Bipolar needle system suitable for steep pulsed field ablation

Abstract

A bipolar needle system suitable for steep pulsed field ablation, comprising a bipolar needle, a steep pulse generation module and a current monitoring module. The bipolar needle comprises a front-end electrode (1), a rear-end electrode (5), a wire, an insulating ring (2), an insulating support ring (3) and a conductive connecting tube (4). The front end of the front-end electrode (1) forms a needle tip of the bipolar needle. The front end of the insulating support ring (3) is connected to the rear end of the front-end electrode (1). The insulating ring (2) and the rear-end electrode (5) are both sleeved outside the insulating support ring (3), the front end of the insulating ring (2) being connected to the rear end of the front-end electrode (1), the rear end of the insulating ring (2) being connected to the front end of the rear-end electrode (5), and the rear end of the rear-end electrode (5) extending out of the insulating support ring (3). The front end of the wire extends into the insulating support ring (3) from the rear end of the insulating support ring (3) and is connected to the rear end of the front-end electrode (1). The bipolar needle system has improved effectiveness and reliability.

Description

A bipolar needle system suitable for steep pulse ablation Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to a bipolar needle system suitable for steep pulse ablation. Background Technology

[0002] In the field of tumor treatment, irreversible electroporation has attracted widespread attention from researchers in the field of bioelectricity both domestically and internationally due to its advantages such as speed, controllability, visualization, selectivity, and non-thermal mechanisms, and is gradually being applied to the clinical treatment of tumors. The treatment mechanism of irreversible electroporation involves generating high-voltage ultrashort nanosecond pulses through a high-voltage power supply and pulse generator. These ultrashort pulses of a certain frequency are emitted, releasing electrical energy through electrodes in the form of a pulsed electric field. This electric field energy is then transmitted to the tumor tissue via electrode needles, causing irreversible electroporation and apoptosis of tumor cells. The electrode needle is the key component of irreversible electroporation for tumor treatment, playing a crucial role in its effectiveness.

[0003] The principle of irreversible electroporation, also known as steep pulse therapy, is as follows: A steep pulse output and control device delivers pulsed high-voltage electrical energy to the lesion site through a steep pulse electrode needle. During energy output, the lesion site is subjected to the pulsed high-voltage electricity, causing the cell membranes of tissue cells to break down. Electrolytes such as cellular fluid flow out of the cells. This process leads to a decrease in impedance within the treatment circuit formed by the body, the steep pulse electrode needle, the steep pulse output, and the control device, resulting in a greater current in the treatment circuit. Conversely, a greater current in the treatment circuit indicates a lower impedance, meaning more and more lesion cells are being broken down. Based on this principle, the steep pulse output and control device samples the current changes in the treatment circuit to determine the current magnitude and thus the extent of lesion cell breakdown.

[0004] For lesion cells, the greater the current, the more thoroughly the lesion cells are eliminated. However, the human body cannot withstand a larger current; there is a safety limit. When this safety limit is reached, the steep pulse output and control device must stop energy output. Therefore, in the treatment circuit consisting of the human body, steep pulse electrodes, steep pulse output, and control device, the accuracy of current acquisition is particularly important.

[0005] Existing electrode needles suitable for irreversible electroporation (i.e., steep pulse ablation) generally include an electrode head, a positive electrode, a negative electrode, and a metal conductive tube. The front end of the metal conductive tube is connected to the electrode head. Both the negative and positive electrodes are sleeved on the outside of the metal conductive tube. The front end of the negative electrode is connected to the electrode head. An insulating element is provided between the rear end of the negative electrode and the front end of the positive electrode. An insulating element is also provided between the positive electrode and the metal conductive tube. Ideally, the current flows in from the metal conductive tube, passes sequentially through the electrode head, the negative electrode, the lesion site, and the positive electrode, and then flows out. For example, the water-circulating steep pulse electrode needle disclosed in patent CN202222019196.1.

[0006] However, in actual use, this type of electrode needle may experience a sudden increase in current exceeding the safety limit at the moment of power-on (that is, the instant when the steep pulse output and control device just start outputting current). The steep pulse output and control device may mistakenly believe that the safety limit has been reached and stop the energy output, which may lead to delays in surgery or failure to achieve the full therapeutic effect. Summary of the Invention

[0007] To address the above problems, the present invention provides a bipolar needle system suitable for steep pulse ablation.

[0008] The technical solution of this invention is as follows:

[0009] A bipolar needle system suitable for steep pulse ablation includes a bipolar needle, a steep pulse generation module, and a current monitoring module;

[0010] The bipolar needle includes a front electrode, a rear electrode, a wire, an insulating ring, and an insulating support ring, wherein the front end of the front electrode forms the tip of the bipolar needle.

[0011] The front end of the insulating support ring is connected to the rear end of the front end electrode; both the insulating ring and the rear end electrode are sleeved and installed outside the insulating support ring, the front end of the insulating ring is connected to the rear end of the front end electrode, the rear end of the insulating ring is connected to the front end of the rear end electrode, and the rear end of the rear end electrode extends out of the insulating support ring.

[0012] The front end of the conductor extends into the insulating support ring from the rear end of the insulating support ring and is connected to the rear end of the front end electrode.

[0013] The steep pulse generating module is used to output a high-voltage steep pulse current; the output terminal of the steep pulse generating module for outputting the high-voltage steep pulse current is connected to the rear end of the conductor, and the high-voltage steep pulse current reaches the front end electrode through the conductor; the input terminal of the steep pulse generating module for receiving the return current is connected to the rear end electrode, and the return current reaches the steep pulse generating module through the rear end electrode.

[0014] The current monitoring module is connected to the steep pulse generation module. The current monitoring module is used to monitor the magnitude of the current output by the steep pulse generation module in real time. The steep pulse generation module is also used to automatically cut off the current output when the current monitoring module detects that the current magnitude exceeds a threshold.

[0015] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the insulating support ring is made of ceramic or high-strength polymer plastic.

[0016] In a preferred embodiment of the bipolar needle system for steep pulse ablation, a conductive connecting tube is also provided; the conductive connecting tube is located inside the insulating support ring, and the front end of the conductive connecting tube is connected to the rear end of the front electrode; the conductive connecting tube is sleeved outside the conductor, and the conductive connecting tube is connected to the front end of the conductor.

[0017] In a preferred embodiment of the bipolar needle system suitable for steep pulse ablation, the wire is welded to the conductive connecting tube;

[0018] The conductive connecting tube contains molten solder for welding, and the front end of the wire is fixedly connected to the solidified molten solder inside the conductive connecting tube.

[0019] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the lead includes a lead core and a lead insulation layer wrapped around the lead core, with the front end of the lead core extending beyond the lead insulation layer.

[0020] The front end of the inner core of the conductor and the front end of the conductor insulation layer are both fixedly connected to the solidified molten tin inside the conductive connecting tube; or, only the front end of the inner core of the conductor is fixedly connected to the solidified molten tin inside the conductive connecting tube, and the conductor insulation layer does not contact the molten tin.

[0021] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the rear electrode, the insulating support ring, and the conductive connecting tube overlap in the radial direction of the bipolar needle. At the overlap, the thickness of the insulating support ring is greater than 1.5 times the thickness of the rear electrode, and the thickness of the insulating support ring is greater than 1.5 times the thickness of the conductive connecting tube.

[0022] In a preferred embodiment of the bipolar needle system suitable for steep pulse ablation, at the overlap of the rear electrode, the insulating support ring, and the conductive connecting tube, the thickness of the insulating support ring is 0.18 mm to 0.22 mm, the thickness of the rear electrode is 0.06 mm to 0.10 mm, and the thickness of the conductive connecting tube is 0.06 mm to 0.10 mm.

[0023] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the front end of the conductive connector is welded to the rear end of the front electrode.

[0024] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the rear end of the front electrode has a first stepped portion, the first stepped portion including a first outer sidewall in the circumferential direction of the front electrode and a first end face on the front electrode facing the rear end direction;

[0025] The front end of the conductive connecting tube is sleeved outside the first outer wall, and the front end of the conductive connecting tube is connected to the first stepped portion.

[0026] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the rear end of the front electrode has a first stepped portion, the first stepped portion including a first outer sidewall in the circumferential direction of the front electrode and a first end face on the front electrode facing the rear end direction;

[0027] The front end of the conductive connecting tube is sleeved outside the first outer side wall, and the front end of the conductive connecting tube is welded to the first stepped portion.

[0028] After the conductive connector is sleeved on the first outer side wall, the rear end face of the front electrode inside the conductive connector is the center end face. The center end face and the inner side wall of the conductive connector form a molten tin receiving tank. The unsolidified molten tin is contained in the molten tin receiving tank. The front end of the wire extends from the rear end of the conductive connector into the conductive connector and into the unsolidified molten tin in the molten tin receiving tank.

[0029] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the front end of the conductive connecting tube is laser-welded to the first stepped portion.

[0030] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the rear end of the front electrode further has a second stepped portion, which is located outside the first stepped portion; the front end of the insulating support ring is sleeved outside the second stepped portion, and the front end of the insulating support ring and the front end of the insulating ring are respectively connected to the second stepped portion to achieve connection with the rear end of the front electrode.

[0031] In a preferred embodiment of the bipolar needle system for steep pulse ablation, both the front end of the insulating support ring and the front end of the insulating ring are welded to the second step portion.

[0032] In a preferred embodiment of the bipolar needle system for steep pulse ablation, the inner core of the lead wire is made of copper alloy.

[0033] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:

[0034] The bipolar needle system for steep pulse ablation provided by this invention involves a high-voltage steep pulse current output from the steep pulse generation module. This current flows sequentially through a wire, a front electrode, the lesion site, and a rear electrode before returning to the input terminal of the steep pulse generation module. During use, the current flow is accurate, preventing a sudden surge in current exceeding safety limits upon power-on.

[0035] The bipolar needle system for steep pulse ablation provided by this invention achieves insulation isolation between the rear electrode and the lead wire (mainly referring to the exposed core of the lead wire) through the setting of an insulating support. At the same time, the setting of the insulating support can improve the strength of the needle tip area of ​​the bipolar needle (the needle tip area includes the needle tip and the part of the structure near the needle tip). Attached Figure Description

[0036] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention.

[0037] Figure 1 is a schematic diagram of the front end portion of a bipolar needle according to the present invention;

[0038] Figure 2 is a cross-sectional schematic diagram of the front end portion of a bipolar needle according to the present invention (the molten solder is not shown in the figure);

[0039] Figure 3 is a partial cross-sectional schematic diagram of a bipolar needle according to the present invention (the molten tin is not shown in the figure);

[0040] Figure 4 is a schematic diagram of the structure of a front-end electrode according to the present invention;

[0041] Figure 5 shows the waveform of a water circulation steep pulse electrode needle in the prior art;

[0042] Figure 6 shows the waveform of a bipolar needle system suitable for steep pulse ablation according to the present invention.

[0043] Explanation of reference numerals in the attached drawings: 1: Front electrode; 11: First step; 111: First outer wall; 112: First end face; 12: Second step; 121: Second outer wall; 122: Second end face; 2: Insulating ring; 3: Insulating support ring; 4: Conductive connecting tube; 5: Rear electrode; 6: Wire insulation layer; 7: Wire core; 8: Needle tube insulation layer. Detailed Implementation

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0045] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0046] Because the external manifestations caused by the instantaneous current surge exceeding the safety limit during power-on in existing technologies are the same as those caused by the increasing number of lesion cells being broken down, both involve detecting the return current increasing to exceed the safety limit, resulting in a steep pulse output and the control device automatically cutting off the current output. Therefore, such problems have not been found in the electrode needles of existing technologies.

[0047] The reason why the current in the electrode needles of the prior art suddenly increases to exceed the safety limit at the moment of power-on is that both the negative electrode and the metal conductive tube are cylindrical, and the negative electrode is sleeved on the metal conductive tube with a very small gap between them, thus forming a capacitor structure between the negative electrode and the metal conductive tube. At the moment of power-on, the initial state of this capacitor structure is uncharged, which is equivalent to a short circuit. Current will flow rapidly to charge the capacitor structure. During this charging process, the voltage of the capacitor structure increases rapidly from zero to the power supply voltage. Since the voltage of the capacitor structure cannot change abruptly, at the moment of power-on, the capacitor structure will absorb a large amount of current to quickly build up the voltage, which will cause the current in the circuit to increase instantaneously.

[0048] Meanwhile, during steep pulse therapy, the amount of electrical energy required to penetrate the cell membranes of tissue cells at the lesion site is crucial. However, this amount of electrical energy cannot be directly measured, so it is usually replaced by the electrical energy output from the steep pulse and the control device. However, due to the presence of the capacitor structure, some of the electrical energy output from the steep pulse and the control device is wasted on the capacitor structure, resulting in a difference between the electrical energy output from the steep pulse and the electrical energy actually reaching the lesion site. Therefore, even if the current does not increase to the safe limit due to the sudden increase in current at the moment of power-on caused by the capacitor structure, and the steep pulse and control device successfully output electrical energy, the difference between the electrical energy output from the steep pulse and the control device and the electrical energy actually reaching the lesion site, coupled with the operator's (usually a doctor) equating the electrical energy output from the steep pulse and the control device with the electrical energy actually reaching the lesion site, will lead to poor treatment results.

[0049] To address the aforementioned problems, this embodiment provides a novel bipolar needle system suitable for steep pulse ablation. Referring to Figures 1 to 4, the bipolar needle system suitable for steep pulse ablation includes a bipolar needle, a steep pulse generation module, and a current monitoring module. The bipolar needle includes a front electrode 1, a rear electrode 5, a lead wire, an insulating ring 2, and an insulating support ring 3. The front end of the front electrode 1 forms the tip of the bipolar needle. The front end of the insulating support ring 3 is connected to the rear end of the front electrode 1; both the insulating ring 2 and the rear electrode 5 are sleeved outside the insulating support ring 3, with the front end of the insulating ring 2 connected to the rear end of the front electrode 1, and the rear end of the insulating ring 2 connected to the front end of the rear electrode 5. The rear end of the rear electrode 5 extends out of the insulating support ring 3. The front end of the lead wire extends from the rear end of the insulating support ring 3 into the insulating support ring 3 and connects to the rear end of the front electrode 1.

[0050] The steep pulse generator module is used to output a high-voltage steep pulse current. The output terminal of the steep pulse generator module, used to output the high-voltage steep pulse current, is connected to the rear end of a lead wire, and the high-voltage steep pulse current reaches the front end electrode via the lead wire. The input terminal of the steep pulse generator module, used to receive the return current, is connected to the rear end electrode, and the return current reaches the steep pulse generator module via the rear end electrode.

[0051] The current monitoring module is connected to the steep pulse generator module, and is used to monitor the current output of the steep pulse generator module in real time. The steep pulse generator module also automatically cuts off the current output when the current monitoring module detects that the current exceeds a threshold (which is the aforementioned safety limit). The current monitoring module is primarily used to prevent the current from exceeding the upper limit acceptable to the human body.

[0052] The bipolar needle system for steep pulse ablation provided in this embodiment features a high-voltage steep pulse current output from the steep pulse generation module. This current flows sequentially through the wire, the front electrode, the lesion site, and the rear electrode before reaching the input terminal of the steep pulse generation module. In this bipolar needle system, there is no capacitor structure within the bipolar needle; therefore, during use, the current flow is accurate, and there will be no situation where the current suddenly increases to exceed the safety limit upon power-on.

[0053] Meanwhile, the insulating support can provide insulation and isolation between the rear electrode 5 and the wire (mainly referring to the exposed core 7 of the wire in the guide wire); and the insulating support can improve the strength of the needle tip area of ​​the bipolar needle (the needle tip area includes the needle tip and the part of the structure near the needle tip).

[0054] The bipolar needle system applicable to steep pulse ablation in this embodiment will be further described below.

[0055] In this embodiment, the front electrode 1 is directly used as the tip of the bipolar needle, so the front end of the front electrode 1 forms a sharp point, specifically a sharp triangle. The rear end of the front electrode 1 has a first step portion 11 and a second step portion 12, with the second step portion 12 located on the outer layer of the first step portion 11.

[0056] The front end of the insulating support ring 3 is sleeved on the second stepped portion 12. Specifically, the second stepped portion 12 includes a second outer side wall 121 circumferentially facing the front electrode 1 and a second end face 122 facing the rear end of the front electrode 1. The front end of the insulating support ring 3 is sleeved on the second outer side wall 121. The front ends of the insulating support ring 3 and the insulating ring 2 are respectively connected to the second stepped portion 12, thereby achieving connection with the rear end of the front electrode 1. Preferably, the connection method can be welding.

[0057] The tip of a bipolar needle generally includes the needle tip and the area near the needle tip. Since the tip of a bipolar needle generally requires a certain structural strength, the insulating support ring 3 is preferably made of ceramic material or high-strength polymer plastic (such as polyetheretherketone) to increase the structural strength of the needle tip.

[0058] In this embodiment, the bipolar needle assembly includes a conductive connecting tube 4. The front electrode 1 and the wire are not directly fixedly connected, but are fixedly connected through the conductive connecting tube 4. Specifically, the conductive connecting tube 4 is located inside the insulating support ring 3. The front end of the conductive connecting tube 4 is connected to the rear end of the front electrode 1. The conductive connecting tube 4 is sleeved outside the wire and connected to the front end of the wire.

[0059] Preferably, the front end of the conductive connector 4 is welded to the rear end of the front electrode 1. Specifically, in the front electrode 1, the first step portion 11 includes a first outer side wall 111 in the circumferential direction of the front electrode 1 and a first end face 112 on the front electrode 1 facing the rear end direction; the front end of the conductive connector 4 is sleeved outside the first outer side wall 111, and the front end of the conductive connector 4 is connected to the first step portion 11. More preferably, the front end of the conductive connector 4 is laser welded to the first step portion 11.

[0060] The preferred method for connecting the wire to the conductive connector 4 is by soldering. Specifically, the conductive connector 4 contains molten solder. Before the solder solidifies, the tip of the wire extends into the molten solder. When the molten solder solidifies in the conductive connector 4, the tip of the wire is fixedly connected to the solidified molten solder within the conductive connector 4. Simultaneously, the solidified molten solder connects to both the conductive connector 4 and the wire, allowing the conductive connector 4 and the wire to conduct electricity smoothly.

[0061] The conductor includes a conductor core 7 and a conductor insulation layer 6 that wraps around the conductor core 7. The front end of the conductor core 7 extends out of the conductor insulation layer 6, meaning that part of the front end of the conductor core 7 is exposed to the outside (here, "outside" refers to the outside relative to the inside formed by the conductor insulation layer 6). The exposed conductor core 7 is electrically connected to the conductive connecting tube 4.

[0062] The front end of the conductor is fixedly connected to the molten solder solidified inside the conductive connector 4. This can be achieved by both the front end of the conductor core 7 and the front end of the conductor insulation layer 6 being fixedly connected to the molten solder inside the conductive connector 4, or by only the front end of the conductor core 7 being fixedly connected to the molten solder inside the conductive connector 4, while the conductor insulation layer 6 does not contact the molten solder. The difference lies in the length of the conductor front end extending into the molten solder before it solidifies. If the extension into the molten solder is long, then after the solder solidifies, both the front ends of the conductor core 7 and the conductor insulation layer 6 will be fixed in the solidified solder. If the extension into the molten solder is short, then only the front end of the conductor core 7 will be fixed in the solidified solder.

[0063] Since the operator needs to tighten the wire when controlling the tip of the bipolar needle, in this embodiment, it is preferable that the front end of the inner core 7 of the wire and the front end of the insulation layer 6 of the wire are both fixedly connected to the solidified molten solder inside the conductive connecting tube 4. In this way, the connection strength between the wire and the conductive connecting tube 4 can be increased, and the insulation layer 6 of the wire can also help the inner core 7 of the wire to share the tension on the wire (if only the inner core 7 of the wire is fixed in the solidified molten solder, then only the inner core 7 of the wire will bear the tension when the wire is pulled). This makes it less likely for the front electrode 1 to loosen and for the front electrode 1 and the wire to break off. The fact that the front electrode 1 is not easy to loosen means that the front electrode 1 can only perform specific operations when the wire is pulled taut. When only the inner core 7 of the wire is fixed in the solidified molten solder, only the inner core 7 of the wire can withstand the tension on the wire. Compared with the case where the inner core 7 of the wire and the insulation layer 6 of the wire are both fixed in the solidified molten solder, the taut tension that the wire can withstand is smaller. If the front electrode 1 is not pulled taut enough by the wire, it is easy for it to loosen. The fact that the front electrode 1 and the wire are not easy to break off means that the wire is fixed in the solidified molten solder to achieve a fixed connection between the wire and the conductive connecting tube 4. Compared with the case where only the inner core 7 of the wire is fixed in the solidified molten solder, when the inner core of the wire and the insulation layer of the wire are both fixed in the solidified molten solder, the connection between the wire and the conductive connecting tube 4 is more secure. In other words, the front electrode 1 and the wire are less likely to break off.

[0064] Meanwhile, the inner core 7 of the lead wire is preferably made of copper alloy (or other materials with high strength and higher conductivity). This ensures a stronger connection between the needle tip (front electrode 1) and the needle body (rear electrode 5, lead wire, etc.) and a more reliable structure. Furthermore, the inner core 7 has lower resistance, resulting in less energy loss. In this embodiment, the inner core 7 should not be made of copper wire, silver wire, or similar materials. Although these materials have high conductivity and low resistance, they have low strength. During operation, the bipolar needle assembly will be subjected to a radial bending force, requiring the lead wire to be taut and straightened. If the lead wire material has low strength, there is a risk of the front electrode 1 loosening and the front electrode 1 breaking off from the lead wire.

[0065] The specific method for welding the front end of the wire to the conductive connector 4 using molten solder can be as follows: After the conductive connector 4 is sleeved on the first outer wall 111, the rear end face of the front electrode 1 inside the conductive connector 4 is the center end face. The center end face and the inner wall of the conductive connector 4 form a molten solder receiving tank. The undried molten solder is contained in the molten solder receiving tank. The front end of the wire extends from the rear end of the conductive connector 4 into the conductive connector 4 and into the undried molten solder in the molten solder receiving tank. When the molten solder solidifies, the front end of the wire is fixedly connected in the solidified molten solder. Of course, in other facility examples, other methods can also be used to weld the front end of the wire and the conductive connector 4 using molten solder, and no limitation is made here.

[0066] In existing technologies, to connect a wire to the front-end electrode 1, a common method is to drill holes in the front-end electrode 1 and crimp the wire. In this embodiment, the connection between the wire and the front-end electrode 1 is achieved using a conductive connecting tube 4 as a transition. One end of the conductive connecting tube 4 is soldered to the front-end electrode 1, and the other end is soldered to the wire using molten solder. This connection method using the conductive connecting tube 4 makes it easier to connect the front-end electrode 1 and the wire in a confined space. Compared to directly drilling holes in the front-end electrode 1 and crimping the wire, this method is more optimized and significantly reduces the difficulty of manufacturing.

[0067] Furthermore, in this embodiment, the rear electrode, insulating support ring, and conductive connector have an overlapping portion in the radial direction of the bipolar needle. At the overlapping portion, the thickness of the insulating support ring is greater than 1.5 times the thickness of the rear electrode, and the thickness of both the insulating support ring and the conductive connector is greater than 1.5 times the thickness of the conductive connector. Specifically, the thickness of the insulating support ring can be 0.18 mm to 0.22 mm, the thickness of the rear electrode can be 0.06 mm to 0.10 mm, and the thickness of the conductive connector can be 0.06 mm to 0.10 mm. More preferably, the thickness of the insulating support ring can be 0.20 mm, and the thickness of both the rear electrode and the conductive connector can be 0.08 mm.

[0068] The bipolar needle assembly also includes a needle insulation layer 8, which is sleeved on the rear electrode 5, and the front end of the rear electrode 5 extends out of the needle insulation layer 8.

[0069] The current monitoring module is mainly used to monitor the current in the treatment circuit; the steep pulse generation module includes at least the functions of outputting high-voltage steep pulse current and cutting off the current output when the current monitoring module detects that the current exceeds the safety limit. Both the steep pulse generation module and the current monitoring module are commonly used modules in steep pulse therapy. As long as they can achieve their required functions, their specific structures are not limited. For example, circuits disclosed in patents CN118244633A and CN116509534A can be used.

[0070] In existing technologies, because the metal conductive tube is nested within the negative and positive electrodes, capacitive coupling is easily formed. This causes the current to surge beyond the safety limit at the moment of power-on. The current monitoring module detects this excess current, but the steep pulse generator cannot distinguish whether the excessive current is due to capacitive coupling or excessive damage to the lesion cells. Therefore, the steep pulse generator cuts off the current output. In reality, if the excessive current is due to capacitive coupling, it directly reaches the capacitor structure and bypasses the lesion site, meaning it doesn't flow through the body. Therefore, there's no need to stop the steep pulse generator's current output; the current will naturally return to normal once the capacitor structure finishes charging. The steep pulse generator mistakenly interprets the excessive current caused by capacitive coupling as current flowing through the body reaching the safety limit and stops energy output, which can lead to surgical delays or incomplete treatment.

[0071] The bipolar needle system for steep pulse ablation provided in this embodiment optimizes the structure of the bipolar needle, effectively eliminating the possibility of capacitive coupling. That is, it will not cause the current to surge to exceed the safety limit at the moment of power-on, as in the prior art. At the same time, there is no additional energy consumption due to the absence of a capacitor structure, which improves the effectiveness and reliability of the bipolar needle system for steep pulse ablation in this embodiment.

[0072] Figures 5 and 6 show the current waveforms obtained by using a current clamp to measure the change in pulse current in the circuit under the same test voltage and resistance conditions, using an electrode needle in the prior art and a bipolar needle in this embodiment. Figure 5 (corresponding to the prior art) shows a large abrupt current spike in the circuit. This spike is caused by a sudden increase in current due to the capacitor structure, indicating the presence of the capacitor structure. Figure 6 (corresponding to this embodiment) clearly shows that the current waveform spike has been effectively eliminated.

[0073] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

A bipolar needle system suitable for steep pulse ablation, characterized in that, Includes a bipolar needle, a steep pulse generation module, and a current monitoring module; The bipolar needle includes a front electrode, a rear electrode, a wire, an insulating ring, and an insulating support ring, with the front end of the front electrode forming the tip of the bipolar needle. The front end of the insulating support ring is connected to the rear end of the front end electrode; both the insulating ring and the rear end electrode are sleeved and installed outside the insulating support ring, the front end of the insulating ring is connected to the rear end of the front end electrode, the rear end of the insulating ring is connected to the front end of the rear end electrode, and the rear end of the rear end electrode extends out of the insulating support ring. The front end of the conductor extends into the insulating support ring from the rear end of the insulating support ring and is connected to the rear end of the front end electrode. The steep pulse generation module is used to output high-voltage steep pulse current; The output terminal of the steep pulse generating module, which is used to output a high-voltage steep pulse current, is connected to the rear end of the conductor, and the high-voltage steep pulse current reaches the front end electrode through the conductor; the input terminal of the steep pulse generating module, which is used to receive the return current, is connected to the rear end electrode, and the return current reaches the steep pulse generating module through the rear end electrode. The current monitoring module is connected to the steep pulse generation module. The current monitoring module is used to monitor the magnitude of the current output by the steep pulse generation module in real time. The steep pulse generation module is also used to automatically cut off the current output when the current monitoring module detects that the current magnitude exceeds a threshold. The bipolar needle system for steep pulse ablation according to claim 1 is characterized in that, The insulating support ring is made of ceramic or high-strength polymer plastic. The bipolar needle system for steep pulse ablation according to claim 1 is characterized in that, It also includes a conductive connecting tube; the conductive connecting tube is located inside the insulating support ring, and the front end of the conductive connecting tube is connected to the rear end of the front electrode; the conductive connecting tube is sleeved outside the wire, and the conductive connecting tube is connected to the front end of the wire. The bipolar needle system for steep pulse ablation according to claim 3 is characterized in that, The wire is welded to the conductive connecting pipe; The conductive connecting tube contains molten solder for welding, and the front end of the wire is fixedly connected to the solidified molten solder inside the conductive connecting tube. The bipolar needle system for steep pulse ablation according to claim 4 is characterized in that, The conductor includes a conductor core and a conductor insulation layer that wraps around the conductor core, with the front end of the conductor core extending out of the conductor insulation layer; The front end of the inner core of the conductor and the front end of the conductor insulation layer are both fixedly connected to the solidified molten tin inside the conductive connecting tube; or, only the front end of the inner core of the conductor is fixedly connected to the solidified molten tin inside the conductive connecting tube, and the conductor insulation layer does not contact the molten tin. The bipolar needle system for steep pulse ablation according to any one of claims 3 to 5 is characterized in that, The rear electrode, the insulating support ring, and the conductive connecting tube have an overlapping portion in the radial direction of the bipolar needle. At the overlapping portion, the thickness of the insulating support ring is greater than 1.5 times the thickness of the rear electrode, and the thickness of the insulating support ring is greater than 1.5 times the thickness of the conductive connecting tube. The bipolar needle system for steep pulse ablation according to claim 6 is characterized in that, At the overlap of the rear electrode, the insulating support ring, and the conductive connecting tube, the thickness of the insulating support ring is 0.18 mm to 0.22 mm, the thickness of the rear electrode is 0.06 mm to 0.10 mm, and the thickness of the conductive connecting tube is 0.06 mm to 0.10 mm. The bipolar needle system for steep pulse ablation according to claim 3 is characterized in that, The front end of the conductive connector is welded to the rear end of the front electrode. The bipolar needle system for steep pulse ablation according to claim 3 is characterized in that, The rear end of the front electrode has a first stepped portion, the first stepped portion including a first outer sidewall in the circumferential direction of the front electrode and a first end face on the front electrode facing the rear end direction; The front end of the conductive connecting tube is sleeved outside the first outer wall, and the front end of the conductive connecting tube is connected to the first stepped portion. The bipolar needle system for steep pulse ablation according to claim 4 is characterized in that, The rear end of the front electrode has a first stepped portion, the first stepped portion including a first outer sidewall in the circumferential direction of the front electrode and a first end face on the front electrode facing the rear end direction; The front end of the conductive connecting tube is sleeved outside the first outer side wall, and the front end of the conductive connecting tube is welded to the first stepped portion. After the conductive connector is sleeved on the first outer side wall, the rear end face of the front electrode inside the conductive connector is the center end face. The center end face and the inner side wall of the conductive connector form a molten tin receiving tank. The unsolidified molten tin is contained in the molten tin receiving tank. The front end of the wire extends from the rear end of the conductive connector into the conductive connector and into the unsolidified molten tin in the molten tin receiving tank. The bipolar needle system for steep pulse ablation according to claim 9 or 10 is characterized in that, The front end of the conductive connecting tube is laser welded to the first stepped portion. The bipolar needle system for steep pulse ablation according to claim 9 or 10 is characterized in that, The rear end of the front electrode also has a second stepped portion, which is located outside the first stepped portion; the front end of the insulating support ring is sleeved outside the second stepped portion, and the front end of the insulating support ring and the front end of the insulating ring are respectively connected to the second stepped portion to achieve connection with the rear end of the front electrode. The bipolar needle system for steep pulse ablation according to claim 12 is characterized in that, The front end of the insulating support ring and the front end of the insulating ring are both welded to the second step portion. The bipolar needle system for steep pulse ablation according to claim 5 is characterized in that, The inner core of the conductor is made of copper alloy.

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