CN113081238A

CN113081238A - Balloon electrode catheter and ablation apparatus including the same

Info

Publication number: CN113081238A
Application number: CN202110349031.8A
Authority: CN
Inventors: 罗中宝; 王海峰; 代聪育; 诸敏
Original assignee: Remedicine Co ltd
Current assignee: Remedicine Co ltd
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2021-07-09

Abstract

The present disclosure relates to an electrode catheter, including: a bladder having a contracted state and an expanded state, the bladder being capsular in the expanded state; a distal rod disposed on a first end of the bladder; a first electrode disposed on the distal shaft; at least two electrode pads disposed on an outer surface of the bladder; and at least three conductors corresponding to and configured to power the at least two electrode pads and the first electrode.

Description

Balloon electrode catheter and ablation apparatus including the same

Technical Field

The present disclosure relates to the field of medical devices, and more particularly, to an electrode catheter and an ablation device including the same.

Background

Atrial Fibrillation (AF) is a common cardiac arrhythmia affecting the lives of over 3300 million people worldwide. Radiofrequency ablation and cryoablation are two common methods currently used clinically to treat cardiac arrhythmias such as atrial fibrillation. Both types of ablation must be sufficiently damaging to the arrhythmic tissue or to substantially interfere with or isolate abnormal electrical conduction in the myocardial tissue, while excessive ablation may affect surrounding healthy tissue as well as neural tissue, but insufficient ablation may not serve to block abnormal electrical conduction. Therefore, it is critical to produce a suitable ablation zone.

The radio frequency ablation adopts point-by-point ablation, the operation time is long, the requirement on the catheter operation level of an operator (such as a doctor) is high, discomfort can be caused due to the long time during the operation of a patient, and the problems of pulmonary vein stenosis and the like easily occur after the operation. In addition, radiofrequency ablation can damage the cardiac endothelial surface, activate the extrinsic coagulation cascade and lead to coke and thrombosis, which in turn can lead to systemic thromboembolism. It follows that the application of radio frequency energy to target tissue can have an effect on non-target tissue, for example, the application of radio frequency energy to atrial wall tissue can cause damage to the digestive system, such as the esophagus, or the nervous system. Radiofrequency ablation may also lead to scarring of the tissue, further leading to embolization problems. Cryoablation has a high probability of causing phrenic nerve damage, and epicardial freezing near the coronary arteries can also lead to thrombosis and progressive coronary stenosis.

Disclosure of Invention

In view of the profound understanding of the problems with the background, that existing radiofrequency ablation is time consuming and has a consequent tissue destruction, and the cryoablation also causes problems such as embolism, the inventor of the present disclosure proposes an electrode catheter using a pulsed electric field ablation technique in the present case, an electrode is arranged on the surface of a sacculus included in the electrode catheter, and another electrode is arranged on a distal rod connected with the sacculus, the electrode is matched with the electrode on the surface of the capsule to generate an effective pulse electric field, the pulse electric field can selectively ablate target tissues to form a continuous effective ablation zone, the adverse effect of noise signals on the heart rate of the heart is successfully blocked, thereby avoiding the occurrence of atrial fibrillation and simultaneously reducing or even avoiding the damage to good tissue cells which do not need to be ablated.

Specifically, a first aspect of the present disclosure proposes an electrode catheter including:

a bladder having a contracted state and an expanded state, the bladder being capsular in the expanded state;

a distal rod disposed on a first end of the bladder;

a first electrode disposed on the distal shaft;

at least two electrode pads disposed on an outer surface of the bladder; and

at least three conductors corresponding to the at least two electrode pads and the first electrode and configured to power the at least two electrode pads and the first electrode.

The present disclosure innovatively proposes to use not only electrodes arranged on the bladder, but also a first electrode arranged outside the bladder, for example on a distal rod provided on a first end of the bladder, to form an electric field, so as to be able to ensure that the resulting ablation zone is, for example, an ablating loop that is continuous both radially as well as circumferentially of the vessel, ensuring that the transmission path of the noise signal to the heart, causing the arrhythmia, can be successfully cut off.

In one embodiment according to the present disclosure, the electrode catheter further includes an outer tube in fluid communication with the bladder via a second end distal from the first end and configured to control the bladder to transition between the contracted state and the expanded state. In this way, the operator of the electrode catheter can be facilitated to control the state of the bladder.

In one embodiment according to the present disclosure, the at least two electrode pads are disposed on a half side of the bladder near the first end and at equal distances from the first electrode. In this way, the formation of unwanted ablation zones can be reduced or even avoided while ensuring the formation of a closed ablating loop, minimizing damage to tissue that does not require ablation.

Optionally, in one embodiment according to the present disclosure, the bladder in the inflated state is a spherical bladder or a conical bladder. Preferably, in one embodiment according to the present disclosure, the at least two electrode sheets are uniformly disposed on the outer surface of the bladder and at least a portion of the at least two electrode sheets are exposed. Optionally or alternatively, in one embodiment according to the present disclosure, a groove is provided on an outer surface of the bladder, the groove being configured to receive at least one conductor of the at least three conductors.

Preferably, in one embodiment according to the present disclosure, at least one conductor of the at least three conductors is provided with an insulator at a side remote from the bladder. Further preferably, in one embodiment according to the present disclosure, the electrode sheet has a rectangular shape, a long axis of the electrode sheet is arranged along an axial direction of the electrode catheter, and a length L of the electrode sheet is related to a preset shortest ablation width W in a vein axial direction and an applied ablation voltage V between the first electrode and the electrode sheet.

In one embodiment according to the present disclosure, a potential difference exists between the first electrode and each of the at least two electrode sheets. In such a manner that an electric field is formed between the first electrode and an electrode pad disposed on the outer surface of the bladder, thereby forming a closed ablating loop. Preferably, in one embodiment according to the present disclosure, the first electrode is configured as a ring-shaped electrode.

In one embodiment according to the present disclosure, the potentials of the first electrode and the electrode sheet are configured in one of the following configurations:

the polarity of the first electrode is positive and negative alternating pulses and the electrode sheet is grounded;

the polarity of the first electrode is a positive pulse or a negative pulse and the electrode sheet is grounded;

the first electrode is grounded and the polarity of the electrode plate is a pulse with alternating positive and negative polarities;

the first electrode is grounded and the polarity of the electrode sheet is a positive pulse or a negative pulse;

the polarity of the first electrode is a positive pulse and the polarity of the electrode sheet is a negative pulse; or

The polarity of the first electrode is a negative pulse and the polarity of the electrode sheet is a positive pulse.

In one embodiment according to the present disclosure, the number of the at least two electrode sheets is 6 to 10, preferably 8.

In one embodiment according to the present disclosure, the electrode catheter further comprises a handle having an electrode power supply interface coupled to the conductor and a fluid input/output port in fluid communication with the bladder.

In one embodiment according to the present disclosure, the first electrode is configured to be movably disposed on the distal rod between a first position and a second position of the distal rod.

In one embodiment according to the present disclosure, the electrode catheter further comprises a first electrode position control device configured to adjust a position of the first electrode on the distal shaft.

In one embodiment according to the present disclosure, the electrode catheter further includes an electrode cap disposed at the free end of the distal shaft, the electrode cap having a polarity different from a polarity of the first electrode.

Furthermore, a second aspect of the present disclosure proposes an ablation apparatus comprising:

a pulse signal generator configured to generate a pulse signal; and

the electrode catheter according to the first aspect of the present disclosure, which is electrically connected with the pulse signal generator.

In summary, the present disclosure innovatively proposes to use not only electrodes arranged on the bladder, but also a first electrode arranged outside the bladder, for example on a distal rod provided on a first end of the bladder, to form an electric field, so as to ensure that the resulting ablation zone is, for example, an ablating loop that is continuous in both the radial direction and the circumferential direction of the vessel, and to ensure that the transmission path of the noise signal to the heart, which causes arrhythmia, can be successfully cut off.

Drawings

Embodiments are shown and described with reference to the drawings. These drawings are provided to illustrate the basic principles and thus only show the aspects necessary for understanding the basic principles. The figures are not to scale. In the drawings, like reference numerals designate similar features.

FIG. 1 shows a schematic view of an electrode catheter 100 according to one embodiment of the present disclosure;

FIG. 2 shows a schematic view of an electrode catheter 200 according to another embodiment of the present disclosure;

FIG. 3 illustrates a cross-sectional view of an electrode catheter 300 according to yet another embodiment of the present disclosure;

FIG. 4 illustrates an exploded view of an electrode catheter 400 according to yet another embodiment of the present disclosure;

FIG. 5 illustrates an exploded view of an electrode catheter 500 according to yet another embodiment of the present disclosure;

fig. 6 shows a schematic diagram of an ablation device 1000 in accordance with an embodiment of the present disclosure;

FIG. 7a shows a schematic view of the position of an electrode catheter 900 in ablation with target tissue by means of an electrode according to the present disclosure; and

fig. 7b shows a schematic view of an ablation region formed at the end of the ablation shown in fig. 7 a.

Other features, characteristics, advantages and benefits of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

Detailed Description

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof. The accompanying drawings illustrate, by way of example, specific embodiments in which the disclosure can be practiced. The example embodiments are not intended to be exhaustive of all embodiments according to the disclosure. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.

The technique used in this disclosure to treat atrial fibrillation is a pulsed electric field technique that applies brief high voltages to the target tissue cells that can produce local high voltage electric fields of several hundred volts per centimeter. The local high voltage electric field destroys the cell membrane by forming a puncture in the cell membrane where the applied electric field is above the cell threshold so that the puncture does not reclose, thereby making such electroporation irreversible. The perforation will allow the exchange of biomolecular material across the cell membrane, resulting in necrosis or apoptosis of the cell.

Since different tissue cells have different voltage penetration thresholds, the high voltage pulse technique can selectively treat myocardial cells with relatively low thresholds without affecting other non-target cell tissues, such as nerve cells, esophageal cells, vascular cells, and blood cells. Meanwhile, the time for releasing energy is very short, so that the pulse electric field technology cannot generate obvious thermal effect, and the problems of tissue damage, pulmonary vein stenosis and the like are avoided.

In particular, pulsed electric field (PET) ablation is a non-thermal damage technique, the damage mechanism being the appearance of nano-scale pores in certain cell membranes by high frequency electrical pulses. Potential advantages of the PET ablation technique that can be used for atrial fibrillation ablation include the following: firstly, the PET ablation technology can pertinently select or avoid target tissues by setting different threshold values, so that surrounding tissues can be protected from being damaged; secondly, the PET ablation technology can be rapidly released within a few seconds, namely the treatment time of the cells of the target tissue is short, and the cells are easy to accept by a user; furthermore, compared to cryoablation, PET ablation does not produce coagulation necrosis, thereby reducing the risk of Pulmonary Vein (PV) stenosis.

In order to apply the pulsed electric field technology PET for ablation, the balloon is used to fix and shape the electrode in the present disclosure, and this is designed because the balloon has a small volume in the contracted state and is easily extended into the target position, and after reaching the target position, the balloon is switched to the expanded state, and the balloon is easily attached, for example, the pulmonary vein opening in one of the application scenarios is usually elliptical, and other target positions may have other shapes, although the target positions have different shapes, when the balloon is pressurized, the shape of the pulmonary vein opening can be changed, and the pulmonary vein openings with different shapes are attached, so that the attaching effect is better, and the subsequent PET ablation effect is better. In addition, after the saccule is inflated, the contrast is obvious under X-rays, so that a doctor can easily observe the fit condition with target tissues, and the fit effect can be further ensured; furthermore, after the balloon is occluded with a target tissue such as the ostium of a pulmonary vein, the balloon occlusion is observed and adjusted via intraluminal injectable contrast.

In addition to applying a bladder that is switchable between a contracted state and an expanded state, the present disclosure also innovatively suggests using not only electrodes disposed on the bladder, but also electrodes disposed outside the bladder, for example, on a distal rod disposed on a first end of the bladder, to form an electric field, thereby enabling to ensure that the resulting ablation zone is an ablation ring that is continuous in both radial and circumferential directions of the pulmonary vein, enabling to successfully cut off a transmission path of arrhythmia caused by conduction of an abnormal signal triggered or driven by an ectopic focus. Preferably, the electrode arranged on the distal rod is movable in the axial direction of the pulmonary vein, so that it can be determined whether the extent of the ablation zone is to be adjusted depending on the ablation effect. It is further preferred that an electrode cap can be provided at the free end of the distal stem remote from the bladder, the polarity of the electrode cap being different from the polarity of the first electrode, so that the extent of the ablation zone can be further adjusted, ensuring a superior ablation effect.

Specifically, the structure of the electrode catheter and the structure of the corresponding ablation apparatus according to the present disclosure will be described below with reference to fig. 1 to 6.

Fig. 1 shows a schematic view of an electrode catheter 100 according to one embodiment of the present disclosure. As can be seen in fig. 1, an electrode catheter 100 in accordance with the present disclosure includes a balloon 110, a distal shaft 120, a first electrode 130, a plurality of

electrode pads

141, 142, 143, 144, 145, a plurality of

conductors

151, 152, 153, 154, 155, and an outer tube 160. Wherein the bladder 110 has a contracted state and an expanded state, only the expanded state of which is shown in fig. 1, the bladder 110 in the contracted state is similar to the shape and thickness dimensions of the left and right distal rods 120 and the outer tube 160. The bladder 110 assumes a bladder in the expanded state shown in fig. 1. Furthermore, a distal rod 120 is arranged at a first end of the capsule 110, in the figure shown in fig. 1 on the left side of the capsule 110, and a first electrode 130 for subsequent formation of an electric field for ablation can be arranged on the distal rod 120. Again, as can be seen in fig. 1, five

electrode pads

141, 142, 143, 144, 145 are shown disposed on the outer surface of the bladder 110. Here, it should be understood by those skilled in the art that five electrode pads are shown, and that electrode pads are also provided on the unseen back surface, and that there are only two electrode pads to form a more desirable electric field with the first electrode 130 provided on the distal rod 120 for ablation, i.e., the number of electrode pads is not limited to an excessive number.

In addition to the above-mentioned components, the electrode catheter disclosed according to the present disclosure includes, for example, a plurality of conductors, five conductors, for example, five wires, are shown in fig. 1, and it should be understood by those skilled in the art that five wires are shown here, and the wires are also provided on the invisible back surface, and the wires are only required to be more than two for the corresponding number of electrode sheets and first electrodes, so as to be able to form a relatively ideal electric field for ablation with the first electrode 130 and the plurality of electrode sheets provided on the distal rod 120, i.e., the number of wires is not limited too much, but in principle, the wires, for example, the five

conductors

151, 152, 153, 154, 155 and the first electrode 130 correspond to the five

electrode sheets

141, 142, 143, 144, 145 and the first electrode 130 and are configured to be used for the five

electrode sheets

141, 142, 143, 144, 145 and the five

electrode sheets

141, 142. 143, 144, 145 and said first electrode 130. Furthermore, the conductors for supplying power to first electrode 130 may be located, for example, inside bladder 110 and thus not shown in fig. 1.

Furthermore, it can be seen that, preferably, in the embodiment shown in fig. 1, the electrode catheter 100 according to the present disclosure can further include, for example, an outer tube 160, the outer tube 160 being in fluid communication with the bladder 110 via a second end (e.g., an end of a right portion of the bladder 110 in the orientation shown in fig. 1) distal from the first end (e.g., an end of a left portion of the bladder 110 in the orientation shown in fig. 1) and configured to control the bladder 110 to transition between the deflated state and the inflated state. Before bladder 110 has reached the target location, bladder 110 assumes, for example, a contracted state in which the thickness of bladder 110 is similar to the left and right distal rods 120 and outer tube 160, thereby allowing electrode catheter 100 with bladder 110 to be easily delivered to the target location, for example, via a venous blood vessel. After reaching the vicinity of the target position, the balloon 110 can be switched from a contracted state to an expanded state, which is an expanded balloon, for example, through the outer tube 160, so as to fit the tissue to be ablated, and after being expanded, the position of the balloon 110 can be finely adjusted, for example, through the outer tube 160, so as to better fit the tissue to be ablated, thereby improving the treatment effect. It will be appreciated by those skilled in the art that assistance can also be provided during the above-described positioning procedure, for example by means of an X-ray machine or by means of a contrast technique, in order to position the tissue precisely, providing a guarantee for a good subsequent ablation effect.

Furthermore, after, for example, ablation is completed, the ablation effect can be evaluated first, and then it is decided whether a predetermined ablation effect is achieved, to further decide whether supplemental ablation is required or the electrode catheter 100 can be withdrawn. After a predetermined ablation effect is achieved, the balloon 110 can be re-switched from the expanded state to the contracted state, e.g., via the outer tube 160, prior to withdrawal of the electrode catheter 100, so that the electrode catheter 110 can be withdrawn with no or less trauma to the venous vessel through which it passed.

As previously mentioned, the present disclosure innovatively proposes to use not only electrodes disposed on this bladder 110, but also first electrodes 130 disposed outside the bladder 110, for example on a distal rod 120 disposed on a first end of the bladder 110, to form an electric field, thereby being able to ensure that the resulting ablation zone is an ablation ring that is continuous in both radial and circumferential directions of the vessel, ensuring that the transmission path of the arrhythmia caused by conduction of an abnormal signal triggered or driven by an ectopic focus can be successfully cut off. In order to achieve a better ablation effect, the first electrode arranged on the distal rod is preferably movable in the axial direction of the vessel, so that the extent of the ablation zone can be adjusted according to the ablation needs.

Fig. 2 shows a schematic view of an electrode catheter 200 according to another embodiment of the present disclosure. As can be seen in fig. 2, an electrode catheter 200 according to the present disclosure includes a balloon 210, a distal shaft 220, a first electrode 230, a plurality of

electrode pads

241, 242, 243, a plurality of

conductors

251, 252, 253, and an outer tube 260. Wherein the bladder 210 has a contracted state and an expanded state, only the expanded state being shown in fig. 2, the bladder 210 in the contracted state is similar to the shape and thickness of the left and right distal rods 220 and the outer tube 260. The bladder 210 assumes a bladder shape in the expanded state shown in fig. 2. Further, a distal rod 220 is provided at a first end of the bladder 210, at the end shown in fig. 2 to the left of the bladder 210, and a first electrode 230 for subsequent formation of an electric field for ablation can be provided on the distal rod 220. Again, as can be seen in fig. 2, three

electrode pads

241, 242, 243 are shown disposed on the outer surface of the bladder 210. Here, it should be understood by those skilled in the art that three electrode pads are shown, and that the electrode pads are also provided on the unseen back surface, and that there are only two electrode pads to form a more desirable electric field with the first electrode 230 provided on the distal rod 220 for ablation, i.e., the number of electrode pads is not limited to an excessive number.

In addition to the above-mentioned components, the electrode catheter 200 disclosed according to the present disclosure further includes, for example, a plurality of conductors, three conductors, such as three

wires

251, 252, 253 are shown in fig. 2, and it should be understood by those skilled in the art that three wires are shown here, and the wires are also provided on the invisible back side, and the wires only need to be more than two for a corresponding number of electrode sheets and first electrodes, so as to be able to form a desired electric field for ablation with the first electrode 230 and the plurality of electrode sheets provided on the distal rod 220, i.e., the number of wires is not limited too much, but in principle, the conductors, such as the at least three

conductors

251, 252, 253 and the first electrode 230, correspond to the at least two

electrode sheets

241, 242, 243 and the first electrode 230 and are configured to form a desired electric field for ablation with the at least two

electrode sheets

241, 252, 253, 242. 243 and said first electrode 230. Also as previously described, the conductors for supplying power to the first electrode 230 may be located, for example, inside the bladder 210 and thus not shown in fig. 2.

Those skilled in the art will appreciate that the above-described control of the state of bladder 110 or bladder 210 using outer tube 160 or outer tube 260 is merely an example, and that rather than, for example, outer tube 160 or outer tube 260, bladder 110 or bladder 210 itself can have a state control component that causes bladder 110 or bladder 210 to be in a contracted state or an expanded state by receiving a control signal.

Furthermore, as can be seen from fig. 2, the first electrode 230 is configured to be movably disposed on the distal rod 220, for example, along the axis AA direction, between a first position (for example, a position shown by a left dashed line in fig. 2) and a second position (for example, a position shown by a right dashed line in fig. 2) of the distal rod 220, that is, the first electrode 230 is capable of moving within a stroke range formed by the distal rod 220 and marked by a symbol T in fig. 2. If a wider ablation zone is desired, the first electrode 230 may be positioned at the location identified by the left dashed line further from the

electrode pads

241, 242, and 243; conversely, if a narrower swath of ablation is desired, the first electrode 230 may be positioned closer to the

electrode pads

241, 242, and 243 as indicated by the dashed right-hand line. Furthermore, as can also be seen in fig. 2, there is a gap 272 on the distal rod 220, through which gap 272 a pull wire present inside the bladder 210 and the outer tube 260 can power the first electrode 230 and control the specific position at which the first electrode 230 moves over the stroke T.

To achieve accurate control of the position of the first electrode, the electrode catheter further comprises a first electrode position control device configured to adjust the position of the first electrode on the distal shaft. Fig. 3 illustrates a cross-sectional view of an electrode catheter 300 according to yet another embodiment of the present disclosure. As can be seen in fig. 3, an electrode catheter 300 according to the present disclosure includes a bladder 310, a distal shaft 320, a first electrode 330, a plurality of

electrode pads

341, 342, a plurality of

conductors

351, 352, and an outer tube 360. Wherein the bladder 310 has a contracted state and an expanded state, only the expanded state being shown in fig. 3, the bladder 310 in the contracted state is similar to the shape and thickness of the left and right distal rods 320 and the outer tube 360. The bladder 310 assumes a bladder shape in the expanded state shown in fig. 3. Further, a distal rod 320 is provided at a first end of the bladder 310, at the end shown in fig. 3 to the left of the bladder 310, and a first electrode 330 for subsequent formation of an electric field for ablation can be provided on the distal rod 320.

Again, as can be seen in fig. 3, two

electrode pads

341, 342 are shown disposed on the outer surface of the bladder 310. In addition to the components described above, the electrode catheter 300 disclosed in accordance with the present disclosure includes, for example, a plurality of conductors, two conductors are shown in fig. 3, e.g., 2

wires

351 and 352, where it will be appreciated by those skilled in the art that 2 wires are shown here, and that wires are also provided on the unseen back side, and that more than two wires are provided for a corresponding number of

electrode pads

341 and 342 and first electrode 330, so as to be able to have a potential difference with the first electrode 330 and the plurality of

electrode pads

341 and 342 provided on the distal shaft 320 to form a more desirable electric field for ablation.

In addition to the above components, it can also be seen from fig. 3 that the electrode catheter 300 further comprises a first electrode position control device 370, wherein the first electrode position control device 370 is configured to adjust the position of the first electrode 330 on the distal rod 320, for example, in the case of the first electrode 330 with its own driving device, the first electrode position control device 370 can, for example, send a control signal to the own driving device of the first electrode 330, and then the own driving device of the first electrode 330 can realize the desired position adjustment according to the control signal.

Of course, the above-mentioned position adjustment can also be achieved by a mechanical driving manner of the first electrode position control device 370, for example, the first electrode position control device 370 can move in an axial direction relative to the outer tube 360, so as to drive the first electrode 330 to move on the distal rod 320, and further adjust the position of the first electrode 330 on the distal rod 320. In one embodiment, the control device 370 includes a pull wire that can be used as both a conductor to provide power to the first electrode 330 and as a control device to effect the position adjustment in a mechanically driven manner. The distal rod 320 is provided with at least one slit in the axial direction through which the pull wire is connected to the first electrode 330.

The above description of fig. 1 to 3 describes the configuration of the front end of the ablation device for the ablation portion, and in all three embodiments, the electrode pads are disposed on the half sides of the

bladders

110, 210, and 310 near the first end, i.e., the left side regions of the

bladders

110, 210, and 310, and are disposed at substantially equal distances from the

first electrodes

130, 230, and 330. By the arrangement, the ablation effect can be ensured to be in accordance with the expected effect, the size of the ablation zone can be minimized as small as possible, and the tissue which is not necessary to be ablated is prevented from being ablated. This is because if the electrode pads are arranged at unequal distances from the

first electrodes

130, 230 and 330, the further electrode pads will form additional ablation zones, which however have little practical effect, i.e. ablation of the zones is not necessary.

Further, the

bladders

110, 210, and 310 are spherical or conical in the inflated state. When high voltage pulses are used, the spherical balloon ablation results are better because the spacing between the electrodes is wider, allowing a wider ablation zone; in contrast, when low voltage pulses are used, the ablation results of the conical balloon are better because the ablation zone is not discontinuous due to the voltage drop because of the closer spacing between the electrodes. However, the

balloons

110, 210, and 310 of the present embodiment, whether spherical or conical, are devoid of ablation blind spots in the ablating loop.

Furthermore, as can be seen from among the

electrode catheters

100, 200, and 300 shown in fig. 1 to 3, the at least two electrode pads are uniformly disposed on the outer surface of the

bladders

110, 210, and 310 and at least a portion of the at least two electrode pads is exposed, for example, at least a portion of the at least two electrode pads on a side away from the

bladders

110, 210, and 310 is exposed. In this manner, the exposed electrode sheet is conformed to the area to be ablated, thereby cooperating with the electrode disposed on the distal shaft to form a suitable ablating loop. When a particular ablation is performed, a potential difference exists between the first electrode 130 and each of the at least two

electrode pads

141, 142, 143, 144 and 145 in fig. 1. Accordingly, a potential difference exists between the first electrode 230 and each of the at least two

electrode sheets

241, 242, and 243 in fig. 2, and a potential difference exists between the first electrode 330 and each of the at least two

electrode sheets

341 and 342 in fig. 3. Thereby an electric field is formed between the first electrode and the electrode slice, so that the subsequent ablation process can be smoothly carried out.

Preferably, such as in the example of the electrode catheter 200 shown in fig. 2, the bladder 210 is provided with a groove on an outer surface thereof, the groove being configured to receive at least one conductor of the at least three conductors, such as the

wires

251, 252 and/or 253. Such a recess is not readily apparent from fig. 2, since it accommodates a wire. It will be appreciated by those skilled in the art that due to the presence of such a groove, the conductor is well received therein, such that the outer surface of the bladder 210 may be flat despite the presence of the conductor thereon, thereby facilitating implantation of the electrode catheter 200. As previously described, at least a portion of

electrode pads

241, 242, and 243 are exposed for use in an ablation process. While the other conductive parts need to be insulated to enable control of the ablated area, not left uncontrolled. To this end, in the example shown in fig. 2, at least one conductor (e.g.,

conductor

251, 252, or 253) of the at least three conductors (e.g.,

conductors

251, 252, and 253) is provided with an insulator on a side away from the bladder 210. Preferably, the entire outer surface of the

conductor

251, 252 or 253 can also be coated or wrapped with an insulator.

As shown in fig. 1 and 2, the

electrode pads

141, 142, 143, 144, 145, 241, 242, 243 have a substantially rectangular shape, the long axes of the

electrode pads

141, 142, 143, 144, 145, 241, 242, 243 are arranged along the axial direction of the

electrode catheter

100, 200, and the electrode pad length L is related to the preset shortest ablation width W in the axial direction of the vein and the applied ablation voltage V between the

first electrode

130, 230 and the

electrode pads

141, 142, 143, 144, 145, 241, 242, 243. For example, the long axis of the

electrode pads

141, 142, 143, 144, 145, 241, 242, 243 is arranged along the axial direction of the

electrode catheter

100, 200 including the

bladder

110, 210, and the length L of the

electrode pads

141, 142, 143, 144, 145, 241, 242, 243 is determined based on the preset ablation width W in the axial direction of the pulmonary vein and the ablation voltage V applied to the

electrode pads

141, 142, 143, 144, 145, 241, 242, 243. Through simulation, in the case of different electrode slice lengths L, for example, L is 3mm, 4mm, 5mm, 6mm or 7mm, the relationship between the ablation width W and the ablation voltage V exhibits the following relationship, for example: the ablation width W is approximately linear with the ablation voltage V and can therefore be fitted using the following fitting function:

W＝a₁(L)V+a₂(L) wherein a₁(L) and a₂(L) represents a function with respect to L.

Preferably, for example, in the electrode catheter 200 shown in fig. 2, the first electrode 230 is configured as a ring electrode. In the examples illustrated in fig. 1 to 3, the potentials of the first electrodes 130, 230, 330 and the electrode sheets 141, 142, 143, 144, 145, 241, 242, 243, 341, 342 are configured in one of the following configurations: the first configuration is that the polarity of the first electrode 130, 230, 330 is a pulse alternating positive and negative and the electrode pads 141, 142, 143, 144, 145, 241, 242, 243, 341, 342 are grounded; the second configuration is that the polarity of the first electrode 130, 230, 330 is a positive or negative pulse and the electrode pad 141, 142, 143, 144, 145, 241, 242, 243, 341, 342 is grounded; a third configuration is a pulse in which the first electrode 130, 230, 330 is grounded and the polarity of the electrode sheet 141, 142, 143, 144, 145, 241, 242, 243, 341, 342 is positive and negative alternately; a fourth configuration is that the first electrode 130, 230, 330 is grounded and the polarity of the electrode pad 141, 142, 143, 144, 145, 241, 242, 243, 341, 342 is a positive or negative pulse; a fifth configuration is that the polarity of the first electrode 130, 230, 330 is a positive pulse and the polarity of the electrode sheet 141, 142, 143, 144, 145, 241, 242, 243, 341, 342 is a negative pulse; or, for example, a sixth configuration is that the polarity of the first electrode 130, 230, 330 is a negative pulse and the polarity of the electrode pad 141, 142, 143, 144, 145, 241, 242, 243, 341, 342 is a positive pulse. Here, the number of the at least two

electrode sheets

141, 142, 143, 144, 145, 241, 242, 243, 341, 342 may be, for example, 6 to 10, and preferably 8. Here, the at least two

electrode sheets

141, 142, 143, 144, 145, 241, 242, 243, 341, 342 may be flexible electrodes.

FIG. 4 illustrates an exploded view of an electrode catheter 400 according to yet another embodiment of the present disclosure; it can be seen from fig. 4 that the left end of the electrode catheter 400 includes a distal rod such as support 420, electrode ring 430, pull wire 471, balloon 410, electrode pad 440, wire 455, cover 456 of wire 455, inner tube 472, and outer tube 460. In the version shown in fig. 4, the support 420 is used for distal support of the spherical balloon 410 and can be used for pulmonary vein ostial positioning; the electrode ring 430 is placed at the distal neck of the balloon 410, and the electrode ring 430 can be controlled by a pulling wire 471 to move a certain distance along the axial direction, so that the electrode ring 430 can be movably arranged, and the pulling wire 471 is simultaneously used as a pulling device and a voltage conveying wire of the electrode ring 430. A pull wire 471 is connected to the electrode ring 430 via a slit axially disposed in the support 420 and extends along the lumen of the inner tube 472 to a handle (not shown in fig. 4), the outer surface of the balloon 410 is grooved to extend to the proximal end of the balloon 410 and to embed the wire 455, an electrode pad 440 is secured to the outer surface of the balloon 410, the electrode pad 440 can be, for example, a flexible electrode or an inert metal electrode, and a cover 456 of the wire 455 covers the wire 455, which can be, for example, a film or glue.

Further, fig. 5 shows an exploded view of an electrode catheter 500 according to yet another embodiment of the present disclosure, from fig. 5 it can be seen that the left end of the electrode catheter 500 comprises a distal rod such as a support 520, an electrode ring 530, a pull wire 571, a balloon 510, an electrode sheet 540, a wire 555, a cover 556 of the wire 555, an inner tube 572 and an outer tube 560. In the version shown in fig. 5, the support 520 is used for distal support of the spherical balloon 510 and can be used for pulmonary vein ostial positioning; the electrode ring 530 is arranged at the distal neck of the spherical balloon 510, the electrode ring 530 can move a certain distance along the axial direction under the control of the traction wire 571, so that the electrode ring 530 can be movably arranged, and the traction wire 571 is simultaneously used as a traction device and a voltage transmission wire of the electrode ring 530. The pull wires 571 are connected to the electrode ring 530 via axially disposed slits in the support 520 and extend along the lumen of the inner tube 572 to a handle (not shown in fig. 5), the outer surface of the spherical balloon 510 is fluted to extend to the proximal end of the spherical balloon 510 and the wire 555 is embedded, securing the electrode pad 540 to the outer surface of the spherical balloon 510, the electrode pad 540 can be, for example, a flexible electrode or an inert metal electrode, and the cover 556 of the wire 555 covers the wire 555, which can be, for example, a film or glue. In addition to the above-described structure, an electrode cover 580 may be added to the head end of the support 520, the electrode cover 580 forming an electric field with the electrode ring 530 for supplemental ablation when the ablation zone formed by the ablation of the electric field between the bladder 510 and the electrode ring 530 is incomplete. The lead of the electrode cover 580 in one particular embodiment is connected to the handle via an inner tube within the distal stem. In the present disclosure, the electrode ring 530 can be moved back and forth as needed for ablation to vary the ablation field area, for example, to extend the ablation area axially inward of the pulmonary vein ostium. The polarity of the electrode cover is different from that of the first electrode, so that the range of the ablation zone can be further adjusted, and the excellent ablation effect is ensured.

In embodiments consistent with the present disclosure,

bladders

110, 210, 310, 410, and 510 may be made of an insulating material such as PEBAX, PET, Nylon, TPU, and the like. While the cross-section of the

conductors

151, 152, 153, 154, 155, 251, 252, 253, 351, 352, 455, 555 can be, for example, circular or rectangular; the

electrode sheets

141, 142, 143, 144, 145, 241, 242, 243, 341, 342, 440, 540 are rectangular, the aspect ratio can be, for example, 2 to 5, preferably 3 to 4, the thickness can be between 0.05 mm and 0.2 mm, the

electrode sheets

141, 142, 143, 144, 145, 241, 242, 243, 341, 342, 440, 540 are uniformly distributed on the same cross section, and the number of the electrodes can be 6 to 10, preferably 8; the diameter of the

outer tube

160, 260, 360, 460, 560 is 9-15 Fr, wherein French (F or Fr) is the diameter unit of a catheter commonly used in the field of medical devices, 3Fr ≈ 1mm, while the

outer tube

160, 260, 360, 460, 560 can be single lumen or multi-lumen; the inner tube is a mapping electrode catheter/guidewire/contrast injection channel. The connection of the supporting piece and the bladder and the connection of the bladder and the outer pipe can adopt glue or a hot melting welding process; the support and the inner tube, the electrode plate and the bladder and the conductor and the bladder can be connected by glue, and the glue is preferably UV glue. Furthermore, the

electrode catheter

100, 200, 300, 400, 500 can preferably also comprise a handle, which can be connected, for example, to the

outer tube

160, 260, 360, 460, 560, on which an electrode power supply interface is provided, which is connected to the conductor, and a fluid input/output port, which is in fluid communication with the bladder.

Fig. 6 shows a schematic view of an ablation device 1000 in accordance with an embodiment of the present disclosure. That is, the present disclosure also relates to an ablation apparatus 1000 for performing irreversible electroporation, the ablation apparatus 1000 having a pulse signal generator configured to generate a pulse signal (not shown in the drawings), the electrode catheter 600 being connected to a pulse signal generation module and transmitting the pulse signal to a target location through an electrode ring and an electrode pad of the electrode catheter 600. Furthermore, the ablation device 1000 further comprises an electrode catheter 600 according to the above, said electrode catheter 600 being electrically connected to said pulse signal generator. Still further, optionally, the ablation device 1000 can further include an operation control part 800, the operation control part 800 (e.g., the aforementioned handle) being configured to control the pulse signal generator and manipulate the electrode catheter 600. Furthermore, as can also be seen in fig. 6, the ablation device 1000 can also include, for example, four interfaces 700, which four interfaces 700 integrate, for example, a positive and negative electrical cable interface, a mapping electrode catheter 600/guidewire/contrast access interface, and a gas/liquid injection interface.

In a particular use of the ablation device 1000 shown in fig. 6, a vascular sheath is first placed into the bilateral femoral vein, for example, using a femoral venipuncture. The coronary sinus electrode is sent to the right position through the left sheath tube; performing atrial septal puncture and left atrial and pulmonary vein angiography through the right femoral vein; then, replacing the pulse ablation delivery system; then, the electrode catheter 600 including the bladder and the mapping catheter are fed; then, mapping the catheter into a target vein of interest; next bladder 600 is inflated into position; finally, the pulmonary vein ostium is blocked by bladder 600 and ablated.

Figure 7a shows a schematic view of the position of an electrode catheter 900 in ablation with target tissue by means of an electrode according to the disclosure, while fig. 7b shows a schematic view of the ablation zone formed at the end of the ablation shown in fig. 7a, it can be seen that by means of an electrode arranged on the balloon of the electrode catheter 900 and a first electrode arranged on the distal rod, an ablation zone 902 can be formed in the form of a concentric circular band, for example around the distal rod, the ablation region 902 is located between the non-ablation region 901 and the non-ablation region 903, and as can be further seen from fig. 7b, the ablation width of the ablation region 902 is relatively uniform, no ablation regions with different widths are formed, and the ablation region is continuously closed, that is, a discontinuous region is not formed in a certain middle position, and a transmission path of arrhythmia caused by the conduction of abnormal signals triggered or driven by the ectopic excitation focus is ensured to be successfully cut off.

While various exemplary embodiments of the disclosure have been described, it will be apparent to those skilled in the art that various changes and modifications can be made which will achieve one or more of the advantages of the disclosure without departing from the spirit and scope of the disclosure. Other components performing the same function may be substituted as appropriate by those skilled in the art. It should be understood that features explained herein with reference to a particular figure may be combined with features of other figures, even in those cases where this is not explicitly mentioned. Further, the methods of the present disclosure may be implemented in either all software implementations using appropriate processor instructions or hybrid implementations using a combination of hardware logic and software logic to achieve the same result. Such modifications to the solution according to the disclosure are intended to be covered by the appended claims.

Claims

1. An electrode catheter, characterized in that the electrode catheter comprises:

a distal rod disposed on a first end of the bladder;

a first electrode disposed on the distal shaft;

at least two electrode pads disposed on an outer surface of the bladder; and

2. The electrode catheter of claim 1, further comprising an outer tube in fluid communication with the bladder via a second end distal from the first end and configured to control the bladder to transition between the contracted state and the expanded state.

3. The electrode catheter of claim 1 or 2, wherein the at least two electrode pads are disposed on a half side of the bladder near the first end and equidistant from the first electrode.

4. The electrode catheter of claim 1 or 2, wherein the balloon is a spherical balloon or a conical balloon in the expanded state.

5. The electrode catheter of claim 1 or 2, wherein the at least two electrode pads are uniformly disposed on the outer surface of the bladder and at least a portion of the at least two electrode pads are exposed.

6. The electrode catheter of claim 1 or 2, wherein a groove is provided on an outer surface of the bladder, the groove being configured to receive at least one conductor of the at least three conductors.

7. The electrode catheter of claim 1 or 2, wherein at least one of the at least three conductors is provided with an insulator on a side remote from the bladder.

8. The electrode catheter as claimed in claim 1 or 2, wherein the electrode sheet has a rectangular shape, a long axis of the electrode sheet is arranged along an axial direction of the electrode catheter, and a length L of the electrode sheet is related to a preset shortest ablation width W in a vein axial direction and an applied ablation voltage V between the first electrode and the electrode sheet.

9. The electrode catheter of claim 1 or 2, wherein there is a potential difference between the first electrode and each of the at least two electrode pads.

10. The electrode catheter of claim 9, wherein the first electrode is configured as a ring electrode.

11. The electrode catheter of claim 9, wherein the electrical potentials of the first electrode and the electrode pad are configured in one of the following configurations:

12. Electrode catheter according to claim 1 or 2, characterized in that the number of the at least two electrode sheets is 6 to 10, preferably 8.

13. The electrode catheter of claim 1 or claim 2, further comprising a handle having an electrode power supply interface connected to the conductor and a fluid input/output port in fluid communication with the bladder.

14. The electrode catheter of claim 1 or 2, wherein the first electrode is configured to be movably disposed on the distal rod between a first position and a second position of the distal rod.

15. The electrode catheter of claim 14, further comprising a first electrode position control device configured to adjust a position of the first electrode on the distal shaft.

16. The electrode catheter of claim 1 or 2, further comprising an electrode cap disposed at the free end of the distal rod, the electrode cap having a polarity different from the polarity of the first electrode.

17. An ablation device, characterized in that the ablation device comprises:

a pulse signal generator configured to generate a pulse signal; and

the electrode catheter of any one of claims 1 to 16, which is electrically connected with the pulse signal generator.

18. The ablation apparatus of claim 17, further comprising:

an operation control part configured to control the pulse signal generator and manipulate the electrode catheter.