. For example, the distal portion 110, removably housed in the lead 102, may be inserted through a retainer 402 and into the brain (e.g., via a drill hole in the skull) until a depth stop 200 contacts the retainer 402. For example, at least as Figure 4B As shown, when the lead 102 and the stylet body 104 assembly are inserted through the receiving portion 404 of the retainer 402 and to a predetermined depth in the brain, the depth stop 200 can contact the proximal surface of the retainer 402. The position of the depth stop 200 on the stylet body 104 in contact with the retainer 402 indicates the appropriate implantation depth of the electrode 106 disposed on the lead 102.

[0085] In cases where a cannula has already been inserted into the brain as discussed herein, the distal portion 110 of the stylet body 104 (removably housed within the lumen 108 of the lead 102) can be inserted through the cannula and into the brain. The distal portion 110 of the stylet body 104 can be inserted into the brain until a depth stop 200 attached to the proximal portion 112 of the stylet body 104 contacts the inserted cannula. For example, the depth stop 200 can contact the proximal end of the cannula. The position where the depth stop 200 on the stylet body 104 contacts the proximal end of the cannula can indicate the appropriate implantation depth of the electrode 106 disposed on the lead 102.

[0086] The position of the depth stop 200 at the proximal portion 112 of the stylet body 104 can be selected such that when the distal portion 110 of the stylet body 104, removably housed in the lead 102, is inserted into the brain until the depth stop contacts the retainer 402 (or, in some embodiments, the cannula), approximately 40% to 80% of the lead 102 can be positioned outside the skull. In some embodiments, after the lead has been properly implanted into the brain, approximately 20%, 30%, 40%, 50%, 60%, 70%, or 80% of the lead 102 can be positioned outside the skull.

[0087] Once the stylet body 104 and the lead 102 are inserted to a predetermined depth in the brain, the method may include removing a distal portion 110 from the lumen 108 of the lead 102, thereby leaving a portion of the lead 102 comprising at least one or more electrodes 106 implanted in the brain. For example, a user may remove the distal portion 110 of the stylet body 104 from the lumen 108 of the lead 102, and subsequently remove the stylet body 104 from the retainer 402 of the stereotactic frame 400.

[0088] In some embodiments, the method may include securing the lead wire 102 to an outer surface of the skull before removing the distal portion 110 of the lead wire body 104 from the lumen 108 of the lead wire 102. In some embodiments, securing the lead wire 102 to the skull may occur after the lead wire body 104 has been removed from the lead wire 102. The lead wire 102 may be secured to the outer surface of the skull at a location near a drilled hole through which the lead wire 102 (and optionally the lead wire body 104) exits. For example, a lead wire securing device may be used to secure a portion of the lead wire 102 to the skull at a location adjacent to the drilled hole. As described herein, a lead wire securing device may be used to secure the lead wire 102 to the skull before removing the lead wire body 104 from the lumen 108 and / or before removing the stereotactic frame 400.

[0089] The method may include removing the stereotactic frame 400 from the skull after removing the stylet body 104 from the cavity 108 of the lead wire 102 and the retainer 402 of the stereotactic frame 400. In some embodiments, the stereotactic frame 400 and / or the depth stop 200 may be removed before removing the stylet body 104 from the cavity 108 of the lead wire 102.

[0090] With the cannula already inserted into the brain, the method may include removing the cannula from the brain after removing the stylet body 104 from the lumen 108 of the lead wire 102. For example, the cannula may include a dissecting cannula that is partially axially divided into two parts, allowing the cannula to be separated and removed while the lead wire 102 is held in place by a stereotactic frame 400. Once the lead wire 102 is secured to the skull, the stereotactic frame 400 and the stylet body 104 can be removed.

[0091] In some embodiments, the method may include connecting the lead wire 102 to an implantable pulse generator (IPG). As discussed herein, the lead wire 102 may include one or more electrical contacts 109 at the proximal portion of the lead wire, and the one or more electrical contacts 109 may be connected to an IPG configured for implantation in or on the skull. In some embodiments, the method may include creating a resection area in the skull, the resection area being configured to receive a skull-mounted IPG. The resection area may be created prior to implanting the lead wire 102 into the skull. The method may include implanting the IPG into the resection area in the skull.

[0092] As discussed herein, the use of lead 102 and / or stylet body 104 is not limited to deep brain stimulation (DBS) systems that include craniotomy-mounted IPGs. For example, lead 102 and / or stylet body 104 can be used in DBS implantation procedures where the IPG is implanted in other parts of the body (e.g., the chest). Therefore, in these cases, the method may include connecting lead 102 to one or more extension leads electrically connected to the IPG. The method may also include preparing additional implantation sites, such as in the chest, and implanting the IPG in the chest.

[0093] Unless otherwise defined, all technical terms, symbols, and other technical and scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some instances, terms with their commonly understood meanings are defined herein for clarity and / or convenience of reference, and the inclusion of such definitions herein should not be construed as representing a material difference from what is commonly understood in the art.

[0094] As used herein, the singular forms “a,” “an,” and “described” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and covers any and all possible combinations of one or more of the related listed items. It should be further understood that, when used herein, the terms “comprising,” “including,” “containing,” and / or “including” specify the presence of the described features, integers, steps, operations, elements, components, and / or units, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, units, and / or groups thereof.

[0095] The disclosed numerical ranges inherently support any range or value within the disclosed numerical ranges, including endpoints, even if no precise range limitation is stated verbatim in the specification, because this disclosure can be practiced within the disclosed numerical ranges.

[0096] For illustrative purposes, the foregoing description has been described with reference to specific embodiments. However, the illustrative examples described above are not exhaustive or limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the foregoing teachings. The embodiments were chosen and described in order to best explain the principles of the technology and its practical application. Therefore, others skilled in the art will be able to best utilize the technology and various embodiments with various modifications suitable for the particular intended use.

[0097] Although this disclosure and examples have been fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications should be understood to be included within the scope of this disclosure and examples as defined by the claims.

Claims

1. A system for implanting electrodes in the brain, comprising: A wire, comprising an inner cavity and one or more electrodes disposed on the wire; as well as A mandrel body includes a distal portion and a proximal portion, wherein the distal portion is configured to be removably received within the cavity such that the length of the wire extends from the end of the distal portion of the mandrel body to a midpoint within the distal portion of the mandrel body, and the proximal portion of the mandrel body is configured to be removably attached to a depth stop.

2. The system according to claim 1, wherein, The position of the depth stop, which is attached along the length of the proximal portion of the core needle body, corresponds to the predetermined depth to which the wire is to be inserted into the brain.

3. The system according to claim 1 or 2, wherein, The predetermined depth in the brain causes 40% to 80% of the length of the wire to be positioned outside the skull.

4. The system according to any one of claims 1 to 3, comprising the depth stop.

5. The system according to claim 4, wherein, The depth stop is configured to contact the proximal surface of the retainer of the stereotactic frame to stop the insertion of the wire into the brain at the predetermined depth.

6. The system according to claim 4 or 5, wherein, The depth stop is configured to contact the proximal end of the cannula inserted into the brain to stop the insertion of the wire into the brain at the predetermined depth.

7. The system according to any one of claims 1 to 6, wherein, The proximal portion of the mandrel body includes a first diameter, and the distal portion of the mandrel body includes a second diameter different from the first diameter.

8. The system according to claim 7, wherein, The first diameter is less than or equal to the diameter of the depth stop, such that the depth stop can be removably secured to the proximal portion of the mandrel body.

9. The system according to claim 7 or 8, wherein, The second diameter is less than or equal to the diameter of the inner cavity, such that the distal portion of the mandrel body can be removably inserted into the inner cavity.

10. The system according to any one of claims 1 to 9, wherein, The core needle body has a length between 10cm and 50cm.

11. The system according to claim 10, wherein, The length of the wire is less than the length of the mandrel body, so that the wire does not engage with the proximal end of the mandrel body.

12. The system according to any one of claims 1 to 11, wherein, The cross-section of the proximal portion of the mandrel body and / or the cross-section of the distal portion of the mandrel body is a square, circle, ellipse, rectangle, triangle, or curved triangle.

13. The system according to claim 12, wherein, The cross-section of the proximal portion includes a first geometry, and the cross-section of the distal portion includes a second geometry different from the first geometry.

14. The system according to any one of claims 1 to 13, wherein, The core needle body comprises one or more biocompatible materials.

15. The system according to claim 14, wherein, The proximal portion of the needle body includes a first biocompatible material, and the distal portion of the needle body includes a second biocompatible material that is different from the first biocompatible material.

16. The system according to claim 14 or 15, wherein, The one or more biocompatible materials include polypropylene, polyethylene, polyetheretherketone (PEEK), polycarbonate (PC), polyphenylene sulfone (PPSU), polyethylene terephthalate (PET), medical-grade stainless steel, titanium, mixtures of polymers, or mixtures of medical-grade metals.

17. The system according to any one of claims 12 to 16, wherein, The core needle body is sterilizable, making it reusable.

18. A deep brain stimulation system, comprising: The system according to any one of claims 1 to 17; as well as A pulse generator, which is configured to be implanted in or on the skull and connected to the wire.

19. A method for implanting electrodes into the brain, the method comprising: Attach the depth stop to the proximal portion of the mandrel body; The distal portion of the stylet body, removably housed within the lumen of a lead wire, is inserted into the brain, wherein the length of the lead wire extends from the end of the distal portion of the stylet body to a midpoint within the distal portion of the stylet body, and wherein a portion of the lead wire includes one or more electrodes; and The distal portion of the core needle body is removed from the lumen of the lead inserted into the brain, thereby leaving at least the portion of the lead including the one or more electrodes in the brain.

20. The method according to claim 19, wherein, Attaching the depth stop to the proximal portion of the mandrel body includes attaching the depth stop along the length of the proximal portion to a location corresponding to a predetermined depth to which the lead is inserted into the brain.

21. The method of claim 19 or 20, further comprising mounting a stereotactic frame to the skull before inserting the distal portion of the core needle body into the brain, such that a retainer of the stereotactic frame is aligned with an implantation site in the skull.

22. The method according to claim 21, wherein, The distal portion of the core needle body is inserted through the retainer of the stereotactic frame and into the brain until the depth stop contacts the proximal surface of the retainer.

23. The method according to claim 21 or 22, wherein, Removing the distal portion of the mandrel body from the lumen of the conductor includes removing the mandrel body from the retainer of the stereotactic frame.

24. The method according to any one of claims 20 to 23, further comprising removing the stereotactic frame from the skull after removing the core needle body from the lumen of the wire and the retainer of the stereotactic frame.

25. The method according to any one of claims 19 to 24, further comprising inserting a cannula into the predetermined depth in the brain before inserting the distal portion of the core needle body into the brain.

26. The method of claim 25, wherein, The distal portion of the core needle body passes through the cannula and is inserted into the brain until the depth stop contacts the proximal end of the cannula inserted into the brain.

27. The method of claim 25 or 26, further comprising removing the cannula from the brain after removing the core needle body from the lumen of the wire.

28. The method according to any one of claims 19 to 27, further comprising securing the wire to the outer surface of the skull before removing the mandrel body from the lumen of the wire.

29. The method according to claim 28, wherein, The wire is fixed to the outer surface of the skull at a location near a drill hole in the skull, and the wire passes through the drill hole.

30. The method according to any one of claims 19 to 29, further comprising inserting the distal portion of the core needle body into the lumen of the lead wire before inserting the distal portion of the core needle body into the brain.

31. The method according to any one of claims 19 to 30, further comprising positioning the depth stop on the proximal portion of the core needle body such that when the distal portion of the core needle body is inserted to a predetermined depth in the brain, 40% to 80% of the length of the lead wire is disposed outside the skull.

32. The method according to claim 31, wherein, The length of the wire is less than the length of the mandrel body, so that the wire does not engage with the proximal end of the mandrel body.

33. The method according to any one of claims 18 to 32, comprising generating a resection area in a skull configured to receive an implantable pulse generator (IPG), and implanting the implantable pulse generator into the resection area.

34. The method of claim 33, further comprising, after inserting the lead into the brain, connecting the implantable pulse generator to one or more electrical contacts disposed on the proximal portion of the lead.

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