Dual-electrode irreversible electroporation ablation needle, ablation method and application

Abstract

The invention discloses a dual-electrode irreversible electroporation ablation needle, an ablation method and application. The method comprises the steps that the number of ablation needles and an electrode combination ablation mode are selected according to the form and the size of a focus; an irreversible electroporation pulse electric signal is applied in a selected electrode combination ablation mode, so that an irreversible electroporation ablation area is formed in the tissue around the needle body, and the focus tissue is ablated; the ablation mode comprises an ablation mode between the first electrode and the second electrode in the single ablation needle; and ablation modes between the first electrodes, between the second electrodes or between the cross electrodes between the different ablation needles. Multiple ablation modes are achieved through the two needles, the ablation mode is flexible, the electric field coverage range is adjustable, incomplete ablation is effectively avoided, the ablation efficiency is improved, the number of the distributed needles is reduced, the consistency, controllability and reliability of ablation are improved while the surgical operation process is simplified, and good clinical application prospects are achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a double-electrode irreversible electroporation ablation needle, an ablation method and application. BACKGROUND

[0002] Irreversible electroporation technology is a non-thermal ablation technology that destroys cell membrane integrity by applying a high-intensity, short-pulse electric field, thereby inducing cell apoptosis or necrosis. Compared with thermal ablation methods such as radiofrequency ablation and microwave ablation, irreversible electroporation technology has less damage to blood vessels, bile ducts and connective tissue, and has obvious advantages in the treatment of tumors in important organs such as the liver and pancreas.

[0003] Existing irreversible electroporation ablation systems mostly use multiple single-electrode ablation needles to form an electric field through electrode combinations between the multiple needles. However, such technical solutions usually have the following disadvantages:

[0004] 1) Multiple ablation needles need to be precisely arranged, which is complex to operate and requires high experience of the operator;

[0005] 2) Positioning errors of multiple needles can easily lead to insufficient electric field coverage, thereby causing incomplete ablation;

[0006] 3) Ablation modes are single and difficult to flexibly adapt to irregular or large-volume lesions;

[0007] Therefore, there is an urgent need for an irreversible electroporation ablation device and method that has a simplified structure, high ablation efficiency, flexible ablation modes, and can effectively avoid incomplete ablation. SUMMARY

[0008] The present application aims to overcome the problems of complex operation, low ablation efficiency and easy incomplete ablation in existing irreversible electroporation ablation technology, and provides a double-electrode irreversible electroporation ablation needle, an ablation method and application.

[0009] The present application integrates two electrodes on a single ablation needle, so that a stable irreversible electroporation electric field can be formed in the tissue, thereby improving the ablation efficiency per unit time. At the same time, different electrode combinations between the two ablation needles form multiple ablation modes, which can flexibly regulate the electric field distribution according to the morphology and volume of the lesion, expand the effective ablation range, reduce the ablation blind area, and avoid the problem of incomplete ablation caused by insufficient electric field coverage.

[0010] In order to solve the problems in the background art, the present application adopts the following technical solutions:

[0011] The double-electrode irreversible electroporation ablation needle comprises:

[0012] An electrode needle body, which is an elongated cylindrical structure extending in the axial direction;

[0013] The first electrode is arranged at the distal end of the electrode needle body and fixedly connected with the electrode needle body by welding to form an integral body.

[0014] The second electrode is arranged at the outer periphery of the electrode needle body and spaced apart from the first electrode along the axial direction of the electrode needle body.

[0015] The insulating isolation part is arranged between the first electrode and the second electrode to achieve electrical isolation therebetween.

[0016] After surface treatment, the first electrode and the second electrode form a micron-level pit structure, and a high-voltage insulating layer is formed between the surfaces of the first electrode and the second electrode by a vacuum vapor deposition process.

[0017] The effective discharge length of the first electrode and the second electrode is 5-15 mm, and the electrode spacing between the first electrode and the second electrode is 10-25 mm.

[0018] Under the action of an external pulse power source, the first electrode and the second electrode can establish a pulse electric field in the external tissue of the ablation needle to form an irreversible electroporation pulse electric field, so that the tissue around the needle body produces an irreversible electroporation effect.

[0019] Further, the insulating isolation part includes an inner insulating layer and an insulating isolation layer, the first electrode is fixedly connected with one end of the electrode needle body by a laser welding or micro-resistance welding process to achieve metallurgical bonding, the electrode needle body is sleeved with the inner insulating layer, the second electrode is sleeved at the outer periphery of the inner insulating layer, and the insulating isolation layer is sleeved on the inner insulating layer between the first electrode and the second electrode.

[0020] Further, the insulating isolation part further includes an outer insulating layer, the outer insulating layer is sleeved on the outer surface of the second electrode, and the effective discharge length of the second electrode is adjusted by covering the outer surface of the second electrode through the outer insulating layer.

[0021] Further, the inner insulating layer, the insulating isolation layer, and the outer insulating layer are made of one or at least two composite materials selected from polyether ether ketone, polyphenylene sulfide, polyxylene, fluoropolymer, and polyimide, and are prepared by a vacuum vapor deposition process; the thickness of the inner insulating layer and the outer insulating layer is controlled to be 0.05-0.1 mm, which meets the withstand voltage margin requirement of 5000V-10000V.

[0022] Further, the first electrode, the insulating isolation layer, and the second electrode are coaxially arranged with the electrode needle body, and the first electrode, the insulating isolation layer, and the second electrode form an equal outer diameter structure with an outer diameter value ranging from 0.8 to 1.2 mm.

[0023] Further, the ablation needle further comprises a structural handle and an electrical connection structure, the structural handle is used to axially fixedly connect the components of the ablation needle by using a pre-embedded injection molding process; and the electrical connection structure is used to connect the first electrode and the second electrode to an external pulse power source respectively.

[0024] The method for ablation by using the double-electrode irreversible electroporation ablation needle comprises the following steps:

[0025] The number of ablation needles and the electrode combination ablation mode are selected according to the shape and volume of the lesion;

[0026] The ablation needle is inserted into the target tissue;

[0027] Irreversible electroporation pulse electrical signals are applied in the selected electrode combination ablation mode, so that an irreversible electroporation ablation area is formed around the tissue of the needle body, thereby ablation is performed on the lesion tissue;

[0028] The electrode combination ablation mode comprises:

[0029] The ablation mode between the first electrode and the second electrode inside a single ablation needle; and

[0030] The ablation mode between the first electrodes, the second electrodes or the cross electrodes of different ablation needles.

[0031] Further, when two ablation needles are used for ablation,

[0032] If the two ablation needles are arranged in parallel, the vertical distance between the axes of the two ablation needles ranges from 5 mm to 20 mm;

[0033] If the two ablation needles are arranged in parallel, the vertical distance between the axes of the two ablation needles ranges from 5 mm to 20 mm;

[0034] Further, the method further comprises:

[0035] During the ablation of the lesion tissue, the electrode combination ablation mode is switched at any time according to the ablation effect, so as to supplement the area not completely covered during ablation.

[0036] The application of the method for ablation by using the double-electrode irreversible electroporation ablation needle, the method is used for ablation of liver tissue or lung tissue.

[0037] The beneficial technical effects of the present application are:

[0038] 1. Compared with the technical idea of increasing the needle spacing to expand the ablation range of the traditional monopolar ablation needle, the present application integrates double electrodes in a single ablation needle, so that a continuous and larger effective ablation area can be formed under a smaller needle spacing, the change of the ablation volume is no longer mainly dependent on the increase of the voltage or the pulse number, the needle spacing becomes a key parameter that can be predicted and designed, under the same pulse parameter conditions, when the double needle spacing is 15-20 mm, the effective ablation volume formed by the present application is significantly larger than that of the comparative scheme using the traditional monopolar needle ablation mode, by reasonably selecting the spatial distance between the double needles, the quantitative regulation of the ablation area volume can be realized without increasing the pulse energy, the ablation effect of the present application is not a simple parameter superposition or linear amplification, but an unexpected technical effect produced by the synergistic effect of the bipolar single needle structure and the needle spacing

[0039] 2. The bipolar single needle structure of the present application can realize various ablation modes through two needles, the ablation mode is flexible, the electric field coverage range is adjustable, the incomplete ablation is effectively avoided, the ablation efficiency is improved, the number of needle arrangement is reduced, the consistency, controllability and reliability of ablation are improved while the operation process is simplified, and the present application has good clinical application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The bipolar irreversible electroporation ablation needle structure provided for the embodiment of the present application is shown in the figure;

[0041] Figure 2 The axial cross-sectional view of the distal end A-A section of the ablation needle in the present application is shown in the figure; Figure 1

[0042] The planar exploded view of the present application is shown in the figure; Figure 3 Figure 2 The B-B radial cross-sectional view of the present application is shown in the figure;

[0043] Figure 4 (a) is the B-B radial cross-sectional view of the present application; Figure 2

[0044] Figure 4 (b) is the C-C radial cross-sectional view of the present application; Figure 2

[0045] Figure 4 (c) is the D-D radial cross-sectional view of the present application; Figure 2

[0046] Figure 5 The handle schematic diagram of the bipolar irreversible electroporation ablation needle structure provided for the embodiment 1 of the present application is shown in the figure;

[0047] Figure 6 is the ablation mode formed between the first electrode and the second electrode inside a single ablation needle provided by the embodiment 2 of the present application;

[0048] Figure 6 (b) is the parallel ablation mode that two ablation needles simultaneously and respectively perform internal ablation provided by the embodiment 2 of the present application;​​​​

[0049] Figure 7(a) shows the ablation mode between the first electrodes of the two ablation needles provided in Embodiment 2 of the present invention;

[0050] Figure 7(b) shows the ablation mode between the second electrodes of the two ablation needles provided in Embodiment 2 of the present invention;

[0051] Figure 8(a) shows the ablation mode between the first electrode of one ablation needle and the second electrode of another ablation needle provided in Embodiment 2 of the present invention;

[0052] Figure 8(b) shows the ablation mode between the second electrode of one ablation needle and the first electrode of another ablation needle provided in Embodiment 2 of the present invention;

[0053] Figure 9 This is a schematic diagram of the bipolar electric field inside the single needle and the composite electric field between the two needles provided in this embodiment of the invention;

[0054] Figure 10(a) shows the liver ablation area ablated using the ablation needle of the present invention in Embodiment 6 of the present invention;

[0055] Figure 10(b) shows the liver ablation area ablated by the ablation needle in the comparative example of Embodiment 6 of the present invention;

[0056] Figure 11(a) shows the lung ablation area ablated using the ablation needle of the present invention in Embodiment 6 of the present invention;

[0057] Figure 11(b) shows the lung ablation area ablated by the ablation needle in Example 6 of the present invention. Detailed Implementation

[0058] The following, in conjunction with the accompanying drawings, provides a clearer and more complete description of the dual-electrode irreversible electroporation ablation needle, ablation method, and applications provided by the present invention:

[0059] Example 1

[0060] like Figure 1 , 2 As shown in Figure 3, the dual-electrode irreversible electroporation ablation needle provided in this embodiment includes an electrode needle body 22, a first electrode 2, a second electrode 4, an insulating layer 3, an inner insulating layer 23, an outer insulating layer 6, a silicone wire 8, and a structural handle 7, etc.

[0061] Specifically, the electrode needle body 22 is made of medical-grade 304 stainless steel, with an outer diameter of 0.5mm–0.75mm; the preferred outer diameter of the electrode needle body is 0.60-0.7mm, and the total length of the needle body is 150–300 mm, of which the effective working section (including the puncture tip to the insulated starting point of the proximal end of the handle) is 150–250 mm, adapting to the clinical needs of different body surface-target area depths.

[0062] The electrode needle body 22 and the first electrode 2 are positioned by a precision tool to realize metallurgical bonding by a laser welding or a micro-resistance welding process, realize precise concentric assembly, have high mechanical connection strength, and can effectively avoid arc discharge or local overheating phenomenon caused by loose contact in the pulse discharge process; the second electrode 4 is a thin-walled tubular electrode structure sleeved on the outer periphery of the electrode needle body 22, the first electrode 2 and the second electrode 4 are coaxial in the length direction to ensure the axial symmetry of the electric field distribution and the consistency of the pulse energy transmission; the inner insulation layer 23 is sleeved on the outer periphery of the electrode needle body 22 and is coaxial with the electrode needle body 22; the insulation isolation layer 3 is sleeved on the outer periphery of the inner insulation layer 23, and the two ends of the insulation isolation layer 3 are respectively coincident with the edges of the first electrode and the second electrode, and are closely connected, which can effectively avoid electric short circuit and arc phenomenon.

[0063] The distal end extension area of the first electrode forms a puncture tip 1, and the puncture tip 1 can have a structure of a triangular pyramid tip, a conical tip, an inclined surface tip, a multi-edge tip, and the like. In this embodiment, the puncture tip is preferably a triangular pyramid tip, which is formed by precisely grinding a medical-grade stainless steel. The tip is formed by three cutting blade surfaces distributed at equal intervals. The three cutting blade surfaces converge at the tip to form a sharp puncture point. This structure has extremely low puncture force and excellent axial stability, which can ensure that the needle body enters the target lesion along the predetermined trajectory.

[0064] The first electrode 2 and the second electrode 4 of the ablation needle are voltage transmission areas, the first electrode 2 is a first high-voltage transmission area, the second electrode 4 is a second voltage transmission area, the first electrode 2 and the second electrode 4 are insulated by the inner insulation layer and the insulation isolation layer, the first electrode and the second electrode are strictly electrically isolated, which ensures that the voltage gradient between the two electrodes is steep and uniform, thereby precisely constructing a transmembrane potential threshold region in the target tissue.

[0065] The first electrode 2 and the second electrode 4 are made of medical-grade 304 stainless steel or other austenitic stainless steel materials, and are formed by laser micro-machining. The two electrodes are coaxially nested along the axis of the electrode needle body. After the surfaces of the first electrode 2 and the second electrode 4 are ground and passivated by electrolytic treatment, a micron-level pit structure is formed. This treatment not only improves the ultrasonic imaging effect, but also further reduces local electric field distortion and tissue Joule heat accumulation. The outer diameters of the first electrode 2 and the second electrode 4 are the same, and the effective discharge lengths of the two electrodes are the same, ranging from 5 to 15 mm. The electrode length and electrode spacing are obtained by considering the controllability of ablation volume and the efficiency of cell electroporation based on animal experiments and clinical data. The two electrodes are respectively connected to the positive and negative high-voltage output terminals of the pulse power supply, or dynamically switched to the same polarity high-voltage output according to the multi-mode ablation requirements. The spacing design ensures sufficient electric field coverage while effectively avoiding the risk of arc breakdown between the electrodes.

[0066] The first electrode, the insulating isolation layer, the second electrode, and the electrode needle body are coaxially arranged, and the first electrode, the insulating isolation layer, and the second electrode form an equal-diameter structure with an outer diameter value ranging from 0.8 to 1.2 mm. This equal-diameter tube has low processing difficulty, high processing precision, is suitable for large-scale automated production, has high yield, and greatly reduces the puncture resistance through the compact integration of the first electrode and the second electrode. It is suitable for deep tissue ablation sensitive to damage and is more likely to achieve uniformity of electric field and consistency of minimally invasive treatment.

[0067] The micron-level pit structure on the surface of the first electrode 2 and the second electrode 4 can increase the contact area with the insulating coating, form a mechanical fitting effect, significantly improve the adhesion strength and bonding firmness of the coating, and use polyether ether ketone, polyphenylene sulfide, polyxylene, fluoropolymer, polyimide material spraying or other film coating processes to form a high-voltage insulating layer. Preferably, Parylene coating is used. Vacuum vapor deposition process is used to form Parylene coating, which has excellent shape retention. Unlike traditional spraying or dipping processes, Parylene molecules can penetrate and uniformly cover the micro-pores on the surface of the electrode and the step edges at the electrode connection, eliminating the risk of 'charge accumulation' and'sharp discharge' caused by uneven coating, and ensuring the insulation reliability in a 3000V or higher steep pulse environment.

[0068] The material of the insulation isolation layer 3 is one of polyether ether ketone, polyphenylene sulfide, poly (dimethylphenylene), fluoropolymer, polyimide or a composite material of at least two of them, preferably a poly (dimethylphenylene) coating, and the inner insulation layer is concentrically and coaxially attached with consistency, prepared by a vacuum vapor deposition process, with excellent dielectric strength, biological inertia and long-term implant stability, effectively blocking the leakage current between the electrodes to protect the pulse waveform; the material of the inner insulation layer 23 is consistent with the insulation isolation layer 3, and is also preferably a poly (dimethylphenylene) coating, with a wall thickness of 0.05-0.1mm, which can withstand a breakdown voltage margin requirement of 5000V-10000V; the inner insulation layer 23 and the insulation isolation layer 3 cooperate in double layers, which not only ensures the dielectric integrity between the electrodes, but also maintains the ultra-fine diameter characteristics of the needle body, meeting the flexibility and targeting accuracy requirements during transcutaneous puncture.

[0069] The outer insulation layer 6 uniformly covers the outer surface of the second electrode 4 and can also be prepared by a poly (dimethylphenylene) vacuum vapor deposition process, with a thickness of 0.05-0.1mm, and its distal end extends to a distance of 5-15mm from the distal edge 5 of the second electrode 4, and its proximal end is precisely connected with the handle sealing interface; the outer insulation layer 6 and the second electrode 4 interface have no micro gap and no bubbles, and can withstand repeated high temperature and high pressure sterilization without peeling off.

[0070] In addition, the surface of the outer insulation layer can also be provided with a dark black marker band 5, which is aligned with the axial center line of the outer insulation layer, and the length of the marker band is 0.5-10mm, and the distance between the marker bands is 5-10mm, to facilitate the real-time observation of the insertion depth of the ablation needle by the doctor during the operation.

[0071] The structural handle 7 is the proximal end component of the double-electrode ablation needle, which is the proximal end fixing part of the ablation needle. The present application uses a pre-embedded injection molding process to realize the axial fixed connection of each component of the needle body by using an injection molding cavity, which can eliminate the mechanical error of manual mechanical assembly, improve the production efficiency of the product, and exclude the air gap by seamless solid packaging, greatly improving the dielectric strength of the handle interior and effectively preventing the internal arc or flashover phenomenon that may occur under a high-voltage pulse of 3000V or above, thereby providing a standardized electric field distribution basis for steep pulse ablation.

[0072] As shown in Figure 5 Fig. 7, the material of the structural handle 7 in this embodiment is ABS resin, and it has a coupling point 71 and a lead wire 73. The coupling point 71 has two places, which are respectively coupled to the lead wire 73 of the first electrode and the second electrode through a precise coupling method. The coupling method can be crimping, welding or elastic insertion, etc. The preferred method in this embodiment is tin soldering process. The coupling point is covered with an insulating material and fixed with a small amount of glue, and it is continuously and smoothly connected with the inner insulation layer 23.

[0073] The silicone wire 8 and the plug 9 are external connection components of the probe. The silicone wire 8 is led out through the sealed interface at the rear end of the structural handle 7 and is firmly connected with the plug 9 through welding. The plug 9 can be connected with the pulse generator and used immediately.

[0074] Under the action of the external pulse power source, the first electrode and the second electrode can establish an irreversible electroporation pulse electric field in the external tissue of the ablation needle to cause irreversible electroporation effect on the tissue around the needle body.

[0075] In this embodiment, as an example, when the ablation needle is assembled, the following steps are included:

[0076] The first electrode 2, the second electrode 4 and the electrode needle body 22 are respectively made into electrode raw materials with required sizes through precise wire drawing, laser cutting, grinding and other processes, as shown in FIG. 2. Figure 3

[0077] The first electrode 2 and the electrode needle body 22 are firmly connected through laser welding process to realize coaxial precise butt joint.

[0078] The first electrode 2, the electrode needle body 22 and the second electrode 4 after welding are placed into a vacuum cavity to implement polydimethylbenzene vapor deposition to obtain an inner insulation layer 23, an outer insulation layer 6 and an insulation isolation layer 3.

[0079] A high-pressure silicone wire is welded at a position 10-15 mm away from the proximal edge of the second electrode 4. Then the proximal end of the electrode needle body 22 (with the first electrode 2 welded) is passed through the distal end side of the second electrode 4 and coincides with the proximal edge of the insulation isolation layer 3, and the edges are tightly connected. Then a proper amount of UV glue is used to fix the proximal end of the second electrode 4, and after curing, the outer covering heat shrink sleeve is heat shrunk and sealed to enhance the mechanical protection and insulation performance.

[0080] Another high-pressure silicone wire is welded at a position 15-20 mm away from the proximal edge of the electrode needle body 22 (with the first electrode 2 welded). Then the preset coupling point 71 is sealed with a small amount of glue (UV glue), and after curing, the outer covering heat shrink sleeve is heat shrunk and sealed to enhance the mechanical protection and insulation performance.

[0081] The proximal end of the ablation needle 10 is placed into a handle injection mold to be integrally covered at the proximal end of the needle body through a pre-embedded injection process to complete the preparation of the structural handle 7.

[0082] Finally, the welding of the plug 9 to the silicone wire 8 led out through the sealed interface at the rear end of the structural handle is completed, and the insulation sleeve is heat shrunk and sealed.

[0083] Embodiment 2

[0084] ​The embodiment provides a system for ablation by using the double-electrode irreversible electroporation ablation needle in the embodiment 1, comprising:

[0085] at least two double-electrode irreversible electroporation ablation needles as described in the embodiment 1;

[0086] a pulse power supply;

[0087] a control module for controlling the pulse power supply to selectively output a pulse electrical signal between different electrodes of the ablation needles;

[0088] wherein, by the control of the control module, the system can form multiple irreversible electroporation ablation modes within a single ablation needle and between different ablation needles.

[0089] Specifically, the ablation modes at least include:

[0090] an ablation mode between the first electrode and the second electrode within a single ablation needle;

[0091] an ablation mode between the first electrodes, the second electrodes or the cross electrodes of different ablation needles.

[0092] Further, a method for ablation by using the double-electrode irreversible electroporation ablation needle in the embodiment 1 can be considered, comprising the following steps:

[0093] selecting the number of ablation needles and the electrode combination ablation mode according to the morphology and volume of the lesion;

[0094] inserting the ablation needles into the target tissue;

[0095] applying irreversible electroporation pulse electrical signals in the selected electrode combination ablation mode to form irreversible electroporation ablation regions around the needle body, so as to ablate the lesion tissue;

[0096] wherein, the electrode combination ablation mode includes:

[0097] an ablation mode between the first electrode and the second electrode within a single ablation needle; and

[0098] an ablation mode between the first electrodes, the second electrodes or the cross electrodes of different ablation needles.

[0099] In addition, it can also be considered that during the ablation of the lesion tissue, the electrode combination ablation mode is switched at any time according to the ablation effect, so as to supplement the area not completely covered during ablation, reduce the ablation blind area and improve the ablation integrity.

[0100] It should be noted that when two ablation needles are needed to cooperate in ablation, the pulse power supply is controlled by the control module to output a pulse electrical signal between different electrodes, and at least six ablation modes can be formed:

[0101] As shown in Fig. 6(a), a single ablation needle forms an ablation pattern between the first electrode and the second electrode inside the needle;

[0102] As shown in Fig. 6(b), two ablation needles simultaneously form a parallel ablation pattern of internal ablation respectively;

[0103] As shown in Fig. 7(a), an ablation pattern between the first electrodes of two ablation needles;

[0104] As shown in Fig. 7(b), an ablation pattern between the second electrodes of two ablation needles;

[0105] As shown in Fig. 8(a), an ablation pattern between the first electrode of one ablation needle and the second electrode of another ablation needle;

[0106] As shown in Fig. 8(b), an ablation pattern between the second electrode of one ablation needle and the first electrode of another ablation needle.

[0107] It should be noted that when ablation is performed with two ablation needles, if the two ablation needles are not parallel, there will also be an ablation area, but the shape and volume of the ablation volume will change, and in order to prevent short circuit caused by breakdown between the electrodes, a minimum distance of 5 mm must be provided between the two ablation needles, and for the two ablation needles existing in the six ablation patterns, due to the existence of an included angle between the two ablation needles, the ablation area will be asymmetric and deformed, therefore, in use, it is first recommended to arrange the needles in parallel, which is beneficial to forming a symmetric ablation area and preventing the existence of a non-complete ablation area; on the other hand, in special application environments, such as anatomical position limitations (such as the existence of large blood vessels interfering with the arrangement of the needles in parallel) or tumor position limitations (the roots cannot be arranged in parallel), the needles can also be arranged non-parallelly to achieve ablation.

[0108] If the two ablation needles are arranged in parallel, the perpendicular distance between the axes of the two ablation needles ranges from 5 to 20 mm;

[0109] If the two ablation needles are arranged non-parallelly, the minimum distance between the axes of the two ablation needles is 5 mm; here, it can be considered to measure before ablation, and if breakdown and short circuit occur, an alarm will be given to remind the user to rearrange the needles and detect again until no breakdown occurs before ablation is performed.

[0110] Through the selection and combination of the above-mentioned various ablation modes, the ablation range can be effectively expanded and the ablation integrity can be improved.

[0111] Example 3

[0112] To further illustrate the significant technical effects of the present application in practical application, especially the innovation and superiority relative to the existing irreversible electroporation ablation mode, the following compares the "double-needle-bipolar ablation mode" of the present embodiment with the traditional multi-single-needle ablation mode disclosed in the existing patent US 2009 / 0281477, in combination with specific parameter settings.

[0113] (1) Comparison condition settings:

[0114] Tissue model: a homogeneous tissue model with electrical parameters equivalent to liver parenchymal tissue (conductivity about 0.2-0.3 S / m);

[0115] Pulse parameters: pulse voltage 2500-3000 V, pulse width 70-100 μs, pulse number 80 times;

[0116] Needle arrangement:

[0117] Comparison scheme (US 2009 / 0281477): two traditional single-electrode ablation needles are used, with a needle spacing of 15-20 mm, and an electric field is formed between the needles;

[0118] Embodiment scheme: two double-electrode irreversible electroporation ablation needles are used, each forming a bipolar electric field inside the ablation needle, and a composite electric field is formed between the two needles;

[0119] (2) Determination of optimal electrode exposure length:

[0120] Through finite element simulation and ex vivo tissue experiments, it is found that when the exposure length of a single electrode of the double-electrode ablation needle of the present application is controlled at 8-12 mm (preferably about 10 mm):

[0121] The circumferential electric field distribution of the needle body is the most uniform;

[0122] The effective volume reaching the irreversible electroporation threshold (>600 V / cm) in the tissue is the largest;

[0123] The electric field distortion and energy waste at the electrode end are significantly reduced.

[0124] (3) Comparison results of ablation effect:

[0125] Under the above optimal electrode exposure length conditions, the comparison results are as follows:

[0126] Effective ablation volume:

[0127] US 2009 / 0281477 mode: an approximately ellipsoidal ablation zone is formed, with obvious axial electric field attenuation;

[0128] The embodiment mode: under the action of the single-needle internal bipolar electric field and the double-needle composite electric field, a continuous and superimposed high-strength electric field area is formed.

[0129] Under the same pulse parameters, the irreversible electroporation effective ablation volume of the present application mode is about 2 times more than that of the comparative scheme.

[0130] Ablation integrity:

[0131] The comparative scheme is prone to have an "ablation blind area" lower than the threshold value in the needle area and the edge area.

[0132] The ablation needle of the present application can significantly reduce or eliminate the above-mentioned blind area through the superposition of multiple ablation modes.

[0133] Energy utilization efficiency:

[0134] The ablation needle of the present application has a significantly reduced energy required per unit volume of tissue due to the shortened electrode spacing and concentrated electric field.

[0135] When the same or larger ablation range is achieved, the total pulse energy required is lower than that of the comparative scheme.

[0136] Compared with the prior art represented by US 2009 / 0281477, the present application has at least the following substantial innovation effects:

[0137] From the "needle-needle monopolar field" to the "single-needle bipolar field + double-needle composite field" ablation paradigm change;

[0138] Under the optimal electrode exposure length, a significant technical effect of about 2 times increase in ablation volume is achieved, and this effect is not simply obtained by parameter amplification;

[0139] While reducing the number of needle arrangements and operation complexity, the ablation efficiency and consistency are significantly improved.

[0140] Embodiment 4

[0141] In order to further quantify the influence of the spatial distance (D) between the two ablation needles in the double-needle-bipolar ablation mode in embodiment 3 on the irreversible electroporation ablation area volume, verify its controllability and technical effect superior to the prior art, the following embodiment is carried out.

[0142] (1) Experiment and simulation conditions:

[0143] Ablation needle parameters:

[0144] Ablation needle type: double-electrode irreversible electroporation ablation needle described in embodiment 1;

[0145] Single electrode exposure length: 10 mm;

[0146] Axial distance between the first electrode and the second electrode: fixedly set;

[0147] Needle-to-needle distance (D): defined as the shortest distance between the axes of the two ablation needles;

[0148] Take 10 mm, 15 mm, 20 mm, and 25 mm respectively;

[0149] Tissue model and pulse parameters:

[0150] Tissue model: a homogeneous electrical model equivalent to liver parenchymal tissue;

[0151] Pulse voltage: 2800 V;

[0152] Pulse width: 90 μs;

[0153] Pulse number: 80 times;

[0154] Evaluation criteria:

[0155] The volume with an electric field strength greater than the irreversible electroporation threshold (about 600 V / cm) in the tissue is defined as the effective ablation volume (V).

[0156] (II) Experimental and simulation results:

[0157] Under the condition of keeping the electrode exposure length and pulse parameters constant, the effective ablation volume results corresponding to different needle-to-needle distances are as follows:

[0158] Needle-to-needle spacing D (mm) Effective ablation volume V (relative value) Ablation zone morphology characteristics 10 mm 1.0 V0 Highly overlapped, electric field concentrated, but local gradient too high 15 mm 1.8 V0 Form a continuous whole ablation zone, the most uniform electric field distribution 20 mm 2.1 V0 The largest ablation volume, balanced axial and radial coverage 25 mm 1.4 V0 Central region electric field attenuation, the emergence of ablation weak zone

[0159] wherein V0 represents the reference ablation volume obtained under the condition of D = 10 mm.

[0160] (III) Quantitative relationship analysis:

[0161] The results show that:

[0162] Under the bipolar single-needle structure, the effective ablation volume V and the needle-to-needle distance D present an obvious nonlinear relationship, rather than a monotonic increase with the distance;

[0163] When D is located in the range of 15-20 mm, the single-needle internal bipolar electric field and the composite electric field between the double needles produce a synergistic enhancement effect, which significantly expands the tissue volume reaching the irreversible electroporation threshold;

[0164] When D is too small, the two needle electric fields are highly overlapped, and the energy utilization efficiency is reduced;

[0165] When D is too large, the electric field coupling between the double needles is weakened, and the central region is prone to be below the irreversible electroporation threshold.

[0166] (IV) Advantages compared with prior art:

[0167] Compared with the technical idea of increasing the needle spacing to expand the ablation range in the traditional monopolar ablation needle, the present application, through the bipolar single-needle structure, makes it possible to:

[0168] form a continuous and larger effective ablation area under a smaller needle spacing;

[0169] the change in ablation volume is no longer mainly dependent on the increase in voltage or pulse number;

[0170] the needle spacing becomes a key parameter that can be predicted and designed.

[0171] Under the same pulse parameter conditions, when the double-needle spacing is 15-20 mm, the effective ablation volume formed by the present application is significantly larger than that of the comparative scheme using the traditional monopolar needle ablation mode;

[0172] (V) Conclusion of the embodiment:

[0173] The above embodiment shows that, under the bipolar single-needle irreversible electroporation ablation structure, by reasonably selecting the spatial distance between the double needles, the quantitative regulation of the ablation area volume can be realized without increasing the pulse energy.

[0174] This quantitative relationship further proves that the ablation effect of the present application is not a simple parameter superposition or linear amplification, but an unexpected technical effect produced by the synergistic action of the bipolar single-needle structure and the needle spacing.

[0175] Embodiment 5

[0176] To further illustrate the significant technical effect embodied in the present application in the synergistic regulation of pulse energy parameters (especially pulse voltage) and double-needle spacing, and to compare it with the monopolar needle ablation mode disclosed in the prior art US 2009 / 0281477, the following embodiment is proposed.

[0177] (I) Purpose of the embodiment:

[0178] Under the same or lower pulse energy conditions, by optimizing the spatial distance between the bipolar single needles, the present application can still obtain an effective ablation volume that is significantly larger than that of the existing monopolar needle ablation mode, thereby proving that this effect is not derived from simply increasing the energy, but is the result of the synergistic action of the structure and parameters;

[0179] (II) Experimental and simulation condition settings:

[0180] Ablation needle structure:

[0181] The present embodiment scheme: two double-electrode irreversible electroporation ablation needles;

[0182] Comparative solution (US 2009 / 0281477): two traditional monopolar irreversible electroporation ablation needles;

[0183] Electrode parameters:

[0184] Single electrode exposure length of the ablation needle of the present embodiment: 10 mm;

[0185] Exposure length of the monopolar needle of the comparative solution: 20 mm;

[0186] Needle-to-needle spacing distance (D) settings:

[0187] The present embodiment solution: D = 15 mm and D = 20 mm;

[0188] Comparative solution: D = 20 mm;

[0189] Pulse parameters (energy variables):

[0190] Pulse voltage: 2200 V, 2600 V, 3000 V, respectively; pulse width: 90 μs; pulse number: 80 times;

[0191] Evaluation index:

[0192] The tissue volume with an electric field strength in the tissue ≥ irreversible electroporation threshold (about 600 V / cm) is defined as the effective ablation volume V;

[0193] The pulse energy required per unit ablation volume is used as an evaluation index of energy utilization efficiency.

[0194] (Three), results and comparative analysis:

[0195] Under different pulse voltage conditions, the effective ablation volume results obtained by the present embodiment solution and the comparative solution are shown in the following table:

[0196] Pulse voltage (V) Ablation needle Double needle spacing D (mm) Effective ablation volume (relative value) 2200 US 2009 / 0281477 monopolar needle 20 0.6 V0 2200 The bipolar ablation needle of the present invention 15 1.2 V0 2600 US 2009 / 0281477 monopolar needle 20 1.0 V0 2600 The bipolar ablation needle of the present invention 15 1.9 V0 3000 US 2009 / 0281477 monopolar needle 20 1.4 V0 3000 The bipolar ablation needle of the present invention 20 2.1 V0

[0197] Among them, V0 represents the reference ablation volume obtained under the condition of 2600 V and the comparative solution.

[0198] (Four), synergistic optimization law analysis:

[0199] From the above results, it can be seen that:

[0200] Under the condition of a lower pulse voltage (2200 V), the traditional monopolar needle ablation mode is difficult to form a continuous and effective irreversible electroporation region;

[0201] The present application can form a stable superimposed composite electric field between the two needles even under a lower pulse energy through the bipolar single-needle structure, thereby obtaining a significantly larger ablation volume;

[0202] When the pulse voltage and the double-needle spacing are both within the respective preferred ranges (2600-3000 V, D = 15-20 mm), the effective ablation volume shows a significant transition increase;

[0203] This increase cannot be achieved by simply increasing the voltage or simply adjusting the needle spacing alone, reflecting the synergistic optimization effect between energy parameters and spatial parameters.

[0204] (Five), the significant technical effects relative to US 2009 / 0281477:

[0205] Compared with the monopolar needle ablation technology disclosed in US 2009 / 0281477, the present application has at least the following significant advantages:

[0206] Under the same pulse voltage conditions, the present application obtains a significantly larger effective ablation volume;

[0207] To achieve the same ablation volume target, the present application requires lower pulse voltage and higher energy utilization efficiency;

[0208] The present application achieves ablation effect improvement through parameter synergy rather than energy stacking, effectively reducing the potential risk to surrounding tissues.

[0209] Therefore, in a bipolar single-needle irreversible electroporation ablation system, by simultaneously optimizing the pulse energy parameters and the double-needle spacing, the effective ablation area can be significantly expanded while reducing energy input; this effect cannot be achieved in existing monopolar needle ablation technology, and belongs to the unexpected technical progress made by the present application in the ablation mechanism and application level.

[0210] Example 6

[0211] To further verify the universality and superiority of the present application in different clinical indications, especially the ablation stability in different tissue electrical properties and anatomical environment conditions, the following selects liver tissue and lung model as representative indications to compare the monopolar needle irreversible electroporation ablation mode disclosed in US 2009 / 0281477.

[0212] (I) Purpose of the design of the example:

[0213] Different organs and tumor tissues have significant differences in electrical conductivity, gas content, blood vessel distribution, and tissue uniformity:

[0214] The liver tissue has high electrical conductivity and relatively uniform tissue, which is suitable for forming a stable electric field;

[0215] The lung tissue has high gas content, low electrical conductivity, and is highly non-uniform, and the electric field is prone to distortion.

[0216] This example aims to prove that:

[0217] The bipolar single needle structure of the present application can form stable and predictable irreversible electroporation ablation regions under different tissue conditions;

[0218] Compared with US 2009 / 0281477, the present application shows better ablation integrity and effective ablation volume under different indications.

[0219] (II) Experimental condition setting:

[0220] Tissue model setting:

[0221] Pig liver

[0222] Pig lung

[0223] Ablation needle and cloth needle method:

[0224] This example scheme: two double-electrode irreversible electroporation ablation needles, double-needle spacing D = 20 mm;

[0225] Comparison scheme (US 2009 / 0281477): two traditional monopolar ablation needles, needle spacing 20 mm;

[0226] Electrode and pulse parameters:

[0227] Exposure length of single electrode of the present application: 10 mm;

[0228] Exposure length of monopolar needle of the comparison scheme: 10 mm;

[0229] Pulse voltage: 1500 V;

[0230] Pulse width: 90 μs;

[0231] Pulse number: 80 times;

[0232] Evaluation index:

[0233] Effective ablation volume under CT image;

[0234] Ablation region continuity and whether there is an ablation blind area.

[0235] (III) Comparison results of liver tissue:

[0236] In the liver tissue model:

[0237] The present application forms a continuous electric field distribution higher than the threshold value in the needle region through the superposition of the single-needle internal bipolar electric field and the double-needle composite electric field, 1.40 cm x 3.41 cm;

[0238] US 2009 / 0281477 The pattern can form a substantially continuous ellipsoidal ablation region, but there is a significant electric field gradient drop in the mid-axis region between the needles, 1.25cm x 2.57cm.

[0239] (Four), lung tissue contrast results:

[0240] In the lung tissue model, due to the influence of tissue non-uniformity and gas-containing structure:

[0241] The bipolar single-needle structure of the present application can first form a stable irreversible electroporation region locally in the single needle, 1.14cm x 2.56cm;

[0242] The needle-needle monopolar electric field relied on by US 2009 / 0281477 has a significant break in the region between the needles, which is easy to form a large area of ablation blind area below the threshold, and the longest distance of the ablation region is 0.9cm;

[0243] (Five), cross-indication consistency analysis:

[0244] The results of the liver and lung models can be seen as follows:

[0245] The ablation effect of the present application is not sensitive to changes in tissue electrical parameters, and has stronger indication generalization ability;

[0246] The bipolar single-needle structure reduces the dependence on tissue uniformity and accurate needle placement between needles;

[0247] Compared with US 2009 / 0281477, the present application can still maintain ablation integrity and predictability in complex tissue environment.

[0248] The above examples further prove that the present application not only performs superior performance in a single tissue model, but also significantly outperforms existing monopolar needle irreversible electroporation ablation technology in different clinical indications (such as liver, lung).

[0249] The cross-indication consistency effect shows that the present application has higher clinical applicability and wider popularization value.

[0250] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without deviating from the principles of the present application, those skilled in the art can make equivalent changes or replacements to related technical features, and the technical solutions after these changes or replacements will fall within the protection scope of the present application.

Claims

1. A bipolar irreversible electroporation ablation needle, characterized in that, The ablation needle comprises: an electrode needle body, which is an elongated cylindrical structure extending in an axial direction; a first electrode, which is arranged at a distal end of the electrode needle body and fixedly connected to the electrode needle body in an integral manner by welding; a second electrode, which is arranged at an outer periphery of the electrode needle body and spaced apart from the first electrode along the axial direction of the electrode needle body; an insulating isolation part, which is arranged between the first electrode and the second electrode and used to achieve electrical isolation therebetween; after surface treatment between the first electrode and the second electrode, a micron-level pit structure is formed, and a high-voltage insulating layer is formed on the surface between the first electrode and the second electrode by a vacuum vapor deposition process; an effective discharge length of the first electrode and / or the second electrode is 5-15 mm, and an electrode spacing between the first electrode and the second electrode is 10-25 mm; under the action of an external pulse power source, the first electrode and the second electrode can establish a pulse electric field in the external tissue of the ablation needle and form an irreversible electroporation pulse electric field, so as to cause irreversible electroporation effect of the tissue around the needle body.

2. The dual electrode irreversible electroporation ablation needle of claim 1, wherein, The insulating isolation part comprises an inner insulating layer and an insulating isolation layer, the inner insulating layer is sleeved on the outer periphery of the electrode needle body, the second electrode is sleeved on the outer periphery of the inner insulating layer, and the insulating isolation layer is sleeved on the inner insulating layer between the first electrode and the second electrode.

3. The dual electrode irreversible electroporation ablation needle of claim 2, wherein, The insulating isolation part further comprises an outer insulating layer, the outer insulating layer is sleeved on the outer surface of the second electrode, and the effective discharge length of the second electrode is adjusted by covering the outer surface of the second electrode through the outer insulating layer.

4. The dual electrode irreversible electroporation ablation needle of claim 3, wherein, The inner insulating layer, the insulating isolation layer and the outer insulating layer are made of one or at least two composite materials selected from polyether ether ketone, polyphenylene sulfide, polyxylene, fluoropolymer and polyimide, and are prepared by a vacuum vapor deposition process; the thickness of the inner insulating layer and the outer insulating layer is controlled to be 0.05-0.1 mm, and a withstand voltage margin requirement of 5000V-10000V is met.

5. The dual electrode irreversible electroporation ablation needle of claim 2, wherein, The first electrode, the insulating isolation layer and the second electrode are coaxially arranged with the electrode needle body, and the first electrode, the insulating isolation layer and the second electrode form an equal outer diameter structure with an outer diameter value in the range of 0.8-1.2 mm.

6. The dual electrode irreversible electroporation ablation needle of claim 3, wherein, The ablation needle further comprises a structural handle and an electrical connection structure, the structural handle is used to axially fixedly connect the components of the ablation needle by a pre-embedded injection molding process, and the electrical connection structure is used to connect the first electrode and the second electrode to the external pulse power source, respectively.

7. A method of performing ablation with the bipolar irreversible electroporation ablation needle according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: selecting the number of ablation needles and an electrode combination ablation mode according to the shape and volume of a lesion; inserting the ablation needles into target tissue; applying irreversible electroporation pulse signals in the selected electrode combination ablation mode to form irreversible electroporation ablation regions around the needle body, so as to ablate the lesion tissue; the electrode combination ablation mode comprises: an ablation mode between the first electrode and the second electrode inside a single ablation needle; and an ablation mode between the first electrodes, between the second electrodes or between cross electrodes of different ablation needles.

8. The method of ablation with a dual electrode irreversible electroporation ablation needle of claim 7, wherein, when two ablation needles are used for ablation, if the two ablation needles are arranged in parallel, the vertical distance between the axes of the two ablation needles is in the range of 5-20 mm; If the two ablation needles are not arranged in parallel, the minimum distance between the axes of the two ablation needles is 5 mm.

9. The method of ablation with a dual electrode irreversible electroporation ablation needle of claim 7, wherein, The method further comprises: During the ablation of the lesion tissue, the electrode combination ablation mode is switched at any time according to the ablation effect, so as to supplement the region not completely covered during ablation.

10. Use of a method of ablation with a bipolar irreversible electroporation ablation needle according to claim 8 or 9, characterized in that, The method is used for ablation of liver tissue or lung tissue.

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