Magnetic resonance compatible implantable electrode wire with shunt structure and medical equipment

Abstract

The invention discloses a magnetic resonance compatible implantable electrode wire with a shunt structure and medical equipment. An electrode tip section comprises a spiral electrode electrically connected with an inner wire body and a ring electrode electrically connected with an outer wire body; the spiral electrode and the ring electrode transmit an electric signal sent by the implanted medical device to a targeted treatment part to be electrically stimulated; the spiral electrode comprises a spiral structure; the spiral structure is a multi-turn equidistant spiral structure, and under the action of a high-frequency energy field, the spiral structure can serve as a series inductor to generate large impedance so as to reduce induction current flowing to the spiral electrode and human tissue, and therefore electrode heating is reduced. The structure of the electrode tip section is improved, and the problems that electromagnetic field energy is coupled, eddy current and induction current are formed, induction heating is generated, and even wrong electric pulse signals are transmitted to a human body on the implantable medical device, so that adverse effects are generated on the safety of a patient are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical electrical wire connectors, and in particular to a magnetic resonance compatible implantable electrode wire with a shunt structure and a medical device. Background Art

[0002] Magnetic resonance imaging (MRI) is a widely used and increasingly popular medical imaging technique. Demand for MRI examinations is rapidly increasing among patients with implantable medical devices (IMDs), particularly the elderly. Compared to other medical imaging techniques such as CT, MRI offers several advantages, including: 1. It is safer and does not deliver high doses of radiation. 2. Multiple scans are performed without causing radiation damage to the human body. 3. Its soft tissue density resolution is significantly higher than CT. 4. It can directly present three-dimensional and cross-sectional images, providing richer and more comprehensive diagnostic information.

[0003] Currently, the electrode leads for medical devices such as pacemakers are mainly divided into active and passive electrode leads. The passive electrode tip has a barbed structure that can be directly hooked onto the myocardial trabeculae. Over time, the electrode tip is wrapped by the myocardium and gradually stabilizes. The active electrode tip, on the other hand, has a spiral structure that telescopes into the myocardium and is fixed in the atrium or ventricle.

[0004] An implantable lead is a medical lead that connects one end to a pacemaker, defibrillator, or other electrical stimulation device and the other end directly to the area of the body that requires electrical stimulation, such as the heart or brain. The primary function of an implantable lead is to transmit tiny electrical pulses from the device to the desired structure and to transmit the body's electrical activity back to the device.

[0005] Magnetic resonance imaging (MRI) technology works through the coordinated cooperation of three magnetic fields, including a high-intensity uniform static magnetic field B0, with common intensities of 1.5T and 3T; a gradient magnetic field G, which can be set to any direction and cooperates with the static magnetic field B0 to encode body spatial information and image specific body parts; and an RF radio frequency field B1 for exciting proton nuclear resonance, which performs high-frequency time-varying switching at the Larmor frequency. In MRI with a static magnetic field B0 of 1.5T and 3T, its frequencies are 64MHz and 128MHz, respectively.

[0006] Implantable products must meet the above-mentioned MRI compatibility requirements. Due to the high-frequency and strong magnetic field working characteristics of MRI, MRI testing has long been an absolute forbidden area for patients undergoing electrical stimulator implantation surgery (typically pacemakers, defibrillators, deep brain stimulators, etc.). The most important reason is the mutual interference between the MRI comprehensive field and ferromagnetic materials and / or conductive objects. The most important hidden danger is the induced heating of the implanted product. The MRI field has a high-frequency energy field, including the rapidly switching gradient field G and RF radio frequency field B1, which will couple electromagnetic field energy to the implanted medical device, forming eddy currents and induced currents, causing induced heating, and may transmit erroneous electrical pulse signals to the human body, which will have an adverse effect on the patient's safety.

[0007] Therefore, the induced heating caused by the aforementioned eddy currents and induced currents is a technical problem that urgently needs to be addressed in this field. In particular, thin, conductive electrode wires behave as antennas in high-frequency energy fields, exhibiting a stronger ability to couple high-frequency field energy. This generates strong induced currents, much of which are converted into heat at the electrode tip / myocardial tissue interface. This can increase the electrical stimulation threshold, induce arrhythmias, and cause perforation, among other serious injuries. Furthermore, the wires can emit pulse voltages at unwanted times and locations, potentially leading to induced stimulation disorders.

[0008] To address the aforementioned issues, patent application CN 103384547 B, for example, discloses a medical electrical wire compatible with magnetic resonance imaging and a method for manufacturing the same. This solution employs an RF filter placed in series with the electrode's electrical path. Under high-frequency RF fields, the RF filter exhibits a high impedance, thereby hindering or reducing the propagation of induced current toward the electrode. However, the electrode wire design requires the addition of an additional RF filter, which increases the size of the wire tip and increases surgical trauma to the patient. Furthermore, the RF filter only provides MRI protection within a specific frequency range. At higher or lower field frequencies, the RF filter cannot prevent the induced current from flowing toward the electrode tip. Instead, it increases the induced current intensity in the RF filter and the wire body, leading to wire temperature rise, damage to the wire, and tissue injury. Furthermore, the larger wire size can also adversely affect MRI imaging, resulting in larger artifacts. Summary of the Invention

[0009] The main purpose of the present invention is to provide a magnetic resonance-compatible implantable electrode lead with a shunt structure, aiming to solve the problem of coupling electromagnetic field energy on implantable medical devices, forming eddy currents and induced currents, causing induced heating, and even transmitting erroneous electrical pulse signals to the human body, which has an adverse impact on patient safety.

[0010] Specifically, in an MRI environment, the slender structure of the electrode wire can couple with the high-frequency energy field, and the current induced within it can flow through the spiral electrode to the tissue, causing an increase in the electrical stimulation threshold, inducing arrhythmias and perforation, and other serious injuries, which is undesirable. Therefore, the present invention aims to achieve: using an electrode wire with a shunt function to shunt the induced current in the high-frequency energy field, thereby weakening the induced current flowing to the interface between the spiral electrode and tissue, reducing heating of the surrounding tissue, and preventing the electrode wire from transmitting pulse voltage at unnecessary times and locations, which may cause stimulation abnormalities.

[0011] To achieve the above objectives, the present invention provides a magnetic resonance compatible implantable electrode lead with a shunt structure, the electrode lead comprising:

[0012] A conductor main body section, the conductor main body section comprising an outer insulating tube and an outer conductor body, an inner insulating tube and an inner conductor body sequentially arranged in the outer insulating tube;

[0013] The electrode lead further includes: an induced current shunt structure for shunting the induced current within the electrode lead to a ring electrode and human body fluid under a high-frequency energy field, wherein the ring electrode is connected to the human body fluid outside the electrode; the induced current shunt structure suppresses heating at the interface between the electrode and tissue, thereby reducing radiofrequency heating of the electrode as a whole;

[0014] The inner cavity of the inner conductor body is nested on the outer peripheral wall of the inner conductor body support section of the electrode core shaft and is electrically connected to the electrode core shaft; the inner conductor body support section and the connecting section of the inner conductor body form an inner conductor body iron core section; the outer side of the inner insulating tube is connected to the ring electrode; under the action of high-frequency signals, the inner conductor body iron core section enhances the local induced electric field e to enhance the shunting ability of the induced current at high frequency.

[0015] Optionally, the induced current shunting structure includes: the electrode sleeve, the electrode core shaft, and a conductive limiter;

[0016] The conductive stopper has an inner contact hole for the electrode core shaft to pass through and to be in electrical contact with the conductive stopper, so that the conductive stopper is electrically connected to the electrode wire;

[0017] An outer contact surface is arranged at a circumferential position of the conductive limiter; the outer contact surface is in contact with the inner surface of the electrode sleeve.

[0018] Optionally, a forming surface is further arranged at a circumferential position of the conductive limiter; a sharp edge structure is formed on the forming surface, and the end point position of the sharp edge forms a diversion tip.

[0019] Optionally, the electrode sleeve and the electrode insulating member form a fixed space, and the fixed space is used to accommodate and positionally fix the conductive limiting member;

[0020] The outer sides of the inner conductor body are connected to the electrode insulating member and the inner insulating tube respectively.

[0021] Optionally, the inner cavity of the inner conductor body is fixedly connected to the outer peripheral wall of the inner conductor body support section by welding; and / or,

[0022] The inner conductor body is respectively bonded and fixed to the electrode insulating member and the inner insulating tube; and / or,

[0023] The end of the inner wire body supporting section close to the spiral electrode is fixed to the front developing ring, and the front developing ring is connected to the spiral electrode; the end of the inner wire body supporting section away from the spiral electrode is fixed to the rear developing ring.

[0024] Optionally, the induced current shunting structure further includes the inner conductor core segment and the ring electrode;

[0025] A portion of the inner conductor core segment serves as a first pole of an equivalent capacitor C, and the ring electrode and a portion of the outer conductor connected to the ring electrode serve as a second pole of the equivalent capacitor C;

[0026] An electrode insulator is fixed to the inner hole of the ring electrode, and the inner insulating tube penetrates the electrode insulator and is fixed to the fixed section of the electrode insulator; the inner insulating tube and the fixed section form mutual insulation between the ring electrode, human body fluids and the inner wire body; and the ring electrode is in direct contact with human body fluids, and the electrode insulator and the inner insulating tube serve as intermediate dielectric materials of the equivalent capacitor C2.

[0027] Optionally, the diameter of the inner conductor support segment is larger than the inner conductor lumen diameter, thereby expanding the inner conductor and reducing the inter-electrode distance between the inner conductor core segment and the ring electrode. This structure can enhance the C-capacitive coupling effect; at the same time, the reduced inter-electrode distance can enhance heat transfer between the inner conductor and the ring electrode, improving heat dissipation.

[0028] Optionally, the diameter of the inner conductor support section ranges from 0.1 mm to 1 mm; and / or

[0029] The magnetic permeability χ of the material of the electrode core shaft is greater than that of the inner conductor body, so as to increase the focusing ability of the induced electric field e; and / or,

[0030] The inner conductor core segment is located on the side of the spiral electrode away from human tissue to prevent the inner conductor with heat diverted from contacting human tissue with the electrode core shaft, thereby causing secondary damage; and / or,

[0031] The inner conductor core segment further includes: a front developing ring and a rear developing ring, and / or a conductive limiting member; and / or,

[0032] The electrode core shaft is made of a conductive material and has paramagnetism and / or diamagnetic properties, as well as low magnetic susceptibility properties, to meet the compatibility requirements of magnetic resonance imaging technology; the electrode core shaft includes: titanium and / or titanium alloy and / or platinum alloy and / or non-magnetic nickel-cobalt-chromium alloy and / or conductive polymer material.

[0033] Optionally, the ring electrode is located in the electrode head section; the outer wire body is nested outside the outer wire body support section of the ring electrode, and there is a cavity inside the outer wire body, and the inner insulating tube passes through the cavity to ensure that the outer wire body and the inner wire body are insulated from each other;

[0034] The rear fixing section of the electrode insulating member is fixedly connected to the inner cavity wall of the contact ring of the ring electrode; and the inner insulating tube extends into the rear fixing section and its inner cavity wall is bonded and fixed to the rear fixing section, forming an overall insulation between the ring electrode and the inner conductor of the outer wire body to the electrode wire.

[0035] Optionally, the outer insulating tube passes through the outer peripheral wall of the outer conductor body and abuts against the outer insulating tube limiting step on the ring electrode;

[0036] There is a bonding gap between the bonding section on the ring electrode and the outer insulating tube for the adhesive to enter; the front fixed end surface of the electrode insulating member is bonded and fixed to the inner surface of the electrode sleeve; and a drug plug is also bonded and fixed to the side of the electrode sleeve facing the spiral electrode tip of the spiral electrode.

[0037] Optionally, by adjusting the wall thickness of the inner insulating tube and the electrode insulating member, as well as the length and diameter of the inner conductor core segment, the capacitance value of the equivalent capacitor C and the ability of the electrode conductor to shunt the induced current under a high-frequency energy field are adjusted.

[0038] Optionally, the wall thickness of the inner insulating tube is 0.1 mm to 0.5 mm to reduce the inter-electrode spacing of the equivalent capacitor C, increase the capacitance value of C, and enhance the shunt capacity; the material of the inner insulating tube includes: any one or more combinations of silicone, polyurethane, polyimide and PTFE.

[0039] Optionally, the first pole of the equivalent capacitor C includes: the inner conductor core segment, and a portion of the inner conductor connected to the inner conductor core segment; and / or,

[0040] The second pole of the equivalent capacitor C includes: the overall structure of the ring electrode, and the portion of the outer conductor connected to the ring electrode.

[0041] Optionally, the length of the inner conductor core segment is 2 mm to 10 mm, and the diameter of the inner conductor core segment is 0.7 mm to 1.2 mm; the axial length of the inner conductor core segment is increased to increase the first pole area of the equivalent capacitor C; and / or,

[0042] The length of the ring electrode is 2mm to 10mm; the length of the contact ring of the ring electrode is 1mm to 10mm, the outer diameter of the contact ring is 1mm to 3mm, and the contact area between the contact ring and the human body fluid is 20mm 2 Up to 100mm 2 At the same time, the surface area of the ring electrode is several times larger than the contact area of the spiral electrode, and the density of the induced current diverted to the surface of the ring electrode and related components is relatively small, resulting in a very small temperature rise.

[0043] Optionally, the spiral electrode further comprises: a spiral electrode tip; during the implantation process, the spiral electrode tip is rotated and inserted into human tissue at the targeted treatment location;

[0044] Optionally, the spiral electrode further comprises a protrusion structure arranged at a circumferential position, and the end position of the protrusion structure has a shunt contact for reducing current density;

[0045] Under the action of the high-frequency energy field, an induced current I is induced inside the electrode wire. The shunt contact disperses the current concentration at the tip of the spiral electrode by increasing the contact area between the spiral electrode and the tissue. It can disperse the current density J at the junction of the electrode tip and the tissue, thereby reducing the induced current density flowing from the spiral electrode to the human tissue, thereby reducing the heating of the electrode in the tissue.

[0046] The calculation formula of the current density J is:

[0047] Where I is the induced current, n is the number of shunt contacts, and A is the area of a single shunt contact. The more shunt contacts there are, the smaller the current density J at each contact.

[0048] The calculation formula of the induced current I heating is:

[0049] Where I is the induced current, R is the conductor resistance, and J 2 is the current density; the heat generation Q is proportional to the current density J. The greater the number and area of the shunt contacts, the more dispersed the induced current I is, and the smaller the current density J at a single contact is. This reduces the heat generation at the spiral electrode tip and the shunt contacts, evenly dissipating tissue heat and reducing localized heating.

[0050] The end of the inner wire body is nested and fixed at the distal outer position of the electrode core shaft away from the spiral electrode tip, and is fixed to the rear developing ring; the proximal position of the electrode core shaft close to the spiral electrode tip is connected to the front developing ring; and the front developing ring is connected to the spiral electrode;

[0051] The inner conductor is driven to rotate in the inner insulating tube, so as to drive the spiral electrode accommodated in the electrode sleeve to move in a driven manner.

[0052] In addition, the conductive limiting parts are respectively arranged corresponding to the front developing ring and the rear developing ring on both sides of the length direction of the electrode core shaft; when the spiral electrode drives the electrode core shaft to extend and retract, the developing ring abuts against the conductive limiting parts to limit the extension and retraction distance of the electrode core shaft; and the position of the spiral electrode is positioned according to the development distance between the conductive limiting parts and the developing ring.

[0053] Optionally, an insulating seal is further provided between any two of the conductive limiters, and the insulating seal fits tightly against the conductive limiters to squeeze the insulating seal against the inner cavity wall of the electrode sleeve to form a sealing structure.

[0054] Optionally, under the action of a high-frequency energy field, an induced electric field e is induced inside the electrode wire; the high magnetic permeability of the inner wire body support segment increases the magnetic field strength at that location; the concentration of magnetic flux generates a higher induced electric field; the induced electric field e is concentrated in the inner wire body iron core segment, which changes the overall distribution of the induced electric field e, resulting in a dispersion of the induced heating area; thereby achieving: dispersion reduces the induced electric field strength at the tip of the spiral electrode, reduces the induced current density distributed at the interface between the spiral electrode and tissue, thereby reducing the heating of the spiral electrode and human tissue, and reducing thermal damage to human tissue caused by the MRI environment; and the inner wire body iron core segment has a large surface area, a low surface current density, and a low heat generation;

[0055] Optionally, the inner wire body is coupled to the ring electrode through a heat difference, and the ring electrode is in direct contact with human body fluids. The heat of the inner wire body can be transferred to the human body fluids through the ring electrode for heat dissipation, thereby reducing the heating of the electrode and avoiding more heat being transferred to the tissue.

[0056] Optional, such as Figure 9 As shown, the conductive limiter, the electrode core shaft, and the inner conductor core segment constitute the first pole of the equivalent capacitor C, and the human body fluid and the ring electrode constitute the second pole of the equivalent capacitor C.

[0057] The IMD is connected to the electrode circuit of the electrode wire, and the electrode circuit includes: a series resistor, a series impedance, a series inductor, and a parallel capacitor; the human tissue and the human body fluid form a resistance R, the inner wire body forms a series resistor R1, the outer wire body forms a series resistor R2, the resistance of the series conductor inside the electrode head segment is a series resistor R3, and the spiral electrode forms an equivalent series inductor L1 under the high-frequency energy field; Z1 and Z2 are the series induced impedances of the inner wire body and the outer wire body under the high-frequency energy field;

[0058] The electrode lead is fixed to the patient's targeted treatment site via a spiral electrode. When the electrode lead is in normal working condition, the electrical pulse is transmitted to the targeted tissue via the spiral electrode, then transmitted to the ring electrode via human tissue and body fluids, and then returned to the IMD to form a loop. The stimulation pulse emitted by the IMD is in low-frequency or DC form, and the equivalent capacitor C is in an open-circuit state. The spiral structure exhibits the properties of a wire at low frequency and does not weaken the strength of the electrical pulse signal.

[0059] The electrode lead is fixed to the patient's targeted treatment area via a spiral electrode. When the electrode lead is in an MRI scanning environment, an induced current is generated within the electrode lead under a high-frequency energy field. The conductive stopper and the inner conductor core segment generate capacitive coupling with the human body fluid and the ring electrode. An induced current I is generated within the electrode circuit. The induced current I sequentially passes through a series resistor R1 representing the inner conductor body resistance and a series resistor R2 representing the electrode core shaft and the conductive stopper resistance. Due to the extremely high frequency of the high-frequency energy field and the extremely low impedance of the equivalent capacitor C, the equivalent capacitor C is in a short-circuit state. The induced current I1 in the induced current I flows through the conductive stopper represented by the series resistor R2 and through the equivalent capacitor C to ground, flowing to the ring electrode and the human body fluid. The induced current I2 is transmitted through the spiral electrode to the human tissue and forms the resistance R. The equivalent series inductor L1 formed by the spiral electrode has a large impedance, further weakening the magnitude of the induced current I2 and increasing the induced current I1 in the human body fluid. When I2 flows through the resistance R represented by the human tissue, it generates Joule heat, causing tissue heating. Although induced current I2 still flows into the human tissue, it is reduced by the shunt and the series inductor L1. As a result, despite the small contact area between the spiral electrode tip and the human tissue, the current density at the interface between the spiral electrode tip and the tissue is low, keeping the temperature rise at the human tissue within an acceptable range. In this case, induced current I1 is greater than induced current I2.

[0060] The induced current shunting structure significantly reduces the induced current flowing to the spiral electrode, reducing heating at the electrode tip and tissue interface. The shunted induced current flows through the ring electrode and human body fluids, generating Joule heat. Since human body fluids have a large specific heat capacity, the temperature rise caused by Joule heat is small, thus preventing damage to human body fluids and tissue. The surface area of the ring electrode is several times larger than the contact area of the spiral electrode. The induced current density shunted to the surface of the ring electrode and associated components is low, resulting in a temperature rise that is only 10%-20% of the temperature rise of the spiral electrode contact under the same induced current. Furthermore, under high-frequency energy fields, the higher magnetic permeability of the inner conductor core segment, due to the presence of the inner conductor support segment 70a, increases the magnetic field strength there. This concentration of magnetic flux induces the induced electric field e to converge at the inner conductor core segment 103, changing the overall distribution of the induced electric field e and enhancing the shunting capability of the induced current under high frequency conditions.

[0061] By adjusting the wall thickness of the dielectric segment, the size and number of the conductive limiters, the wall thickness of the inner insulating tube and the electrode insulating member, and the length and diameter of the inner conductor core segment, the capacitance value of the equivalent capacitor C can be adjusted, thereby obtaining the ability to shunt induced current under a wide-spectrum high-frequency energy field.

[0062] A medical device, comprising:

[0063] A machine body having a connection interface; and

[0064] The electrode wire is the above-mentioned electrode wire, and the connector of the electrode wire is inserted into the connection interface.

[0065] In general, the electrode lead of the present invention is designed to shunt the induced current generated under the high-frequency energy field to the body fluids and the ring electrode and associated components, and will not affect the transmission of the stimulation pulse during normal operation. The electrode lead of the present invention adopts one or more of the aforementioned structures for dispersing the induced electric field e and shunting the induced current I, so that the electrode presents a normal path under the working electric pulse, and only a very small amount of the working electric pulse signal is shunted, ensuring the normal progress of the treatment; and during MRI scanning, the structure can disperse the induced electric field e, weaken the self-heating of the spiral electrode, and at the same time, the structure presents a low impedance similar to a short circuit, which can enhance the shunting capacity, can shunt most of the induced current to the body fluids and the ring electrode associated components, weaken the induced current flowing to the spiral electrode 1, reduce thermal damage to the tissue, and at the same time concentrate the heating points in the body fluids and the ring electrode associated components where the temperature rise is small, so the overall heat generation is small and away from the tissue, thereby ensuring the safety of the electrode lead during MRI scanning.

[0066] During normal operation, the electrical stimulation current that is shunted accounts for less than about 5% of the total stimulation current.

[0067] During MRI scanning, the induced current shunted to structures such as body fluids and ring electrodes accounts for more than about 60% of the total induced current. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0069] Figure 1 A schematic cross-sectional view of the structure of the electrode tip section in the electrode wire provided by the present invention;

[0070] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the MRI-compatible electrode wire provided by the present invention;

[0071] Figure 3 A schematic diagram of the electrode core shaft structure provided by the present invention;

[0072] Figure 4 A schematic longitudinal cross-sectional view of the inner conductor core segment provided by the present invention;

[0073] Figure 5 A schematic longitudinal section diagram of an electrode insulating member provided by the present invention;

[0074] Figure 6 A schematic diagram of the three-dimensional structure of the ring electrode provided by the present invention;

[0075] Figure 7 A schematic diagram of the three-dimensional structure of the spiral electrode provided by the present invention;

[0076] Figure 8a This is a schematic diagram of the longitudinal cross-section structure of the inner conductor core segment provided by the present invention;

[0077] Figure 8b This is a schematic diagram of the cross-sectional structure of the inner conductor core segment provided by the present invention;

[0078] Figure 9 A schematic diagram of the pulse flow direction of a normal stimulation pulse after the electrode lead provided by the present invention is implanted;

[0079] Figure 10 This is an electric field distribution diagram of the electrode wire tip end provided by the present invention when it is exposed to a high-frequency energy field and the induced electric field e is concentrated in the iron core segment;

[0080] Figure 11 A schematic diagram of the current flow direction of the electrode lead provided by the present invention after being implanted and exposed to a high-frequency energy field;

[0081] Figure 12 A schematic circuit diagram of the medical system provided by the present invention, wherein the electrode lead is connected to the IMD and the system is exposed to a high-frequency energy field;

[0082] Figure 13 This is a schematic diagram of the three-dimensional structure of the conductive limiter provided by the present invention.

[0083] Description of Figure Numbers:

[0084]

[0085]

[0086] The implementation, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0087] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0088] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0089] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text is to include three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution in which both A and B are satisfied. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0090] Example 1

[0091] An implantable lead is a medically implanted electrical wire that connects to a pacemaker, defibrillator, or other electrical stimulation device at one end and directly to the heart, brain, or other part of the body that requires electrical stimulation. The primary function of an implantable lead is to transmit tiny electrical pulses from the device to the desired body structure and to transmit the body's electrical activity back to the device.

[0092] In an MRI scanning environment, the electrode wire 300 is affected by the high-frequency energy field 6, which includes a changing gradient magnetic field G and RF high-frequency pulses B1 (e.g., frequencies of 64 MHz and 128 MHz). The high-frequency energy field 6 couples energy within the elongated electrode wire 300, generating an induced electric field e and an induced current I along the length of the wire. The electrode wire 300 is a conductor, and its length may be a multiple of the wavelength λ0 of the high-frequency energy field 6, resulting in an enhanced coupling effect and a larger internal induced current I. The electrode wire contacts the human tissue 4 through the spiral electrode 1 to form a loop, and the induced current I flows through the spiral electrode 1 to the human tissue 4. However, the small contact area between the spiral electrode and the human tissue 4 results in a high current density at the interface between the electrode tip and the tissue, which can cause a significant temperature rise in the spiral electrode 1, resulting in serious damage such as changes in the electrical stimulation threshold and tissue perforation. It can also cause the electrode wire 300 to emit erroneous pulses at unnecessary times and locations, inducing stimulation abnormalities.

[0093] To disperse the induced electric field e and shunt the induced current, the electrodes maintain a normal path under the working electrical pulses, with only a minimal amount of the working electrical pulse signal being shunted, ensuring normal treatment. The present invention provides an electrode lead suitable for various medical devices, particularly, but not limited to, defibrillators, pacemakers, or other electrical stimulation devices.

[0094] See Figure 1 and Figure 2 , Figure 1 A schematic cross-sectional view of the structure of the electrode tip section in the electrode wire is shown; Figure 2 The figure shows the overall three-dimensional structure of the MRI-compatible electrode lead. The MRI-compatible implantable electrode lead with a shunt structure, the electrode lead 300 includes:

[0095] The conductor body section 400 includes an outer insulating tube 91 and an outer conductor body 40, an inner insulating tube 90, and an inner conductor body 30 sequentially disposed within the outer insulating tube 91;

[0096] The electrode lead 300 further includes an induced current shunt structure 101 for shunting the induced current within the electrode lead to the ring electrode 2 and the human body fluid 5 under a high-frequency energy field. The ring electrode 2 is connected to the human body fluid 5 outside the electrode. The induced current shunt structure 101 suppresses heating at the interface between the electrode and tissue, thereby reducing radiofrequency heating of the electrode as a whole.

[0097] like Figure 1 and Figure 3 The inner cavity of the inner conductor body 30 is nested on the outer peripheral wall of the inner conductor body support section 70a of the electrode core shaft 70 and is electrically connected to the electrode core shaft 70; Figure 4 as well as Figure 8a and 8b As shown, the inner conductor support segment 70a and the connecting segment of the inner conductor 30 form an inner conductor core segment 103. The outer side of the inner insulating tube 90 is connected to the ring electrode 2. Under the action of the high-frequency signal 6, the inner conductor core segment 103 enhances the local induced electric field e, thereby strengthening the ability to shunt the induced current at high frequencies. Furthermore, the end of the inner conductor support segment 70a closest to the spiral electrode 1 is fixed to the front developing ring 50, which is connected to the spiral electrode 1. The end of the inner conductor support segment 70a farther from the spiral electrode 1 is fixed to the rear developing ring 51.

[0098] In this embodiment, the diameter of the inner conductor support section 70a ranges from 0.1 mm to 1 mm. The magnetic permeability x of the material of the electrode core shaft 70 is greater than that of the inner conductor 30, so as to increase the focusing ability of the induced electric field e.

[0099] In this embodiment, the induced current shunting structure 101 includes: the electrode sleeve 80, the electrode core shaft 70, and the conductive limiter 60; Figure 13 FIG. 1 is a schematic diagram of the three-dimensional structure of the conductive stopper provided by the present invention. The conductive stopper 60 has an inner contact hole 62 for the electrode core shaft 70 to pass through and electrically connect to the conductive stopper 60, so that the conductive stopper 60 is electrically connected to the electrode wire 300.

[0100] The conductive limiter 60 is circumferentially provided with an outer contact surface 61 and a forming surface 63 ; the outer contact surface 61 is bonded to the inner surface of the electrode sleeve 80 ; the forming surface 63 is formed with a sharp edge structure, the end point of the sharp edge forms a diversion tip 64 .

[0101] In addition, the electrode sleeve 80 and the electrode insulating member 85 form a fixed space for accommodating and fixing the conductive limiting member 60 ; the outer side of the inner conductor body 30 is connected to the electrode insulating member 85 and the inner insulating tube 90 respectively.

[0102] In addition, an insulating seal 55 is provided between any two of the conductive limiters 60 , and the insulating seal 55 fits tightly against the conductive limiters 60 to squeeze the insulating seal 55 against the inner cavity wall of the electrode sleeve 80 to form a sealing structure.

[0103] In this embodiment, the induced current shunting structure further includes: an inner conductor core segment 103 and a ring electrode 2;

[0104] like Figure 8a and Figure 8b As shown, a portion of the inner conductor core segment 103 serves as the first pole of the equivalent capacitor C, and the ring electrode 2 and the other portion of the outer conductor 40 connected to the ring electrode 2 serve as the second pole of the equivalent capacitor C. The inner conductor core segment 103 is located on the side of the spiral electrode 1 away from the human tissue 4 to prevent the inner conductor 30, which has diverted heat, from contacting the human tissue 4 with the electrode core shaft 70, causing secondary damage.

[0105] An electrode insulator 85 is fixed to the inner hole of the ring electrode 2, and the inner insulating tube 90 penetrates the electrode insulator 85 and is fixed to the fixed section 85a of the electrode insulator 85; the inner insulating tube 90 and the fixed section 85a form mutual insulation between the ring electrode 2, the human body fluid 5 and the inner wire body 30; and the ring electrode 2 is in direct contact with the human body fluid 5, and the electrode insulator 85 and the inner insulating tube 90 serve as the intermediate dielectric material of the equivalent capacitor C.

[0106] Furthermore, the diameter of the inner conductor support segment 70a is larger than the inner diameter of the inner conductor 30, thereby expanding the inner conductor 30 and reducing the inter-electrode distance between the inner conductor core segment 103 and the ring electrode 2. This structure enhances the C-capacitive coupling effect; at the same time, the reduced inter-electrode distance enhances heat transfer between the inner conductor and the ring electrode, improving heat dissipation.

[0107] In this embodiment, the capacitance of the equivalent capacitor C and the ability of the electrode conductor 300 to shunt induced current in a high-frequency energy field are adjusted by adjusting the wall thickness of the inner insulating tube 90 and the electrode insulator 85, as well as the length and diameter of the inner conductor core segment 103. The wall thickness of the inner insulating tube 90 is 0.1 mm to 0.5 mm, which reduces the inter-electrode spacing of the equivalent capacitor C, increases the capacitance of C, and enhances the shunt capability. The material of the inner insulating tube 90 includes any one or a combination of silicone, polyurethane, polyimide, and PTFE.

[0108] In this embodiment, if Figure 6The schematic diagram of the three-dimensional structure of the ring electrode is shown, wherein the ring electrode 2 is located at the electrode head section 100; the outer conductor body 40 is nested outside the outer conductor body support section 25 of the ring electrode 2, and there is a cavity inside the outer conductor body 40, through which the inner insulating tube 90 passes to ensure mutual insulation between the outer conductor body 40 and the inner conductor body 30. Figure 5 The longitudinal cross-sectional view of the electrode insulation member is shown. The rear fixing section 85a of the electrode insulation member 85 is fixedly connected to the inner cavity wall of the contact ring 21 of the ring electrode 2; and the inner insulating tube 90 extends into the rear fixing section 85a and is bonded and fixed to the inner cavity wall of the rear fixing section 85a, thereby forming an integral insulation between the inner conductor of the ring electrode 2 and the outer conductor body 40. Figure 6 As shown, the outer insulating tube 91 passes through the outer peripheral wall of the outer wire body 40 and abuts against the outer insulating tube limiting step 23 on the ring electrode 2; there is a bonding gap between the bonding section 22 on the ring electrode 2 and the outer insulating tube 91 for the adhesive to enter; the front fixed end face 85b of the electrode insulating member 85 is bonded and fixed to the inner surface of the electrode sleeve 80; the drug plug 3 is also bonded and fixed to the side of the electrode sleeve 80 facing the spiral electrode tip 1a of the spiral electrode 1.

[0109] In this embodiment, if Figure 7 The spiral electrode 1 further comprises a spiral electrode tip 1a, which rotates and penetrates into the human tissue 4 at the target treatment location during implantation.

[0110] See Figure 7 The spiral electrode 1 further comprises a circumferential arrangement of protruding structures 1c, the end points of which have shunt contacts 1d for reducing current density.

[0111] Under the action of the high-frequency energy field, an induced current I is induced inside the electrode wire. The shunt contact 1d increases the contact area between the spiral electrode and the tissue, dispersing the current density J at the interface between the spiral electrode tip 1a and the tissue, thereby reducing the induced current density flowing from the spiral electrode 1 to the human tissue 4, thereby reducing the heating of the electrode in the tissue.

[0112] The calculation formula of the current density J is:

[0113] Where I is the induced current, n is the number of shunt contacts, and A is the area of the shunt contact. The more shunt contacts there are, the smaller the current density J at each contact.

[0114] The calculation formula of the induced current I heating is:

[0115] Where I is the induced current, R is the conductor resistance, and J 2 is the current density; the heat generation Q is proportional to the current density J. The greater the number and area of the shunt contacts, the more dispersed the induced current I is, and the smaller the current density J at a single contact is. This reduces the heat generation at the spiral electrode tip 1a and the shunt contact 1d, evenly dissipating tissue heat and reducing localized heating.

[0116] Furthermore, in a preferred embodiment, the end of the inner wire body 30 is nested and fixed in the outer position of the distal end of the electrode core shaft 70 away from the spiral electrode tip 1a, and is fixed to the rear developing ring 51; the electrode core shaft 70 is close to the proximal end of the spiral electrode tip 1a and is connected to the front developing ring 50; and the front developing ring 50 is connected to the spiral electrode 1;

[0117] The inner conductor 30 is driven to rotate in the inner insulating tube 90, thereby driving the spiral electrode 1 accommodated in the electrode sleeve 80 to be driven to extend and retract;

[0118] In addition, the conductive limiting member 60 is respectively arranged corresponding to the front developing ring 50 and the rear developing ring 51 on both sides of the length direction of the electrode core shaft 70; when the spiral electrode 1 drives the electrode core shaft 70 to extend and retract, the developing ring abuts against the conductive limiting member 60 to limit the extension and retraction distance of the electrode core shaft 70; and the position of the spiral electrode 1 is positioned according to the development distance between the conductive limiting member 60 and the developing ring.

[0119] Under the action of the high-frequency energy field 6, the electrode wire 300 induces an induced electric field e inside the electrode wire 300; the high magnetic permeability of the inner wire body support segment 70a increases the magnetic field strength at this position, and the concentration of magnetic flux generates a higher induced electric field e; the induced electric field e is concentrated in the inner wire body core segment 103, which changes the overall distribution of the induced electric field e, resulting in a dispersion of the induced heating area; thereby achieving: dispersion reduces the induced electric field strength of the spiral electrode tip 1a, reduces the induced current density distributed at the interface between the spiral electrode and tissue, thereby reducing the heating of the spiral electrode 1 and the heating of the human tissue 4, and reducing the thermal damage to the human tissue 4 caused by the MRI environment; and the inner wire body core segment 103 has a large surface area, a low surface current density, and a low heat generation.

[0120] like Figure 9 and Figure 12 As shown, the conductive limiter 60, the electrode core shaft 70 and the inner conductor core segment 103 constitute the first pole of the equivalent capacitor C, and the human body fluid 5 and the ring electrode 2 constitute the second pole of the equivalent capacitor C;

[0121] The IMD is connected to the electrode circuit 7 of the electrode wire 300. The electrode circuit 7 includes: a series resistor, a series impedance, a series inductor, and a parallel capacitor. The human tissue 4 and the human body fluid 5 form a resistor R, the inner conductor 30 forms a series resistor R1, the outer conductor 40 forms a series resistor R2, the resistance of the series conductor inside the electrode head segment 100 is a series resistor R3, and the spiral electrode 1 forms an equivalent series inductor L1 under the high-frequency energy field 6. Z1 and Z2 are the series induced impedances of the inner conductor 30 and the outer conductor 40 under the high-frequency energy field 6.

[0122] The electrode lead 300 is fixed to the patient's targeted treatment area via the spiral electrode 1. When the electrode lead is in normal working condition, the electrical pulse is transmitted to the targeted tissue via the spiral electrode 1, then transmitted to the ring electrode 2 via the human tissue 4 and the human body fluid 5, and then returns to the IMD to form a loop. The stimulation pulse emitted by the IMD is in low-frequency or DC form, and the equivalent capacitor C is in an open-circuit state. The spiral structure 1b exhibits the properties of a conductor at low frequencies and does not weaken the strength of the electrical pulse signal.

[0123] like Figure 10 and Figure 11 As shown, the electrode wire 300 is fixed to the patient's targeted treatment site through the spiral electrode 1. When the electrode wire is in an MRI scanning environment, an induced current I is induced in the electrode circuit 7. The induced current I passes through the series resistor R1 representing the resistance of the inner wire body 30 and the series resistor R2 representing the resistance of the electrode core shaft 70 and the wire limiter 60 in sequence; Figure 12 Because the frequency of the high-frequency energy field 6 is extremely high and the impedance of the equivalent capacitor C is extremely low, the equivalent capacitor C is in a short-circuit state. The induced current I1 in the induced current I flows through the wire stopper 60 represented by the series resistor R2 and through the equivalent capacitor C to the ground, flowing to the human body fluid 5. The induced current I2 is transmitted through the spiral electrode 1 to the human tissue 4, forming the resistance R. The equivalent series inductor L1 formed by the spiral electrode 1 has a large impedance, further weakening the magnitude of the induced current I2 and increasing the induced current I1 in the human body fluid 5. The flow of I2 through the resistance R represented by the human tissue 4 generates Joule heating, causing tissue temperature to rise. Although the induced current I2 still flows to the human tissue 4, it is smaller due to the shunting and the obstruction of the series inductor L1. As a result, despite the small contact area between the spiral electrode 1 and the human tissue 4, the current density at the interface between the spiral electrode tip 1a and the tissue is low, and the temperature rise at the location of the human tissue 4 is within an acceptable range. The induced current I1 is greater than the induced current I2.

[0124] The induced current shunting structure 101 significantly reduces the induced current flowing to the spiral electrode 1, reducing heat generation at the electrode tip and tissue interface. The shunted induced current flows through the ring electrode 2 and human body fluid 5, generating Joule heating. Since human body fluid 5 has a large specific heat capacity, the temperature rise caused by Joule heating is small, thus avoiding damage to human body fluid 5 and human tissue 4. The surface area of the ring electrode 2 is several times larger than the area of the spiral electrode contact. The density of the induced current shunted to the surface of the ring electrode 2 and associated components is low, resulting in a temperature rise of only 10%-20% of the temperature rise of the spiral electrode contact under the same induced current.

[0125] like Figure 4 and Figure 10 As shown, the inner conductor core segment 103 is under the high-frequency energy field 6. Due to the presence of the inner conductor support segment 70a, its higher magnetic permeability makes the magnetic field intensity here higher. The concentration of magnetic flux induces the induced electric field e to gather in the inner conductor core segment 103, changing the overall distribution of the induced electric field e, and can enhance the shunting ability of the induced current under high frequency.

[0126] By adjusting the wall thickness of the dielectric segment 80a, the size and number of the conductive limiters 60, the wall thickness of the inner insulating tube 90 and the electrode insulating member 85, and the length and diameter of the inner conductor core segment 103, the capacitance value of the equivalent capacitor C can be adjusted, thereby obtaining the ability to shunt induced current under a wide-spectrum high-frequency energy field.

[0127] Of course, this embodiment does not specifically limit the fixing method of the inner conductor body 30 and the inner conductor body support segment 70a. In other embodiments, the inner cavity of the inner conductor body 30 and the outer peripheral wall of the inner conductor body support segment 70a can be fixedly connected by welding or other methods.

[0128] Of course, this embodiment does not specifically limit the fixing method of the inner wire body 30 to the electrode insulating member 85 and the ring electrode 2 respectively. In other embodiments, the inner wire body 30 is fixed to the electrode insulating member 85 and the ring electrode 2 respectively by bonding or other means.

[0129] Of course, this embodiment does not specifically limit the components included in the inner conductor core segment 103. In other embodiments, the inner conductor core segment 103 also includes: a front developing ring 50, a rear developing ring 51 and a conductive limiter 60.

[0130] Of course, this embodiment does not specifically limit the specific parameters of the inner conductor core segment 103. In other embodiments, the length of the inner conductor core segment 103 is 2 mm to 10 mm, and the diameter of the inner conductor core segment 103 is 0.7 mm to 1.2 mm; the axial length of the inner conductor core segment 103 is increased to increase the first pole area of the equivalent capacitor C; the diameter of the inner conductor core segment 103 is increased to reduce the pole spacing of the equivalent capacitor C and increase the capacitance value of the equivalent capacitor C to enhance the shunting capability.

[0131] Of course, this embodiment does not specifically limit the specific parameters of the ring electrode 2. In other embodiments, the length of the ring electrode 2 is 2 mm to 10 mm; the length of the contact ring 21 of the ring electrode 2 is 1 mm to 10 mm, the outer diameter of the contact ring 21 is 1 mm to 3 mm, and the contact area between the contact ring 21 and the human body fluid 5 is 20 mm. 2 Up to 100mm 2 The surface area of the ring electrode 2 is increased to increase the second pole area of the equivalent capacitor C, increase the contact area with the human body fluid 5, and enhance the heat dissipation effect.

[0132] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present description and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A magnetic resonance compatible implantable electrode lead with a shunt structure, the electrode lead (300) comprising: A conductor main body section (400), comprising an outer insulating tube (91) and an outer conductor body (40), an inner insulating tube (90) and an inner conductor body (30) sequentially arranged in the outer insulating tube (91); characterized in that: The electrode lead (300) further comprises: an induced current shunt structure (101) for shunting the induced current inside the electrode lead to the ring electrode (2) and human body fluid (5) under a high-frequency energy field, wherein the ring electrode (2) is connected to the human body fluid (5) outside the electrode; the induced current shunt structure (101) suppresses heating of the electrode and tissue interface, thereby reducing radio frequency heating of the electrode as a whole; The inner cavity of the inner conductor body (30) is nested in the outer peripheral wall of the inner conductor body support section (70a) of the electrode core shaft (70) and is electrically connected to the electrode core shaft (70); the inner conductor body support section (70a) and the connecting section of the inner conductor body (30) form an inner conductor body iron core section (103); the outer side of the inner insulating tube (90) is connected to the ring electrode (2); under the action of a high-frequency signal, the inner conductor body iron core section (103) enhances the local induced electric field e, thereby strengthening the shunting capability of the induced current at high frequencies.

2. The electrode lead according to claim 1, wherein: An induced current shunting structure (101) comprises: an electrode sleeve (80), the electrode core shaft (70), and a conductive limiting member (60); The conductive stopper (60) has an inner contact hole (62) for the electrode core shaft (70) to pass through and to be in contact and electrically connected with the conductive stopper (60), so that the conductive stopper (60) is electrically connected to the electrode wire (300); An outer contact surface (61) is arranged at a circumferential position of the conductive limiter (60); the outer contact surface (61) is in contact with the inner surface of the electrode sleeve (80).

3. The electrode lead according to claim 2, characterized in that The electrode sleeve (80) and the electrode insulating member (85) form a fixed space, and the fixed space is used to accommodate and positionally fix the conductive limiting member (60); The outer sides of the inner insulating tube (90) are respectively connected to the electrode insulating member (85) and the ring electrode (2).

4. The electrode lead according to claim 3, characterized in that The inner cavity of the inner conductor body (30) is fixedly connected to the outer peripheral wall of the inner conductor body support section (70a) by welding; and / or, The inner conductor (30) is bonded and fixed to the electrode insulating member (85) and the ring electrode (2) respectively; and / or, The end of the inner wire body support section (70a) close to the spiral electrode (1) is fixed to the front developing ring (50), and the front developing ring (50) is connected to the spiral electrode (1); the end of the inner wire body support section (70a) away from the spiral electrode (1) is fixed to the rear developing ring (51); and / or, A forming surface (63) is also arranged at a circumferential position of the conductive limiter (60); a sharp edge structure is formed on the forming surface (63), and the end point of the sharp edge forms a diversion tip (64).

5. The electrode lead according to any one of claims 2 to 4, characterized in that: The induced current shunting structure (101) further includes an inner conductor core segment (103) and the ring electrode (2); A portion of the inner conductor core segment (103) serves as a first pole of an equivalent capacitor C, and the ring electrode (2) and a portion of the outer conductor (40) connected to the ring electrode (2) serve as a second pole of the equivalent capacitor C; An electrode insulating member (85) is fixed to the inner hole of the ring electrode (2); the inner insulating tube (90) penetrates the electrode insulating member (85) and is fixed to the rear fixing section (85a) of the electrode insulating member (85); the inner insulating tube (90) and the rear fixing section (85a) form mutual insulation between the ring electrode (2), the human body fluid (5) and the inner wire body (30); and the ring electrode (2) is in direct contact with the human body fluid (5), and the electrode insulating member (85) and the inner insulating tube (90) serve as intermediate dielectric materials of the equivalent capacitor C.

6. The electrode lead according to claim 5, characterized in that A portion of the inner conductor core segment (103) serves as a first pole of an equivalent capacitor C, and the ring electrode (2) and a portion of the outer conductor (40) connected to the ring electrode (2) serve as a second pole of the equivalent capacitor C.

7. The electrode lead according to claim 6, characterized in that The diameter of the inner conductor support section (70a) ranges from 0.1 mm to 1 mm; and / or The material magnetic permeability χ of the electrode core shaft (70) is greater than that of the inner conductor (30), so as to increase the focusing ability of the induced electric field e; and / or, The inner conductor iron core segment (103) is located on the side of the spiral electrode (1) away from the human tissue (4) to prevent the inner conductor (30) with the heat diverted from contacting the human tissue (4) with the electrode core shaft (70) to cause secondary damage; and / or, The inner conductor core segment (103) further includes: a front developing ring (50) and a rear developing ring (51), and / or a conductive limiting member (60); and / or, The electrode core shaft (70) is a conductive material having paramagnetism and / or diamagnetic properties and low magnetic susceptibility properties to meet the compatibility requirements of magnetic resonance imaging technology; the electrode core shaft (70) includes: titanium and / or titanium alloy and / or platinum alloy and / or non-magnetic nickel-cobalt-chromium alloy and / or conductive polymer material; and / or, The diameter of the inner conductor support section (70a) is larger than the inner cavity diameter of the inner conductor (30), so as to expand the inner conductor (30) and reduce the inter-pole distance between the inner conductor core section (103) and the ring electrode (2).

8. The electrode lead according to claim 6, characterized in that The ring electrode (2) is located in the electrode head section (100); the outer conductor body (40) is nested outside the outer conductor body support section (25) of the ring electrode (2), and a cavity is also present inside the outer conductor body (40), and the inner insulating tube (90) passes through the cavity to ensure that the outer conductor body (40) and the inner conductor body (30) are insulated from each other; The rear fixing section (85a) of the electrode insulating member (85) is fixedly connected to the inner cavity wall of the contact ring (21) of the ring electrode (2); and the inner insulating tube (90) extends into the rear fixing section (85a) and is fixed to the inner cavity wall of the rear fixing section (85a), thereby forming an overall insulation between the inner conductor of the electrode wire of the ring electrode (2) and the outer wire body (40).

9. The electrode lead according to claim 8, characterized in that The outer insulating tube (91) passes through the outer peripheral wall of the outer conductor body (40) and abuts against the outer insulating tube limiting step (23) on the ring electrode (2); A bonding gap for the adhesive to enter is provided between the bonding section (22) on the ring electrode (2) and the outer insulating tube (91); the front fixed end surface (85b) of the electrode insulating member (85) is fixed to the inner surface of the electrode sleeve (80); and a drug plug (3) is also fixed to the side of the electrode sleeve (80) facing the spiral electrode tip (1a) of the spiral electrode (1).

10. The electrode lead according to any one of claims 5 to 9, characterized in that: By adjusting the wall thickness values of the inner insulating tube (90) and the electrode insulating member (85), as well as the length and diameter of the inner conductor core segment (103), the capacitance value of the equivalent capacitor C and the ability of the electrode conductor (300) to shunt induced current under a high-frequency energy field are adjusted.

11. The electrode lead according to claim 10, characterized in that: The wall thickness of the inner insulating tube (90) is 0.1 mm to 0.5 mm, so as to reduce the inter-electrode distance of the equivalent capacitor C; the material of the inner insulating tube (90) includes any one of silicone, polyurethane, polyimide and PTFE, or a combination of multiple thereof.

12. The electrode lead according to claim 10, characterized in that The first pole of the equivalent capacitor C comprises: the inner conductor core segment (103), and a portion of the inner conductor (30) connected to the inner conductor core segment (103); and / or, The second pole of the equivalent capacitor C comprises: the overall structure of the ring electrode (2), and the portion of the outer conductor (40) connected to the ring electrode (2).

13. The electrode lead according to claim 12, characterized in that: The length of the inner conductor core segment (103) is 2 mm to 10 mm, and the diameter of the inner conductor core segment (103) is 0.7 mm to 1.2 mm; the axial length of the inner conductor core segment (103) is increased to increase the first pole area of the equivalent capacitor C; and / or, The length of the ring electrode (2) is 2 mm to 10 mm; the length of the contact ring (21) of the ring electrode (2) is 1 mm to 10 mm, the outer diameter of the contact ring (21) is 1 mm to 3 mm, and the contact area between the contact ring (21) and the body fluid is 20 mm. 2 Up to 100mm 2 At the same time, the surface area of the ring electrode (2) is several times larger than the contact area of the spiral electrode.

14. The electrode lead according to claim 4, characterized in that The spiral electrode (1) further comprises: a spiral electrode tip (1a); during the implantation process, the spiral electrode tip (1a) is rotated and inserted into the human tissue (4) at the targeted treatment location; The spiral structure (1b) of the spiral electrode (1) is provided with a protruding structure (1c) at a circumferential position, and the end position of the protruding structure (1c) has a shunt contact (1d) for reducing current density; Under the action of the high-frequency energy field (6), an induced current I is induced inside the electrode wire, and the shunt contact (1d) can disperse the current density J at the junction of the electrode tip (1a) and the tissue, so as to reduce the induced current density flowing from the spiral electrode (1) to the human tissue (4), thereby reducing the heating of the electrode in the tissue; The calculation formula of the current density J is: Where I is the induced current, n is the number of shunt contacts, and A is the area of a single shunt contact. The more shunt contacts there are, the larger the area and the smaller the current density J. The calculation formula for the heat generated by the induced current I is: Q = I 2 R∝J 2 Where I is the induced current, R is the conductor resistance, and J 2 is the current density; the calorific value Q is proportional to the current density J.

15. The electrode lead according to claim 14, characterized in that The end of the inner wire body (30) is nested and fixed in a distal outer position of the electrode core shaft (70) away from the spiral electrode tip (1a), and is fixed to the rear developing ring (51); the electrode core shaft (70) is close to the proximal end of the spiral electrode tip (1a) and is connected to the front developing ring (50); and the front developing ring (50) is connected to the spiral electrode (1); The inner conductor (30) is driven to rotate in the inner insulating tube (90), thereby driving the spiral electrode (1) accommodated in the electrode sleeve (80) to move in a driven manner. Furthermore, the conductive limiting member (60) is respectively arranged corresponding to the front developing ring (50) and the rear developing ring (51) at both sides of the length direction of the electrode core shaft (70); when the spiral electrode (1) drives the electrode core shaft (70) to extend and retract, the developing ring abuts against the conductive limiting member (60) to limit the extension and retraction distance of the electrode core shaft (70); and the position of the spiral electrode (1) is positioned according to the developing distance between the conductive limiting member (60) and the developing ring.

16. The electrode lead according to claim 15, characterized in that An insulating seal (55) is also provided between any two of the conductive limiters (60), and the insulating seal (55) is tightly fitted with the conductive limiters (60) to squeeze the insulating seal (55) and fit the inner cavity wall of the electrode sleeve (80) to form a sealing structure.

17. The electrode lead according to any one of claims 1 to 16, characterized in that: Under the action of the high-frequency energy field (6), an induced electric field e is induced inside the electrode conductor (300); the high magnetic permeability of the inner conductor support section (70a) increases the magnetic field intensity at that location, and the concentration of magnetic flux generates a higher induced electric field e; the induced electric field e is concentrated in the inner conductor iron core section (103), changing the overall distribution of the induced electric field e, resulting in a dispersed induced heating area; and the inner conductor iron core section (103) has a large surface area, a low surface current density, and a low heat generation.

18. The electrode lead according to claim 17, characterized in that The inner conductor (30) and the ring electrode (2) are coupled via a heat difference, the ring electrode (2) is in direct contact with the human body fluid (5), and the heat of the inner conductor (30) can be transferred to the human body fluid (5) via the ring electrode (2) for heat dissipation.

19. The electrode lead according to claim 9, characterized in that The conductive limiter (60), the electrode core shaft (70) and the inner conductor iron core segment (103) constitute the first pole of the equivalent capacitor C, and the human body fluid (5) and the ring electrode (2) constitute the second pole of the equivalent capacitor C; The IMD is connected to the electrode circuit (7) of the electrode wire (300), and the electrode circuit (7) includes: a series resistor, a series impedance, a series inductor, and a parallel capacitor; the human tissue (4) and the human body fluid (5) form a resistor R, the inner wire body (30) forms a series resistor R1, the outer wire body (40) forms a series resistor R2, the resistance of the internal series conductor of the electrode head segment (100) is a series resistor R3, and the spiral electrode (1) forms an equivalent series inductor L1 under the high-frequency energy field (6); The electrode wire (300) is fixed to the patient's targeted treatment site via the spiral electrode (1). When the electrode wire is in normal working condition, the electric pulse is transmitted to the targeted tissue via the spiral electrode (1), and then transmitted to the ring electrode (2) via the human tissue (4) and the human body fluid (5) and returns to the IMD to form a loop; wherein the stimulation pulse emitted by the IMD is in low frequency or DC form, and the equivalent capacitor C is in an open circuit state; the spiral structure (1b) of the spiral electrode (1) exhibits the properties of a wire at low frequency and does not weaken the strength of the electric pulse signal; The electrode wire (300) is fixed to the patient's targeted treatment site through the spiral electrode (1). When the electrode wire is in an MRI scanning environment: under the high-frequency energy field (6), an induced current is formed in the electrode wire (300), and the conductive limiter (60) and the inner wire body iron core segment (103) are capacitively coupled with the human body fluid (5) and the ring electrode (2); an induced current I is induced in the electrode circuit (7), and the induced current I passes through the series resistor R1 and the series resistor R2 in sequence; the equivalent capacitor C is in a short-circuit state, and the induced current I1 in the induced current I passes through the series resistor R2 and the equivalent capacitor C to the ground and flows to the ring electrode (2) and the human body fluid (5); the induced current I2 is transmitted through the spiral electrode (1) to the resistor R formed by the human tissue (4); wherein, the induced current I1 is greater than the induced current I2.

20. A medical device, characterized in that The medical equipment includes: A machine body having a connection interface; and An electrode wire, wherein the electrode wire is the electrode wire according to any one of claims 1 to 19, and a connector of the electrode wire is inserted into the connection interface.

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