Electrode assembly for shock wave generating catheter

Abstract

An electrode assembly for a shock wave generating catheter is provided. The electrode assembly includes at least one electrically non-conductive layer, a first electrode, and a second electrode, wherein the first electrode and the second electrode are physically separated from each other and connectable to a voltage power source. The electrode assembly has a tubular configuration with an outer surface and an inner surface, the inner surface forming a lumen. The outer surface of the electrode assembly is formed from an outermost electrically non-conductive layer of at least one electrically non-conductive layer, the outermost electrically non-conductive layer being disposed over the first electrode and the second electrode. The at least one electrically non-conductive layer has a first hole extending therethrough, exposing a portion of the first electrode to the ambient environment. The at least one electrically non-conductive layer also has a second hole extending therethrough, exposing a portion of the second electrode to the ambient environment. The first hole and the second hole are configured to allow an electric arc discharge to pass from the first electrode to the second electrode, or vice versa, when a potential difference is applied between the first electrode and the second electrode by the voltage power source. Also provided are a shockwave generating unit including an electrode assembly, a shockwave generating system including one or more shockwave generating units, and a shockwave generating catheter including the shockwave generating system.

Description

[Technical Field]

[0001] The present invention relates to an electrode assembly for a shockwave generating catheter. The present invention also relates to a shockwave generating catheter comprising a shockwave generating unit, a shockwave generating system and one or more electrode assemblies. [Background technology]

[0002] The listing or discussion of a prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is general general knowledge.

[0003] Balloon angioplasty catheters are interventional devices used to dilate blood vessels and soften calcified lesions to restore normal blood flow. Over the years, numerous improvements have been made to conventional balloons, including the addition of an electrode assembly that generates shock waves within the balloon, softening or cracking calcifications on the vessel's inner wall. The shock wave generator generates high-power shock waves that impact the hard, brittle calcium, while the balloon exerts physical pressure. The combined effect of the shock waves and balloon pressure has been proven to more effectively restore vascular patency over the long term. However, limitations of current devices lie in the power of the shock waves generated and the lifespan of the generator that generates them.

[0004] Therefore, a need exists for alternative and / or improved electrode assemblies for shockwave generating systems and catheters. Summary of the Invention

[0005] Aspects and embodiments of the present invention are described in the following numbered aspects. 1. 1. An electrode assembly for a shockwave generating catheter, said electrode assembly comprising: comprising at least one electrically non-conductive layer, a first electrode, and a second electrode, wherein the first electrode and the second electrode are physically separated from each other and connectable to a voltage source; the electrode assembly has a tubular configuration with an outer surface and an inner surface, the inner surface defining a lumen; an outer surface of the electrode assembly formed from an outermost electrically non-conductive layer of at least one electrically non-conductive layer, the outermost electrically non-conductive layer being disposed over the first electrode and the second electrode; the at least one electrically non-conductive layer has a first hole extending therethrough and exposing a portion of the first electrode to the ambient environment; the at least one electrically non-conductive layer has a second hole extending therethrough and exposing a portion of the second electrode to the ambient environment; wherein the first and second holes are configured to allow an electric arc discharge to pass from the first electrode to the second electrode, or vice versa, when a potential difference is applied between the first and second electrodes by a voltage power supply; Electrode assembly. 2. 2. The electrode assembly of claim 1, wherein the inner surface of the electrode assembly is formed from an innermost electrically non-conductive layer. 3. 3. The electrode assembly of claim 2, further comprising one or more inner electrically non-conductive layers disposed between the innermost and outermost electrically non-conductive layers. 4. 4. The electrode assembly of aspect 3, wherein the electrode assembly further comprises at least two internal electrically non-conductive layers, e.g., two, three, four, five, or six internal electrically non-conductive layers. 5. 5. The electrode assembly of any one of aspects 3-4, wherein the first electrode and the second electrode are each independently embedded in the innermost electrically non-conductive layer or one of the inner electrically non-conductive layers. 6. 6. The electrode assembly according to any one of aspects 2 to 5, wherein the first electrode and the second electrode are embedded in different electrically non-conductive layers. 7. 7. The electrode assembly according to any one of aspects 2 to 6, wherein the first electrode is embedded within the innermost electrically non-conductive layer. 8. 7. The electrode assembly according to any one of aspects 2 to 6, wherein the first electrode and the second electrode are each independently embedded in one of the internal electrically non-conductive layers. 9. 9. The electrode assembly of any one of aspects 3 to 8, wherein each of the inner electrically non-conductive layers is formed from a polymer independently selected from the group consisting of a thermoplastic elastomer (e.g., a polyimide), a fluoropolymer (e.g., a fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), an epoxy resin, and one or more combinations thereof. 10. The electrode assembly consists of: a first inner electrically non-conductive layer disposed on the innermost electrically non-conductive layer; a second inner electrically non-conductive layer disposed on the first inner electrically non-conductive layer; a third inner electrically non-conductive layer disposed on the second inner electrically non-conductive layer; and an outermost electrically non-conductive layer disposed on a third inner electrically non-conductive layer; 10. The electrode assembly according to any one of aspects 3 to 9, comprising: 11. the first inner electrically non-conductive layer is formed from polyimide; the second inner electrically non-conductive layer is formed of an epoxy resin; the third inner electrically non-conductive layer is formed of polyimide; 11. An electrode assembly according to aspect 10. 12. 12. The electrode assembly of claim 11, wherein the first electrode is embedded within an innermost electrically non-conductive layer and the second electrode is embedded within a second, inner, electrically non-conductive layer. 13. 12. The electrode assembly according to any one of aspects 2 to 11, wherein the innermost electrically non-conductive layer is formed of an epoxy resin. 14. 13. The electrode assembly according to any one of aspects 2 to 12, wherein the outermost electrically non-conductive layer is formed from an impact-resistant and / or impact-absorbing material, for example, the outermost electrically non-conductive layer is formed from an epoxy resin having impact-resistant and / or impact-absorbing properties. 15. 15. The electrode assembly of any one of aspects 2 to 14, wherein the first electrode and the second electrode are offset relative to one another along a longitudinal axis of the electrode assembly. 16. 2. The electrode assembly of claim 1, wherein the inner surface of the electrode assembly is formed from an innermost layer of the first and second electrodes and an electrically non-conductive member, the electrically non-conductive member physically separating the first and second electrodes from each other. 17. The electrode assembly according to aspect 1, further comprising one or more inner electrically non-conductive layers disposed between the innermost layer and the outermost layer. 18. the electrically non-conductive member is formed from one or more of the group consisting of a polymer, a ceramic, an epoxy, an adhesive, and combinations thereof; Optionally, the polymer is selected from the group consisting of a thermoplastic elastomer (e.g., a polyimide), a fluoropolymer (e.g., fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), and combinations thereof; For example, the electrode assembly according to any one of aspects 16 to 17, wherein the polymer is made of polyimide. 19. 19. The electrode assembly according to any one of aspects 16 to 18, wherein the electrically non-conductive member has a maximum radius corresponding to a maximum radius of the first and second electrodes. 20. 19. The electrode assembly according to any one of aspects 16 to 18, wherein the electrically non-conductive member has a maximum radius that is greater than a maximum radius of each of the first and second electrodes. twenty one. the inner surface of the electrode assembly is formed from a first electrode and a first portion of the innermost electrically non-conductive layer; a second portion of the innermost electrically non-conductive layer disposed between the first electrode and the outermost electrically non-conductive layer; a second electrode disposed between the first portion of the innermost electrically non-conductive layer and the outermost electrically non-conductive layer; The electrode assembly according to aspect 1. twenty two. an innermost electrically non-conductive layer formed of nylon, poly(ether-b-amide) (e.g., Pebax®), or heat-shrinkable tubing (e.g., fluorinated ethylene propylene, polyethylene terephthalate); The outermost electrically non-conductive layer is formed from an impact-resistant and / or impact-absorbing material, for example, the outermost electrically non-conductive layer is formed from an epoxy resin having impact-resistant and / or impact-absorbing properties. 22. An electrode assembly according to aspect 21. twenty three. 23. The electrode assembly of any of aspects 1 to 22, wherein the first and / or second electrode is formed from one or more of the group consisting of tungsten, steel, titanium, cobalt, platinum, iridium, nickel, and alloys thereof. twenty four. 24. The electrode assembly of any one of aspects 1 to 23, wherein the first and second holes are offset from one another along a longitudinal axis of the electrode assembly. twenty five. 25. The electrode assembly of any one of aspects 1 to 24, wherein the first and second holes are offset from one another around the circumference of the electrode assembly. 26. 26. The electrode assembly of any one of aspects 1 to 25, wherein the first and second holes have substantially the same diameter. 27. 27. The electrode assembly according to any one of aspects 1 to 26, wherein the first and second holes have different diameters. 28. 28. The electrode assembly of any one of aspects 1 to 27, wherein the portion of the first and / or second electrode exposed to the ambient environment has a surface shape configured to concentrate the location of the electric arc discharge. 29. 30. The electrode assembly of claim 28, wherein the surface shape configured to concentrate the location of the arc discharge comprises a surface depression. 30. 29. The electrode assembly of aspect 28, wherein the surface depression has a shape selected from the group consisting of a hemispherical depression, a cone, and a cylindrical debossment (e.g., a cylindrical debossment). 31. the surface features configured to concentrate the location of the arc discharge include surface protrusions; 29. The electrode assembly of aspect 28, wherein optionally the surface protrusions are conical or hemispherical. 32. 32. The electrode assembly of any one of aspects 1 to 31, wherein the diameters of the first and second holes are both about 0.2 mm to about 1 mm. 33. 33. The electrode assembly according to any one of aspects 1 to 32, wherein the minimum distance from the edge of the first hole to the edge of the second hole is from about 0.05 mm to about 10 mm. 34. at least one of the electrically non-conductive layers has a thickness of about 0.02 mm to about 0.8 mm; Optionally, each of the electrically non-conductive layers has a thickness of about 0.02 mm to about 0.8 mm. 34. The electrode assembly according to any one of aspects 1 to 33. 35. a third hole extending through the at least one electrically non-conductive layer and exposing a portion of the first electrode to the ambient environment; a fourth hole extending through the at least one electrically non-conductive layer and exposing a portion of the second electrode to the ambient environment; The third and fourth holes are configured to allow an electric arc discharge to pass from the first electrode to the second electrode or vice versa when the first and second electrodes are connected to a high voltage power supply; 35. The electrode assembly according to any one of aspects 1 to 34. 36. A shock wave generating unit comprising: an electrode assembly according to any one of aspects 1 to 35; and an axially extending elongated member extending through an inner lumen of the electrode assembly; Optionally, the shock wave generating unit, wherein the axially extending elongated member has an outer surface made of polyimide. 37. 1. A shock wave generation system using a shock wave generating catheter, comprising: one or more shock wave generating units according to aspect 36; a high-voltage power supply having electrical output terminals electrically connected to the first and second electrodes of the one or more shock wave generating units; Optionally, the high voltage power supply has a voltage of 1000V to 5000V. Shock wave generation system. 38. A shock wave generating system as described in aspect 37, wherein the electrical output terminals of the high voltage power supply are connected to the first and second electrodes of the one or more shock wave generating units by wires extending from the terminals along the outer surface of the axially extending elongated member or through the interior of the elongated member. 39. A shock wave generating system according to any one of aspects 37 to 38, further comprising an integrated electronic printed circuit board configured to determine the output voltage of the high voltage power supply. 40. A shock wave generating system according to any one of Aspects 37 to 39, an inflatable balloon disposed over the axially extending elongated member and the one or more shock wave generating units; A shock wave generating catheter comprising: [Brief explanation of the drawings]

[0006] [Figure 1A] FIG. 1 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having two electrically non-conductive layers. [Figure 1B] FIG. 1 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having three electrically non-conductive layers. [Figure 2A] FIG. 1 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having a single electrically non-conductive layer. [Figure 2B]2B is a partial cross-sectional view of a shock wave generating unit of the present disclosure having a single electrically non-conductive layer of less thickness than the embodiment shown in FIG. 2A. [Figure 3] FIG. 1 is a partial cross-sectional view showing a shock wave generating unit of the present disclosure, comprising an electrically non-conductive member having a larger diameter than the first and second electrodes. [Figure 4] FIG. 1 is a perspective view of a shock wave generating unit of the present disclosure having first and second holes offset relative to one another around the circumference of the electrode assembly. [Figure 5] FIG. 1 is a perspective view of a shock wave generating unit of the present disclosure, in which the first and second holes have different diameters. [Figure 6] FIG. 10 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having third and fourth holes extending through a single electrically non-conductive layer. [Figure 7A] FIG. 2 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having a hemispherical concave depression. [Figure 7B] FIG. 7B is an enlarged view of the hemispherical concave depression of the shock wave generating unit shown in FIG. 7A. [Figure 8] FIG. 1 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having a conical surface depression. [Figure 9] FIG. 10 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having a cylindrical debossed surface depression. [Figure 10A] FIG. 1 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having hemispherical surface protrusions. [Figure 10B] FIG. 10 is a partial cross-sectional view of a shock wave generating unit of the present disclosure having conical surface protrusions. [Figure 11] 1 is a partial cross-sectional view of a shock wave generating unit of the present disclosure, in which the inner surface of the electrode assembly is formed by a first electrode and a first portion of the innermost electrically non-conductive layer, and a second electrode is disposed between the first portion of the innermost electrically non-conductive layer and the outermost electrically non-conductive layer. [Figure 12A]FIG. 1 is a perspective view of a shock wave generating unit of the present disclosure, wherein a first electrode is disposed within an innermost electrically non-conductive layer, first, second and third inner electrically non-conductive layers and an outermost electrically non-conductive layer are disposed on the innermost electrically non-conductive layer, and a second electrode is disposed within the second inner electrically non-conductive layer. [Figure 12B] FIG. 12B is a cross-sectional view of the shock wave generating unit shown in FIG. 12A. [Figure 12C] FIG. 12B is a cross-sectional view of the shock wave generating unit shown in FIG. 12A. DETAILED DESCRIPTION OF THE INVENTION

[0007] In the embodiments of the present specification, the word "comprising" may be interpreted as requiring the recited features, but not limiting the presence of other features. Alternatively, the word "comprising" may relate to a situation in which only the recited components / features are intended to be present (e.g., the word "comprising" may be replaced with the phrase "consisting of" or "consisting essentially of"). It is expressly stated herein that both the broader and narrower interpretations may apply to all aspects and embodiments of the present invention. In other words, the word "comprising" and its synonyms may be replaced with the word "consisting of" or "consisting essentially of" or their synonyms, and vice versa.

[0008] As used herein, the phrase "consisting essentially of" and its alternative names may be interpreted to refer to a material in which minor impurities may be present, such as a material that is at least 90% pure, such as at least 95% pure, such as at least 97% pure, such as at least 99% pure, such as at least 99.9% pure, such as at least 99.99% pure, such as at least 99.999% pure, such as at least 100% pure, etc.

[0009] Provided herein is an electrode assembly for a shockwave generating catheter, the electrode assembly comprising: comprising at least one electrically non-conductive layer, a first electrode, and a second electrode, the first electrode and the second electrode being physically separated from each other and connectable to a voltage power supply (e.g., a high voltage power supply); The electrode assembly has a tubular configuration having an outer surface and an inner surface, the inner surface forming a lumen. an outer surface of the electrode assembly formed from an outermost electrically non-conductive layer of the at least one electrically non-conductive layer, the outermost electrically non-conductive layer being disposed over the first electrode and the second electrode; a first hole extending through the at least one non-conductive layer to expose a portion of the first electrode to the ambient environment; a second hole extending through the at least one non-conductive layer to expose a portion of the second electrode to the ambient environment; Here, the first hole and the second hole are configured to allow an electric arc discharge to pass from the first electrode to the second electrode or vice versa when a potential difference is applied between the first electrode and the second electrode by a voltage power supply.

[0010] In certain embodiments, the electrode assembly comprises an axially extending elongate member that extends through the lumen. Typically, the axially extending elongate member has an outer surface that is comprised of polyimide.

[0011] As used herein, the phrase "tubular configuration" encompasses any configuration having the form of a tube, including, but not limited to, a tubular configuration having a substantially circular cross-section, an elliptical cross-section, a regular polygonal cross-section having substantially equal sides (e.g., a square cross-section, a pentagonal cross-section), or an irregular polygonal cross-section having unequal sides. In certain embodiments, the electrode assembly has a tubular configuration having a substantially circular cross-section.

[0012] The electrode assembly of the present invention will now be described with reference to the accompanying drawings. The electrode assembly of the present invention, comprising an axially extending elongated member extending through the lumen of the electrode assembly, may be referred to herein as a shock wave generating unit. The electrode assembly of the present invention will now be described in connection with the shock wave generating unit.

[0013] FIG. 1A illustrates a shockwave generating unit 100 of the present disclosure suitable for generating shockwaves. The shockwave generating unit comprises an electrode assembly of the present invention having an axially extending elongated member 101 extending through the lumen of the electrode assembly. The axially extending elongated member 101 has a first electrode 102 and a second electrode 103 disposed on its outer surface. The electrodes are connectable to a high-voltage power supply. The electrodes are electrically conductive and may be constructed from a conductive material such as, but not limited to, tungsten, steel, titanium, cobalt, platinum, iridium, nickel, or alloys thereof. Separating (e.g., disposed between) the first and second electrodes is an electrically non-conductive member 104 that physically and electrically separates the two electrodes. The electrically non-conductive member 104 may be constructed from an electrically insulating (i.e., electrically non-conductive) material such as, but not limited to, a thermoplastic elastomer, ceramic, or fluoropolymer. The first electrode 102, the second electrode 103, and the electrically non-conductive member 104 have approximately the same inner and outer diameters, fit concentrically within the axially extending elongated member 101, and are radially flush with one another with respect to their outer surfaces. The matching inner and outer diameters allow the two electrodes to be completely electrically isolated from one another. Cylindrically disposed above the first electrode 102, the second electrode 103, and the electrically non-conductive member 104 is a first (inner) electrically non-conductive layer 105. Cylindrically disposed above the first (inner) electrically non-conductive layer 105 is a second (outermost) electrically non-conductive layer 106. The first and second electrically non-conductive layers 105 and 106 can be composed of an electrically non-conductive material, such as, but not limited to, a polymer, such as a polyimide or a fluoropolymer, or an adhesive. Together, the first electrode 102, the second electrode 103, the electrically non-conductive member 104, the first (inner) electrically non-conductive layer 105, and the second (outermost) electrically non-conductive layer form an electrode assembly having a tubular configuration with an outer surface and an inner surface, the inner surface forming a lumen through which the axially extending elongated member 101 extends. The inner surface of the electrode assembly is formed by the first and second electrodes 102, 103 and the electrically non-conductive member 104, with the electrically non-conductive member physically separating the first and second electrodes from each other.

[0014] In one variation of the shockwave generating unit 100, the first (inner) electrically non-conductive layer 105 may preferably be constructed of a polyimide sheath for electrical insulation, and the second (outermost) electrically non-conductive layer 106 may preferably be constructed of fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE) for high temperature resistance.

[0015] In the second variant of the shock wave generating unit 100, the first (inner) electrically non-conductive layer 105 may preferably be made of a suitable curable adhesive for bonding the first and second electrodes 102, 103 and the electrically non-conductive member 104, and the second (outermost) electrically non-conductive layer 106 may preferably be made of a polyimide sheath for optimal electrical insulation.

[0016] In another variation of the shock wave generating unit 100, the first (inner) electrically non-conductive layer 105 may preferably be composed of a suitable hardening adhesive for bonding the first and second electrodes 102 and 103 and the electrically non-conductive member 104, and the second (outermost) electrically non-conductive layer 106 may preferably be composed of FEP or PTFE heat shrink tubing for further fixing the shock wave generating unit 100.

[0017] Variations in the materials used and their combinations allow the overall device to adopt different mechanical properties suited to different operations. For example, in a durable shock wave generating unit, using adhesive as the first (inner) electrically non-conductive layer and heat shrink tubing as the second (outermost) electrically non-conductive layer can provide a higher level of abrasion resistance to shock waves.

[0018] Another variation of the shock wave generating unit, as shown in FIG. 1B, may include a third (second inner) electrically non-conductive layer 107 disposed between a first (first inner) electrically non-conductive layer 105 and a second (outermost) electrically non-conductive layer 106. Multiple electrically non-conductive layers made of different materials not only provide higher insulating strength but also protect against impact damage from the generated shock waves. To generate an electric arc between the two electrodes 102 and 103, a conductive point exists on each electrode. A first hole 108 and a second hole 109 extending through the insulating (i.e., electrically non-conductive) layer expose small portions 111 and 112 of each electrode 102 and 103, respectively, to the surrounding environment. These exposed areas form conductive regions, and when a voltage pulse is applied to a circuit consisting of the electrodes and a high-voltage source external to the device, a conductive flow, or electric arc, is generated between the exposed regions of the two conductive electrodes. Cavitation bubbles form within the conductive flow due to the generated electric arc, which rapidly expand and collapse, generating powerful shock waves.

[0019] The strength of the shock waves can be modified by adjusting the depth of the holes in the non-conductive layer or layers of the electrode assembly. Deep holes facilitate focusing of the shock waves generated within the channels formed by the holes. This focusing effect gathers and intensifies the shock wave intensity through constructive interference, resulting in less wasted non-incident energy. The depth of the holes can be adjusted by adjusting the thickness of the electrically non-conductive layer or layers. For example, in Figure 2A, holes 201 and 202 have a depth determined by electrically non-conductive layer 203. This hole depth can impart a set level of reflective capability to the shock waves generated within them. On the other hand, Figure 2B shows holes 204 and 205, whose depth is determined by electrically non-conductive layer 206, which is shallower than those shown in Figure 2A. At this depth, the shock waves are less focused in one direction and are diffusely scattered immediately after exiting the cylindrical holes, which could theoretically reduce the reflective capability of the shock waves generated within them. The hole depth can be adjusted in this way to create an optimal level of reflective capability.

[0020] 2A and 2B, the shock wave generating unit is shown as consisting of an electrode assembly made up of a single electrically non-conductive layer 203, 206. As such, each of the electrically non-conductive layers 203, 206 is considered the outermost electrically non-conductive layer of the electrode assembly shown in these figures.

[0021] The depth of the hole can be adjusted directly by varying the thickness of the electrically non-conductive layer, but it can also be adjusted by varying the number of electrically non-conductive layers. Returning to Figures 1A and 1B, multiple electrically non-conductive layers can be used, as permitted by the size constraints of the catheter. While this may have the same effect as varying the thickness of each layer, the advantage of using multiple layers is that it allows for the use of multiple types of materials in the construction of the shock wave generating unit. As previously mentioned, one layer may be an adhesive used to improve the adhesive strength of all components within the unit, while another layer may be a fluoropolymer that provides electrical insulation and resistance to damage from shock waves.

[0022] Typically, each electrically non-conductive layer of the electrode assembly disclosed herein has a thickness of about 0.02 mm to about 0.8 mm. For example, each electrically non-conductive layer can have a thickness of at least about 0.2 mm, e.g., about 0.2 mm to about 0.4 mm. The total thickness of all electrically non-conductive layers of the shock wave generating unit is usually at least about 0.4 mm, e.g., about 0.4 mm to about 1 mm, e.g., about 0.4 mm to about 0.8 mm.

[0023] The depth of the hole can also be adjusted by varying the outer diameter of the electrodes. For example, Figure 3 shows a shock wave generating unit 300 in which the first electrode 301 and the second electrode 302 have outer diameters smaller than the outer diameter of the electrically non-conductive member 304. This allows the conductive surface of each electrode to be positioned lower within the device. This is useful when the overall outer diameter of the catheter is limited. It should also be noted that the outer diameter of one electrode does not need to be the same as that of the other. This allows for variable hole depth and is also useful from a durability perspective, given that catheter designs permanently limit the use of positive and negative electrodes. For example, it is theorized that the spark point of a plasma arc is greater in the area surrounding the positive electrode. Therefore, electrodes are constructed with a smaller outer diameter around the positive electrode, resulting in a deeper hole. A deeper hole allows more material for the spark to burn off, thereby extending the life of the insulating layer around the positive electrode during operation.

[0024] Another feature that can be adjusted to change the strength of the shock waves generated by the shock wave generating unit of the present disclosure is the distance between the holes in the shock wave generating unit. The location of the holes determines the spacing between the holes, which in turn determines the spark gap between the electrodes. This spark gap is the distance the conductive fluid extends across, allowing an electric arc to electrically bridge the conductive electrodes. A greater spacing between the holes results in a greater resistance to the arc, resulting in lower shock wave output. Referring back to FIG. 1 , the two holes 108 and 109 are aligned with each other around the circumference of the electrode assembly but offset from each other along the longitudinal axis of the electrode assembly. This is the most basic hole configuration. The distance between the holes can be varied by positioning them farther apart along the longitudinal axis of the electrode assembly. However, due to space constraints in the catheter, this may not be the most practical way to increase the spark gap between the conductive electrodes. Alternatively, the two holes may be offset from each other both around the circumference of the electrode assembly and along the longitudinal axis of the electrode assembly. The distance between the two holes along the longitudinal axis of the electrode assembly remains the same as that shown in FIG. 1, but the holes are offset from each other along the circumference of the electrode assembly, increasing their actual displacement from each other.

[0025] Typically, the distance from the edge of a first hole to the corresponding edge of a second hole in the electrode assemblies disclosed herein is from about 0.05 mm to about 10 mm, for example from about 1 mm to about 5 mm (e.g., from about 1.5 mm to about 3.5 mm, such as from about 2 mm to about 3 mm).

[0026] Another feature that can be adjusted to change the strength of the shock waves generated by the shock wave generating unit of the present disclosure is the size of the holes; by changing the size of the holes, the characteristics of the electric arc can be changed, and the resulting shock waves can be changed. Figure 5 shows holes 501 and 502, with hole 502 having a larger diameter than hole 501. Varying the size of the holes can change the exposed surface area of ​​the electrode. This changes the charge concentration of the current at the positive electrode before the electric arc forms, which can affect the strength of the shock waves generated.

[0027] Typically, the first and second holes of the electrode assemblies disclosed herein can each have a diameter of about 0.2 mm to about 1 mm (eg, about 0.5 mm).

[0028] The number of holes present in the shock wave generating unit of the present disclosure may be varied to affect the number of zones in which electric arcs can form. The formation of multiple parallel spark gaps can generate multiple shock waves from one or more locations around the catheter's circumference. Figure 6 shows an example of a shock wave generating unit 600 configured with multiple holes across its entire surface. In this case, holes 601 and 602 are circumferentially opposite holes 603 and 604. This configuration is useful for certain body locations, such as within blood vessels, because it allows multiple targeted shock waves to be generated with a single voltage pulse discharge. Therefore, it is not necessary to rotate the catheter within the vessel or body to target opposite sides. This also allows power to be distributed between the two arcs, thereby extending the life of the conductive electrodes.

[0029] To increase the intensity of the shock waves generated by the shock wave generating unit of the present disclosure, the portions of the first electrode and / or second electrode exposed to the ambient environment may have a surface geometry configured to concentrate the location of the electrical arc discharge. This can take the form of depressions in the electrode surface. The depressions increase strength in part because they also effectively increase the depth of cut. However, the majority of the increase comes from the effect of reducing the surface area available for conducting electrical current. As noted above, when the surface area is reduced, charge tends to concentrate more tightly around the remaining available surface area, allowing more current to arc to the other conductive electrode, thereby increasing the power of the generated shock waves.

[0030] Exemplary surface geometries are shown in Figures 7-10 and are described below.

[0031] 7A shows a shock wave generating unit 700, in which a first electrode 701 and a second electrode 702 have depressions 703 and 704 disposed on their outer surfaces, which are concentric with holes 705 and 706 in the electrodes 701 and 702, respectively. The depressions 703 and 704 are in the form of hemispherical depressions.

[0032] FIG. 7B further shows a close-up view of one of the depressions 703 and 704, with 708 being the point where charge concentrates when current reaches electrode 702. Because much of the curved surface of electrode 702 has been removed, point 708 is the closest point of contact with another point 707 on electrode 701, forming an arc as the conductive fluid flows. Varying the shape of the depressions can also change the power and temporal duration of the resulting shock wave. These shapes affect the final topology of the electrode's exposed surface area as erosion due to arcing begins, and therefore how much of its original power is retained after multiple arcing events.

[0033] FIG. 8 shows a conical depression, and FIG. 9 shows a simple cylindrical depression drilled into the electrode material.

[0034] As an alternative to the depressions described above, protrusions can be used in place of debosses or depressions in the surface material of the electrode. Figures 10A-10B show how the corresponding shapes of Figures 7A and 8 can be modified to include protrusions. By forming conical or hemispherical protrusions 1001 and 1002, respectively, the concentration of charge can be advantageously concentrated at the apex of either type of protrusion, increasing the power of the resulting shock wave.

[0035] A further embodiment of the shock wave generating unit of the present disclosure is shown in FIG. 11. In this embodiment, the inner surface of the electrode assembly is formed from a first electrode 1102 and a first portion 1103a of an innermost electrically non-conductive layer 1103. A second portion 1103b of the innermost electrically non-conductive layer 1103 is disposed between the first electrode 1102 and the outermost electrically non-conductive layer 1104. A second electrode 1101 is disposed between the first portion of the innermost electrically non-conductive layer and the outermost electrically non-conductive layer. In this arrangement, the innermost electrically non-conductive layer physically separates the first and second electrodes from each other. In this embodiment, the innermost electrically non-conductive layer can be considered an electrically non-conductive member. This arrangement eliminates the need for a separate physical object disposed between the conductive electrodes, resulting in advantages such as a reduced overall length and profile of the unit, increased catheter flexibility, and reduced manufacturing costs. This embodiment consists of an (outermost) electrically non-conductive layer 1104 covering each of the first electrode 1101 and second electrode 1102 .

[0036] A further embodiment of the electrode assembly of the present disclosure is shown in Figures 12A-12C in the context of a shock wave generating unit. The shock wave generating unit 1200 is comprised of a plurality of electrically non-conductive layers, more specifically, five electrically non-conductive layers 1204-1208 disposed on the outer surface of an axially extending elongated member 1203. The first and second electrodes 1201, 1202 are each independently embedded within one of the plurality of electrically non-conductive layers. Typically, the elongated member 1203 is formed from polyimide.

[0037] In this embodiment, the electrode assembly is formed by five electrically non-conductive layers 1204-1208 and first and second electrodes 1201, 1202. Together, these components form a tubular structure with an outer surface and an inner surface, the inner surface defining a lumen. An axially extending elongated member 1203 extends through the lumen.

[0038] The inner surface of the electrode assembly is formed by an innermost electrically non-conductive layer 1204. The outer surface of the electrode assembly is formed by an outermost electrically non-conductive layer 1208. The assembly is composed of inner electrically non-conductive layers 1205, 1206, and 1207 disposed between the innermost and outermost electrically non-conductive layers. In FIGS. 12A-12C, there are three inner electrically non-conductive layers. A first inner electrically non-conductive layer 1205 is disposed on the innermost electrically non-conductive layer 1204, a second inner electrically non-conductive layer 1206 is disposed on the first inner electrically non-conductive layer 1205, and a third inner electrically non-conductive layer 1207 is disposed on the second inner electrically non-conductive layer 1206. An outermost electrically non-conductive layer 1208 is disposed on the third inner electrically non-conductive layer, thereby forming the outer surface of the electrode assembly.

[0039] The outermost layer, the innermost layer, and the inner electrically non-conductive layer may each be formed from a polymer independently selected from the following group: a thermoplastic elastomer (e.g., polyimide), a fluoropolymer (e.g., fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), an epoxy resin (e.g., a cured epoxy or a cured epoxy, preferably a biocompatible, impact-resistant, and / or shock-absorbing epoxy), and one or more combinations thereof. Typically, the first and third inner electrically non-conductive layers are formed from a polyimide, and the second inner electrically non-conductive layer is formed from an epoxy resin. Typically, the innermost electrically non-conductive layer is formed from an epoxy resin, and the outermost electrically non-conductive layer is formed from a polyimide. Polyimide resin and / or epoxy resin can provide the shock wave generating unit with excellent impact resistance, high-temperature resistance, and electrical resistance.

[0040] In this embodiment, the first electrode 1201 and the second electrode 1202 are independently disposed (e.g., embedded) within one of the electrically non-conductive layers. In FIG. 12B, the first electrode 1201 is embedded within the innermost electrically non-conductive layer 1204, upon which the first, second, third, and outermost electrically non-conductive layers 1205-1208 are disposed. The second electrode 1202 is embedded within the second inner electrically non-conductive layer 1206. Preferably, the first and second electrodes are offset from one another along the longitudinal axis of the electrode assembly and are typically embedded within different electrically non-conductive layers. Typically, the two electrodes are separated by at least one electrically non-conductive layer formed from polyimide. The innermost electrode (e.g., a first electrode embedded in the innermost electrically non-conductive layer) may be thicker than the second electrode to help the first electrode resist stronger corrosion caused by stronger shock waves within the deeper layers of the electrode assembly.

[0041] Because the first electrode 1201 and the second electrode 1202 are embedded in the innermost and second inner electrically non-conductive layers, respectively, the first hole 1209 extends through the outermost electrically non-conductive layer and the third, second, and first inner electrically non-conductive layers, exposing a portion of the first electrode 1201 to the ambient environment. The second hole 1210 extends through the outermost electrically non-conductive layer and the third inner electrically non-conductive layer to expose a portion of the second electrode 1202 to the ambient environment. Therefore, the first hole 1209 is deeper than the second hole 1210. As explained above, the deeper the hole, the easier it is to focus shock waves generated within the channel formed by the hole. This focusing effect concentrates and enhances the intensity of the shock waves through constructive interference. On the other hand, if the hole is shallower, the shock waves are less focused in one direction and are diffusely scattered immediately after exiting the hole, theoretically reducing the reflection ability of shock waves generated within the channel. The holes can be positioned so as to be offset from one another along the longitudinal axis of the electrode assembly. Additionally, the holes can be positioned so as to be offset from one another around the circumference of the electrode assembly.

[0042] The present invention can also be expressed in terms of the following numbering scheme: 1. 1. A shock wave generating unit using a shock wave generating catheter, comprising: an axially extending elongated member having an outer surface; a first electrode and a second electrode respectively disposed on an outer surface of the elongated member, wherein the first electrode and the second electrode are connectable to a high voltage power supply; an electrically non-conductive member separating the first electrode and the second electrode; at least one electrically non-conductive layer disposed on each of the first electrode and the second electrode; a first hole extending through one or more of the at least one electrically non-conductive layers and exposing a portion of the first electrode to the ambient environment; a second hole extending through one or more of the at least one electrically non-conductive layers and exposing a portion of said second electrode to the ambient environment; Equipped with The first hole and the second hole are configured to allow an electric arc discharge to pass from the first electrode to the second electrode or vice versa when a potential difference is applied between the first electrode and the second electrode by a high voltage power supply. 2. 2. The shock wave generating unit according to aspect 1, wherein the first electrode and / or the second electrode are formed from one or more of the group consisting of tungsten, steel, titanium, cobalt, platinum, iridium, nickel, and alloys thereof. 3. the electrically non-conductive member is formed from one or more of the group consisting of a polymer, a ceramic, an adhesive, and combinations thereof; Optionally, the polymer is selected from the group consisting of a thermoplastic elastomer (e.g., polyimide), a fluoropolymer (e.g., fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), and combinations thereof; Further optionally, the polymer comprises polyimide. The shock wave generating unit according to aspect 1 or 2. 4. at least one of the at least one electrically non-conductive layer disposed on each of the first electrode and the second electrode is formed from one or more of the group consisting of a polymer, a ceramic, an adhesive, and combinations thereof; Optionally, the polymer is selected from the group consisting of a thermoplastic elastomer (e.g., polyimide), a fluoropolymer (e.g., fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), and combinations thereof; Further optionally, the polymer comprises polyimide. The shock wave generating unit according to any one of the first to third aspects. 5. an outermost electrically non-conductive layer of the at least one electrically non-conductive layer is formed from a polymer; Optionally, the polymer is selected from the group consisting of a thermoplastic elastomer (e.g., polyimide), a fluoropolymer (e.g., fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), and combinations thereof; Further optionally, the polymer comprises polyimide. A shock wave generating unit according to aspect 4. 6. At least one electrically non-conductive layer disposed on each of the first electrode and the second electrode comprises: a first electrically non-conductive layer disposed on each of the first electrode and the second electrode; a second electrically non-conductive layer disposed on each of the first electrode and the second electrode; It consists of the first and second holes extending through the first and second electrically non-conductive layers, respectively; The shock wave generating unit according to any one of the first to fifth aspects. 7. At least one electrically non-conductive layer disposed on each of the first electrode and the second electrode comprises: a first electrically non-conductive layer disposed on each of the first electrode and the second electrode; a second electrically non-conductive layer disposed on each of the first electrode and the second electrode; a third electrically non-conductive layer disposed on each of the first electrode and the second electrode; It consists of the first hole and the second hole extend through the first, second and third electrically non-conductive layers, respectively; The shock wave generating unit according to any one of the first to sixth aspects. 8. the first electrically non-conductive layer is formed from a polyimide or an adhesive; the second electrically non-conductive layer is formed from nylon, poly(ether-b-amide) (e.g., Pebax®), or heat-shrink tubing (e.g., fluorinated ethylene propylene or polyethylene terephthalate); The shock wave generating unit according to any one of Aspects 6 to 7. 9. The shock wave generating unit according to any one of aspects 1 to 8, wherein the electrically non-conductive member has a maximum radius corresponding to the maximum radius of the first electrode and the second electrode. 10. The shock wave generating unit according to any one of aspects 1 to 9, wherein the electrically non-conductive member has a maximum radius that is larger than the maximum radius of each of the first electrode and the second electrode. 11. 11. The shock wave generating unit according to any one of aspects 1 to 10, wherein the first hole and the second hole are offset from each other in the axial direction. 12. 12. The shock wave generating unit according to any one of aspects 1 to 11, wherein the first hole and the second hole are parallel to the axial direction. 13. 13. The shock wave generating unit according to any one of aspects 1 to 12, wherein the first hole and the second hole have substantially the same diameter. 14. 13. The shock wave generating unit according to any one of aspects 1 to 12, wherein the first hole and the second hole have different diameters. 15. a third hole extending through one or more of the at least one electrically non-conductive layers and exposing a portion of the first electrode to the ambient environment; a fourth hole extending through one or more of the at least one electrically non-conductive layers and exposing a portion of the second electrode to the ambient environment; The third hole and the fourth hole are configured to allow an electric arc discharge to pass from the first electrode to the second electrode or vice versa when the first electrode and the second electrode are connected to a high voltage power supply; The shock wave generating unit according to any one of the first to fourteenth aspects. 16. 15. The shock wave generating unit according to any one of aspects 1 to 14, wherein the portion of the first electrode and / or the second electrode exposed to the ambient environment has a surface shape configured to concentrate the location of the electric arc discharge. 17. 17. The shock wave generating unit according to aspect 16, wherein the surface shape configured to concentrate the location of the arc discharge comprises a depression in the surface. 18. 18. The shock wave generating unit of aspect 17, wherein the depression in the surface has a shape selected from the group consisting of a hemispherical depression, a cone, and a cylindrical debossment (e.g., a cylindrical debossment). 19. the surface features configured to concentrate the location of the arc discharge comprise surface protrusions; Optionally, the surface protrusions have a conical or hemispherical shape. A shock wave generating unit according to aspect 16. 20. the electrically non-conductive member forms an electrically non-conductive layer disposed on the second electrode but not on the first electrode; the second hole and, if present, the fourth hole extend through the electrically non-conductive member and through one or more of the at least one electrically non-conductive layers to expose a portion of the second electrode to the surrounding environment; A shock wave generating unit according to any one of aspects 1 to 19. twenty one. 21. The shock wave generating unit according to any one of Aspects 1 to 20, wherein the diameters of the first hole and the second hole are each 0.2 to 1 mm. twenty two. 22. The shock wave generating unit according to any one of aspects 1 to 21, wherein the minimum distance from the edge of the first hole to the edge of the second hole is 0.05 to 10 mm. twenty three. At least one of the at least one electrically non-conductive layer disposed on each of the first electrode and the second electrode has a thickness of 0.04 to 1 mm; Optionally, each of the at least one electrically non-conductive layer disposed on each of the first electrode and the second electrode has a thickness of 0.04 to 1 mm. A shock wave generating unit according to any one of aspects 1 to 21. twenty four. 1. A shock wave generation system using a shock wave generating catheter, comprising: one or more shock wave generating units according to any one of aspects 1 to 23; a high voltage power supply having electrical output terminals electrically connected to the first electrode and the second electrode of the one or more shock wave generating units; and When the shock wave generating system is composed of multiple shock wave generating units, the electrodes of the shock wave generating units are arranged in series; Optional high voltage power supplies provide voltages from 1000V to 5000V. Shock wave generation system. twenty five. A shock wave generating system as described in aspect 24, wherein the electrical output terminals of the high voltage power supply are connected to the first and second electrodes of the one or more shock wave generating units by wires extending along the outer surface of the elongated member extending axially from the terminals or through the interior of the elongated member. 26. 26. The shock wave generating system according to aspect 24 or 25, further comprising an integrated electronic printed circuit board configured to determine the output voltage of the high voltage power supply. 27. A shock wave generating system according to any one of Aspects 24 to 26, an inflatable balloon disposed over the axially extending elongated member and the one or more shock wave generating units; A shock wave generating catheter comprising:

[0043] The present invention has been described broadly and generically herein. Those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the particular use or application for which the invention is used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Accordingly, the above-described embodiments are provided by way of example only, and the invention may be practiced otherwise than as specifically described and claimed, within the scope of the appended claims and their equivalents. The present invention is directed to each individual feature, system, article, material, kit, and / or method described herein. Furthermore, combinations of two or more such features, systems, articles, materials, kits, and / or methods are within the scope of the invention, provided that such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent. Furthermore, each narrower species and subgeneric grouping falling within the generic disclosure also forms part of the present invention. This includes the general description of the invention with any provisos or negative limitations, whether or not specifically described herein.

Claims

1. 1. An electrode assembly for a shockwave generating catheter, the electrode assembly comprising: at least one electrically non-conductive layer, a first electrode, and a second electrode, wherein the first electrode and the second electrode are physically separated from each other and connectable to a voltage source; the electrode assembly having a tubular configuration with an outer surface and an inner surface, the inner surface defining a lumen; an outer surface of the electrode assembly formed from an outermost electrically non-conductive layer of at least one electrically non-conductive layer, the outermost electrically non-conductive layer being disposed over the first electrode and the second electrode; the at least one electrically non-conductive layer has a first hole extending therethrough and exposing a portion of the first electrode to the ambient environment; the at least one electrically non-conductive layer has a second hole extending therethrough and exposing a portion of the second electrode to the ambient environment; wherein the first and second holes are configured to allow an electric arc discharge to pass from the first electrode to the second electrode, or vice versa, when a potential difference is applied between the first and second electrodes by a voltage power supply; Electrode assembly.

2. The electrode assembly of claim 1 , wherein the inner surface of the electrode assembly is formed from an innermost electrically non-conductive layer.

3. The electrode assembly of claim 2 , further comprising one or more inner electrically non-conductive layers disposed between the innermost and outermost electrically non-conductive layers.

4. 4. The electrode assembly of claim 3, wherein the electrode assembly further comprises at least two interior electrically non-conductive layers, e.g., two, three, four, five, or six interior electrically non-conductive layers.

5. 5. The electrode assembly of claim 3, wherein the first electrode and the second electrode are each independently embedded in the innermost electrically non-conductive layer or one of the inner electrically non-conductive layers.

6. 6. The electrode assembly according to claim 2, wherein the first electrode and the second electrode are embedded in different electrically non-conductive layers.

7. 7. The electrode assembly according to claim 2, wherein the first electrode is embedded in the innermost electrically non-conductive layer.

8. 7. The electrode assembly according to claim 2, wherein the first electrode and the second electrode are each independently embedded in one of the internal electrically non-conductive layers.

9. 9. The electrode assembly of claim 3, wherein each of the inner electrically non-conductive layers is formed from a polymer independently selected from the group consisting of a thermoplastic elastomer (e.g., polyimide), a fluoropolymer (e.g., fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), an epoxy resin, and one or more combinations thereof.

10. The electrode assembly comprises: a first inner electrically non-conductive layer disposed on the innermost electrically non-conductive layer; a second inner electrically non-conductive layer disposed on the first inner electrically non-conductive layer; a third inner electrically non-conductive layer disposed on the second inner electrically non-conductive layer; and an outermost electrically non-conductive layer disposed on a third, inner electrically non-conductive layer; 10. The electrode assembly according to claim 3, comprising:

11. the first inner electrically non-conductive layer is formed from polyimide; the second inner electrically non-conductive layer is formed of an epoxy resin; the third inner electrically non-conductive layer is formed of polyimide; 11. The electrode assembly of claim 10.

12. 12. The electrode assembly of claim 11, wherein the first electrode is embedded within an innermost electrically non-conductive layer and the second electrode is embedded within a second, inner, electrically non-conductive layer.

13. 12. The electrode assembly according to claim 2, wherein the innermost electrically non-conductive layer is formed from an epoxy resin.

14. 13. The electrode assembly according to claim 2, wherein the outermost electrically non-conductive layer is formed from an impact-resistant and / or impact-absorbing material, for example, the outermost electrically non-conductive layer is formed from an epoxy resin having impact-resistant and / or impact-absorbing properties.

15. 15. The electrode assembly of any of claims 2 to 14, wherein the first and second electrodes are offset relative to each other along a longitudinal axis of the electrode assembly.

16. 10. The electrode assembly of claim 1, wherein the inner surface of the electrode assembly is formed from an innermost layer of the first and second electrodes and an electrically non-conductive member, the electrically non-conductive member physically separating the first and second electrodes from one another.

17. The electrode assembly further includes one or more inner electrically non-conductive layers disposed between the innermost and outermost layers. The electrode assembly of claim 1 .

18. the electrically non-conductive member is formed from one or more of the group consisting of a polymer, a ceramic, an epoxy, an adhesive, and combinations thereof; Optionally, the polymer is selected from the group consisting of a thermoplastic elastomer (e.g., polyimide), a fluoropolymer (e.g., fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE)), and combinations thereof; For example, the electrode assembly according to any one of claims 16 to 17, wherein the polymer is made of polyimide.

19. 19. An electrode assembly according to any one of claims 16 to 18, wherein the electrically non-conductive member has a maximum radius corresponding to a maximum radius of the first and second electrodes.

20. 19. The electrode assembly according to claim 16, wherein the electrically non-conductive member has a maximum radius that is greater than the maximum radius of each of the first and second electrodes.

21. the inner surface of the electrode assembly is formed from a first electrode and a first portion of the innermost electrically non-conductive layer; a second portion of the innermost electrically non-conductive layer disposed between the first electrode and the outermost electrically non-conductive layer; a second electrode disposed between the first portion of the innermost electrically non-conductive layer and the outermost electrically non-conductive layer; The electrode assembly of claim 1 .

22. an innermost electrically non-conductive layer formed of nylon, poly(ether-b-amide) (e.g., Pebax®), or heat-shrinkable tubing (e.g., fluorinated ethylene propylene, polyethylene terephthalate); The outermost electrically non-conductive layer is formed from an impact-resistant and / or impact-absorbing material, for example, the outermost electrically non-conductive layer is formed from an impact-resistant and / or impact-absorbing epoxy resin.

22. The electrode assembly of claim 21.

23. 23. The electrode assembly of any preceding claim, wherein the first and / or second electrode is formed from one or more of the group consisting of tungsten, steel, titanium, cobalt, platinum, iridium, nickel, and alloys thereof.

24. 24. An electrode assembly according to any preceding claim, wherein the first and second holes are offset from one another along a longitudinal axis of the electrode assembly.

25. An electrode assembly according to any preceding claim, wherein the first and second holes are offset from one another around the circumference of the electrode assembly.

26. 26. An electrode assembly according to any preceding claim, wherein the first and second holes have substantially the same diameter.

27. 27. An electrode assembly according to any preceding claim, wherein the first and second holes have different diameters.

28. 28. An electrode assembly according to any preceding claim, wherein the portion of the first and / or second electrode exposed to the ambient environment has a surface shape configured to concentrate the location of the electric arc discharge.

29. 30. The electrode assembly of claim 28, wherein the surface features configured to concentrate the location of the arc discharge include surface depressions.

30. 30. The electrode assembly of claim 28, wherein the surface depression has a shape selected from the group consisting of a hemispherical depression, a cone, and a cylindrical debossment (e.g., a cylindrical debossment).

31. the surface features configured to concentrate the location of the arc discharge include surface protrusions; 30. The electrode assembly of claim 28, wherein optionally the surface protrusions are conical or hemispherical.

32. 32. The electrode assembly of claim 1, wherein the first and second holes each have a diameter of about 0.2 mm to about 1 mm.

33. 33. The electrode assembly of any preceding claim, wherein the minimum distance from the edge of the first hole to the edge of the second hole is from about 0.05 mm to about 10 mm.

34. at least one of the electrically non-conductive layers has a thickness of about 0.02 mm to about 0.8 mm; Optionally, each of the at least one electrically non-conductive layer has a thickness of from about 0.02 mm to about 0.8 mm.

34. An electrode assembly according to any one of claims 1 to 33.

35. a third hole extending through the at least one electrically non-conductive layer and exposing a portion of the first electrode to the ambient environment; a fourth hole extending through the at least one electrically non-conductive layer and exposing a portion of the second electrode to the ambient environment; the third and fourth holes are configured to allow an electric arc discharge to pass from the first electrode to the second electrode, or vice versa, when the first and second electrodes are connected to a high voltage power supply; An electrode assembly according to any one of claims 1 to 34.

36. A shock wave generating unit comprising: an electrode assembly according to any one of claims 1 to 35; and an axially extending elongate member extending through an inner lumen of the electrode assembly; Optionally, the shock wave generating unit, wherein the axially extending elongated member has an outer surface made of polyimide.

37. 1. A shock wave generation system using a shock wave generating catheter, comprising: one or more shockwave generating units according to claim 36; a high-voltage power supply having electrical output terminals electrically connected to the first and second electrodes of the one or more shock wave generating units; Optionally, the high voltage power supply has a voltage of 1000V to 5000V. Shock wave generation system.

38. 38. The shockwave generating system according to claim 37, wherein the electrical output terminals of the high voltage power supply are connected to the first and second electrodes of the one or more shockwave generating units by wires extending from said terminals along an outer surface of or through the interior of said axially extending elongated member.

39. 39. The shock wave generating system according to any of claims 37 to 38, further comprising an integrated electronic printed circuit board configured to determine the output voltage of the high voltage power supply.

40. A shock wave generating system according to any one of claims 37 to 39; an inflatable balloon disposed over the axially extending elongated member and the one or more shock wave generating units; A shock wave generating catheter comprising:

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