CN110811761B

CN110811761B - Shock wave generation system applied to angioplasty

Info

Publication number: CN110811761B
Application number: CN201910589157.5A
Authority: CN
Inventors: 艾睿; 彭惠群; 吴献蔚
Original assignee: Spectron Medical Technology Shanghai Co ltd
Current assignee: Spectron Medical Technology Shanghai Co ltd
Priority date: 2019-05-17
Filing date: 2019-07-02
Publication date: 2021-01-22
Anticipated expiration: 2039-07-02
Also published as: CN110811761A

Abstract

The invention discloses a shock wave generating system applied to angioplasty, which comprises: an axially extending elongated member having an outer surface; arranging a plurality of wired electrodes in a series; at least one non-conductive gap; a non-conductive component disposed over the at least one non-conductive gap, wherein: each of said wire electrodes being connected to an output terminal of a high voltage source by a wire extending from one terminal on the outer surface of the elongate member to the wired electrode; and each non-conductive component has a shape whose configuration affects the direction and/or intensity of a shock wave generated by an arc discharge from the first electrode to the second electrode, or affects the direction and/or intensity of a shock wave generated by an arc discharge from the second electrode to the first electrode. The invention can effectively break calcified plaques in the artery without damaging the vascular tissue, is beneficial to further interventional therapy of calcified arteries and can reduce the occurrence of dissection and restenosis.

Description

Shock wave generation system applied to angioplasty

Technical Field

The invention belongs to the field of medical instruments, and particularly relates to a shock wave generation system applied to angioplasty.

Technical Field

Atherosclerosis is a narrowing and hardening disease of the arteries caused by plaque build-up. The plaque is composed of fibrous tissue, fat, and calcium. The accumulated calcified plaque prevents the normal flow of blood, reducing the supply of oxygen and nutrients to the body. Of particular concern are arterial diseases of the arteries that supply blood to critical parts of the body, including the brain, heart and limbs.

The use of shock wave assisted balloon angioplasty is one method of treating highly calcified plaque. Although traditional balloon angioplasty can enlarge the luminal space by balloon inflation, it does not improve vascular compliance, and dissection and restenosis are common complications during and after surgery, respectively. Embedding shock wave generating electrodes within the balloon can help break up plaque, providing a more durable treatment for atherosclerotic disease. Arcing across the electrodes causes the bubbles to expand and collapse rapidly, producing a shock wave. The shock wave propagates through the liquid medium in the balloon and strikes the calcified plaque, breaking up the hard material. This facilitates further interventional treatment of the calcified artery, such as stenting, and also reduces the incidence of restenosis. Therefore, in order to treat atherosclerosis, it is necessary to develop a balloon angioplasty catheter that uses shock waves to break down and fragment calcium in blood vessels.

Disclosure of Invention

Shock wave therapy devices and systems for treating highly calcified human atherosclerotic blood vessels are described herein. Shock waves are essentially impulsive in nature and, when directed at hard calcified plaque, they can damage the plaque and soften the blood vessels. Once the calcified plaque in the vessel is removed, blood flow is naturally improved. This would be a better alternative to conventional balloon angioplasty, which simply compresses the plaque and enlarges the lumen, but does not eliminate the subsurface calcium.

A shock wave generating system for use in angioplasty applications includes an axially extending elongate member having an outer surface and a plurality of wired electrodes disposed on the outer surface of the elongate member, wherein the electrodes are arranged in series.

Further comprising at least one non-conductive gap separating a first wired electrode and a second wired electrode of the plurality of wired electrodes, wherein each wired electrode is connected to an output of the high voltage power supply by a wire, wherein the wire extends from the output to an outer surface of the elongated member where the wire is connected to the wired electrode, and wherein the gap is configured to allow an arc discharge point to pass from the first wired electrode to the second wired electrode or the second wired electrode to the first wired electrode when the high voltage is applied at the output.

One or more physically isolated wireless electrodes may also be included, the wireless electrodes being disposed between the non-conductive gaps of the two wired electrodes. Each non-conductive member is shaped to control the direction and/or intensity of a shock wave generated by an arc discharge from the first electrode to the second electrode, or from the second electrode to the first electrode.

In embodiments of the invention, the shape of each non-conductive component may be individually selected from the following forms: a convex shape, a concave shape, and a combination of a convex profile and a concave profile with respect to electrodes disposed on both sides of the non-conductive member.

In an embodiment of the invention, the non-conductive member is shaped to direct the shock wave radially outwardly from the elongated structure.

Thus, in some embodiments, the one or more non-conductive components block the shortest path between two adjacent electrodes, thereby forcing the ionization path away from the elongated member arc such that all shock waves generated are directed radially outward. Controlling the path of gas ionization prior to arc formation may allow for more stable generation of the shock wave produced. This effect may be further achieved by using one or more non-conductive components with a protruding profile, wherein the maximum radial diameter of the non-conductive components is larger than the maximum radial diameter of the electrodes arranged on both sides of the non-conductive components. The convex shape may be a re-convex shape.

In some embodiments, the one or more non-conductive components are concave in shape, e.g., the maximum radial diameter of the non-conductive component relative to the maximum radial diameter of electrodes disposed on either side of the non-conductive component; and the maximum radial diameter of the non-conductive component is smaller than the maximum radial diameter of the electrodes disposed on either side of the non-conductive component. The concave shape of the non-conductive member facilitates the possibility of directing the shock wave radially outwardly from the elongate structure. The concave shape may be a concave shape.

In some embodiments, the one or more non-conductive components are a combination of convex and concave shapes, e.g., wherein the maximum radial diameter of the at least one non-conductive component is greater than the maximum radial diameter of an electrode adjacent to the at least one non-conductive component; the minimum radial diameter of the at least one non-conductive component is less than the maximum radial diameter of electrodes disposed on either side of the at least one non-conductive component. The convex and concave shape of each non-conductive component can affect the direction and intensity of the shock wave by affecting the ionization path and shock wave deflection.

In all embodiments, the non-conductive component may also act as a physical barrier to prevent shock waves from being transmitted into the central catheter shaft, protecting the inner axially extending elongate member and any conductive wires along the non-conductive component from being impacted and damaged by the shock waves. Further, the non-conductive member may serve as electrodes separately disposed on both sides of the non-conductive member. This ensures that the end faces of two adjacent electrodes in the assembly do not physically contact each other, even if the wire is bent at a large angle. This maintains a non-conductive gap so that current can pass through the electrodes via the arc discharge to generate a shock wave. The non-conductive member may be in contact with the electrodes disposed on both sides of the non-conductive member, or may be out of contact with the electrodes disposed on both sides of the non-conductive member.

Typically, the non-conductive component has a ring-like structure, and the non-conductive component and non-conductive structural ring may be used interchangeably herein.

Those skilled in the art will appreciate that any of the embodiments discussed herein may be combined in any manner that is technically compatible.

The present invention also provides an angioplasty catheter incorporating a shock wave generating system.

Another function of the non-conductive member is to act as an output modifier for the generated shock wave. The non-conductive member is arranged between the two electrodes so that the generation of arc discharges and shock waves can be influenced. In a preferred embodiment, the non-conductive member is a shock wave guide for projecting shock waves radially outwardly relative to the central axis of the conduit. The non-conductive member may have a concave upper portion in cross-section, with the waves of the non-conductive member having the concave upper portion being most effective to direct shock waves outwardly. In another embodiment, it is an arc discharge regulator for specifying the ionization path of the gas through which the arc passes. The non-conductive member may be convex and result in a protrusion between the two electrodes. This shape forces the ionization path into a fixed minimum arc curve. This ensures that no arc is formed below the outer surface of the electrode and therefore all shock waves generated are directed radially outwards with respect to the central axis of the catheter. It is to be understood that the shape of the non-conductive circumferential ring may take any form of protruding shape or any form of concave shape, as well as any form of combination of protruding and concave shapes.

The high voltage source may be an external high voltage generator providing the necessary potential difference to drive current through the catheter circuit. There may be various combinations of balloon size and length to accommodate different instances of calcified lesions, and thus, various electrode configurations may exist over the length of the treatment portion of the catheter. To accommodate different lengths at the lesion, the length of the treatment portion may range from short (e.g., two shock wave sources) to extremely long (e.g., nine shock wave sources). For different numbers of shock wave sources, the high voltage generator may require different voltage levels in order to produce a stable and predictable current for each conduit.

For example, nine electrodes connected in series require a significantly higher potential difference to be applied across the high voltage generator, rather than a two-electrode series circuit, in order to achieve the same current consumption of the nine electrodes, and therefore the same pressure intensity of the shock wave generated by each shock wave source. Thus, the system may contain passive electrical devices that act as markers to be recognized by the high voltage generator when the conduit system is connected. The electrical device may take the form of a Printed Circuit Board (PCB) containing a unique combination of on-board components that will determine the voltage output by the high voltage generator when connected. For example, the electrical device may be connected in the same PCB circuit as the high voltage generator. The PCB may have a resistance level that causes the circuit to adjust to a certain voltage output that is ultimately applied to the circuitry of the electrodes. The two-electrode system requires only a low voltage output and the PCB board can be set to a settable resistance value so that when connected to the high voltage generator, the low voltage output is selected. The nine electrode system requires a higher voltage output and therefore the PCB board can be set to another resistance value, thereby allowing a higher voltage to be output by the high voltage generator. Thus, the operator can simply connect the catheter of their choice according to the patient's needs, and the high voltage generator will automatically select the appropriate voltage level corresponding to that particular catheter, thereby reducing human error in operation.

Drawings

FIG. 1 is a diagrammatic view of a shock wave generation system including a plurality of components. 101 is an angioplasty balloon in an inflated state. 102 are a pair of electrodes on the interior of an angioplasty balloon catheter. The above-mentioned components constitute a shock wave source. 103 is a non-conductive gap between a pair of electrodes. 104 is a wire harness connecting the electrodes and the high voltage generator 105 in the circuit. The wire bundle 104 passes through the PCB board 106 and finally returns to the high voltage generator 105 in a wire bundle 107.

Fig. 2 is a close-up view of an electrode array within an angioplasty balloon on a catheter.

Electrodes

201 and 202 are disposed on an elongated member 203. Between 201 and 202 there is an annular non-conductive member 204.

Fig. 3A is a ring-shaped structure of a ring-shaped non-conductive member located between the pair of electrodes 302, the ring-shaped structure being concave in shape. Fig. 3B is another ring-like structure of a ring-shaped non-conductive member located between the pair of electrodes 302, which is convex in shape. Fig. 3C is another ring-like structure of a ring-shaped non-conductive member located between the pair of electrodes 302, which is a combination of convex and concave shapes.

FIG. 4A is an illustration of a shockwave generation system having a four-electrode structure 401 in one embodiment. 402 and 403 are corresponding PCB boards and high voltage generators.

FIG. 4B is a schematic representation of a shockwave generation system having a four-electrode structure 401 in another embodiment. 405 and 406 are corresponding PCB boards and high voltage generators.

Detailed Description

Described herein is a device and system for shock wave therapy for treatment of highly calcified body lumen atherosclerotic blood vessels. The present invention provides a shock wave generating system as described above. Figure 1 shows a stylized diagram of the shock wave generation system. The angioplasty balloon 101 can be pressurized with a liquid medium (e.g., saline or contrast agent) and electrodes inside the balloon will generate shock waves that will propagate through the medium to the hard, brittle calcium in the atherosclerotic plaque. The electrodes may be disposed in adjacent opposing positions, as shown at 102. These electrodes are disposed on the elongated member 203 and are connected to the high voltage generator 105 by electrically conductive wires. 106 is a PCB board through wires. The PCB determines the output voltage of the high voltage generator.

In order to generate the shock wave, an arc discharge that generates cavitation bubbles must be allowed. This can be achieved by physically separating two adjacent electrodes, thus requiring a non-conductive gap, such as 103 shown in FIG. 1. In fig. 2, a non-conductive member is placed in the non-conductive gap between

electrodes

201 and 202. The non-conductive member is in the shape of a ring for physically separating two adjacent electrodes to ensure that a space is always maintained between the two adjacent electrodes. Such a shape is suitable for use in tortuous arterial vessels. The non-conductive component may be constructed of a non-conductive material such as plastic or ceramic. In order to fill all the space between the two electrodes, the non-conductive member may or may not physically contact both electrodes, depending on the desired situation. For maximum flexibility, a resilient insulator, such as silicone, may also be selected.

One advantage of using a physical separator between the electrodes is the ability to influence the trajectory of the shock wave generated at the gap. Fig. 3a depicts a non-conductive ring 301 having a concave shape, forming a concave region between an electrode pair 302. The concave shape provides a deflection-modifying effect on any incident shock wave and redirects the shock wave radially outward relative to the central axis. This will help to ensure a more even distribution of the shock wave at any point on the conduit.

Another possible non-conductive ring configuration is a convex shape. Fig. 3B illustrates the convex shape of the curve outward of the electrode pair 304. This shape of the ring controls the path of gas ionization prior to arc formation. Under the influence of such a convex shape, a shock wave of uniform intensity can be generated more stably. This shape of the ring also forces the arc path to a set minimum arc shape so that no arc is formed below the outer surface of the electrode, and therefore all of the shock waves generated are radially outward relative to the central axis of the conduit.

The shape of the ring may be more than merely curved convex or concave. The ring may be a combination of protrusions and recesses, such as the 305 ring shown in fig. 3 c. The combined shape is more angular than convex and concave shapes. These varying angles will be more advantageous in controlling the characteristics of the generated shock wave and its intensity.

One of the most prominent and useful features of the present invention is the ability to control the number of electrodes on the catheter and thus the source of the shock wave. The catheter may have only two shock wave sources or three sets of nine electrodes each including two non-conductive gaps to form six shock wave sources. A catheter with only one shock wave source may be used to deliver shock waves in a point-of-delivery manner to a single location in the vasculature. Catheters with long shock wave sources would be advantageous for treating lesions at deeper locations, such as those found in the peripheral vasculature. Thus, catheters with more electrodes require more current to drive than catheters with fewer electrodes. Since the electrodes are connected in series with the high voltage generator, more electrodes will require a higher voltage output from the generator.

Although the operator may manually select the output voltage of the generator, passive electronics may also be used to allow the generator to automatically identify the type of conduit connected thereto and to select the appropriate voltage output by itself. The present invention utilizes a PCB board as shown at 106 in fig. 1. The PCB has no power supply and forms a circuit with the high voltage generator. In one embodiment of the system, the circuit is continuous, with the electrodes on the catheter and generator connected in series. However, in a preferred embodiment, the circuit is separate from the electrodes and only connects the PCB board to another set of electronics within the high voltage generator. The circuit may include a combination of resistors therein that form a composite resistance. When the conduit is connected to the high voltage generator, its resistance value causes the output voltage of the generator to drop or increase. As in fig. 4A and 4B, the conduits of different electrode counts are assigned different PCB boards of different resistance values. In fig. 4A, a four electrode system has a PCB board 402 that sets a resistance value of 1. The high voltage generator identifies the resistance value through the electrical connection and adjusts to produce a lower output voltage. In fig. 4B, the four-electrode system has a PCB board 405 that sets a resistance value of 2. More electrodes require a greater output voltage than previous catheters in order to produce shock waves of the same intensity at each shock wave source. Thus, the PCB board provides a resistance value that is recognized by the high voltage generator as a trigger to generate a higher output voltage. Therefore, the PCB board can enable the high voltage generator to automatically select the correct output voltage value, and prevent the risk of human errors.

Claims

1. A shock wave generation system for use in angioplasty, comprising:

an axially extending elongated member having an outer surface;

a plurality of wired electrodes disposed on an outer surface of the elongated member, wherein the wired electrodes are arranged in series therebetween;

at least one non-conductive gap separating a first wired electrode and a second wired electrode of the plurality of wired electrodes, wherein the non-conductive gap is configured to allow an arc discharge to pass from the first wired electrode to the second wired electrode or the second wired electrode to the first wired electrode;

a non-conductive component disposed over the at least one non-conductive gap, wherein:

each of the wire electrodes being connected to an output terminal of a high voltage source by a lead extending from one of the terminals on the outer surface of the elongated member to the wire electrode, and

each non-conductive component has a shape whose configuration affects the direction and/or intensity of a shock wave generated by an arc discharge from the first electrode to the second electrode, or affects the direction and/or intensity of a shock wave generated by an arc discharge from the second electrode to the first electrode;

each non-conductive component independently has a shape selected from the group consisting of: concave shapes, convex shapes, and combinations of concave and convex shapes with respect to electrodes disposed on either side of the non-conductive member.

2. The system of claim 1, wherein the system is used in angioplasty procedures: the system also includes one or more physically isolated wireless electrodes disposed within a non-conductive gap between two wired electrodes to form a secondary non-conductive gap between the wireless electrodes, wherein the non-conductive component is disposed in each second non-conductive gap.

3. The system of claim 1, wherein the system is used in angioplasty procedures: the non-conductive component has a shape configured to direct shock waves radially outward from the elongate member.

4. A shock wave generation system for use in angioplasty according to any one of claims 1 to 3, wherein: the non-conductive member blocks a shortest path between two adjacent ones of the wired electrodes.

5. A shock wave generation system for use in angioplasty according to any one of claims 1 to 3, wherein: when at least one of the non-conductive components has a convex shape, the maximum radial diameter of the non-conductive component is greater than the maximum radial diameter of electrodes disposed on either side of the non-conductive component.

6. The system of claim 5, wherein the system is used in angioplasty procedures: each non-conductive member having a convex shape has a convex profile.

7. A shock wave generation system for use in angioplasty according to any one of claims 1 to 3, wherein: when at least one of the non-conductive members has a concave shape, the maximum radial diameter of the non-conductive member coincides with the maximum radial diameter of an electrode disposed adjacent to the non-conductive member; and the smallest radial diameter of the non-conductive member is less than the largest radial diameter of the electrodes disposed on either side of the non-conductive member.

8. The system of claim 7, wherein the system is used in angioplasty procedures: each non-conductive member having a concave shape has a concave profile.

9. A shock wave generation system for use in angioplasty according to any one of claims 1 to 3, wherein: when at least one of the non-conductive members has a combined shape of a concave surface and a convex surface, the maximum radial diameter of the non-conductive member is larger than the maximum radial diameter of an electrode disposed adjacent to the non-conductive member; and the smallest radial diameter of the non-conductive member is less than the largest radial diameter of the electrodes disposed on either side of the non-conductive member.

10. A shock wave generation system for use in angioplasty according to any one of claims 1 to 3, wherein: further comprising an integrated electronic printed circuit board which determines the output voltage of said high voltage source.