Ablation catheter and ablation device with high-precision ablation boundary

Abstract

The purpose of the present invention is to solve the problem that some tissues to be ablated in the existing electric pulse ablation technology are specially distributed, close to or close to important organ tissues or sandwiched between normal tissues, and are easy to damage surrounding important organs or normal tissues during electric pulse ablation. An ablation catheter, ablation equipment and operation method thereof with high-precision ablation boundaries are proposed, wherein the ablation catheter includes a cage electrode and a core electrode located in the cage electrode; the cage electrode is a structure formed by a plurality of electrodes arranged in a uniform circumference, with the root gathering, the ends gradually diffusing to form a cage-shaped encirclement, and the middle being a cavity; one or more short discharge electrodes are distributed on the surface of the core electrode; a high-voltage pulse signal is connected to the cage electrode and the short discharge electrode, or is connected to any two short discharge electrodes to form a pulse electric field with the cage-shaped encirclement as the boundary. The cage electrode and core electrode matching structure of the present application helps to generate pulse electric fields of different ranges to adapt to the parts to be ablated in different tissue structures.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to an ablation catheter and an ablation device with a high-precision ablation boundary. Background Art

[0002] At present, the application of electric pulse tumor ablation technology is in the ascendant, and the technological development has also achieved gratifying results. At the same time, it also faces some technical pain points and difficulties that need to be solved urgently. Tumor ablation is a minimally invasive surgery. The distribution of tumors in the same tissue is often uneven. For example, large blood vessels or nerves are sandwiched between two tumor tissues, or tumor tissues are located below or above normal tissues, or there is a tumor tissue sandwiched between two normal tissues. When the existing ablation catheter performs electric field ablation, it is impossible to avoid normal tissues as needed, and normal tissues are damaged while tumor ablation is being performed. In addition, the ablation boundary of the current high-voltage pulse signal is not clear and accurate enough, and there is often a risk of electromagnetic energy leakage. The leakage of electromagnetic energy can easily cause damage to surrounding organs and tissues and severe muscle tremors, which is not conducive to the ablation effect, and there is a risk of causing the ablation needle to deviate and damage important tissues. Designing a device and method with precise and controllable boundaries of the ablation area, and being able to adjust the local ablation range, will have very good practical application prospects. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the tissue to be ablated is specially distributed in the existing electric pulse ablation technology, is close to or close to important organ tissue, or the two are closely related and difficult to separate, which makes it easy to damage surrounding important organs or normal tissues during electric pulse ablation. An ablation catheter and ablation device with high-precision ablation boundaries are proposed.

[0004] The present invention is achieved through the following technical measures: an ablation catheter with a high-precision ablation boundary, comprising a cage electrode and a core electrode located in the cage electrode; the cage electrode is a structure formed by a plurality of electrodes arranged in a uniform circumference, with roots gathered, ends gradually diffused to form a cage-shaped encirclement, and a cavity in the middle; one or more short discharge electrodes are distributed on the surface of the core electrode, and the short discharge electrode is located in the cage-shaped encirclement; a high-voltage pulse signal is connected to the cage electrode and the short discharge electrode, or to any two short discharge electrodes, to form a pulse electric field with the cage-shaped encirclement as the boundary.

[0005] Preferably, the spacing between the electrodes around the cage-shaped enclosure is smaller than the wavelength of the received pulse signal.

[0006] Preferably, the electrode comprises a first straight section and a third section, and an arc-shaped second connecting section for connecting the first straight section and the third section; the surfaces of the first straight sections of adjacent electrodes contact each other and gather into roots; the diameter of the cavity corresponding to the second connecting section tends to gradually increase from top to bottom, so that the third sections of multiple electrodes are separated from each other to form a claw-shaped cage-type encirclement.

[0007] Preferably, the electrode portion located around the cage-shaped surrounding ring is exposed for conductivity, and the surface of the other portion is covered with an insulating layer.

[0008] Preferably, the cage electrode has 10 electrodes.

[0009] Preferably, the core electrode is located at the center of the cage electrode, including a sleeve and a wire located in the sleeve, a short electrode connection position connected to the wire is provided in the sleeve, and a discharge short electrode is distributed at a portion of the sleeve surface located in the cage-shaped encirclement corresponding to the short electrode connection position.

[0010] Preferably, a wire and a short electrode connection point connected to the wire are provided in the sleeve, and the wire and the cage electrode are respectively connected to two poles of the high-voltage pulse signal to form a pulse electric field between the discharge short electrode and the cage electrode.

[0011] Preferably, two or more wires and a corresponding number of short electrode connection positions are provided in the sleeve and connected accordingly, any two wires are connected to the two poles of the high-voltage pulse signal, and an independent or superimposed pulse electric field is formed between the corresponding two discharge short electrodes; or one or several wires and the cage-shaped electrode are respectively connected to the two poles of the high-voltage pulse signal, and a pulse electric field is formed between the corresponding discharge short electrode and the cage-shaped encirclement.

[0012] Preferably, the position of the core electrode relative to the cage electrode can be adjusted up and down.

[0013] The present application also provides an ablation device, including a pulse generator for generating a high-voltage pulse signal and any of the above-mentioned ablation catheters, wherein the pulse generator is electrically connected to the ablation catheter to apply the high-voltage pulse signal to the tissue structure through the cage electrode and the core electrode.

[0014] The present application also provides an operating method for an ablation device, which comprises extending an ablation catheter into the tissue to be ablated so that the tissue to be ablated is located within the boundary range of the cage-shaped encirclement of the ablation catheter; applying a high-voltage pulse signal between one or more short electrodes of the cage electrode and the core electrode, or between different short electrodes of the core electrode, to obtain a pulse electric field range suitable for the tissue to be ablated; or, under a high-voltage pulse signal of the same intensity, adjusting the relative position of the core electrode and the cage electrode to obtain a pulse electric field range suitable for the tissue to be ablated; or adjusting the size of the high-voltage pulse signal to obtain a pulse electric field range suitable for the tissue to be ablated.

[0015] Beneficial effects of the present application: The present application can adjust the high-voltage pulse signal to connect with one or more short electrodes of the cage electrode and the core electrode, or to connect with any two short electrodes of the core electrode, or to generate pulse electric fields of different ranges by adjusting the relative positions of the core electrode and the cage electrode, so as to adapt to the part to be ablated in different tissue structures; the cage electrode structure helps to form a clear and precise ablation boundary, prevent the leakage of electromagnetic energy causing damage to surrounding organs, tissues and severe muscle tremors, which is not conducive to the ablation effect, and there is a risk of causing the ablation needle to deviate and damage important tissues. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings:

[0017] Figure 1 This is a structural diagram of the ablation catheter;

[0018] Figure 2 is the electrode structure diagram;

[0019] Figure 3 Figure 1 is a diagram of the core electrode structure;

[0020] Figure 4 A structural diagram of an ablation catheter including a core electrode with a short electrode;

[0021] Figure 5 The ablation catheters include 4, 6, 8, and 10 electrodes, respectively, the structural diagrams of the two poles of the high-voltage pulse signal connected to the cage electrode and the short discharge electrode, the pulse electric field diagrams in two directions, and the stereogram;

[0022] Figure 6 A structural diagram of an ablation catheter including a core electrode with two short electrodes;

[0023] Figure 7The ablation catheters include 4, 6, 8, and 10 electrodes respectively, the structural diagrams of the two poles of the high-voltage pulse signal connected to the cage electrode and two short discharge electrodes respectively, the pulse electric field diagrams in two directions, and the stereogram;

[0024] Figure 8 for Figure 6 When the pulse intensity of the structure is weakened, the two poles of the high-voltage pulse signal are connected to two short electrodes, to a cage electrode and a short electrode, and to a cage electrode ring and two short electrodes respectively;

[0025] Fig. 9 A structural diagram of an ablation catheter including a core electrode with three short electrodes;

[0026] Fig.10 The ablation catheters include 4, 6, 8, and 10 electrodes respectively, the structural diagrams of the two poles of the high-voltage pulse signal connected to the cage electrode and three short discharge electrodes respectively, the pulse electric field diagrams in two directions, and the stereogram;

[0027] Fig.11 for Fig. 9 When the pulse intensity of the structure is weakened, the two poles of the high-voltage pulse signal are connected to two non-adjacent short electrodes and two adjacent short electrodes respectively;

[0028] Fig.12 for Fig. 9 When the pulse intensity of the structure is weakened, when the two poles of the high-voltage pulse signal are connected to the cage electrode and the second short electrode respectively, the pulse electric field diagram of the structure connected to the cage electrode and the first short electrode or the second short electrode respectively;

[0029] In the figure: 111, the first straight section, 112, the second connecting section, 113, the third section; 210, the bushing, 220, the wire, 230, the short discharge electrode. DETAILED DESCRIPTION

[0030] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0031] An ablation catheter with high-precision ablation boundaries, such as Figure 1 As shown, it includes a core electrode and a structure in which a plurality of electrodes are evenly arranged in a circle, the root is gathered, the ends gradually diffuse to form a cage-shaped surrounding circle, and the middle is a cavity, and the core electrode is located in the cage-shaped electrode cavity.

[0032] Specifically, Figure 2 As shown, each electrode includes a first straight section 111, a third section 113, and an arc-shaped second connecting section 112 for connecting the first straight section and the third section, and the third section can be straight or arc-shaped. When multiple electrodes are arranged in a circle, the surfaces of the first straight sections of adjacent electrodes contact each other, and the diameters of the cavities corresponding to the second connecting sections of all electrodes tend to gradually increase, that is, each second connecting section of the electrode is convex outward relative to the middle cavity, so that the third sections of multiple electrodes are separated from each other to form a claw-shaped cage-type encirclement, and the cross-section of the claw-shaped cage-type encirclement range is greater than or equal to the cross-section of the cavity range surrounded by the second connecting section. The electrode portion located around the cage-shaped encirclement is exposed for conductivity, and the electric pulse is directly released to the tissue in the claw-shaped cage-type encirclement, and the surface of the other portion is covered with an insulating layer. When the first straight sections of multiple electrodes are energized, they act as equipotential bodies.

[0033] The core electrode is located at the center of the cage electrode, e.g. Figure 3 As shown, it includes a sleeve 210 and one or more wires 220 located in the sleeve, one or more short electrode connection positions are arranged inside the sleeve part located in the claw-shaped cage-shaped encirclement, and the short electrode connection positions are connected to the wires one by one, and discharge short electrodes 230 are distributed at the sleeve surface corresponding to the short electrode connection positions, and the discharge short electrodes are located within the far end range of the cage-shaped electrode. The core electrode can be pushed and pulled relative to the cage-shaped electrode for active adjustment, and can also be fixed.

[0034] Embodiment 1:

[0035] There is a core electrode in the cage electrode, a wire and a corresponding short electrode connection position are arranged in the sleeve, and a discharge short electrode is arranged outside the sleeve. Figure 4 shown.

[0036] The two poles of the high voltage pulse signal are connected to the cage electrode and the short discharge electrode respectively, forming a pulse electric field between the cage electrode and the short discharge electrode. Figure 5 As shown in the figure, the distribution diagram of the pulse electric field along the height direction of the ablation catheter, the distribution diagram along the length direction of the ablation catheter, and the corresponding stereogram are listed when the cage electrode includes 4, 6, 8, and 10 electrodes (surrounded by blue dots). Figure 5 In the column (a), it is obvious that the ablation boundary is not obvious, and it spreads to a certain range outside the cage electrode. There is leakage of electromagnetic energy. This is reflected in the fact that the electric field is radiated around the ablation site during the ablation process, causing some surrounding tissues to be affected by the ablation operation and destroying cell activity. As the number of electrodes increases, Figure 5 As can be seen from columns (b), (c), and (d), the range of the pulsed electric field gradually shrinks inward, basically surrounding the cage-shaped electrode, forming a clear ablation boundary.

[0037] Embodiment 2

[0038] There is a core electrode in the cage electrode, two wires and two corresponding short electrode connection positions are arranged in the sleeve, and two discharge short electrodes are arranged outside the sleeve. Figure 6 shown.

[0039] (1) One end of the high voltage pulse signal is connected to the cage electrode, and the other end is connected to two short discharge electrodes.

[0040] The pulse electric field is formed between the two short discharge electrodes, the cage electrode and the core electrode. Figure 7 As shown in FIG. 1 , the distribution diagrams along the height direction of the ablation catheter, the distribution diagrams along the length direction of the ablation catheter, and the corresponding stereograms are listed when the cage electrode includes 4, 6, 8, and 10 electrodes. Figure 7 (a) When the cage electrode includes four electrodes, it is obvious that the ablation boundary is not obvious on the working surface, and it spreads to a certain range outside the cage electrode, and there is leakage of electromagnetic energy. In addition, there is an obvious inward contraction phenomenon between the two electrodes, which is consistent with Figure 5 Compared with the column (a), in the direction perpendicular to the working surface, the radiation depth is significantly greater than that of the case with only one short discharge electrode under the same conditions. Figure 5 As can be seen from columns (b), (c), and (d), the range of the pulse electric field on the working surface gradually shrinks inward, basically surrounding the cage-shaped electrode, presenting a multi-petal plum blossom shape. When the number of electrodes reaches 10, a clear ablation boundary can be formed. Compared with the case where there is only one short discharge electrode under the same conditions in the embodiment, the field strength of the pulse electric field in the direction perpendicular to the working surface is significantly enhanced, and the depth of the action on the tissue to be ablated is deeper. When the pulse intensity is weakened, it is obvious that the electric field focused around the two short electrodes is as shown in the figure. Figure 8 As shown in (c), the electric field is concentrated between the short electrode and the cage electrode, forming an electric field vacancy zone between the two short electrodes.

[0041] (2) The high voltage pulse signal is connected to two short discharge electrodes;

[0042] like Figure 8 As shown in (a), the high-voltage pulse signal is connected to two short discharge electrodes respectively. When the pulse intensity is weak, two separated pulse electric fields are formed around the two short discharge electrodes.

[0043] (3) The high voltage pulse signal is connected to the cage electrode and one of the short discharge electrodes respectively.

[0044] like Figure 8As shown in (b), the high-voltage pulse signal is connected to the cage electrode and a short discharge electrode respectively. When the pulse intensity is weak, an obvious pulse electric field is formed between the short discharge electrode and the cage electrode.

[0045] Embodiment 3

[0046] There is a core electrode in the cage electrode, 3 wires and 3 corresponding short electrode connection positions are arranged in the sleeve, and 3 discharge short electrodes are arranged outside the sleeve. Fig. 9 shown.

[0047] (1) One end of the high-voltage pulse signal is connected to the cage electrode, and the other end is connected to three short discharge electrodes;

[0048] The superposition electric field of three groups of pulse electric fields is formed between the electrodes around the cage electrode and the three short discharge electrodes of the core electrode. Fig.10 As shown, the distribution diagram of the pulse electric field along the height direction of the ablation catheter, the distribution diagram along the length direction of the ablation catheter, and the corresponding stereogram are listed when the cage electrode includes 4, 6, 8, and 10 electrodes. Fig.10 (a) When the cage electrode includes four electrodes, it is obvious that the ablation boundary is not obvious on the working surface, and it spreads to a certain range outside the cage electrode, and there is leakage of electromagnetic energy. In addition, compared with the case with only two short electrodes, the obvious inward contraction phenomenon between the two electrodes is weakened. In the direction perpendicular to the working surface, the radiation depth is significantly greater than that of the case with only one short electrode and the case with two short electrodes under the same conditions. As the number of electrodes increases, such as Fig.10 As can be seen from columns (b), (c), and (d), the range of the pulsed electric field on the working surface gradually shrinks inward, basically surrounding the cage electrode, presenting a multi-petal plum blossom shape, with weaker radiation outside the cage electrode and better inward focusing effect. When the number of electrodes reaches 10, a clear ablation boundary can be formed. Compared with the case of only one short electrode and two short electrodes under the same conditions in embodiments 1 and 2, the field strength of the pulsed electric field in this embodiment along the direction perpendicular to the working surface is further enhanced, and the depth of the ablation tissue to be ablated is deeper.

[0049] (2) A high voltage pulse signal is connected to two of the short discharge electrodes respectively;

[0050] like Fig.11 As shown in (a), the high-voltage pulse signal is connected to the first discharge short electrode L1 and the third discharge short electrode L3 respectively. When the pulse intensity is weak, independent pulse electric fields are formed around the first discharge short electrode L1 and the third discharge short electrode L3 respectively, and an electric field vacancy is formed at the position of the first discharge short electrode L2; Fig.11As shown in (b), the high-voltage pulse signal is connected to the first short discharge electrode L1 and the second short discharge electrode L2 respectively. When the pulse intensity is weak, independent pulse electric fields are formed around the first short discharge electrode L1 and the second short discharge electrode L2 respectively. Since the two electric fields are close to each other, they merge into a larger electric field, resulting in an electric field vacancy at the position of the third short discharge electrode L3.

[0051] (3) The high-voltage pulse signal is connected to the cage electrode and one of the short discharge electrodes respectively

[0052] Fig.12 As shown in (a), the high-voltage pulse signal is connected to the cage electrode and the second short discharge electrode L2 respectively. When the pulse intensity is weak, a pulse electric field is formed between the cage electrode and the second short discharge electrode L2. Fig.12 As shown in (b), the high-voltage pulse signal is connected to the cage electrode, the first short discharge electrode L1 or the third short discharge electrode L3 respectively. When the pulse intensity is weak, a pulse electric field is formed between the cage electrode and the first short discharge electrode L1 or the third short discharge electrode L3.

[0053] It can be seen that the coverage ranges of the pulse electric fields formed by different numbers of short discharge electrodes and short discharge electrodes at different positions are all different. When the core electrode changes relative to the cage electrode, the coverage range of the pulse electric field also changes accordingly. By selecting different catheter structures and high-voltage pulse signal connection methods, precise positioning of the ablation range can be achieved.

[0054] It can be seen from the above simulation diagrams that the more the number of electrodes of the cage electrode, the more obvious the ablation boundary. However, considering the manufacturing difficulty, the number of electrodes cannot be increased infinitely. Generally, when the number of electrodes of the cage electrode reaches 10, a dense wrapping circle can be formed and the ablation boundary is clear.

[0055] Furthermore, considering that although the ablation boundary of the high-voltage pulse signal is clear but not precise enough, there is often a risk of electromagnetic energy leakage. Electromagnetic energy leakage is likely to cause damage to surrounding organs and tissues and severe muscle tremors, which is not conducive to the ablation effect and may also cause the ablation needle to shift and damage important tissues. The ablation boundary of the cage electrode is limited by the spacing between the electrodes (the third section) (abbreviated as the cage hole). The electrode spacing depends on the wavelength of the received high-voltage pulse signal. When the cage hole size is smaller than the wavelength, the expected shielding effect can be achieved; if the cage hole size is larger than the wavelength, electromagnetic wave leakage will occur and the desired shielding effect cannot be achieved. Therefore, in this embodiment, the cage hole λ1 < C*T. According to engineering experience, the relationship between the wavelength and the pulse rise time, based on C = λ / T, where λ represents the wavelength and T represents the period, it can be further obtained that λ = C*T*10 -3 , where C = 3X10 8 , when the pulse width is 10uS, T = 10uS, and the cage hole λ1 < (3X108 *10X10 -6 X10 -3 )=3cm; when the pulse width is 500nS, the cage hole λ1<(3X10 8 *500X10 -9 X10 -3 =0.15cm.

[0056] An ablation device comprises a pulse generator for generating a high-voltage pulse signal and the above-mentioned ablation catheter. The pulse generator is electrically connected to the ablation catheter to apply the high-voltage pulse signal to the tissue structure through a cage electrode and a core electrode.

[0057] An operating method of the ablation device is to extend the ablation catheter into the tissue to be ablated so that the tissue to be ablated is located within the boundary range of the cage-shaped encirclement of the ablation catheter, and a pulse generator generates high-voltage pulse signals of different intensities, which are applied between the cage electrode and one or more short electrodes of the core electrode, or between different short electrodes of the core electrode, or by adjusting the relative position of the core electrode and the cage electrode, to obtain a pulse electric field range suitable for the tissue to be ablated.

[0058] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An ablation catheter with a high-precision ablation boundary, characterized in that: It includes a cage electrode and a core electrode located in the cage electrode; The cage electrode is a structure in which multiple electrodes are evenly arranged in a circle, the roots are gathered, the ends gradually spread to form a cage-shaped encirclement, and the middle is a cavity; One or more short discharge electrodes are distributed on the surface of the core electrode, and the short discharge electrodes are located in a cage-shaped encirclement; The high voltage pulse signal is connected to the cage electrode and the short discharge electrode, or to any two short discharge electrodes, to form a pulse electric field with the cage encirclement as the boundary.

2. The ablation catheter according to claim 1, characterized in that: The spacing between the electrodes around the cage-shaped enclosure is smaller than the wavelength of the received pulse signal.

3. The ablation catheter according to claim 1, characterized in that: The electrode used to form the cage-shaped electrode includes a first straight section and a third section, and an arc-shaped second connecting section for connecting the first straight section and the third section; the surfaces of the first straight sections of adjacent electrodes contact each other and gather to form a root; the diameter of the cavity corresponding to the second connecting section tends to gradually increase from top to bottom, so that the third sections of multiple electrodes are separated from each other to form a claw-shaped cage-type encirclement.

4. The ablation catheter according to claim 1 or 3, characterized in that: The electrode portion located around the cage-shaped surrounding ring is exposed for conductivity, and the surface of the other portion is covered with an insulating layer.

5. The ablation catheter according to claim 1, characterized in that: The cage electrode has 10 electrodes.

6. The ablation catheter according to claim 1, characterized in that: The core electrode is located at the center of the cage electrode, including a sleeve and a wire located in the sleeve. A short electrode connection position connected to the wire is arranged in the sleeve. A discharge short electrode is distributed at the portion of the sleeve surface located in the cage-shaped encirclement corresponding to the short electrode connection position.

7. The ablation catheter according to claim 6, characterized in that: A wire and a short electrode connection position connected to the wire are arranged in the sleeve. The wire and the cage electrode are respectively connected to two poles of the high-voltage pulse signal to form a pulse electric field between the discharge short electrode and the cage electrode.

8. The ablation catheter according to claim 6, characterized in that: Two or more wires and a corresponding number of short electrode connection positions are arranged in the sleeve and connected correspondingly, and any two wires are connected to the two poles of the high-voltage pulse signal to form an independent or superimposed pulse electric field between the corresponding two discharge short electrodes; Or one or several of the wires and the cage-shaped electrode are respectively connected to the two poles of the high-voltage pulse signal, forming a pulse electric field between the corresponding discharge short electrode and the cage-shaped encirclement.

9. The ablation catheter according to claim 1 or 2 or 3 or 5 or 6 or 7 or 8, characterized in that: The position of the core electrode relative to the cage electrode can be adjusted up and down.

10. An ablation device, characterized in that: It comprises a pulse generator for generating a high-voltage pulse signal and an ablation catheter as claimed in any one of claims 9, wherein the pulse generator is electrically connected to the ablation catheter to apply the high-voltage pulse signal to the tissue structure through the cage electrode and the core electrode.

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