An implantable electrode lead

Abstract

This utility model belongs to the field of medical device technology and discloses an implantable electrode lead. The implantable electrode lead includes a stimulation segment, a middle segment, and a connecting segment connected sequentially. The stimulation segment includes several stimulation contacts, the connecting segment includes several connecting contacts, and the middle segment includes an outer sheath and several guidewires housed within the sheath. The guidewires electrically connect the stimulation contacts and connecting contacts one-to-one. The stimulation segment and at least a portion of the middle segment are implanted intracranially to form an intracranial segment. The middle segment near and fixed to the skull forms a cranial segment, and the portion of the middle segment extending outside the skull and the connecting segment form an extracranial segment. The guidewires in the intracranial segment are straight, those in the cranial segment are spiral, and at least a portion of the guidewires in the extracranial segment are spiral, with the pitch of the spiral in the cranial segment being smaller than that in the extracranial segment. This utility model reduces manufacturing costs and heat generation; furthermore, it facilitates intraoperative operation and ensures a comfortable postoperative experience for the user.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to an implantable electrode lead. Background Technology

[0002] In existing deep brain stimulation (DBS) treatment, the stimulation signal is mainly transmitted from the stimulator to the extension lead, then from the extension lead to the electrode lead, and finally from the electrode lead to the target nucleus.

[0003] Existing electrode leads can be divided into a connecting section, a middle section, and a stimulation section. The connecting section has several metal connecting rings, and the stimulation section has several metal electrode rings, typically made of platinum-iridium alloy. The middle section contains coated multi-strand helical metal wires. Existing electrode leads achieve electrical connection between the connecting and stimulation sections by the multi-strand helical precious metal wires in the middle section running through the entire electrode. Currently, because the helical metal wires provide a certain bending or tensile allowance for the electrode leads, they have strong adaptability and can meet complex working conditions. Therefore, existing electrode leads typically use multi-strand helical precious metal wires throughout.

[0004] However, the multi-strand spiral metal wires lead to a sharp increase in the length of the precious metal wires, which in turn increases the cost of the electrode leads. In addition, the inductance and parasitic capacitance of the spiral metal wires will form a resonant circuit. The RF field frequency is close to the resonant frequency of the spiral metal wires, which will lead to enhanced resonance absorption. Furthermore, the longer spiral metal wires significantly improve the heating efficiency, thereby reducing the user's postoperative discomfort. Utility Model Content

[0005] The purpose of this invention is to provide an implantable electrode lead that reduces the manufacturing cost of existing electrode leads, reduces electrode heating efficiency due to resonance absorption, and improves the postoperative experience.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] An implantable electrode lead includes a stimulation segment, a middle segment, and a connecting segment connected sequentially. The stimulation segment includes a plurality of stimulation contacts, and the connecting segment includes a plurality of connection contacts. The middle segment includes an outer sheath and a plurality of guidewires housed within the outer sheath. The guidewires electrically connect the stimulation contacts and the connection contacts one-to-one. The stimulation segment and at least a portion of the middle segment are implanted intracranially to form an intracranial segment. The portion of the middle segment near and fixed to the skull constitutes a cranial segment, and the portion of the middle segment extending outside the skull and the connecting segment constitute an extracranial segment.

[0008] The guidewire located in the intracranial segment is straight, the guidewire located in the cranial segment is spiral, and the guidewire located in the extracranial segment is at least partially spiral, with the pitch of the guidewire in the cranial segment being smaller than that in the extracranial segment.

[0009] As an alternative to implantable electrode lead, the extracranial segment includes a first sub-segment and a second sub-segment, one end of the first sub-segment being connected to the cranial segment, the other end of the first sub-segment being connected to the second sub-segment, and the second sub-segment being at least partially used for electrical connection to an extension lead or stimulator.

[0010] As an alternative to implantable electrode leads, the pitch of the first segment gradually changes in the direction of helical extension, or the first segment has a first pitch in the direction of helical extension.

[0011] As an alternative to implantable electrode leads, both the first segment and the second segment are helical, with the pitch of the first segment being smaller than that of the second segment.

[0012] As an alternative to implantable electrode leads, the first segment is spiral-shaped and the second segment is straight-shaped.

[0013] As an alternative to implantable electrode leads, the second segment is provided with a support.

[0014] As an alternative to implantable electrode leads, the pitch of the extracranial segment gradually increases in the direction away from the skull.

[0015] As an alternative to implantable electrode leads, the pitch of the cranial segment gradually increases in the direction in which the intracranial segment extends toward the extracranial segment.

[0016] As an alternative to implantable electrode leads, the cranial segment has a second pitch in the direction of helical extension.

[0017] As an alternative to implantable electrode leads, a first flexible tube is provided inside the spiral of the guidewire in the cranial segment, and a second flexible tube is provided outside the spiral of the guidewire in the cranial segment.

[0018] Beneficial effects:

[0019] In this invention, the electrode lead, by incorporating a straight intracranial segment and a larger pitch extracranial segment, reduces the length of the guidewire compared to a continuous spiral, thus decreasing the amount of precious metals used and consequently lowering the overall manufacturing cost of the implantable electrode lead. Furthermore, the reduced guidewire length also lowers the DC resistance, further reducing heat generation. On the other hand, the intracranial and extracranial segments require a certain degree of rigidity for surgical manipulation; the straight intracranial segment and larger pitch extracranial segment enhance this rigidity, ensuring a smooth implantation procedure. Moreover, the straight intracranial segment reduces the length of the spiral portion of the electrode lead, thereby decreasing the probability of enhanced absorption due to resonance, reducing heat generation efficiency, and ensuring a comfortable postoperative experience for the user. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the conductive body provided in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the guidewire provided in an embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional view of the electrode wire provided in an embodiment of this utility model.

[0023] In the picture:

[0024] 100. Stimulus segment; 110. Intermediate segment; 120. Connective segment;

[0025] 200. Extension lead; 300. Stimulator;

[0026] 11. Intracranial segment; 12. Skull segment; 13. Extracranial segment; 131. First sub-segment; 132. Second sub-segment; 2. First flexible tube; 3. Second flexible tube; 4. Support body. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0028] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0031] The technical field and related terms that may be involved in the embodiments of this application are briefly described below.

[0032] Implantable medical systems include implantable neurostimulation systems, implantable cardiac stimulation systems (also known as pacemakers), implantable drug delivery systems (IDDS), and lead transfer systems. Examples of implantable neurostimulation systems include deep brain stimulation (DBS), cortical nerve stimulation (CNS), spinal cord stimulation (SCS), sacral nerve stimulation (SNS), and vagus nerve stimulation (VNS).

[0033] Implantable neurostimulation systems consist of a stimulator implanted in the patient's body (i.e., an implantable neurostimulator) and a programmed device placed outside the patient's body. In other words, the stimulator is a medical device, or medical devices include stimulators. Related neuromodulation techniques primarily involve stereotactic surgery to implant electrodes (e.g., electrode wires) at specific sites (target points) in the body's tissues. Discharge pulses are then delivered through these electrodes to the target points, modulating the electrical activity and function of corresponding neural structures and networks, thereby improving symptoms and alleviating pain.

[0034] As an example, a DBS includes an IPG (Implantable Pulse Generator), extension leads, and electrode leads. The IPG is connected to the electrode leads via the extension leads. The IPG is implanted in the patient's body, for example, in the chest or other internal locations.

[0035] As another example, DBS includes an IPG and electrode leads, with the IPG directly connected to the electrode leads. The IPG is implanted in the patient's head, for example, by creating a groove in the patient's skull and then placing the IPG in the groove. In this case, the IPG may not protrude from the outer surface of the skull, or it may protrude partially from the outer surface of the skull.

[0036] In this system, the IPG responds to programmed commands sent by a programmable device, relying on sealed batteries and circuits to provide controllable electrical stimulation therapy (or electrical stimulation energy) to tissues within the body. The IPG delivers one or more controllable specific electrical stimuli to specific areas of tissues within the body via electrode leads.

[0037] In some embodiments, the extension wire is used in conjunction with the IPG as a medium for transmitting electrical stimulation, thereby transmitting the electrical stimulation generated by the IPG to the electrode wire.

[0038] In some embodiments, electrical stimulation can be delivered in the form of a pulsed signal or a non-pulsed signal. For example, electrical stimulation can be delivered as a signal with various waveform shapes, frequencies, and amplitudes. Therefore, non-pulsed signal electrical stimulation can be a continuous signal, which can have a sinusoidal waveform or other continuous waveforms.

[0039] After receiving electrical stimulation from the IPG or extension leads, the electrode leads deliver the stimulation to specific areas of tissue within the body via multiple electrode contacts. The stimulator may have one or more electrode leads on one or both sides, with multiple electrode contacts on each lead. These contacts may be evenly or non-uniformly arranged circumferentially on the electrode leads. As an example, the electrode contacts may be arranged in a 4x3 array (a total of 12 contacts) circumferentially on the electrode leads. The electrode contacts may include stimulating electrode contacts and / or collecting electrode contacts. The electrode contacts may be in shapes such as sheet-like, ring-like, or dot-like.

[0040] In some embodiments, the stimulated tissue may be the patient's brain tissue, and the stimulated site may be a specific location within the brain tissue. Generally, the stimulated site differs depending on the patient's disease type, and the number of stimulation contacts (single-source or multi-source), the application of one or more specific electrical stimulation pathways (single-channel or multi-channel), and the stimulation parameters (values) also vary.

[0041] This application does not limit the applicable disease types, but can be any disease type applicable to deep brain stimulation (DBS), spinal cord stimulation (SCS), sacral nerve stimulation, gastric stimulation, peripheral nerve stimulation, or functional electrical stimulation. Among these, DBS can be used to treat or manage diseases including, but not limited to: spastic disorders (e.g., epilepsy), pain, migraines, mental illnesses (e.g., major depressive disorder (MDD)), bipolar disorder, anxiety disorders, post-traumatic stress disorder, mild depression, obsessive-compulsive disorder (OCD), behavioral disorders, mood disorders, memory disorders, mental state disorders, mobility disorders (e.g., essential tremor or Parkinson's disease), Huntington's disease, Alzheimer's disease, drug addiction, autism, or other neurological or psychiatric diseases and impairments.

[0042] In this embodiment of the application, when the programmable device and the stimulator establish a programmable connection, the programmable device can be used to adjust one or more stimulation parameters of the stimulator (or one or more stimulation parameters of the pulse generator, with different stimulation parameters corresponding to different electrical stimuli). Alternatively, the stimulator can sense the patient's electrophysiological activity to collect electrophysiological signals, and the collected electrophysiological signals can be used to continue adjusting the stimulation parameters of the stimulator to achieve closed-loop control (or adaptive adjustment) of the stimulation parameters.

[0043] Stimulation parameters may include at least one of the following: electrode contact identification for delivering electrical stimulation (e.g., electrode contact #2 and electrode contact #3), frequency (e.g., the number of electrical stimulation pulse signals per second, in Hz), pulse width (duration of each pulse, in μs), amplitude (generally expressed as voltage, i.e., the intensity of each pulse, in V), timing (e.g., continuous or bursty, bursty refers to discontinuous timing behavior composed of multiple processes), stimulation mode (including one or more of current mode, voltage mode, timed stimulation mode, and cyclic stimulation mode), physician control upper and lower limits (the range that the physician can adjust), and patient control upper and lower limits (the range that the patient can adjust independently).

[0044] In some embodiments, the stimulation parameters of the stimulator can be adjusted in current mode or voltage mode.

[0045] Programmable devices can include physician-controlled devices (i.e., devices used by physicians) and / or patient-controlled devices (i.e., devices used by patients). Physician-controlled devices are, for example, smart terminal devices such as tablets, laptops, desktop computers, and mobile phones equipped with programming software. Patient-controlled devices are, for example, smart terminal devices such as tablets, laptops, desktop computers, and mobile phones equipped with programming software; patient-controlled devices can also be other electronic devices with programming functions (e.g., chargers with programming functions, electrophysiological acquisition devices, etc.).

[0046] Please see the appendix Figure 1 - Appendix Figure 3 This embodiment relates to an implantable electrode lead, specifically including a stimulation segment 100, an intermediate segment 110, and a connecting segment 120 connected in sequence. The stimulation segment 100 includes a plurality of stimulation contacts, the connecting segment 120 includes a plurality of connecting contacts, and the intermediate segment 110 includes an outer sheath and a plurality of guidewires housed within the outer sheath. The guidewires electrically connect the stimulation contacts and the connecting contacts one-to-one. The stimulation segment 100 and at least a portion of the intermediate segment 110 are implanted into the cranium to form an intracranial segment 11. The portion of the intermediate segment 110 near and fixed to the skull forms a cranial segment 12, and the portion of the intermediate segment 110 extending outside the skull and the connecting segment 120 form an extracranial segment 13. The guidewires located in the intracranial segment 11 are straight, the guidewires located in the cranial segment 12 are spiral, and at least a portion of the guidewires located in the extracranial segment 13 are spiral, with the pitch of the guidewire in the cranial segment 12 being smaller than the pitch of the extracranial segment 13.

[0047] In this embodiment, the implantable electrode lead is functionally divided into a stimulation segment 100, an intermediate segment 110, and a connecting segment 120. The stimulation segment 100 has several stimulation contacts for contacting the target nucleus and directly stimulating it. The connecting segment 120 has several connecting contacts for electrical connection. Meanwhile, the guide wire inside the intermediate segment 110 transmits current, and the outer sheath provides isolation, protection, and insulation. The stimulation contacts and connecting contacts are electrically connected in a one-to-one correspondence via the guide wire.

[0048] It should be noted that the guidewire is usually made of coated metal wire. The metal wire is usually made of precious metals such as platinum-iridium alloy, and the coating is usually made of ETFE / PTFE.

[0049] Furthermore, the implantable electrode lead can be segmented according to its location relative to the brain, specifically into an intracranial segment 11, a cranial segment 12, and an extracranial segment 13. The intracranial segment 11 corresponds to the interior of the brain. Since the intracranial segment 11 experiences relatively low load, primarily due to the adhesion force of brain tissue, it does not undergo significant deformation; therefore, the guidewire for the intracranial segment 11 is straight. Because the thickness of the skull is typically 2–10 mm, the guidewire for the cranial segment 12 needs sufficient deformability to accommodate its bending arrangement. The guidewire for the cranial segment 12 is helical to allow it to withstand bending and tensile loads. Therefore, the cranial segment 12 should maximize its bending and tensile strength; hence, the guidewire for the cranial segment 12 uses a densely spirally wound metal wire to achieve lower rigidity and stronger deformability, thus facilitating the bending arrangement and fixation of the cranial segment 12. Furthermore, the extracranial segment 13 typically does not require significant bending deformation. Therefore, the guidewire of the extracranial segment 13 can be at least partially spiral-shaped to accommodate scenarios where the extracranial segment 13 undergoes moderate deformation. Meanwhile, the extracranial segment 13 typically needs to be connected to the extension wire 200 or the stimulator 300. Therefore, increasing the rigidity of the extracranial segment 13 is highly beneficial for ensuring smooth insertion of both.

[0050] In this embodiment, the guidewire in the intracranial segment 11 is straight, the guidewire in the cranial segment 12 is helical, and the guidewire in the extracranial segment 13 is at least partially helical, with the pitch of the cranial segment 12 being smaller than that of the extracranial segment 13. This segmented arrangement allows for a customized design of the guidewire structure, adjusting the pitch and extension shape according to the actual operating conditions of the electrode wire. This effectively avoids the high cost and poor adaptability issues associated with the prior art where the entire electrode wire is machined into a helical shape with the same pitch.

[0051] Specifically, this implantable electrode lead, due to its straight intracranial segment 11 and larger pitch extracranial segment 13, significantly reduces the length of the guidewire compared to a continuous spiral, thus reducing the amount of precious metals used and lowering the overall manufacturing cost. Furthermore, the reduced guidewire length also decreases DC resistance, further reducing heat generation. On the other hand, the intracranial segment 11 and extracranial segment 13 require a certain degree of rigidity to facilitate intraoperative manipulation. The straight intracranial segment 11 and larger pitch extracranial segment 13 enhance the rigidity of these areas, ensuring a smooth implantation procedure. Moreover, the straight intracranial segment 11 reduces the length of the spiral portion of the electrode lead, thereby reducing MRI interference and the probability of absorption due to enhanced resonance, further reducing heat generation efficiency and ensuring a comfortable postoperative experience for the user.

[0052] In implantable electrode leads composed of multi-strand spiral guide wires, the implantable electrode leads of this embodiment have significantly reduced costs and DC resistance compared to the existing single-segment spiral electrode leads. In particular, the cost can be reduced to half that of existing electrode leads.

[0053] Optionally, the extracranial segment 13 includes a first sub-segment 131 and a second sub-segment 132, one end of the first sub-segment 131 being connected to the cranial segment 12, and the other end of the first sub-segment 131 being connected to the second sub-segment 132, the second sub-segment 132 being at least partially used for electrical connection to the extension lead 200 or the stimulator 300.

[0054] Specifically, for the extracranial segment 13, part of it needs to be coiled around the surface of the skull, and part of it needs to be inserted into the extension wire 200 to form an electrical connection.

[0055] In this embodiment, the first segment 131 is coiled around the surface of the skull and extends to the back of the head. The second segment 132 is connected to the first segment 131 and forms an electrical connection with the extension wire 200 or the stimulator 300. At the connection between the second segment 132 and the extension wire 200 or the stimulator 300, a clamping sheet (titanium mesh, titanium sheet, or PEEK sheet) can be used for fixation, or it can be directly bound to the subcutaneous tissue to prevent the electrode wire from shifting when stretched.

[0056] Optionally, both the first segment 131 and the second segment 132 are helical, and the pitch of the first segment 131 is smaller than the pitch of the second segment 132.

[0057] Specifically, on the extracranial segment 13, the first sub-segment 131 corresponds to the coiled portion, where the coiling bending radius is generally greater than 15mm, and the bending stress it experiences is relatively smaller than that of the cranial segment 12. Furthermore, after multiple coiling turns, the tensile load it experiences is also somewhat buffered. Therefore, the pitch of the first sub-segment 131 can be larger than that of the cranial segment 12, and its rigidity is improved relative to that of the cranial segment 12. Another part needs to be inserted into the extension wire 200 to form an electrical connection. This part corresponds to the second sub-segment 132. In this part, the bending radius is larger, and the bending stress it experiences is smaller than that of the first sub-segment 131. Therefore, the pitch of the cranial segment 12 is greater than that of the first sub-segment 131, thereby further reducing the number of turns of the spiral, and thus reducing the overall length of the electrode wire and lowering the material cost of the precious metal wire.

[0058] Furthermore, the first sub-segment 131 is spiral-shaped, and the second sub-segment 132 is linear.

[0059] Of course, in this embodiment, the second segment 132 can also be set as a straight line, which can not only save costs to the maximum extent, but also ensure that the second segment 132 has greater rigidity, making it convenient for the operator to hold the electrode wire and insert the extension wire 200 during the operation.

[0060] Optionally, the pitch of the first segment 131 gradually changes in the direction of helical extension.

[0061] Specifically, the first sub-segment 131 corresponds to the coiled portion of the extracranial segment 13. In the extension direction of the first sub-segment 131, the coiling bending radius in the coiled portion may gradually decrease or gradually increase. Therefore, in order to adapt to the change in bending radius, the first sub-segment 131 can also adopt a variable pitch method. According to the surface extension of the subcutaneous tissue of the patient's head, the pitch design of the first sub-segment 131 can be adaptively adjusted, which can improve adaptability and save the cost of precious metal materials.

[0062] Optionally, the first segment 131 has a first pitch in the direction of helical extension.

[0063] Of course, the first segment 131 can also use a fixed pitch, that is, the fixed pitch is the first pitch, thereby reducing the machining difficulty of the first segment 131 and reducing the machining cost.

[0064] Optionally, the second sub-segment 132 is provided with a support 4.

[0065] In the non-coiled portion of the extracranial segment 13, since the extension wire 200 needs to be inserted manually, greater rigidity is required to improve the smoothness of the insertion. By adding a support 4 to the second sub-segment 132, which can be made of epoxy resin, silicone rubber, or polyurethane, the rigidity of the second sub-segment 132 can be further improved.

[0066] In this embodiment, the pitch of the extracranial segment 13 gradually increases along the direction away from the skull. This configuration allows the extracranial segment 13 to adapt to situations where the bending radius gradually transitions from small to large, thus accommodating the gradual change in the bending radius of the extracranial segment 13. While ensuring the required stiffness of each part of the extracranial segment 13, it also further saves material costs.

[0067] Optionally, the pitch of the cranial segment 12 gradually increases in the direction in which the intracranial segment 11 extends toward the extracranial segment 13.

[0068] Specifically, the cranial segment 12 can have a fixed pitch in the direction of helical extension, namely the second pitch. A fixed pitch cranial segment 12 can reduce the difficulty of processing; of course, the pitch of the cranial segment 12 can also be gradually increased, so that the cranial segment 12 can adapt to the gradually increasing bending radius in the direction from the intracranial segment 11 to the extracranial segment 13, and can further reduce the number of turns of the cranial segment 12, thereby reducing costs.

[0069] Optionally, a first flexible tube 2 is provided inside the spiral of the guidewire of the skull segment 12, and a second flexible tube 3 is provided outside the spiral of the guidewire of the skull segment 12.

[0070] The first flexible tube 2 and the second flexible tube 3 can be made of polymer flexible tubes to protect the densely spirally wound skull segment 12. At the same time, the flexible tubes can also avoid affecting the rigidity of the entire skull segment 12 after introduction, thus improving reliability.

[0071] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An implantable electrode lead, characterized in that, The device comprises a stimulation segment (100), a middle segment (110), and a connecting segment (120) connected in sequence. The stimulation segment (100) includes a plurality of stimulation contacts, the connecting segment (120) includes a plurality of connecting contacts, and the middle segment (110) includes an outer sheath and a plurality of guidewires housed within the outer sheath. The guidewires electrically connect the stimulation contacts and the connecting contacts one-to-one. The stimulation segment (100) and at least a portion of the middle segment (110) are implanted into the cranium to form an intracranial segment (11). The portion of the middle segment (110) near and fixed to the skull forms a cranial segment (12), and the portion of the middle segment (110) extending outside the skull and the connecting segment (120) form an extracranial segment (13). The guidewire located in the intracranial segment (11) is straight, the guidewire located in the cranial segment (12) is spiral, and the guidewire located in the extracranial segment (13) is at least partially spiral, and the pitch of the cranial segment (12) is smaller than the pitch of the extracranial segment (13).

2. The implantable electrode lead according to claim 1, characterized in that, The extracranial segment (13) includes a first sub-segment (131) and a second sub-segment (132), one end of the first sub-segment (131) being connected to the cranial segment (12), and the other end of the first sub-segment (131) being connected to the second sub-segment (132), the second sub-segment (132) being at least partially used for electrical connection to an extension lead (200) or a stimulator (300).

3. The implantable electrode lead according to claim 2, characterized in that, The pitch of the first sub-segment (131) gradually changes in the direction of helical extension, or the first sub-segment (131) has a first pitch in the direction of helical extension.

4. The implantable electrode lead according to claim 2, characterized in that, Both the first sub-segment (131) and the second sub-segment (132) are spiral-shaped, and the pitch of the first sub-segment (131) is smaller than the pitch of the second sub-segment (132).

5. The implantable electrode lead according to claim 2, characterized in that, The first sub-segment (131) is spiral-shaped, and the second sub-segment (132) is linear.

6. The implantable electrode lead according to claim 2, characterized in that, The second sub-segment (132) is provided with a support (4).

7. The implantable electrode lead according to claim 1, characterized in that, The pitch of the extracranial segment (13) gradually increases in the direction away from the skull.

8. The implantable electrode lead according to claim 1, characterized in that, The pitch of the cranial segment (12) gradually increases in the direction in which the intracranial segment (11) extends toward the extracranial segment (13).

9. The implantable electrode lead according to claim 1, characterized in that, The cranial segment (12) has a second pitch in the direction of spiral extension.

10. The implantable electrode lead according to claim 1, characterized in that, A first flexible tube (2) is provided inside the spiral of the guidewire of the cranial segment (12), and a second flexible tube (3) is provided outside the spiral of the guidewire of the cranial segment (12).

Images