Systems and methods for implanting electrodes in the brain
The lead and stylet system for DBS addresses inefficiencies and complications by enabling precise implantation of shorter leads to a cranially mounted pulse generator, reducing surgical sites and complications through accurate depth control using a detachable stylet and depth stop.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- EPIA NEURO INC
- Filing Date
- 2024-06-20
- Publication Date
- 2026-07-08
AI Technical Summary
Existing deep brain stimulation (DBS) systems require multiple surgical sites and procedures, leading to inefficiency and increased risk of complications due to dislodged or loose extension leads between the brain and pulse generator, necessitating additional surgeries.
A lead and stylet system with a detachable stylet body and depth stop for precise implantation of shorter leads directly to a cranially mounted pulse generator, minimizing excess lead length and reducing surgical sites by using a stereotactic frame or cannula for accurate depth control.
This system reduces surgical complications and inefficiencies by allowing for precise implantation of shorter leads, minimizing scalp erosion, and enhancing power transmission efficiency while reducing the number of surgical sites required.
Smart Images
Figure 2026522647000001_ABST
Abstract
Description
Technical Field
[0001] Cross - Reference to Related Applications This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 509,236, filed on June 20, 2023, which is hereby incorporated by reference in its entirety.
[0002] This disclosure generally relates to leads and stylets, and more specifically to leads and stylets for implanting electrodes into the brain during deep brain stimulation (DBS) implantation procedures.
Background Art
[0003] Deep brain stimulation (DBS) is a neuromodulation therapy that can be used to treat neurodegenerative diseases such as epilepsy and Parkinson's disease (PD). In DBS, an artificial current is supplied to specific regions of the brain to stimulate neurons, thereby alleviating the symptoms experienced in various brain states. For example, in PD patients, high - frequency stimulation is provided to regions of the basal ganglia (e.g., the subthalamic nucleus (STN) or the internal globus pallidus (GPi)) to correct the excitatory - inhibitory imbalance in the basal ganglia circuits. DBS can alleviate the motor symptoms experienced in PD and reduce the need for drug therapy.
[0004] A deep brain stimulation (DVT) system typically includes one or more leads (e.g., equipped with electrodes) implanted in the brain and a pulse generator (e.g., a battery for the stimulator) 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 to allow for the implantation of leads into the brain. A stereotactic brain surgery frame can be used to precisely position the electrodes on the skull and implant them in the target area of the brain. In some cases, a cannula can be used to maintain an open pathway for introducing the leads into the target when inserting them into the brain. The stereotactic brain surgery frame can guide and engage with a stylet to implant a lead that is otherwise flexible and equipped with electrodes into the brain. The leads may be stimulating leads, sensing leads, or combination leads (e.g., sensing and stimulating leads). The appropriate depth of the leads when implanted in the brain can be ensured using a depth stop located on the stylet body. The depth stop indicates the appropriate depth when engaged with, for example, a stereotactic neurosurgical frame and / or cannula.
[0005] In addition to implanting leads in the brain, a small incision is made in the upper chest to create a soft tissue pocket for the pulse generator. The leads are connected to the pulse generator using extension wires that tunnel under the skin between the leads extending from the skull and the pulse generator in the upper chest. However, these extension leads can become dislodged, causing pain and discomfort to the patient. Furthermore, the extension leads may loosen, detach from the pulse generator, or break, each of which requires subsequent surgical intervention to fix, reattach, or replace the leads. Additional surgical interventions may increase the risk of intraoperative and / or postoperative surgical complications, such as infection, bleeding, swelling, and in more serious cases, coma, sepsis, and stroke. Furthermore, the implantation of leads and pulse generators requires preparation of at least two surgical sites (e.g., the upper chest and one or more sites on the skull), and each procedure is typically performed individually during separate visits, which is a source of inefficiency in the operating room and also carries an increased risk of surgical complications (i.e., due to the number of procedures). [Overview of the project]
[0006] This specification describes lead and stylet systems and methods for implanting leads into the brain using a stylet, for example, during implantation procedures in deep brain stimulation (DBS). The lead may be designed to extend from a suitable implantation site for electrodes in the brain to an implantation site on the skull surface suitable for a pulse generator (e.g., an implantable pulse generator mounted in the skull, i.e., an IPG), minimizing excess lead length between sites. The lead may have a lumen along the length of the lead, configured to detachably house a stylet body used to assist in the implantation of leads with electrodes into the brain. The distal portion of the stylet body may be housed within the lead, and the proximal portion of the stylet body may be detachably 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 brain surgery frame mounted in the skull and / or a cannula inserted into the brain to indicate the appropriate depth of electrodes on the lead in the brain.
[0007] In some embodiments, a system is provided for implanting electrodes in the brain, comprising: a lead having a lumen and one or more electrodes arranged on the lead; and a stylet body having a distal portion and a proximal portion, the distal portion being configured to be removably housed in the lumen such that the length of the lead extends from the distal end of the stylet body to the midpoint within the distal portion of the stylet body, and the proximal portion being configured to be removably attached to a depth stop.
[0008] In some embodiments, the position of a depth stop, mounted along the proximal length of the stylet body, corresponds to a predetermined depth in the brain into which the lead is inserted.
[0009] In some embodiments, a predetermined depth within the brain places a length between 40% and 80% of the lead outside the skull.
[0010] In some embodiments, the system includes a depth stop.
[0011] In some embodiments, the depth stop is configured to contact the proximal surface of the holder of the stereotactic neurosurgery frame to stop the insertion of the lead into the brain at a predetermined depth.
[0012] In some embodiments, a depth stop is configured to contact the proximal end of a cannula inserted into the brain in order to stop the insertion of the lead into the brain at a predetermined depth.
[0013] In some embodiments, the proximal portion of the stylet body has a first diameter, and the distal portion of the stylet body has a second diameter different from the first diameter.
[0014] In some embodiments, the first diameter is less than or equal to the diameter of the depth stop so that the depth stop can be removably fixed to the proximal part of the stylet body.
[0015] In some embodiments, the second diameter is less than or equal to the diameter of the lumen so that the distal portion of the stylet body can be removably inserted into the lumen.
[0016] In some embodiments, the stylet body has a length between 10 cm and 50 cm.
[0017] In some embodiments, the length of the lead is shorter than the length of the stylet body so that the lead does not engage with the proximal end of the stylet body.
[0018] In some embodiments, the cross-section of the proximal part of the stylet body and / or the cross-section of the distal part of the stylet body are square, circular, elliptical, rectangular, triangular, or curved triangular.
[0019] In some embodiments, the cross-section of the proximal portion has a first geometric shape, and the cross-section of the distal portion has a second geometric shape different from the first geometric shape.
[0020] In some embodiments, the stylet body comprises one or more biocompatible materials.
[0021] In some embodiments, the proximal portion of the stylet body comprises a first biocompatible material, and the distal portion of the stylet body comprises a second biocompatible material different from the first biocompatible material.
[0022] In some embodiments, one or more biocompatible materials include polypropylene, polyethylene, polyetheretherketone (PEEK), polycarbonate (PC), polyphenylsulfone (PPSU), polyethylene terephthalate (PET), medical-grade stainless steel, titanium, a mixture of polymers, or a mixture of medical-grade metals.
[0023] In some embodiments, the stylet body is sterilizable so that the stylet body can be reused.
[0024] In some embodiments, a deep brain stimulation therapy system is provided, comprising any one of the systems described above and a pulse generator configured to be implanted in or on the skull and coupled to a lead.
[0025] In some embodiments, a method for implanting an electrode into the brain, the method comprising attaching a depth stop to a proximal portion of a stylet body and inserting a distal portion of the stylet body removably received within a lumen of a lead into the brain, wherein the length of the lead extends from an end of the distal portion of the stylet body to an intermediate point within the distal portion of the stylet body and wherein a portion of the lead comprises one or more electrodes, and removing the distal portion of the stylet body from the lumen of the lead inserted into the brain, thereby leaving at least a portion of the lead comprising one or more electrodes within the brain.
[0026] In some embodiments, attaching a depth stop to a proximal portion of a stylet body comprises attaching the depth stop at a position along the length of the proximal portion corresponding to a predetermined depth within the brain into which the lead is to be inserted.
[0027] In some embodiments, the method comprises attaching a stereotactic brain surgery frame to the skull such that a holder of the stereotactic brain surgery frame is aligned with an implantation site within the skull before inserting the distal portion of the stylet body into the brain.
[0028] In some embodiments, the distal portion of the stylet body is inserted into the brain through a holder of the stereotactic brain surgery frame until the depth stop contacts a proximal surface of the holder.
[0029] In some embodiments, removing the distal portion of the stylet body from the lumen of the lead comprises removing the stylet body from a holder of the stereotactic brain surgery frame.
[0030] In some embodiments, the method comprises removing the stereotactic brain surgery frame attached to the skull after removing the stylet body from the lumen of the lead and from the holder of the stereotactic brain surgery frame.
[0031] In some embodiments, the method includes inserting the cannula to a predetermined depth in the brain before inserting the distal portion of the stylet body into the brain.
[0032] In some embodiments, the distal portion of the stylet body is inserted into the brain via a cannula until the depth stop contacts the proximal end of the cannula inserted into the brain.
[0033] In some embodiments, the method includes removing the stylet body from the lumen of the lead, and then removing the cannula from the brain.
[0034] In some embodiments, the method includes securing the reed to the outer surface of the skull before removing the stylet body from the lumen of the reed.
[0035] In some embodiments, the lead is fixed to the outer surface of the skull at a location close to the trepanation hole in the skull from which the lead exits.
[0036] In some embodiments, the method includes inserting the distal end of the stylet body into the lumen of the lead before inserting the distal end of the stylet body into the brain.
[0037] In some embodiments, the method includes positioning a 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, the length of the lead between 40% and 80% is located outside the skull.
[0038] In some embodiments, the length of the lead is shorter than the length of the stylet body so that the lead does not engage with the proximal end of the stylet body.
[0039] In some embodiments, the method includes forming a resection of the skull configured to receive an implantable pulse generator (IPG), and implanting the IPG within the resection.
[0040] In some embodiments, the method includes inserting a lead into the brain and then connecting an implantable pulse generator to one or more electrical contacts located proximal to the lead. [Brief explanation of the drawing]
[0041] Various aspects of the disclosed systems and methods are described in detail 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 exemplary embodiments and the accompanying drawings.
[0042] [Figure 1A] Figure 1A shows perspective views of lead and stylet systems according to several embodiments.
[0043] [Figure 1B] Figure 1B shows another perspective view of the lead and stylet system according to several embodiments.
[0044] [Figure 1C] Figure 1C shows an enlarged partial view of a lead according to several embodiments.
[0045] [Figure 1D] Figure 1D shows partial cross-sectional views of a lead according to several embodiments.
[0046] [Figure 2A] Figure 2A shows perspective views of depth stops according to several embodiments.
[0047] [Figure 2B] Figure 2B shows another perspective view of a depth stop according to several embodiments.
[0048] [Figure 3] Figure 3 shows perspective views of assemblies comprising a lead, stylet, and depth stop according to several embodiments.
[0049] [Figure 4A] Figure 4A shows perspective views of lead and stylet systems with stereotactic brain surgery frames according to several embodiments.
[0050] [Figure 4B] Figure 4B shows detailed diagrams of lead and stylet systems with stereotactic brain surgery frames according to several embodiments. [Modes for carrying out the invention]
[0051] Lead and stylet systems, and methods for implanting leads using stylets, are described herein. Stylet bodies and leads may be used to implant leads of appropriate length into the brain during deep brain stimulation (DBS) implantation procedures for a cranially mounted pulse generator (e.g., an implantable pulse generator, i.e., an IPG). As discussed herein, lead lengths may be shorter than those used in DBS systems with a chest-implanted IPG. The stylets of the lead and stylet systems described herein can facilitate the proper implantation of shorter leads into the brain by positioning the distal portion of the stylet body within the lead lumen. Furthermore, the proximal portion of the stylet body can engage with a stereotactic brain surgery frame and / or a cannula inserted into the brain to attach to a depth stop indicating the appropriate insertion depth of the electrode in the brain.
[0052] The DBS systems discussed herein may include a cranially mounted IPG rather than an IPG implanted in the patient's chest, thereby eliminating the need for long leads and / or extension wires tunneling between the skull and chest. A cranially mounted IPG can also reduce the number of surgical sites required to implant the DBS system, thereby reducing the amount of time spent during the DBS implantation procedure. For example, attempting to use these long leads with a cranially mounted IPG by bundling the excess lead length at the implantation site into a pocket within the scalp can cause scalp erosion, thus necessitating a system with shorter lead lengths. Shorter lead lengths may also result in more efficient power transmission during deep brain stimulation than the longer leads used in DBS systems with chest-mounted IPGs. However, shorter lead lengths may result in minimal lead length remaining outside the skull, potentially not extending to the stereotactic brain surgery frame for proper alignment and positioning. Therefore, the stylet provided herein can be attached to a depth stop that contacts a stereotactic neurosurgery frame, with the distal portion of the stylet body being fed into the lumen of the lead and for proper positioning and placement of the lead.
[0053] Figures 1A-1B show a system 100 for implanting electrodes in the brain, the system 100 comprising a lead 102 and a stylet body 104. The lead 102 may comprise a lumen 108 and one or more electrodes 106 arranged on the lead. The lead 102 may be a stimulating lead, a sensing lead, or a combination lead (e.g., a lead capable of both sensing and stimulating). The stylet body 104 may comprise a distal portion 110 and a proximal portion 112, the distal portion 110 being configured to be removably housed 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 the midpoint within the distal portion 110 of the stylet body 104. The proximal portion 112 may be configured to be removably attached to a depth stop (e.g., at least the depth stop 200 shown in Figures 2A-2B). The stylet body 104 and the lead 102 will be described in more detail below.
[0054] Stylet body As shown in at least Figures 1A-1B, the stylet body 104 may comprise a proximal portion 112 having a first diameter and a distal portion 110 having a second diameter. The first and second diameters may be substantially the same, or they may be different (as shown). In some embodiments, the cross-sectional shapes of the proximal portion 112 and the distal portion 110 of the stylet body 104 may differ rather than having different diameter measurements. For example, the cross-sectional shape of one or more portions of the stylet body 104 may be square, circular, elliptical, rectangular, triangular, curved triangular, or another polygonal shape.
[0055] In some embodiments, the first diameter of the proximal portion 112 of the stylet body 104 may be 3 mm or less, 2.75 mm or less, 2.5 mm or less, 2.25 mm or less, 2 mm or less, 1.75 mm or less, or 1.5 mm or less. In some embodiments, the first diameter of the proximal portion 112 of the stylet body 104 may be 0.5 mm or more, 0.75 mm or more, 1 mm or more, 1.25 mm or more, 1.5 mm or more, 1.75 mm or more, or 2 mm or more. The first diameter of the proximal portion 112 may be less than or equal to the diameter of the depth stop (for example, at least the diameter of the receiving portion 202 of the depth stop 200 shown in Figures 2A to 2B).
[0056] In some embodiments, the second diameter of the distal portion 110 of the stylet body 104 may be 1.5 mm or less, 1.25 mm or less, 1.0 mm or less, 0.75 mm or less, or 0.5 mm or less. In some embodiments, the second diameter of the distal portion 110 of the stylet body 104 may be 0.1 mm or more, 0.25 mm or more, 0.5 mm or more, or 0.75 mm or more. The second diameter of the distal portion 110 of the stylet body 104 may be less than or equal to the diameter of the lumen 108 of the lead, so that the distal portion 110 can be removably inserted into the lumen 108.
[0057] In some embodiments, the length of the stylet body 104 may be 5 cm or less, 10 cm or less, 20 cm or less, 25 cm or less, 30 cm or less, 40 cm or less, 50 cm or less, or 60 cm or less. In some embodiments, the length of the stylet body 104 may be 5 cm or more, 10 cm or more, 20 cm or more, 25 cm or more, 30 cm or more, 40 cm or more, 50 cm or more, or 60 cm or more. 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 lead 102 selected for a particular patient.
[0058] In some embodiments, the distal portion 110 may comprise about half the length of the stylet body 104, and the proximal portion 112 may comprise the other half the length of the stylet body 104. For example, the distal portion 110 may comprise about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or more of the length of the stylet body 104, while the proximal portion 112 may comprise the remaining 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% of the length of the stylet body 104.
[0059] In some embodiments, the stylet body 104 may be made from one or more biocompatible materials. For example, the stylet body 104 may contain, but is not limited to, one or more biocompatible materials including, polypropylene, polyethylene, polyetheretherketone (PEEK), polycarbonate (PC), polyphenylsulfone (PPSU), polyethylene terephthalate (PET), medical-grade stainless steel, titanium (e.g., nickel-titanium), polymer mixtures, medical-grade metal mixtures, or polymer and medical-grade metal mixtures. In some embodiments, the distal portion 110 may contain a first mixture of materials (e.g., one or more materials), and the proximal portion 112 may contain a second mixture of materials (e.g., one or more materials) different from the first mixture of materials. For example, the distal portion 110 may contain one or more medical-grade metals (e.g., stainless steel, titanium, etc.), and the proximal portion 112 may contain 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.
[0060] In some embodiments, the material of the stylet body 104 may be selected so that the stylet body 104 is sterilizable and reusable for multiple lead stimulation implantation procedures. For example, the stylet body 104 may be sterilizable using moist heat (steam), dry heat, radiation, ethylene oxide gas, vaporized hydrogen peroxide, and / or other sterilization methods (e.g., chlorine dioxide gas, vaporized peracetic acid, nitrogen dioxide, etc.).
[0061] Lead The lead 102 may be configured to deliver an artificial current to a region of the brain via one or more electrodes 106 arranged on the lead. For example, the lead 102 may have an array of electrodes 106 arranged at least at the distal end of the lead 102. In some embodiments, multiple 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 the current to a specific location and / or in a specific direction. Segmented electrodes may offer advantages over, for example, solid ring electrodes that are geometrically shaped and axially symmetric in treatment.
[0062] As shown in at least Figures 1A to 1D, the lead 102 may have one or more additional electrical contacts 109. The electrical contacts 109 may be configured to be electrically coupled to an implantable pulse generator (IPG) that is implanted in the skull. For example, the IPG may have a receptor configured to receive and connect to the electrical contacts 109. Thus, when implanted, the IPG can generate stimulation pulses that can be supplied to the electrical contacts 109, and these stimulation pulses can propagate through the lead 102 to the electrode 106 (for example, via one or more extension wires electrically connecting the electrical contacts 109 to the electrode 106). The electrode 106 can then stimulate the region of the brain in which the electrode 106 is implanted with the stimulation pulses.
[0063] As described above, and at least as shown in Figure 1D, the lead 102 may include a lumen 108 configured to accommodate the distal portion 110 of the stylet body 104. The lumen 108 may be a through-hole extending through at least a portion of the length of the lead 102. For example, the lumen 108 may extend from the proximal end of the lead 102 toward the distal end of the lead 102. The proximal end may be configured to first receive the stylet body 104. The lumen 108 does not have to penetrate to the distal end of the lead 102, and as a result, when the distal portion 110 of the stylet body 104 is inserted into the lead 102, the lumen 108 may be inserted until it reaches a midpoint in the lead 102 where it terminates. In some embodiments, the lumens 108 may comprise about 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99% of the length of the lead 102.
[0064] The cross-sectional shape of the lumen 108 may be substantially the same as the cross-sectional shape of the distal portion 110 of the stylet body 104. For example, if the cross-section of the lumen 108 is circular, the diameter of the lumen 108 may be 1.5 mm or less, 1.25 mm or less, 1.0 mm or less, 0.75 mm or less, or 0.5 mm or less. In some embodiments, the diameter of the lumen 108 may be 0.25 mm or more, 0.5 mm or more, 0.75 mm or more, or 1 mm or more.
[0065] The length of the lead 102 may extend from the electrode implantation site in the brain to the IPG implantation site in the skull, minimizing excess lead length. Therefore, its length may be shorter than that of the leads in a deep brain stimulation (DBS) system with a pulse generator implanted in the chest. For example, the length of the lead 102 may be 50 cm or less, 40 cm or less, 30 cm or less, 20 cm or less, 15 cm or less, 10 cm or less, 5 cm or less, or 1 cm or less. In some embodiments, the length of the lead 102 may be 0.5 cm or more, 1 cm or more, 5 cm or more, 10 cm or more, 15 cm or more, or 20 cm or more. The lead 102 may be selected so that the lead length corresponds to one or more measurements of the patient. Therefore, leads 102 of different lengths may be used for different patients. The length of the lead 102 may be shorter than the length of the stylet body 104 so that the lead 102 does not engage with the proximal end of the stylet body 104. For example, as discussed herein, the lead 102 may extend from the end of the distal portion 112 of the stylet body 104 to the midpoint within the distal portion 112 of the stylet body 104. Figure 3 shows an assembly 300 in which the stylet body 104 is removably inserted into the lumen 108 of the lead 102.
[0066] Lead 102 may contain one or more biocompatible materials to enable the lead to be safely implanted in the patient's brain. The technical features and materials of Lead 102 are not intended to be limited to the disclosures provided herein, but rather may include any one or more features of leads known to those skilled in the art.
[0067] Lead, stylet, and depth stop assembly As discussed herein, the stylet body 104 may be configured to be removably attached to a depth stop. For example, the stylet body 104 may be directly attached to the depth stop (e.g., not to the lead). In some embodiments, the stylet body 104 may be indirectly attached to the depth stop (e.g., the lead may be attached to the depth stop). Figures 2A-2B show an exemplary depth stop 200 configured to be removably attached to the stylet body 104. As shown, the depth stop 200 may have a receiving portion 202 (e.g., a through-hole) configured to receive at least the proximal portion 112 of the stylet body 104. For example, Figure 3 shows an assembly 300 in which the depth stop 200 is attached to the proximal portion 112 of the stylet body 104.
[0068] The depth stop 200 may have an opening that allows the user to removably insert the stylet body 104 into the receiving portion 202 of the depth stop 200. For example, the depth stop 200 may have a semi-annular body, and the opening within the annular shape may be sized so that the stylet body 104 can be removably inserted through the opening.
[0069] As shown in Figure 2B, the depth stop 200 may include a fastener 204 that can engage with the stylet body 104 when inserted into the receiving portion 202 of the depth stop 200 in order to maintain the position of the depth stop 200 on the stylet body 104. The user can move the fastener 204 into / out of the receiving portion 202 by rotating, turning, pushing, and / or pulling a knob 206 coupled to the fastener 204. For example, the fastener 204 may have threads that allow for fine adjustment of the fastener 204 by rotating the knob 206. In some embodiments, the fastener 204 may be movable between two or more positions (e.g., a locked position and an unlocked position), and the user can move the fastener 204 between two or more positions by operating the knob 206 (e.g., rotating, pushing, pulling, and / or turning).
[0070] In some embodiments, the depth stop 200 may be configured to clamp onto the stylet wire rather than the stylet body 104.
[0071] In some embodiments, the lead and stylet system 100 described herein may be provided as a component of a deep brain stimulation (DBS) system. For example, the DBS system may include, in addition to at least the lead 102 and stylet body 104 discussed herein, a pulse generator configured to be implanted in the skull and coupled to the lead 102. In some embodiments, a depth stop 200 may be included in the DBS system. Nevertheless, it should be understood by those skilled in the art that the lead and stylet system described herein is not limited to a deep brain stimulation (DBS) system comprising a pulse generator mounted in the skull, and may be adapted for use in other systems, including but not limited to other DBS systems in which the IPG can be implanted in other locations in the human body (other than the skull).
[0072] How to use the reed and stylet system As discussed herein, the lead and stylet system 100 may be used to implant electrodes (e.g., electrode 106) in the brain. For example, electrode 106 may be implanted for deep brain stimulation therapy. A method for implanting electrode 106 in the brain may include attaching a depth stop 200 to the proximal portion 112 of the stylet body 104. For example, the depth stop 200 may be attached to the stylet body 104 at a position along the length of the proximal portion 112 that can correspond to a predetermined depth in the brain into which the lead 102 is inserted.
[0073] In some embodiments, the method may include inserting the distal portion 110 of the stylet body 104 into the lumen 108 of the lead 102. In some embodiments, the lead 102 and the stylet body 104 may be provided to the user in an assembled state, as shown in the assembly 300 of Figure 3. The length of the lead 102 may extend from the end of the distal portion 110 of the stylet body 104 to the midpoint within the distal portion 110 of the stylet body 104.
[0074] In some embodiments, the method may include forming an excision (e.g., a trepanation hole) on the surface of the skull at a predetermined location corresponding to the intended electrode implantation site in the brain.
[0075] In some embodiments, the method may include attaching a stereotactic neurosurgical frame to the skull. For example, Figures 4A-4B show exemplary stereotactic neurosurgical frames 400 that can be attached to the skull. Attaching the stereotactic neurosurgical frame 200 may include adjusting the position of the frame along one or more axes (e.g., X, Y, and Z labeled on the stereotactic neurosurgical frame 400 shown in Figure 4). In some embodiments, the stereotactic neurosurgical frame 400 may already be attached to the skull, in which case the method may not include attaching the frame to the skull.
[0076] The stereotactic brain surgery frame 400 may include a holder 402 configured to receive the stylet body 104 and maintain the position of the stylet body 104 (inserted into the lead 102) while the lead 102 is being inserted into the brain. For example, as shown in Figure 4B, the holder 402 may include a receiving portion 404 (e.g., a through-hole) configured to receive the stylet body 104.
[0077] The stereotactic neurosurgery frame 400 (for example, one or more movable components of the stereotactic neurosurgery frame 400) may be positioned so that the holder 402 can be aligned with the implantation site in the skull. For example, the holder 402 may be positioned above the implantation site on the skull, but away from the implantation site. The position of the holder 402 may be modified in one or more planes relative to the stereotactic neurosurgery frame 400. As shown in Figure 4, the position of the holder 402 may be adjustable in one or more directions represented by arrows 406, 408 and / or 410 in Figure 4.
[0078] 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 burr hole created in the surface of the skull. The cannula may be used to create an opening in the brain to facilitate lead implantation. One or more of the exemplary stereotactic brain surgery frame systems discussed herein may be used in combination with a cannula.
[0079] The method may include inserting the distal portion 110 of the stylet body 104, which is removably housed within the lumen 108 of the lead 102, into the brain. For example, the distal portion 110, which is removably housed within the lead 102, may be inserted into the brain (e.g., through a trepanation hole in the skull) via the holder 402 until the depth stop 200 contacts the holder 402. For example, when the assembly of the lead 102 and stylet body 104 is inserted into the brain to a predetermined depth through the receptive portion 404 of the holder 402, as shown at least in Figure 4B, the depth stop 200 may contact the proximal surface of the holder 402. The position where the depth stop 200 on the stylet body 104 contacts the holder 402 may indicate an appropriate implantation depth for the electrode 106 positioned on the lead 102.
[0080] If the cannula discussed herein has been previously inserted into the brain, the distal portion 110 of the stylet body 104 (removably housed within the lumen 108 of the lead 102) may be inserted into the brain via the cannula. The distal portion 110 of the stylet body 104 may be inserted into the brain until a depth stop 200 attached to the proximal portion 112 of the stylet body 104 contacts the cannula inserted into the brain. For example, the depth stop 200 may 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 may indicate an appropriate implantation depth for the electrode 106 positioned on the lead 102.
[0081] The position of the depth stop 200 on the proximal portion 112 of the stylet body 104 may be selected such that when the distal portion 110 of the stylet body 104, which is removably housed within the lead 102, is inserted into the brain until the depth stop contacts the holder 402 (or a cannula in some embodiments), about 40% to 80% of the lead 102 is positioned outside the skull. In some embodiments, once the lead is properly implanted into the brain, about 20%, 30%, 40%, 50%, 60%, 70%, or 80% of the lead 102 may be positioned outside the skull.
[0082] Once the stylet body 104 and lead 102 have been inserted to a predetermined depth in the brain, the method may include removing the distal portion 110 of the lead 102 from the lumen 108, thereby leaving a portion of the lead 102 with at least one electrode 106 implanted in the brain. For example, the user may remove the distal portion 110 of the stylet body 104 from the lumen 108 of the lead 102, and then remove the stylet body 104 from the holder 402 of the stereotactic brain surgery frame 400.
[0083] In some embodiments, the method may include fixing the lead 102 to the outer surface of the skull before removing the distal portion 110 of the stylet body 104 from the lumen 108 of the lead 102. In some embodiments, the fixation of the lead 102 to the skull may be performed after the stylet body 104 has been removed from the lead 102. The lead 102 may be fixed to the outer surface of the skull in a location close to the trepanation hole in the skull from which the lead 102 (and optionally the stylet body 104) will exit. For example, a lead fixation device may be used to fix a portion of the lead 102 to the skull in a location adjacent to the trepanation hole. The lead fixation device may be used to fix the lead 102 to the skull before removing the stylet body 104 from the lumen 108 and / or before removing the stereotactic brain surgery frame 400, as described herein.
[0084] The method may include removing the stylet body 104 from the lumen 108 of the lead 102 and the holder 402 of the stereotactic neurosurgical frame 400, and then removing the stereotactic neurosurgical frame 400 from the skull. In some embodiments, the stereotactic neurosurgical frame 400 and / or depth stop 200 may be removed before removing the stylet body 104 from the lumen 108 of the lead 102.
[0085] If a cannula is inserted into the brain, the method may include removing the stylet body 104 from the lumen 108 of the lead 102, and then removing the cannula from the brain. For example, the cannula may include a peel-away cannula, which is partially divided into two axial pieces so that the cannula can be separated and removed while the lead 102 is held in place by the stereotactic brain surgery frame 400. Once the lead 102 is fixed to the skull, the stereotactic brain surgery frame 400 and the stylet body 104 can be removed.
[0086] In some embodiments, the method may include connecting the lead 102 to an implantable pulse generator (IPG). As discussed herein, the lead 102 may have one or more electrical contacts 109 at its proximal end, and one or more electrical contacts 109 may be connected to an IPG configured to be mounted in or on the skull. In some embodiments, the method may include forming a resection in the skull that can be configured to receive a skull-mounted IPG. The resection may be created before implanting the lead 102 in the skull. The method may also include implanting the IPG within the resection in the skull.
[0087] As discussed herein, the use of lead 102 and / or stylet body 104 is not limited to deep brain stimulation (DBS) systems with an IPG implanted in the skull. For example, lead 102 and / or stylet body 104 may be used in DBS implantation procedures in which the IPG is implanted in another location on the human body (e.g., the chest). Thus, in these examples, the method may include connecting lead 102 to one or more extension leads electrically connected to the IPG. The method may also include preparing an additional implantation site, such as the chest, and implanting the IPG in the chest.
[0088] Unless otherwise defined, all technical terms, notations, and other technical and scientific terms or terms used herein are intended to have the same meaning as those generally understood by those skilled in the art in which the claimed subject matter belongs. In some cases, terms that have a generally understood meaning are defined herein for clarity and / or for ease of reference, and the inclusion of such definitions herein should not necessarily be interpreted as representing a substantial difference from those generally understood in the art.
[0089] Where used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, the term “and / or” as used herein should be understood to refer to and include any and all possible combinations of one or more of the enumerated items in question. Further understanding is that where used herein, the terms “includes,” “including,” “comprises,” and / or “comprising” identify 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.
[0090] The disclosed numerical range essentially supports any range or value within the disclosed numerical range (including endpoints), even if the specification does not specify a verbatim, precise range limitation. This is because the disclosure may be implemented across the entire disclosed numerical range.
[0091] The above description is written with reference to specific embodiments for illustrative purposes. However, the above illustrative discussion is not intended to be exhaustive or to limit the invention to the exact form disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments have been selected and described to best illustrate the principles of the art and its practical applications. This will enable other persons skilled in the art to best utilize the art and various embodiments with various modifications suitable for specific intended uses.
[0092] While the present disclosure and examples are fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will be apparent to those skilled in the art. Such changes and modifications should be understood to be within the scope of the present disclosure and examples as defined by the claims.
Claims
1. It is a system for implanting electrodes in the brain. A lead comprising a lumen and one or more electrodes arranged on the lead, A stylet body comprising a distal portion and a proximal portion, wherein the distal portion is configured to be removably housed within the lumen such that the length of the lead extends from the end of the distal portion of the stylet body to the 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, A system equipped with these features.
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 stylet body, corresponds to a predetermined depth in the brain into which the lead is inserted.
3. The system according to claim 1 or 2, wherein the predetermined depth in the brain is such that the length of the lead between 40% and 80% is located outside the skull.
4. A 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 holder of the stereotactic neurosurgery frame in order to stop the insertion of the lead into the brain at a predetermined depth.
6. A system according to claim 4 or 5, wherein the depth stop is configured to contact the proximal end of a cannula inserted into the brain to stop the insertion of the lead into the brain at a predetermined depth.
7. A system according to any one of claims 1 to 6, wherein the proximal portion of the stylet body has a first diameter, and the distal portion of the stylet body has 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 so that the depth stop can be removably fixed to the proximal portion of the stylet body.
9. The system according to claim 7 or 8, wherein the second diameter is less than or equal to the diameter of the lumen so that the distal portion of the stylet body can be removably inserted into the lumen.
10. A system according to any one of claims 1 to 9, wherein the stylet body has a length between 10 cm and 50 cm.
11. The system according to claim 10, wherein the length of the lead is shorter than the length of the stylet body so that the lead does not engage with the proximal end of the stylet body.
12. A system according to any one of claims 1 to 11, wherein the cross-section of the proximal portion of the stylet body and / or the cross-section of the distal portion of the stylet body is square, circular, elliptical, rectangular, triangular, or curved triangular.
13. A system according to claim 12, wherein the cross-section of the proximal portion has a first geometric shape, and the cross-section of the distal portion has a second geometric shape different from the first geometric shape.
14. A system according to any one of claims 1 to 13, wherein the stylet body comprises one or more biocompatible materials.
15. A system according to claim 14, wherein the proximal portion of the stylet body comprises a first biocompatible material, and the distal portion of the stylet body comprises a second biocompatible material different from the first biocompatible material.
16. A system according to claim 14 or 15, wherein the one or more biocompatible materials include polypropylene, polyethylene, polyetheretherketone (PEEK), polycarbonate (PC), polyphenylsulfone (PPSU), polyethylene terephthalate (PET), medical-grade stainless steel, titanium, a mixture of polymers, or a mixture of medical-grade metals.
17. A system according to any one of claims 12 to 16, wherein the stylet body is sterilizable so that the stylet body is reusable.
18. It is a deep brain stimulation therapy system, A system according to any one of claims 1 to 17, A pulse generator, which is embedded in or on the skull and configured to be coupled to the lead, A deep brain stimulation therapy system equipped with these features.
19. A method for implanting electrodes in the brain, wherein the method is The depth stop is attached to the proximal part of the stylet body, The method involves inserting the distal portion of the stylet body, which is removably housed within the lumen of the lead, into the brain, wherein the length of the lead extends from the end of the distal portion of the stylet body to the midpoint within the distal portion of the stylet body, and a portion of the lead comprises one or more electrodes. A method comprising removing the distal portion of the stylet body from the lumen of the lead inserted into the brain, thereby leaving at least a portion of the lead comprising one or more electrodes in the brain.
20. A method according to claim 19, wherein attaching the depth stop to the proximal portion of the stylet body includes attaching the depth stop to a position along the length of the proximal portion corresponding to a predetermined depth in the brain into which the lead is inserted.
21. A method according to claim 19 or 20, comprising attaching the stereotactic neurosurgical frame to the skull such that the holder of the stereotactic neurosurgical frame is aligned with an implantation site in the skull before inserting the distal portion of the stylet body into the brain.
22. A method according to claim 21, wherein the distal portion of the stylet body is inserted into the brain via the holder of the stereotactic neurosurgical frame until the depth stop contacts the proximal surface of the holder.
23. A method according to claim 21 or 22, wherein removing the distal portion of the stylet body from the lumen of the lead includes removing the stylet body from the holder of the stereotactic neurosurgery frame.
24. A method according to any one of claims 20 to 23, comprising removing the stylet body from the lumen of the lead and the holder of the stereotactic neurosurgical frame, and then removing the stereotactic neurosurgical frame that is attached to the skull.
25. A method according to any one of claims 19 to 24, comprising inserting a cannula into the brain to a predetermined depth before inserting the distal portion of the stylet body into the brain.
26. A method according to claim 25, wherein the distal portion of the stylet body is inserted into the brain via the cannula until the depth stop contacts the proximal end of the cannula inserted into the brain.
27. A method according to claim 25 or 26, comprising removing the stylet body from the lumen of the lead, and then removing the cannula from the brain.
28. A method according to any one of claims 19 to 27, comprising fixing the lead to the outer surface of the skull before removing the stylet body from the lumen of the lead.
29. A method according to claim 28, wherein the lead is fixed to the outer surface of the skull at a location adjacent to a trepanation hole in the skull from which the lead exits.
30. A method according to any one of claims 19 to 29, comprising inserting the distal portion of the stylet body into the lumen of the lead before inserting the distal portion of the stylet body into the brain.
31. A method according to any one of claims 19 to 30, comprising 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, the length of the lead between 40% and 80% is located outside the skull.
32. A method according to claim 31, wherein the length of the lead is shorter than the length of the stylet body so that the lead does not engage with the proximal end of the stylet body.
33. A method according to any one of claims 18 to 32, comprising forming a resection of a skull configured to receive an implantable pulse generator (IPG), and implanting the IPG within the resection.
34. A method according to claim 33, comprising inserting the lead into the brain and then connecting the implantable pulse generator to one or more electrical contacts located proximal to the lead.