Magnetic resonance compatible implantable electrode wire and medical equipment

Abstract

The invention discloses a magnetic resonance compatible implantable electrode wire and medical equipment, the electrode wire comprises an induced current shunting structure used for shunting induced current in the electrode wire to a ring electrode and human body fluid under a high-frequency energy field, and the ring electrode is connected with the human body fluid outside the electrode. The induced current shunting structure comprises an electrode sleeve, the electrode core shaft and a conductive limiting piece. The induced current shunting structure can greatly reduce the induced current flowing to the spiral electrode, inhibit the heating of the electrode and a tissue interface, and reduce the overall radio frequency heating of the electrode.

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 and medical equipment. Background Art

[0002] Magnetic resonance imaging (MRI) is a widely used and increasingly popular medical imaging technique. The demand for MRI examinations among patients with implantable medical devices (IMDs), particularly elderly patients, is also rapidly increasing. 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 that of 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 aforementioned MRI compatibility requirements. Due to the high-frequency, high-magnetic-field characteristics of MRI, MRI has long been an absolute no-go zone for patients undergoing surgical implantation of electrical stimulators (typically pacemakers, defibrillators, and deep brain stimulators). The primary reason for this is the interference between the MRI integrated field and ferromagnetic materials and / or conductive objects. The primary potential risks are induced heating of the implanted product and the impact of artifacts generated during MRI scanning on disease diagnosis. The high-frequency energy field in the MRI field, including the rapidly switching gradient field G and RF radio frequency field B1, can couple electromagnetic field energy to the implanted medical device, generating eddy currents and induced currents, generating induced heating, and potentially transmitting erroneous electrical pulse signals to the human body, adversely affecting patient safety. Furthermore, metal and conductive objects in the implant affect the uniformity of the B0 magnetic field, causing distortion and deformation of the MRI image, impacting disease diagnosis.

[0007] Therefore, the aforementioned eddy currents and induced currents, resulting in induced heating and artifacts in MRI scans, are urgent technical issues in this field. In particular, thin, conductive electrode wires act 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. Summary of the Invention

[0008] The main purpose of the present invention is to provide a magnetic resonance compatible implantable electrode lead, which aims 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.

[0009] Specifically, in an MRI environment, the slender structure of the electrode wire will couple with the high-frequency energy field, and the current induced inside will 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.

[0010] To achieve the above objectives, the present invention provides an MRI-compatible implantable electrode lead, the electrode lead comprising:

[0011] A conductor main body section has a first end and a second end opposite to each other, the conductor main body section including 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;

[0012] an electrode head section, provided at a first end of the lead body section; and a connector section, provided at a second end of the lead body section and connected to a medical device via a connector;

[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 induced current shunting structure includes a stopper-type induced current shunting structure comprising an electrode sleeve, the electrode core shaft, and a conductive stopper; the conductive stopper has an internal contact hole through which the electrode core shaft passes and is electrically connected to the conductive stopper, thereby electrically connecting the conductive stopper to the electrode wire; an external contact surface is arranged circumferentially of the conductive stopper; the external contact surface is in contact with the inner surface of the electrode sleeve. A drug plug is provided on the electrode sleeve near the spiral electrode.

[0015] Optionally, the ring electrode has a hollow thin wall, and is provided with magnetic flux holes distributed along its circumference and / or axial direction; and / or,

[0016] Magnetic flux holes are provided on the ring electrode and the signal connection ring.

[0017] 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;

[0018] The rear fixing section of the electrode insulator is fixedly connected to the inner wall of the contact ring of the ring electrode. Furthermore, the inner insulating tube extends into the rear fixing section and is fixed to the inner wall of the lumen of the ring electrode. This ensures that the ring electrode and the outer conductor body are completely insulated from the inner conductor of the electrode lead. The front fixing end surface 85b of the electrode insulator 85 is bonded and fixed to the inner surface of the electrode sleeve 80.

[0019] Optionally, the combination of the conductive limiter and the electrode core shaft can serve as a first pole of an equivalent capacitor C2, human body fluid serves as a second pole of the equivalent capacitor C2, and at least a portion of the electrode sleeve dielectric segment on the electrode sleeve serves as an intermediate dielectric material;

[0020] During normal operation, the electrical pulses emitted by the IMD are in the form of low frequency and / or DC, and the conductive limiter is insulated from the body fluids so that the electrical pulses are transmitted into the tissue;

[0021] By adjusting the diameter of the electrode core shaft, the size and number of the conductive limiters, the capacitance of the equivalent capacitor C2 can be adjusted, thereby adjusting the ability to shunt the induced current under the high-frequency energy field.

[0022] 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;

[0023] The fixing step of the electrode sleeve and the end of the electrode insulating member facing the spiral electrode tip form a fixed space, and the fixed space is used to accommodate and position the conductive limiting member;

[0024] The outer sides of the inner insulating tube are respectively connected to the electrode insulating member and the ring electrode;

[0025] The outer contact surface of the conductive limiter is in contact with the inner cavity wall of the dielectric section of the electrode sleeve, and the outer surface of the dielectric section contacts human body fluids.

[0026] Optionally, a transmission tooth is provided in the electrode sleeve; the transmission tooth is connected to the spiral electrode for transmission, converting the rotational motion of the spiral electrode into a telescopic motion along the axial direction of the spiral electrode;

[0027] The inner conductor body is driven to rotate in the inner insulating tube, and the spiral electrode accommodated in the electrode sleeve is driven to extend and retract through the latching tooth structure.

[0028] Optionally, the conductive limiter is provided with an outer contact surface and a forming surface at a circumferential position; the outer contact surface is bonded to the inner surface of the electrode sleeve; a sharp edge structure is formed on the forming surface, and the end point of the sharp edge forms a diversion tip.

[0029] Optionally, the conductive limiter is a columnar structure; the forming surface is a groove formed on the outer peripheral wall of the conductive limiter, and the diverter tip is formed at the connection position between the forming surface and the outer contact surface; or,

[0030] The conductive limiter is an elliptical structure with an opening on the outer periphery; the diversion tip is formed at a circumferential position of the outer peripheral wall of the conductive limiter, and the outer contact surface is a section formed on the outer peripheral wall of the conductive limiter.

[0031] Optionally, the end of the inner wire body is nested and fixed at a 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;

[0032] At least two of the conductive limiters in any group are respectively arranged corresponding to the front developing ring and the rear developing ring at both sides of the length direction of the electrode core axis;

[0033] When the spiral electrode drives the electrode core shaft to extend and retract, the developing ring abuts against the conductive limiting member to limit the extension and retraction distance of the electrode core shaft; and the position of the spiral electrode is located according to the developing distance between the conductive limiting member and the developing ring.

[0034] Optionally, the inner cavity of the inner wire body is nested in the outer peripheral wall of the inner wire body support section of the electrode core shaft and is electrically connected to the electrode core shaft; at least a portion of the inner wire body support section is inserted into the inner cavity of the inner wire body to form an inner wire body iron core section; under the action of the high-frequency energy field, an induced electric field e will be induced inside the electrode wire, and the induced electric field e is concentrated due to the action of the inner wire body iron core section, thereby inducing the induced electric field e to gather in the inner wire body iron core section, so as to change the distribution of the induced electric field e, disperse and reduce the induced electric field strength of the electrode head section, reduce the induced current density distributed at the spiral electrode or tissue interface, thereby reducing the heating of the spiral electrode and the heating of human tissue, and reducing the thermal damage to human tissue by the MRI environment.

[0035] Optionally, the inner conductor body and the inner conductor body core segment constitute a ring electrode inductive current shunt structure; the inductive current shunt structure further comprises: the ring electrode inductive current shunt structure;

[0036] At least a portion of the inner conductor core segment serves as the first pole of the equivalent capacitor C1, and the ring electrode serves as the second pole of the equivalent capacitor C1; under the action of the high-frequency energy field, the inner conductor core segment gathers the induced electric field to enhance the effect of capacitive coupling.

[0037] Optionally, 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 are adjusted to adjust the capacitance value of the equivalent capacitor C1 and the ability of the electrode conductor to shunt the induced current under a high-frequency energy field.

[0038] Optionally, the diameter of the inner conductor support segment is larger than the inner cavity diameter of the inner conductor, so as to expand the inner conductor and reduce the inter-electrode distance between the inner conductor core segment and the ring electrode;

[0039] 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.

[0040] Optionally, 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 the human body fluids, and the electrode insulator and the inner insulating tube serve as intermediate dielectric materials of the equivalent capacitor C1;

[0041] During normal operation, the electric pulses emitted by the IMD are in low-frequency and / or DC form, the ring electrode is insulated from the inner wire body, the equivalent capacitor C1 is in an open-circuit state, and the electric pulse signal can be transmitted from the inner wire body to the target tissue to complete the stimulation work.

[0042] Optionally, 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; human tissue and 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 resistance of the series conductor outside the electrode head segment is a series resistor R4; the inner wire body, the ring electrode, and part of the outer wire body constitute an equivalent capacitor C1; the combination of the conductive limiter and the electrode core shaft can serve as the first pole of the equivalent capacitor C2, and the human body fluid serves as the second pole of the equivalent capacitor C2; the spiral electrode equivalently forms a series inductor L1 under a high-frequency energy field;

[0043] When MRI scans, a large current I is induced in the electrode circuit. 感应电流 , I 感应电流 The energy is transmitted along the inner conductor represented by the series resistor R1 to the electrode core shaft represented by the series resistor R2. Due to the extremely high frequency of the high-frequency energy field, the impedance of the equivalent capacitor C1 is extremely small, which is approximately a short circuit. 感应电流 Part of the shunt induced current I1 is transferred to the ring electrode through the electrode core shaft and the inner conductor through the equivalent capacitor C1. The shunt induced current I1 is shunted again at the ring electrode, and part of it returns to the IMD through the outer conductor represented by the series resistor R3 and series resistor R4. The remaining part I1 flows through the ring electrode to the human body fluid; the remaining I 感应电流 Continue to pass through the conductive limiter, at this time the impedance of the equivalent capacitor C2 is extremely small, which is close to a short circuit, I 感应电流 Part of the current I2 flows through the conductive limiter represented by the series resistor R2, passes through the equivalent capacitor C2 and is grounded to the human body fluid. 感应电流The remaining small induced current I3 is transferred through the spiral electrode to the resistance R formed by the human tissue. At this time, due to the large impedance of the series inductor L1 formed by the spiral electrode, the current I3 flowing to the human tissue is further weakened. The resistance R represented by I3 flowing through the human tissue will generate Joule heat, causing the tissue to heat up. Although there is still induced current I3 flowing to the human tissue, it is extremely small after being shunted and blocked by the inductor L1, making the current density at the spiral electrode tip or the tissue interface small, and the temperature rise at the human tissue is within an acceptable range.

[0044] During normal operation, the electrical pulses emitted by the IMD are usually low-frequency or DC. The impedance of the equivalent capacitors C1 and C2 is large, which is close to an open circuit. The inner and outer conductors are insulated from each other. The electrical pulses emitted by the IMD are transmitted to the target tissue through the spiral electrode, and then transmitted to the ring electrode through the tissue and body fluids to return to the IMD to form a loop. The spiral structure exhibits the properties of a conductor at low frequency and will not weaken the strength of the electrical pulse signal.

[0045] Optionally, the wall thickness of the inner insulating tube is 0.15 mm to 0.18 mm to reduce the inter-electrode spacing of the equivalent capacitor C; and / or,

[0046] The axial length of the inner conductor core segment is increased to increase the first pole area of the equivalent capacitor C; and / or,

[0047] The length of the ring electrode is 7.3 mm; the length of the contact ring of the ring electrode is 3.5 mm, the outer diameter of the contact ring is 2 mm, and the contact area between the contact ring and the human body fluid is 22 mm. 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 / or,

[0048] The electrode sleeve is made of a biocompatible insulating material: polyurethane; and / or

[0049] The wall thickness of the dielectric segment is 0.25 mm; and / or,

[0050] There are at least two conductive limiting members.

[0051] Optionally, the ring electrode has a contact ring; in use, when the electrode wire is implanted in the human body, the contact ring is immersed in body fluids, forming a loop to transmit pulses and sensing signals;

[0052] The outer insulating tube passes through the outside of the outer conductor and abuts against the outer insulating tube limiting step on the ring electrode. The ring electrode is also provided with a first bonding section bonded to the outer insulating tube by an adhesive.

[0053] The first bonding section is located in the middle of the ring electrode, and the magnetic flux holes are arranged in the circumferential position of the first bonding section; and the magnetic flux holes on the first bonding section are rounded rectangular holes with rounded corners to reduce sharp corners and edges of the holes.

[0054] Optionally, the magnetic flux hole is arranged on the first bonding section, and the area of a single magnetic flux hole is 1.2 mm 2 and / or,

[0055] The magnetic flux holes on the first bonding section are evenly distributed on the first bonding section, and there are two magnetic flux holes arranged circumferentially on the first bonding section.

[0056] Optionally, the connector segment is used for plugging into a connection interface of an IMD, and transmits an electrical pulse signal emitted by the IMD to the electrode head segment through a signal connection pin and a signal connection ring;

[0057] The signal connection pin is connected to an end of the connector shaft on the connector segment away from the connector segment; the connector insulating member located in the signal connection ring and the inner cavity of the long seal and the short seal passes through the support shaft and is arranged opposite to the signal connection pin through the insulating member limiting step on the connector shaft to limit the axial extension and contraction position of the connector shaft;

[0058] The connector shaft is movably connected to the connector insulating member, and the signal connection needle is rotated to drive the inner wire body to rotate, thereby driving the spiral electrode to rotate and penetrate into the patient's tissue.

[0059] Optionally, the signal connection ring is fixedly connected to the outer wall of the connector insulation member; the connection seat welding section on the signal connection ring is fixedly connected to the front welding section on the signal connection seat, and the outer wire body is sleeved on the rear welding section on the signal connection seat and fixedly connected thereto;

[0060] The outer insulating tube passes through the outer conductor body and is bonded and fixed thereto; the long sealing member located on the outside of the outer insulating tube is snap-fitted and positioned with the sealing member limiting protrusion on the signal connecting ring; the long sealing member is fixed to the second bonding section on the signal connecting ring by an adhesive; the short sealing member faces one end of the signal connecting ring, abuts against the short sealing member limiting surface at the end of the signal connecting ring, and is fixedly connected to the outer wall of the connector insulating member.

[0061] The second bonding section is located in the middle of the signal connection ring, and the magnetic flux hole is arranged at a circumferential position of the second bonding section; and the magnetic flux hole on the second bonding section is a rounded rectangular hole with rounded corners to reduce sharp corners and edges of the hole.

[0062] Optionally, the magnetic flux hole is arranged on the second bonding section, and the area of a single magnetic flux hole is 1.3 mm 2 and / or,

[0063] The magnetic flux holes on the second bonding section are evenly distributed on the second bonding section, and the number of the magnetic flux holes arranged in the circumferential direction and the axial direction on the second bonding section is four.

[0064] Optionally, the first bonding section is provided with an outer insulating tube limiting step and an outer conductor body welding step at positions close to and far from the spiral electrode respectively;

[0065] The step protrusion height range of the outer insulating tube limiting step and the outer wire body welding step is 0.1mm, and the step is transitioned by a rounded corner; the end of the outer wire body close to the spiral electrode is nested in the outer wall of the outer wire body support section, and abuts against the outer wire body welding step, and is continuously welded to form a first connecting section; the outer diameter of the end of the outer wire body away from the spiral electrode is close to the diameter of the outer wire body welding step; and / or,

[0066] One end of the inner conductor body close to the spiral electrode tip has a diameter similar to that of the rear developing ring when inserted into the inner conductor body support section, so as to reduce the difference in splicing sections; and the inner conductor body and the rear developing ring are connected by continuous welding to form a second connecting section; and / or,

[0067] There is a connecting section difference between the insulating part limiting step and the inner conductor body welding section on the connector shaft, and the connecting section difference is transitioned by a circular arc to avoid the generation of a right-angle step; the inner conductor body welding section is further provided with a tapered transition section toward one end of the inner conductor body to enable the connector shaft to be nested and connected with the inner conductor body cavity; the inner conductor body and the inner conductor body welding section are connected by continuous welding to form a third connecting section.

[0068] Optionally, the spiral electrode comprises: the spiral electrode tip and a spiral structure; the spiral electrode tip is a tip structure, and adopts a smooth transition tip centered on a central parabolic tip structure;

[0069] In an MRI scanning environment, the smoothly transitioned tip can reduce edge effects and smoothly transition magnetic field changes, thereby reducing tip artifacts; at the same time, it can reduce the induced electric field concentration of the electrode wire and reduce tip heating.

[0070] A medical device, comprising:

[0071] A machine body having a connection interface; and

[0072] The electrode wire and the connector of the electrode wire are inserted into the connection interface.

[0073] 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. At the same time, the wire of the present invention optimizes the design of the component shape, provides magnetic flux holes, and provides a rounded transition appearance, reduces the step difference at the connection, avoids the generation of right-angle steps, sharp points, and edges, and reduces the amount of metal used. The preferred connection methods are continuous welding and bonding. This overall reduces the mechanical forces applied to the wire in the MRI environment and reduces the area of MRI artifacts caused by magnetic field distortion caused by the electrodes. Furthermore, the electrode wire of the present invention minimizes structures such as sharp corners, protrusions, and edges, reducing the accumulation of induced electric fields at sharp corners and other structures. This can, to a certain extent, reduce the hot spots of the electrode under high-frequency energy fields and improve the heating condition of the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] 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.

[0075] Figure 1 A schematic cross-sectional view of the structure of the electrode tip section in the electrode wire provided by the present invention;

[0076] Figure 2 A cross-sectional view showing the internal structure of the connector section of the electrode wire provided by the present invention;

[0077] Figure 3 This is a schematic diagram of the overall three-dimensional structure of the MRI-compatible electrode wire provided by the present invention;

[0078] Figure 4 A schematic diagram of the three-dimensional structure of the ring electrode provided by the present invention;

[0079] Figure 5 A schematic diagram of the three-dimensional structure of the conductive limiter provided by the present invention;

[0080] Figure 6 A schematic diagram of the three-dimensional structure of the spiral electrode provided by the present invention;

[0081] Figure 7 A schematic diagram of the connection structure between the electrode core shaft and the developing ring provided by the present invention;

[0082] Figure 8 A schematic longitudinal cross-sectional view of the inner conductor core segment provided by the present invention;

[0083] Figure 9 A cross-sectional view of the electrode sleeve provided by the present invention;

[0084] Figure 10 A schematic longitudinal section diagram of an electrode insulating member provided by the present invention;

[0085] Figure 11 A schematic diagram of the three-dimensional structure of the signal connection ring provided by the present invention;

[0086] Figure 12 A schematic diagram of the three-dimensional structure of the signal connection socket provided by the present invention;

[0087] Figure 13 A schematic diagram of the three-dimensional structure of the connector shaft provided by the present invention;

[0088] Figure 14a A schematic longitudinal cross-sectional view of the inductive current shunting structure of the position-limiting member provided by the present invention;

[0089] Figure 14b The present invention provides Figure 14a , a schematic cross-sectional view of the induced current shunting structure of the limiter;

[0090] Figure 15a A schematic diagram of the longitudinal cross-section of the ring electrode induction current shunt structure provided by the present invention;

[0091] Figure 15b The present invention provides Figure 15a Middle, schematic diagram of the cross-sectional structure of the ring electrode induction current shunt structure;

[0092] Figure 16 A schematic diagram of the pulse flow direction of a normal stimulation pulse after the electrode lead provided by the present invention is implanted;

[0093] Figure 17 A schematic diagram of the flow of induced current inside the electrode lead provided by the present invention after implantation when exposed to a high-frequency energy field;

[0094] Figure 18A circuit diagram of the medical system exposed to a high-frequency energy field after the electrode wire provided by the present invention is connected to the IMD.

[0095] Figure 19 This is a schematic diagram of the magnetic flux line distribution of the ring electrode with magnetic flux holes provided by the present invention in a uniform magnetic field.

[0096] Description of Figure Numbers:

[0097]

[0098]

[0099] 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

[0100] 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.

[0101] 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.

[0102] 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.

[0103] Example 1

[0104] 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.

[0105] 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.

[0106] To disperse the induced electric field e and shunt the induced current, while ensuring that the electrodes present a normal path under the working electrical pulse, with only a minimal amount of the working electrical pulse signal being shunted, thus ensuring normal treatment; and to prevent artifacts generated by the implanted electrodes during MRI scanning that could affect disease diagnosis, the present invention provides an electrode lead suitable for various medical devices, particularly defibrillators, pacemakers, or other electrical stimulation devices, including but not limited to these.

[0107] See Figures 1 to 3 , Figure 1 A schematic cross-sectional view of the structure of an electrode tip section in an electrode wire in an embodiment of the present invention is shown. Figure 2 A cross-sectional view of the internal structure of the connector section in the electrode wire in an embodiment of the present invention is shown. Figure 3 A schematic diagram of the overall three-dimensional structure of an MRI-compatible electrode wire in an embodiment of the present invention is shown.

[0108] The present invention provides a magnetic resonance compatible implantable electrode lead, wherein the electrode lead 300 comprises:

[0109] The conductor body section 400 has a first end and a second end opposite to each other. 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.

[0110] The electrode tip section 100 is provided at the first end of the main wire section 400; and the connector section 200 is provided at the second end of the main wire section 400 and is connected to the medical device via a connector. The spiral electrode 1 of the electrode tip section 100 has a specific structure including: the spiral electrode tip 1a and the spiral structure 1b. The spiral electrode tip 1a is a tip structure, which adopts a smooth transition tip centered on a central parabolic tip structure. In an MRI scanning environment, the smooth transition tip can reduce edge effects and smoothly transition magnetic field changes, thereby reducing the generation of tip artifacts. At the same time, it reduces the induced electric field concentration of the electrode wire 300 and reduces tip heating.

[0111] The electrode wire 300 also includes: an induced current shunt structure for shunting the induced current inside the electrode wire 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 suppresses heating of the electrode and tissue interface, reducing the overall radio frequency heating of the electrode; and the ring electrode 2 has a hollow thin wall, and is provided with magnetic flux holes distributed along its circumference; in an MRI environment, the above-mentioned magnetic flux holes have the function of guiding the passage of magnetic flux lines and reducing the amount of metal used, which can reduce the distortion of the local magnetic field and disperse MRI artifacts, thereby reducing the overall artifact area of the metal part and reducing the self-heating of the metal part. At the same time, the holes enhance the heat dissipation effect.

[0112] In this embodiment, if Figure 1 as well as Figure 7 、 Figure 9 As shown: the limiter induced current shunt structure 101 includes: an electrode sleeve 80, the electrode core shaft 70, and a conductive limiter 60; the conductive limiter 60 has an inner contact hole 62 for the electrode core shaft 70 to pass through and to be in electrical contact with the conductive limiter 60, so that the conductive limiter 60 is electrically connected to the electrode wire 300; Figure 5 As shown, an outer contact surface 61 is arranged at a circumferential position of the conductive limiter 60; the outer contact surface 61 is connected to the inner surface of the electrode sleeve 80. A drug plug 3 is provided at a position of the electrode sleeve 80 near the spiral electrode 1. Among the outer contact surface 61 and the molding surface 63 arranged at the circumferential position of the conductive limiter 60: the outer contact surface 61 is connected to the inner surface of the electrode sleeve 80; a sharp edge structure is formed on the molding surface 63, and the end point of the sharp edge forms a diverter tip 64. The conductive limiter 60 is a columnar structure; the molding surface 63 is a groove formed on the outer peripheral wall of the conductive limiter 60, and the diverter tip 64 is formed at the connection position between the molding surface 63 and the outer contact surface 61.

[0113] The combination of the conductive stopper 60 and the electrode core shaft 70 serves as the first pole of the equivalent capacitor C2, the human body fluid 5 serves as the second pole of the equivalent capacitor C2, and at least a portion of the electrode sleeve dielectric segment 80a on the electrode sleeve 80 serves as the intermediate dielectric material;

[0114] During normal operation, the electric pulses emitted by the IMD are in low-frequency and / or DC form, and the conductive limiter 60 is insulated from the human body fluid 5 so that the electric pulses are transmitted into the tissue; by adjusting the diameter value of the electrode core shaft 70 and the size and number of the conductive limiter 60, the capacitance value of the equivalent capacitor C2 is adjusted, thereby adjusting the ability to shunt the induced current under the high-frequency energy field.

[0115] In this embodiment, if Figure 1 as well as Figure 4 As shown, the ring electrode 2 is located in the electrode head section 100; the outer wire body 40 is nested outside the outer wire body support section 25 of the ring electrode 2, and there is a cavity inside the outer wire body 40, and the inner insulating tube 90 passes through the cavity to ensure that the outer wire body 40 and the inner wire body 30 are insulated from each other;

[0116] The rear fixing section 85a of the electrode insulator 85 is fixedly connected to the inner wall of the contact ring 21 of the ring electrode 2. Furthermore, the inner insulating tube 90 extends into the rear fixing section 85a and is fixed to the inner wall of the contact ring 21 of the ring electrode 2. This provides overall insulation between the ring electrode 2 and the outer conductor body 40 from the inner conductor of the electrode wire. The front fixing end surface 85b of the electrode insulator 85 is bonded and fixed to the inner surface of the electrode sleeve 80.

[0117] In this embodiment, if Figure 1 as well as Figure 6 As shown, the spiral electrode 1 also includes: 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 position; the fixed step 80b of the electrode sleeve 80 and the electrode insulating member 85 form a fixed space toward the end of the spiral electrode tip 1a, and the fixed space is used to accommodate and limit the conductive limiter 60; the outer side of the inner insulating tube 90 is respectively connected to the electrode insulating member 85 and the ring electrode 2; the outer contact surface 61 of the conductive limiter 60 is in contact with the inner cavity wall of the dielectric segment 80a of the electrode sleeve 80, and the outer surface of the dielectric segment 80a contacts the human body fluid 5.

[0118] And, as Figure 9As shown, a transmission latch 80c is provided in the above-mentioned electrode sleeve 80; the transmission latch 80c is transmission-connected to the spiral electrode 1, converting the rotational motion of the spiral electrode 1 into a telescopic motion along the axial direction of the spiral electrode 1; the inner conductor 30 is driven to rotate in the inner insulating tube 90, and the spiral electrode 1 accommodated in the electrode sleeve 80 is driven to telescopic motion through the latch structure.

[0119] In this embodiment, if Figure 1 As shown, 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;

[0120] like Figure 1 ,as well as Figure 14a and Figure 14b As shown, the two conductive limiting members 60 are 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.

[0121] In this embodiment, if Figure 8 The figure shows a longitudinal cross-sectional view of the inner conductor core segment. The inner cavity of the inner conductor 30 is nested in the outer peripheral wall of the inner conductor support segment 70a of the electrode core shaft 70 and is electrically connected to the electrode core shaft 70. At least a portion of the inner conductor support segment 70a is inserted into the inner cavity of the inner conductor 30 to form an inner conductor core segment 103. Under the action of the high-frequency energy field 6, an induced electric field e is induced inside the electrode conductor 300. Due to the action of the inner conductor core segment 103, the induced electric field e is concentrated and induced to gather in the inner conductor core segment 103, thereby changing the distribution of the induced electric field e, dispersing it, and reducing the induced electric field intensity of the electrode tip segment 100. This reduces the induced current density distributed on the spiral electrode 1 or at the tissue interface, thereby reducing heating of the spiral electrode and human tissue, and reducing thermal damage to human tissue caused by the MRI environment.

[0122] 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-pole distance between the inner conductor core segment 103 and the ring electrode 2. The magnetic permeability x of the material of the electrode core shaft 70 is greater than that of the inner conductor 30, thereby increasing the focusing ability of the induced electric field e.

[0123] In this embodiment, if Figure 15a and Figure 15b A schematic diagram of the inner conductor core section is shown; and Figure 18 As shown, the ring electrode 2 and the inner conductor core segment 103 form a ring electrode induced current shunting structure 102; at least a portion of the inner conductor core segment 103 serves as the first pole of the equivalent capacitor C1, and the ring electrode 2 serves as the second pole of the equivalent capacitor C1; under the action of the high-frequency energy field 6, the inner conductor core segment 103 concentrates the induced electric field to enhance the capacitive coupling effect. In this embodiment, the wall thickness of the inner insulating tube 90 and the electrode insulation 85, as well as the length and diameter of the inner conductor core segment 103, can be adjusted to adjust the capacitance value of the equivalent capacitor C1 and the ability of the electrode conductor 300 to shunt the induced current under the high-frequency energy field.

[0124] In this embodiment, if Figure 10 The longitudinal cross-sectional view of the electrode insulator is shown. An electrode insulator 85 is fixed to the inner hole of the ring electrode 2. The inner insulating tube 90 penetrates the electrode insulator 85 and is fixed to the fixing section 85a of the electrode insulator 85. The inner insulating tube 90 and the fixing section 85a provide mutual insulation between the ring electrode 2, the human body fluid 5, and the inner conductor 30. Furthermore, 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 C1.

[0125] During normal operation, the electric pulses emitted by the IMD are in low-frequency and / or DC form, the ring electrode 2 is insulated from the inner wire body 30, the equivalent capacitor C1 is in an open-circuit state, and the electric pulse signal can be transmitted from the inner wire body 30 to the target tissue to complete the stimulation work.

[0126] like Figure 18 A circuit diagram of a medical system exposed to a high-frequency energy field after the electrode leads are connected to the IMD is shown.

[0127] 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 resistance of the external series conductor of the electrode head segment 100 is a series resistor R4; the inner wire body 30 and the ring electrode 2 and a part of the outer wire body 40 constitute an equivalent capacitor C1; the combination of the conductive limiter 60 and the electrode core shaft 70 can serve as the first pole of the equivalent capacitor C2, and the human body fluid 5 serves as the second pole of the equivalent capacitor C2; the spiral electrode 1 forms an equivalent series inductor L1 under the high-frequency energy field 6;

[0128] like Figure 16 Schematic diagram of the pulse flow of normal stimulation pulses after the electrode lead is implanted; and Figure 17 The diagram shows the internal structure of the electrode lead after implantation and exposure to a high-frequency energy field.

[0129] During MRI scanning, a large current I 感应电流 , I 感应电流 The energy is transmitted along the inner conductor 30 represented by the series resistor R1 to the electrode core shaft 70 represented by the series resistor R2. Since the frequency of the high-frequency energy field 6 is extremely high, the impedance of the equivalent capacitor C1 is extremely small, which is approximately a short circuit. 感应电流 Part of the shunted induced current I1 is transferred to the ring electrode 2 through the electrode core shaft 70 and the inner conductor 30 through the equivalent capacitor C1. The shunted induced current I1 is split again at the ring electrode 2, and part of it returns to the IMD through the outer conductor 40 represented by the series resistors R3 and R4. The remaining part I1 flows through the ring electrode 2 to the human body fluid 5; the remaining I1 感应电流 Continue to pass through the conductive limiter 60, at this time the impedance of the equivalent capacitor C2 is extremely small, which is close to a short circuit, I 感应电流 Part of the current I2 flows through the conductive limiter 60 represented by the series resistor R2, passes through the equivalent capacitor C2 and is grounded to the human body fluid 5. 感应电流 The remaining small amount of induced current I3 is transferred through the spiral electrode 1 to the resistance R formed by the human tissue 4. At this time, the series inductor L1 formed by the spiral electrode 1 has a large impedance, further weakening the magnitude of the current I3 flowing to the human tissue 4. The resistance R represented by the human tissue 4 represented by I3 will generate Joule heat, causing the tissue to heat up. Although the induced current I3 still flows to the human tissue, it is extremely small due to the shunt and the obstruction of the inductor L1, resulting in a low current density at the spiral electrode tip 1a or the tissue interface, and the temperature rise at the human tissue 4 is within an acceptable range.

[0130] During normal operation, the electrical pulses emitted by the IMD are usually low-frequency or DC, such as <5 kHz. The impedance of the equivalent capacitor C1 and the equivalent capacitor C2 is large, approximately an open circuit. The inner conductor 30 and the outer conductor 40 are insulated from each other. The electrical pulses emitted by the IMD are all transmitted to the target tissue through the spiral electrode 1, and then transmitted to the ring electrode 2 through the tissue and body fluids to return to the IMD to form a loop. The spiral structure 1b exhibits the properties of a conductor at low frequency and will not weaken the strength of the electrical pulse signal.

[0131] In this embodiment, if Figure 4 As shown, the ring electrode 2 has a contact ring 21; in use, when the electrode wire 300 is implanted in the human body, the contact ring 21 is immersed in body fluids, forming a loop to transmit pulses and sensing signals;

[0132] The outer insulating tube 91 passes through the outer side of the outer conductor 40 and abuts against the outer insulating tube limiting step 23 on the ring electrode 2. The ring electrode 2 is also provided with a first bonding section 22 bonded to the outer insulating tube 91 by an adhesive.

[0133] The first bonding section 22 is located in the middle of the ring electrode 2, and the magnetic flux holes are arranged circumferentially around the first bonding section 22. The magnetic flux holes on the first bonding section 22 are rounded rectangular holes with rounded corners to reduce sharp corners and edges. The magnetic flux holes on the first bonding section 22 are evenly distributed.

[0134] In this embodiment, if Figure 19 The figure shows the distribution of magnetic flux lines of a ring electrode with a magnetic flux hole in a uniform magnetic field.

[0135] According to the principle of magnetic flux continuity, magnetic field lines always tend to flow along paths with high magnetic permeability. The magnetic permeability of metal components is greater than that of surrounding tissue, which guides the magnetic field lines to gather within the metal layer and pass through, causing a strong distortion of the surrounding magnetic field. During MRI scanning, which relies on a uniform magnetic field to encode spatial information, the magnetic field distortion caused by the implanted electrode components manifests as shadows on the MRI image, causing image distortion and affecting the diagnosis of the disease. When the implanted electrode component has a magnetic flux hole, the magnetic flux hole has the function of guiding magnetic flux lines through the metal. The magnetic field lines can pass through the implanted wire component with minimal deformation and more uniformly, reducing the sharp changes in the uniform magnetic field and the generation of MRI artifacts. At the same time, the magnetic flux hole reduces the metal content of the component. The high magnetic permeability χ of the metal is the main factor causing magnetic field changes. Reducing the metal content also greatly reduces the distortion of the local magnetic field, thereby reducing the overall artifact area of the metal component.

[0136] In this embodiment, if Figure 2A cross-sectional view of the internal structure of the connector section in the electrode lead. The connector section 200 is used to connect to the connection interface of the IMD and transmit the electrical pulse signal generated by the IMD to the electrode head section 100 through the signal connection pin 170 and the signal connection ring 150;

[0137] The signal connection pin 170 is connected to the end of the connector shaft 140 on the connector section 200 away from the connector section 200; the connector insulator 130 located in the inner cavity of the signal connection ring 150 and the long seal 111 and the short seal 110 passes through the support shaft 144 and is arranged opposite to the signal connection pin 170 via the insulating member limiting step 145 on the connector shaft 140 to limit the axial extension and contraction position of the connector shaft 140;

[0138] The connector shaft 140 is movably connected to the connector insulating member 130 , and the signal connection needle 170 is rotated to drive the inner wire body 30 to rotate, thereby driving the spiral electrode 1 to rotate and penetrate into the patient's tissue.

[0139] In addition, if Figure 11 The signal connection ring stereoscopic structure diagram shown in FIG; and Figure 12 The three-dimensional structure diagram of the signal connection base is shown. The signal connection ring 150 is fixedly connected to the outer wall of the connector insulation 130; the connection base welding section 154 on the signal connection ring 150 is fixedly connected to the front welding section 161 on the signal connection base 160, and the external conductor 40 is placed on the rear welding section 163 on the signal connection base 160 and fixedly connected thereto;

[0140] The outer insulating tube 91 passes through the outer wire body 40 and is bonded and fixed thereto; the long sealing member 111 located on the outside of the outer insulating tube 91 is snap-connected and positioned with the sealing member limiting protrusion 151 on the signal connecting ring 150; the long sealing member 111 is fixed to the second bonding section 152 on the signal connecting ring 150 by an adhesive; the short sealing member 110 faces one end of the signal connecting ring 150, abuts against the short sealing member limiting surface 155 at the end of the signal connecting ring 150, and is fixedly connected to the outer wall of the connector insulating member 130.

[0141] The above welding structure is as follows:

[0142] The first bonding section 22 is respectively provided with an outer insulating tube limiting step 23 and an outer conductor welding step 24 at positions close to and far from the spiral electrode 1;

[0143] The outer insulating tube limiting step 23 and the outer conductor welding step 24 have rounded transitions. The end of the outer conductor 40 away from the spiral electrode 1 is nested in the outer wall of the outer conductor support section 25 and abuts against the outer conductor welding step 24 to form a first connecting section 1000 through continuous welding. The outer diameter of the end of the outer conductor 40 away from the spiral electrode 1 is similar to the diameter of the outer conductor welding step 24.

[0144] The end of the inner conductor 30 adjacent to the spiral electrode tip 1a, when inserted into the inner conductor support section 70a, has a diameter similar to that of the rear developing ring 51 to reduce the difference in the splicing step; and the inner conductor 30 and the rear developing ring 51 are connected by continuous welding to form a second connecting section 1100.

[0145] like Figure 13 A schematic diagram of the three-dimensional structure of the connector shaft is shown. A connecting step is defined between the insulating member limiting step 145 and the inner conductor welding section 143 on the connector shaft 140. This connecting step is formed by a circular arc transition to avoid a right-angle step. The inner conductor welding section 143, on one end facing the inner conductor 30, is further provided with a tapered transition section to nest the connector shaft 140 within the inner conductor 30 cavity. The inner conductor 30 and the inner conductor welding section 143 are connected by continuous welding to form a third connecting section 1200.

[0146] Of course, this embodiment does not specifically limit the position of the magnetic flux hole. In other embodiments, the signal connection ring 150 on the electrode wire 300 is provided with a magnetic flux hole.

[0147] Of course, this embodiment does not specifically limit the specific structure of the conductive limiter 60. In other embodiments, the conductive limiter 60 is an elliptical structure with an opening on the outer periphery; the diversion tip 64 is formed on the circumferential position of the outer peripheral wall of the conductive limiter 60, and the outer contact surface 61 is a cross-section formed on the outer peripheral wall of the conductive limiter 60.

[0148] Example 2

[0149] A medical device, comprising:

[0150] The machine body is provided with a connection interface; and

[0151] The electrode wire is the electrode wire disclosed in the embodiment. The connector of the electrode wire is plugged into the connection interface.

[0152] 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, the electrode lead (300) comprising: A wire main body section (400) has a first end and a second end opposite to each other, the wire main body section (400) comprising an outer insulating tube (91) and an outer wire body (40), an inner insulating tube (90) and an inner wire body (30) sequentially arranged in the outer insulating tube (91); An electrode head section (100) is provided at a first end of the wire main section (400); and a connector section (200) is provided at a second end of the wire main section (400) and is connected to a medical device via a connector; It is characterized in that The electrode lead (300) further comprises: an induced current shunt structure 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 suppresses heating of the electrode and tissue interface, thereby reducing radio frequency heating of the electrode as a whole; The induced current shunt structure comprises: a limiter induced current shunt structure (101), comprising: an electrode sleeve (80), an electrode core shaft (70), and a conductive limiter (60); the conductive limiter (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 limiter (60), so that the conductive limiter (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).

2. The magnetic resonance compatible implantable electrode lead according to claim 1, characterized in that: The ring electrode (2) has a hollow thin wall, and the ring electrode (2) is provided with magnetic flux holes distributed along its circumferential direction and / or axial direction; and / or, Magnetic flux holes are provided on the ring electrode (2) and the signal connection ring (150).

3. The magnetic resonance compatible implantable electrode lead according to claim 1, wherein: 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; An electrode insulating member (85) is fixed to the inner hole of the ring electrode (2), and a 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).

4. The magnetic resonance compatible implantable electrode lead according to claim 1, wherein: The combination of the conductive stopper (60) and the electrode core shaft (70) can serve as the first pole of the equivalent capacitor C2, the human body fluid (5) serves as the second pole of the equivalent capacitor C2, and at least a portion of the electrode sleeve dielectric section (80a) on the electrode sleeve (80) serves as an intermediate dielectric material; During normal operation, the electric pulses emitted by the IMD are in the form of low frequency and / or DC, and the conductive limiter (60) and the human body fluid (5) are insulated so that the electric pulses are transmitted into the tissue; By adjusting the diameter value of the electrode core shaft (70), the size and number of the conductive limiter (60), the capacitance value of the equivalent capacitor C2 is adjusted, thereby adjusting the ability to shunt the induced current under a high-frequency energy field.

5. The magnetic resonance compatible implantable electrode lead according to claim 4, characterized in that: Also includes: Spiral electrode (1); The spiral electrode (1) 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 fixed step (80b) of the electrode sleeve (80) and the end of the electrode insulating member (85) facing the spiral electrode tip (1a) 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); The outer contact surface (61) of the conductive limiter (60) is in contact with the inner wall of the dielectric section (80a) of the electrode sleeve (80), and the outer surface of the dielectric section (80a) contacts the human body fluid (5).

6. The magnetic resonance compatible implantable electrode lead according to claim 5, characterized in that: A transmission tooth (80c) is provided in the electrode sleeve (80); the transmission tooth (80c) is transmission-connected to the spiral electrode (1) to convert the rotational motion of the spiral electrode (1) into a telescopic motion along the axial direction of the spiral electrode (1); The inner conductor (30) is driven to rotate in the inner insulating tube (90), and the spiral electrode (1) accommodated in the electrode sleeve (80) is driven to move in a telescopic manner through the latching tooth structure.

7. The magnetic resonance compatible implantable electrode lead according to claim 5, characterized in that: The conductive limiter (60) is provided with an outer contact surface (61) and a molding surface (63) at a circumferential position; the outer contact surface (61) is bonded to the inner surface of the electrode sleeve (80); a sharp edge structure is formed on the molding surface (63), and the end point of the sharp edge forms a diversion tip (64).

8. The magnetic resonance compatible implantable electrode lead according to claim 7, wherein: The conductive stopper (60) is a columnar structure; the forming surface (63) is a groove formed on the outer peripheral wall of the conductive stopper (60); the diversion tip (64) is formed at the connection position between the forming surface (63) and the outer contact surface (61); or, The conductive limiting member (60) is an elliptical structure with an opening at the outer peripheral edge; the diversion tip (64) is formed at a circumferential position of the outer peripheral wall of the conductive limiting member (60); and the outer contact surface (61) is a section formed on the outer peripheral wall of the conductive limiting member (60).

9. The magnetic resonance compatible implantable electrode lead according to claim 5, 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 two conductive limiters (60) are 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); During the process of the spiral electrode (1) driving 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.

10. The magnetic resonance compatible implantable electrode lead according to claim 5, characterized in that: 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); at least a portion of the inner conductor body support section (70a) is inserted into the inner cavity of the inner conductor body (30) to form an inner conductor body iron core section (103); under the action of the high-frequency energy field (6), an induced electric field e is induced inside the electrode conductor (300); due to the action of the inner conductor body iron core section (103), the induced electric field e is concentrated, and the induced electric field e is induced to concentrate in the inner conductor body iron core section (103), so as to change the distribution and dispersion of the induced electric field e and reduce the induced electric field intensity of the electrode head section (100), thereby reducing the induced current density distributed on the spiral electrode (1) or the tissue interface, thereby reducing the heating of the spiral electrode and the heating of human tissue, and reducing the thermal damage to human tissue caused by the MRI environment.

11. The magnetic resonance compatible implantable electrode lead according to claim 10, characterized in that: The inner conductor body (30) and the inner conductor body iron core segment (103) constitute a ring electrode induction current shunt structure (102); the induction current shunt structure further comprises: the ring electrode induction current shunt structure (102); At least a portion of the inner conductor core segment (103) serves as the first pole of the equivalent capacitor C1, and the ring electrode (2) serves as the second pole of the equivalent capacitor C1; under the action of the high-frequency energy field (6), the inner conductor core segment (103) gathers the induced electric field to enhance the effect of capacitive coupling.

12. The magnetic resonance compatible implantable electrode lead according to claim 11, characterized in that: 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) are adjusted, thereby adjusting the capacitance value of the equivalent capacitor C1 and adjusting the ability of the electrode conductor (300) to shunt induced current under a high-frequency energy field.

13. The magnetic resonance compatible implantable electrode lead according to claim 11, wherein: The diameter of the inner conductor support section (70a) is larger than the inner cavity diameter of the inner conductor (30), so as to open the inner conductor (30) and reduce the inter-electrode distance between the inner conductor core section (103) and the ring electrode (2); 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 gathering capability of the induced electric field e.

14. The magnetic resonance compatible implantable electrode lead according to claim 11, wherein: 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 C1; During normal operation, the electric pulses emitted by the IMD are in low-frequency and / or DC form, the ring electrode (2) is insulated from the inner conductor (30), the equivalent capacitor C1 is in an open-circuit state, and the electric pulse signal can be transmitted from the inner conductor (30) to the target tissue to complete the stimulation work.

15. The magnetic resonance compatible implantable electrode lead according to claim 2, wherein: The ring electrode (2) has a contact ring (21); in a use state, when the electrode wire (300) is implanted in a human body, the contact ring (21) is immersed in a body fluid environment, forming a loop to transmit pulses and sensing signals; The outer insulating tube (91) passes through the outside of the outer conductor (40) and abuts against the outer insulating tube limiting step (23) on the ring electrode (2); the ring electrode (2) is further provided with a first bonding section (22) bonded to the outer insulating tube (91) by an adhesive; The first bonding section (22) is located in the middle of the ring electrode (2), and the magnetic flux hole is arranged at a circumferential position of the first bonding section (22); and the magnetic flux hole on the first bonding section (22) is a rounded rectangular hole with a rounded shape to reduce sharp corners and edges of the hole.

16. The magnetic resonance compatible implantable electrode lead according to claim 15, characterized in that: The connector section (200) is used for plugging into the connection interface of the IMD, and transmits the electric pulse signal emitted by the IMD through the signal connection pin (170) and the signal connection ring (150), and transmits the electric pulse signal to the electrode head section (100); The signal connection needle (170) is connected to an end of the connector shaft (140) on the connector section (200) away from the connector section (200); the connector insulating member (130) located in the inner cavity of the signal connection ring (150) and the long sealing member (111) and the short sealing member (110) passes through the support shaft (144) and is arranged opposite to the signal connection needle (170) through the insulating member limiting step (145) on the connector shaft (140) to limit the axial extension and contraction position of the connector shaft (140); The connector shaft (140) is movably connected to the connector insulating member (130), and the signal connection needle (170) is rotated to drive the inner wire body (30) to rotate, thereby driving the spiral electrode (1) to rotate and penetrate into the patient's tissue.

17. The magnetic resonance compatible implantable electrode lead according to claim 16, wherein: The signal connection ring (150) is fixedly connected to the outer wall of the connector insulating member (130); the connection seat welding section (154) on the signal connection ring (150) is fixedly connected to the front welding section (161) on the signal connection seat (160); the outer conductor (40) is sleeved on the rear welding section (163) on the signal connection seat (160) and fixedly connected thereto; The outer insulating tube (91) passes through the outer conductor (40) and is bonded and fixed thereto; the long sealing member (111) located outside the outer insulating tube (91) is snap-fitted and positioned with the sealing member limiting protrusion (151) on the signal connection ring (150); the long sealing member (111) is fixed to the second bonding section (152) on the signal connection ring (150) by means of an adhesive; the short sealing member (110) faces one end of the signal connection ring (150), abuts against the short sealing member limiting surface (155) at the end of the signal connection ring (150), and is fixedly connected to the outer wall of the connector insulating member (130); The second bonding section (152) is located in the middle of the signal connection ring (150), and the magnetic flux hole is arranged at a circumferential position of the second bonding section (152); and the magnetic flux hole on the second bonding section (152) is a rounded rectangular hole with a rounded shape to reduce sharp corners and edges of the hole.

18. The magnetic resonance compatible implantable electrode lead according to claim 16, wherein: The first bonding section (22) is provided with an outer insulating tube limiting step (23) and an outer conductor welding step (24) at positions close to and far from the spiral electrode (1). The step is a rounded transition; the outer conductor (40) is close to one end of the spiral electrode (1), is nested in the outer wall of the outer conductor support section (25), and is in contact with the outer conductor welding step (24), and is continuously welded to form a first connection section (1000); and / or, One end of the inner conductor (30) close to the spiral electrode tip (1a) has a diameter similar to that of the rear developing ring (51) when inserted into the inner conductor support section (70a) to reduce the difference in splicing sections; and the inner conductor (30) and the rear developing ring (51) are connected by continuous welding to form a second connecting section (1100); and / or, A connection step difference is provided between the insulating member limiting step (145) and the inner conductor body welding section (143) on the connector shaft (140), and the connection step difference is transitioned by an arc to avoid generating a right-angle step; the inner conductor body welding section (143) is further provided with a tapered transition section at one end facing the inner conductor body (30) so that the connector shaft (140) and the inner conductor body (30) are nested and connected; the inner conductor body (30) and the inner conductor body welding section (143) are connected by continuous welding to form a third connection section (1200).

19. The magnetic resonance compatible implantable electrode lead according to claim 5, characterized in that: The spiral electrode (1) comprises: the spiral electrode tip (1a) and a spiral structure (1b); the spiral electrode tip (1a) is a tip structure, and adopts a smooth transition tip centered on a central parabolic tip structure; In an MRI scanning environment, the smoothly transitioned tip can reduce edge effects and smoothly transition magnetic field changes, thereby reducing tip artifacts; at the same time, it reduces the induced electric field concentration of the electrode wire (300) and reduces tip heating.

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.

Images