Diffusers for shock wave transducers.

Abstract

A shock wave transducer (100) for a lithotriptor comprises a shock wave source (130) and a body having an exit opening. The transducer is configured to generate shock waves that propagate from the body through the exit opening. The body comprises at least one diffuser (210, 220) that engages within the shock waves propagating from the body. The at least one diffuser (210, 220) comprises a material that has a propagation speed different from the propagation speed of the surrounding medium.

Description

[Technical field]

[0001] The present invention relates to an apparatus for reducing the number and / or size of cavitation cavities generated by a shock wave transducer in a medical shock wave device, such as a lithotriptor, without compromising the effectiveness of the shock waves.

[0002] 2. Description of Related Art In WO 01 / 66189, high intensity focused ultrasound heating is provided by administering therapeutic ultrasound with an array of transducers. Cavitation is detected by detecting ultrasound emitted or reflected from the patient's body or interface using some or all of the transducers in the array. Based on such detection, a feedback signal is generated. If the feedback signal indicates the presence of cavitation, the therapeutic ultrasound is terminated or altered.

[0003] Summary of the Invention A shock wave transducer in a medical shock wave device, e.g. a lithotriptor, generates shock waves in a medium, e.g. water, and couples the shock waves into the human or animal body. The shock waves travel through the medium in which they are generated into the body and reach a target area. The shock waves are focused on the target area in the body. The target area may be a stone inside the body, e.g. a kidney stone, or a specific soft tissue area.

[0004] Usually, the positive pressure pulse of the shock wave is followed by a smaller negative pressure pulse (extension wave). Cavitation cavities, also called cavitation bubbles or cavitation voids, are generated by the negative pressure waves associated with the shock wave. The negative pressure waves are generated by diffracted waves, especially at the edges of the opening. Usually, the negative pressure waves propagate in a divergent manner, i.e. with decreasing amplitude, but there are spatial regions where the negative pressure waves concentrate and generate significant negative pressure by phase-locked superposition. In this superposition zone, mostly in the axis and surrounding areas of the shock wave source. Cavitation cavities collapse within microseconds and generate localized spherical shock waves that cause undesirable damage to biological tissues. In particular, cavitation cavities cause damage (usually in the form of petechia and hematomas) when they come into contact with tissues (blood vessels, capillaries).

[0005] The problem to be solved by the present invention is to reduce the size of stones and soft tissue treatments while reducing damage and injury to body tissues, e.g. hematomas. Another object of the present invention is to reduce the cavitation cavities generated without compromising the effectiveness of the shock waves. A further object of the present invention is to avoid shutting down the device or interrupting or terminating treatment when cavitation occurs.

[0006] The solution to this problem is set forth in the independent claims. The dependent claims relate to further refinements of the invention.

[0007] In an embodiment, a shockwave converter may comprise a shockwave source and a body having an exit opening. The body may have a cavity filled with a shockwave conducting medium. The body may carry a shockwave source. The shockwave source is configured to generate shockwaves. Typically, a shockwave is a type of disturbance that propagates in a medium, such as a fluid (e.g. water), gas or plasma. Shockwaves may transport energy and may propagate through a medium and may be characterized by abrupt, nearly discontinuous changes in pressure, temperature and density of the medium.

[0008] The body further comprises an exit opening for exiting the shock waves from the body, the transducer being configured to induce the shock waves to propagate through the exit opening.

[0009] The body may further include at least one reflector and / or focusing element. The reflector may be elliptical or parabolic. A lens may be provided for focusing. In an embodiment, the reflector may be a spherical segment carrying a piezoelectric device. Shock waves generated by the shock wave source may exit the body through an exit opening.

[0010] The geometry of the body depends on the shockwave source, which may be a point source, a planar source or a cylindrical source. A point source may have an ellipsoidal reflector, a planar source may have an acoustic lens and a cylindrical source may have a parabolic reflector. The shockwave converter may comprise a cylindrical source with a parabolic reflector.

[0011] The body may have an upper surface, a lower surface, an inner surface, an outer surface, an edge, a central axis, and an exit opening. The edge may surround the exit opening. The cavity of the body is a three-dimensional space defined by the inner surface of the body and a plane passing through the edge.

[0012] The shock wave source may include a coil. The coil may have a cylindrical shape. The coil may be located on the central axis of the reflector. Alternatively, the shock wave source may include a flat coil or a piezoelectric element or a spark gap.

[0013] The shockwave source is configured to generate shockwaves that propagate from the transducer. The shockwave transducer may be connected to a generator. The generator may generate a high power signal. The high power signal may be applied to the shockwave source to generate shockwaves. The shockwaves propagate from the transducer and may be guided, reflected or directed to the focal region.

[0014] The shock wave converter may comprise a shock wave source with a cylindrical coil. The coil is disposed inside a body, which further comprises a reflector. The cylindrical coil may be disposed with its central axis at the reflector central axis. The cylindrical coil may generate cylindrical waves propagating in the radial direction of the coil and may be symmetrical about the central axis. The waves may be reflected by the reflector towards a focal region, which may be a focal point. The focal region may be on the central axis and at a distance from the coil. The distance may be in the range of 2 cm to 25 cm depending on the design of the reflector and coil to leave enough space to position the patient so that stones can be broken up or soft tissue target regions can be treated. All the waves propagating from the shock wave source to the focal region or focal point define a wave propagation region.

[0015] This wave propagation region may be located inside a volume defined by the cavity of the body. Moreover, the wave propagation region may extend beyond the body into a volume that corresponds approximately to a cylindrical space in a region close to the edge. The cylindrical space may have the same base as the exit opening. The cylindrical space may have the same inner diameter as the edge of the body. The cylindrical space may extend from the body. The cylindrical space may extend from the body coaxially to the central axis of the body. The cylindrical space may extend up to 0.5 cm, 1 cm, 2 cm, 5 cm, 10 cm, 30 cm or 50 cm above the edge of the body. The cylindrical space may have a volume. This volume may be a three-dimensional space surrounding the wave propagation region, surrounded by a physical, preferably virtual, extension of the edge along the direction of the propagating wave. The body and the cylindrical space may have a joint volume. This joint volume may be the volume of the cavity of the body combined with the volume of the cylindrical space, in other words, the three-dimensional space defined by the inner surface of the body and the three-dimensional space enclosed by the cylindrical space.

[0016] The shock wave converter may have at least one diffuser. The body of the shock wave converter may include at least one diffuser. The at least one diffuser may be engaged in the shock wave propagating from the shock wave source. The at least one diffuser may be engaged in the wave propagating from the body through the exit opening. From a geometrical point of view, the at least one diffuser may extend within a volume defined by the body and / or within a cylindrical space having the same inner diameter as the edge of the body, which may be the exit opening.

[0017] The body has a cavity filled with a shock wave conducting medium, and the at least one diffuser comprises a material having a propagation speed different from that of the shock wave conducting medium and / or the at least one diffuser comprises a shock wave reflecting material. The shock wave conducting medium may be water.

[0018] The body may include at least one diffuser arranged at the exit opening, and the at least one diffuser includes a material having a propagation speed different from that of the shock wave conducting medium and / or the at least one diffuser includes a shock wave reflecting material. The at least one diffuser may be immovably arranged at the exit opening. In this case, "immovably" means that the diffuser must not pivot, rotate or swing. This has the advantage that the diffuser stay does not move or displace when a force is applied to the diffuser. Additionally, an immovable diffuser makes the handling of the transducer and the medical shock wave device safer and more convenient. Furthermore, the diffuser does not shift out of position.

[0019] The different propagation velocities and / or reflectivities of the materials create a phase shift, preventing structural interference that leads to cavitation cavities and ultimately damage to body tissue. The at least one diffuser material may be adapted accordingly to the shock waves generated by the shock wave source. Depending on the appropriate material selected, the shock waves may be refracted, reflected, diffracted, transmitted, and / or absorbed. The at least one diffuser material may include a material having a propagation velocity different from that of water.

[0020] The material may include a material with low absorption, which may be less than 50%. Absorbent materials cause attenuation of the shock waves, compromising the effectiveness of the shock waves and ultimately the lithotriptor.

[0021] The at least one diffuser may be located on the body and / or may be the body itself. The at least one diffuser may include at least one segment. If the at least one diffuser includes more than one segment, each such segment may be separately bonded to the body. The at least one diffuser may be monolithic and may include only one member. The at least one diffuser may be annular, although any shape known to those skilled in the art is possible.

[0022] At least one diffuser may be located on the inner surface of the body, may be bonded to the upper surface of the body, may be formed by the body, may be located against the edge of the body, preferably at least one diffuser is located on the edge of the body. At least one diffuser may also be located below the edge of the body on the inner surface of the body. Locating the diffuser on or against the edge of the body has the advantage that the device can be placed directly on the body of the individual to be treated. This is particularly advantageous when treating obese individuals who occupy the entire space between the edge and the focal area or focal point located in the patient. By locating at least one diffuser on or against the edge of the body, the treatment depth is not shortened and the device can be reliably applied for the treatment of individuals of all sizes.

[0023] The at least one diffuser may be an outer diffuser arranged in an annular shape around the outer periphery of the exit opening, and / or the at least one diffuser may be an inner diffuser arranged in annular shape around the inner periphery of the exit opening.

[0024] At least one diffuser may include grooves and / or protrusions distributed around its periphery.

[0025] The grooves and / or protrusions may be irregularly distributed over the entire circumference of the outer diffuser and / or the inner diffuser.

[0026] The material of the at least one diffuser may be a metallic material, a non-metallic inorganic material or preferably a polymeric material (e.g. polyethylene, polystyrene). The different propagation speeds and / or reflectivities of the at least one diffuser may change the phase and / or amplitude of the waves by causing refraction and diffraction. The material of the at least one diffuser must not absorb the waves, since this would cause attenuation of the waves and thus impair the effectiveness of the shock wave converter.

[0027] The diffuser has the effect that the shock wave is locally changed in terms of its phase and / or amplitude and / or is reflected. The reflection can be specular and / or non-specular. The diffuser can have the effect that the shock wave is scattered in non-specular directions, thereby causing diffuse reflection. The outer and / or inner diffuser can prevent constructive interference of the shock waves in the superposition zone. As a result, only a diffuse superposition with a significantly reduced peak value occurs.

[0028] At least one diffuser, which may be an inner and / or outer diffuser, may have an upper surface, a lower surface, a transducer-side surface and a surface opposite the transducer. The transducer-side surface may be the part of the diffuser that interacts with the wave. The upper surface may be the part that faces away from the body and the lower surface may be the part of the diffuser that faces towards the body. The outer diffuser's surface opposite the transducer is the part of the outer diffuser that faces away from the transducer. The inner diffuser's surface opposite the transducer may be the part of the diffuser that faces towards the central axis of the shock wave source. The surface opposite the transducer may not have any grooves or protrusions.

[0029] The grooves and / or protrusions of each diffuser may be located on the transducer-facing surface of the diffuser. The outer diffuser may be connected to the body at the underside of the outer diffuser. The inner diffuser may be connected to the shock wave source at the underside of the inner diffuser. In other words, the outer and / or inner diffuser may be connected to the transducer at its underside. The inner and / or outer diffuser may be connected to the transducer by a removable connection, a fixed connection, and / or may be integrated into the body. The inner and / or outer diffuser may be fixedly connected to the transducer. The inner and / or outer diffuser must not swivel, rotate and / or rock. Fixed removal prevents displacement of the inner and / or outer diffuser when a force is applied to the diffuser. The removable connection may be achieved by a form-fit and / or a friction-fit, e.g. a clamp, a bayonet joint, a screw thread, a plug connection, or any other removable connection known to a person skilled in the art is also possible. The fixed connection may be achieved by a material connection, for example by gluing or welding. The body and the at least one diffuser may be integral and / or monolithic.

[0030] Alternatively, the at least one diffuser may be integrated into the body. In other words, the body itself may be the at least one diffuser or a part thereof. For example, the body may be an external diffuser. The grooves of the at least one diffuser may be formed by recesses and / or notches provided in the body. The grooves may penetrate the edges and / or inner surface of the body, but not the outer surface of the body. The protrusions of the at least one diffuser may be parts of the body that do not have a groove. In other words, the protrusions may be parts of the body that do not have a recess on the edges and / or inner surface. Thus, the diffuser comprises a shock wave reflecting material consisting of the body. This shock wave reflecting material may be a metal, for example steel, brass, tin or aluminum. The grooves may be inserted into the body, for example by cutting, milling, drilling and / or sawing. The grooves inserted into the body may be approximately rectangular, triangular and / or parabolic.

[0031] The outer diffuser may be the body itself with a complementary diffuser bonded to the edge. The transducer-facing surface of the complementary diffuser may be the groove side of a diffuser integrated into the body.

[0032] Because the inner and / or outer diffusers can be coupled to the shock wave transducer, almost any shock wave transducer and / or medical shock wave device, such as a lithotriptor, can be retrofitted with inner and / or outer diffusers, thus providing an inexpensive and convenient way to reduce potential damage.

[0033] The grooves and protrusions of the inner diffuser or the outer diffuser or the inner and outer diffuser may be irregularly distributed over the entire circumference of the inner diffuser and / or the outer diffuser.

[0034] A regular distribution causes homogeneous waves to project beyond the body, resulting in a homogeneous pressure distribution. The advantage of a non-regular distribution is that structural interference and resonance can be avoided. Since structural interference and resonance are the cause of cavitation cavities, a non-regular distribution of grooves and / or protrusions around the entire circumference of the inner and / or outer diffuser can minimize the effects of cavitation cavities. As a result, damage and injury to body tissue is reduced.

[0035] The protrusions may project radially relative to a central axis of the body, the outer diffuser protrusions may project toward the central axis and the inner diffuser protrusions may project away from the central axis.

[0036] The outer diffuser protrusions or inner diffuser protrusions may protrude into the area defined by the wave propagating outwardly from the reflector. Alternatively, the inner diffuser and outer diffuser protrusions may protrude into the area defined by the wave propagating outwardly from the reflector.

[0037] The region defined by the wave propagating outwardly from the body through the exit opening may be located inside a junction volume defined by the body and the cylindrical space. The cylindrical space may have the same inner diameter as the edge of the body. The cylindrical space may have the same base as the exit opening. The cylindrical space may extend from the body. The cylindrical space may extend up to 0.5 cm, 1 cm, 2 cm, 5 cm, 10 cm, 30 cm or 50 cm upward from the edge of the body. The cylindrical space may define a volume. Thus, the protrusions of the inner diffuser or the outer diffuser or the protrusions of both the inner and outer diffusers may protrude into the junction volume defined by the body and into the volume defined by the cylindrical space. Thus, the inner diffuser and / or the outer diffuser may be engaged within the wave propagating from the body.

[0038] The depth of the grooves of the outer and / or inner diffuser may be adapted to the shock waves to be generated. The depth of the grooves may be in the range of 1 mm to 40 mm, preferably 1 mm to 10 mm.

[0039] The outer and / or inner diffuser may have a thickness between 1 mm and 40 mm. The thickness of the outer and / or inner diffuser may vary from the face of the outer and / or inner diffuser opposite the transducer to the face of the transducer. The thickness of the outer and / or inner diffuser may decrease from the face of the outer and / or inner diffuser opposite the transducer to the face of the transducer. As a result, the outer and / or inner diffuser may be conical or tapered. The conical or tapered shape of the diffuser also helps to block structural interference of the shock wave.

[0040] In some embodiments, the body may be a reflector. A reflector is any means capable of reflecting shock waves generated by a shockwave source. The reflector may be a concave reflector. The reflector may have an upper surface, a lower surface, an inner surface, an outer surface, an edge, and a central axis. The reflector may be rotationally symmetric. The reflector may define a cavity. The cavity may have a volume. The volume of the reflector is the three-dimensional space defined by the inner surface of the reflector and a plane passing through the edge.

[0041] The shock wave converter may comprise a shock wave source with a cylindrical coil. The cylindrical coil may be located with its central axis on the reflector central axis. The cylindrical coil may generate cylindrical waves that propagate radially of the coil and may be symmetrical about the central axis. The waves may be reflected by the reflector towards a focal region, which may be a focal point. The focal region may be on the central axis and may be at a distance from the coil. The distance may be in the range of 2 cm to 25 cm depending on the design of the reflector and coil to leave enough space to position the patient so that stones can be broken up or soft tissue target regions can be treated. All the waves propagating from the shock wave source to the focal region or focal point define a wave propagation region.

[0042] The shockwave converter may comprise an inner diffuser.Accordingly, the shockwave converter may comprise an outer diffuser or an inner diffuser or both.

[0043] The shockwave source may have an inner diffuser. The inner diffuser may be coupled to the shockwave source, preferably to the edge of the shockwave source. The inner diffuser may have grooves and protrusions distributed over its entire circumference. The inner diffuser may include at least one segment. If the inner diffuser includes more than one segment, these segments may be coupled to the shockwave source. The inner diffuser may comprise only one member. The inner diffuser may be annular, but any other shape known to a person skilled in the art is also possible.

[0044] The cylindrical coil may be disposed with its central axis on the reflector central axis. The cylindrical coil may generate cylindrical waves propagating radially of the coil and may be symmetrical about the central axis. The waves may be reflected by the reflector towards a focal region, which may be a focal point. The focal region may be on the central axis and may be at a distance from the coil. The distance may be in the range of 2 cm to 25 cm depending on the design of the reflector and coil to leave enough space to position the patient so that stones can be broken up or soft tissue target regions can be treated. All the waves propagating from the shock wave source to the focal region or focal point define the wave propagation region.

[0045] The outer diffuser protrusions may protrude toward the central axis and the inner diffuser protrusions may protrude away from the central axis.

[0046] The outer diffuser protrusions or inner diffuser protrusions may protrude into the area defined by the wave propagating outwardly from the reflector. Alternatively, the inner diffuser and outer diffuser protrusions may protrude into the area defined by the wave propagating outwardly from the reflector. [Brief description of the drawings]

[0047] Without limiting the general inventive concept, several examples of embodiments of the invention will now be illustrated with reference to the drawings. [Figure 1] 1 is a cross-sectional view of an exemplary embodiment of a shock wave transducer. [Diagram 2] 1 is a cross-sectional view of another exemplary embodiment of a shock wave transducer. [Diagram 3] FIG. 1 is a diagram illustrating wave propagation. [Figure 4] FIG. 2 is a plan view of the outer and inner diffusers. [Diagram 5] FIG. 1 is a perspective view of an exemplary embodiment of a shock wave converter. [Figure 6a] FIG. 1 illustrates an alternative exemplary embodiment of a shock wave converter. [Figure 6b] FIG. 1 illustrates an alternative exemplary embodiment of a shock wave converter. [Figure 6c] FIG. 1 illustrates an alternative exemplary embodiment of a shock wave converter. [Figure 7] FIG. 13 is a perspective view of another embodiment. [Figure 8] FIG. 8 shows a combination of the embodiments of FIGS. 5 and 7.

[0048] In Fig. 1, a cross-sectional view of an exemplary embodiment is shown. The shockwave converter 100 comprises a reflector 110 and a shockwave source 130. The reflector 110 and the shockwave source 130 may be rotationally symmetric and may have a common central axis 190. The shockwave source may comprise a coil 120. The coil may have a cylindrical shape that may be defined by a cylinder that holds its windings. Alternatively, the shockwave source coil may comprise a flat coil or a piezoelectric element or a spark gap (see Figs. 6a-6c). The reflector 110 may have a parabolic shape such that the waves generated by the shockwave source 130 are deflected at the inner surface 140 of the reflector 110 to a focusing area 400 that may be on the common central axis 190. The shockwave converter 100 comprises an outer diffuser 210. The outer diffuser 210 may be coupled to an edge 150 of the reflector 110. Furthermore, the shockwave converter 100 may have an inner diffuser 220. The inner diffuser 220 may be coupled to the shockwave source 130. The inner diffuser 220 may be coupled to the edge 160 of the shockwave source. The outer diffuser (210) may be rigidly coupled to the edge 150 of the reflector 110 and / or the inner diffuser (220) may be rigidly coupled to the shockwave source 130. In this exemplary embodiment, the inner diffuser protrusion 222 and / or the outer diffuser protrusion 212 may be oriented approximately parallel (within a range of ±10°, preferably within a range of ±5°, particularly preferably within a range of ±2.5° or less) to the plane 182 passing through the edge 115.

[0049] As exemplarily shown in FIG. 2, the inner diffuser protrusion 221 and / or the outer diffuser protrusion 213 may protrude inside the reflector cavity 180, or the inner diffuser protrusion 223 and / or the outer diffuser protrusion 211 may protrude into the volume of a cylindrical space 300. The reflector cavity 180 may have a volume. The cylindrical space 300 may extend up to 0.5 cm, 1 cm, 2 cm, 5 cm or 10 cm above the edge 150 of the reflector. The cylindrical space 300 may have a volume. This volume of the cylindrical space 300 is a three-dimensional space surrounding the wave propagation area, surrounded by the physical extension, preferably the virtual extension, of the edge along the direction of the propagating wave.

[0050] 3 symbolically illustrates wave propagation 410 from the shockwave source 120 to a focal region 400. The reflector may be optimized to obtain a particular shape of the focal region 400. All the waves 410 propagating from the shockwave source 120 to the focal region or focal point 400 define a wave propagation region. The focal point 400 may be located on the central axis 190.

[0051] 4 shows an exemplary embodiment of the inner diffuser 220 and the outer diffuser 210. The inner diffuser 220 and the outer diffuser 210 may be annular. The outer diffuser 210 and the inner diffuser 220 may have upper surfaces 215, 225, lower surfaces 216, 226, transducer-facing surfaces 217, 227, and transducer-opposite surfaces 218, 228. The outer diffuser and the inner diffuser may have grooves 214, 224 and protrusions 212, 222. The grooves 214, 224 and protrusions 212, 222 may be located on the transducer-facing surfaces 217, 227 of the outer diffuser 210 and the inner diffuser 220. The grooves 214, 224 and protrusions 212, 222 may be distributed around the entire circumference of the corresponding diffuser 210, 220. The grooves 214,224 and protrusions 212,222 may be regularly or preferably irregularly distributed over the entire circumference of the outer diffuser 210 and / or the inner diffuser 220.

[0052] Figure 5 shows a perspective view of an exemplary embodiment of the shockwave converter 100 shown in Figure 1. The outer diffuser 210 is coupled to the edge 115 of the reflector 110. The inner diffuser 220 is coupled to the edge 160 of the shockwave source 130. In this exemplary embodiment, the shockwave source 120 may have a cylindrical shape and the reflector 110 may have a parabolic shape. Figure 6a shows a cross-sectional view of the exemplary embodiment.

[0053] In Fig. 6a, an electrohydraulic ellipsoid is shown. The shockwave source 120 may be located on the central axis of the body 110. The shockwave source may be a point source. The body 110 may include an ellipsoidal reflector. The reflector 110 may be rotationally symmetric and may have a central axis 190. The reflector 110 may have an ellipsoidal shape such that the waves generated by the shockwave source 120 are deflected at the inner surface 140 of the reflector 110 to a focal region 400 that may be on the common central axis 190. The shockwave converter 100 includes a diffuser 210. The diffuser 210 may be coupled to the edge 150 of the reflector 110. All the waves 410 propagating from the shockwave source 120 to the focal region or focal point 400 define a wave propagation region. At least one diffuser 210 may protrude inside the reflector cavity 180 and into the wave propagation area.

[0054] In Fig. 6b, a cross-sectional view of another exemplary embodiment is shown. In Fig. 6b, a shockwave converter 100 with a piezoelectric sphere is shown. The body 110 may include a spherical section and the shockwave source 120 may be a spherical assembly of piezoelectric elements. The shockwave source 120 may be self-focusing, e.g., no additional focusing components are required. The body 110 may be rotationally symmetric and may have a central axis 190. The shockwave converter 100 has at least one diffuser, which may be an outer diffuser 210. The diffuser 210 may be coupled to the edge 150 of the body 110. All the waves 410 propagating from the shockwave source 120 to the focal region or focal point 400 define a wave propagation region. At least one diffuser 210 may protrude inside the body cavity 180 and into the wave propagation region.

[0055] In Fig. 6c, a cross-sectional view of another exemplary embodiment is shown. In Fig. 6c, a shockwave converter 100 is shown. The shockwave converter may have a central axis 190. The shockwave source 120 may be a flat coil. The shockwaves generated by the flat coil may be focused by a focusing element 125. The focusing element may be an acoustic lens. The acoustic lens may be part of the body 110. The shockwave converter 100 has an outer diffuser 210. The outer diffuser 210 may be coupled to the edge 150 of the acoustic lens. All the waves 410 propagating from the shockwave source 120 to the focal region or focal point 400 define a wave propagation region. At least one diffuser 210 may protrude inside the cavity 180 of the body and into the wave propagation region.

[0056] In Fig. 7, a perspective view of another embodiment of the shock wave converter 100 is shown. At least one diffuser 210 may be part of the body 110 itself. For example, the body 110 may include an outer diffuser 210 and / or an inner diffuser 220 may be arranged on the shock wave source 120. The body 110 may be a reflector. The grooves 214 of the outer diffuser 210 may be formed by recesses and / or notches provided in the body 110. The grooves 214 may penetrate the edge 150 and / or the inner surface 140 of the body, but may not penetrate the outer surface of the body 110. The protrusions 212 of the outer diffuser 210 may be the part of the body 110 that does not have the grooves 214. In other words, the protrusions 212 may be the part of the body 110 that does not have recesses on the edge 150 and / or the inner surface 140. Thus, the diffuser includes a shock wave reflecting material made of the body. The grooves 214 may be inserted in the body 110, for example, by cutting, milling, drilling and / or sawing. The grooves 214 inserted in the body 110 may be, for example, rectangular, triangular and / or parabolic. The grooves 214 and the protrusions 212 of the outer diffuser may be distributed over the entire circumference of the body 110 and / or the edge 150. The grooves 214 and the protrusions 212 may be distributed regularly, preferably irregularly, over the entire circumference of the body 110 and / or the edge 150. The grooves 214 and the protrusions 212 of the outer diffuser may be stationary arranged over the entire circumference of the body 110 and / or the edge 150.

[0057] In Fig. 8, a perspective view of another embodiment of the shock wave converter 100 is shown. This embodiment is a combination of the embodiments of Fig. 5 and Fig. 7. In this embodiment, the outer diffuser may be the body itself combined with a complementary diffuser (outer diffuser) of the embodiment according to Fig. 5. The transducer-side face of the complementary diffuser may be on the side of a groove formed in the body. [Explanation of symbols]

[0058] 100 Shock Wave Converter 110 Main unit 120 Shockwave Source 125 Focusing element 130 Coil 140 Inside 150 Edge advance opening 160 Edge of shock wave source 180 Hollow Body 182 plane 190 Center axis 210 Outer Diffuser 211~213 Protrusion 214 Groove 215 Top surface 216 Bottom surface 217 Converter side surface 218 Opposite side of the transducer 220 Inner Diffuser 221~223 Protrusion 224 Groove 225 Top 226 Bottom surface 227 Converter side surface 228 Opposite side of the transducer 300 Cylindrical Space 400 Focus Area 410 Wave Propagation

Claims

1. A shock wave converter (100) for a medical shock wave device, comprising: The transducer (100) comprises a body (110); The body (110) has a cavity filled with a shock wave conducting medium; The body (110) carries a shock wave source (120) configured to generate shock waves; The body (110) further comprises an exit opening for allowing the shock wave to exit the body (110); The transducer (100) is configured to induce the shock wave to propagate through the exit opening. In the shock wave converter (100), The shock wave converter (100) is characterized in that the body has at least one diffuser (210, 220) arranged at the exit opening, the at least one diffuser (210, 220) is arranged at the exit opening so as not to swivel, rotate or swing, and the at least one diffuser (210, 220) comprises a material having a propagation speed different from the propagation speed of the shock wave conducting medium.

2. The shock wave converter (100) of claim 1, characterized in that the at least one diffuser (210, 220) extends into the cavity of the body and / or into a cylindrical space (300) having the same base as the exit opening and extending from the body (110).

3. The shock wave converter (100) of claim 2, wherein said cylindrical space (300) has a height between 0.5 cm and 30 cm.

4. The shock wave converter (100) according to any one of claims 1 to 3, characterized in that part or all of at least one diffuser (210, 220) is located within the propagation path of the shock wave propagating from the shock wave source (120).

5. said at least one diffuser (210, 220) being an outer diffuser (210) arranged in an annular shape around the periphery of said exit opening; and / or The at least one diffuser (210, 220) is an inner diffuser (220) arranged annularly around the inner circumference of the exit opening. A shock wave converter (100) according to any one of claims 1 to 4, characterised in that

6. The shock wave converter (100) according to any one of claims 1 to 4, characterized in that the at least one diffuser (210, 220) has grooves (214) and protrusions (211-213) distributed over its entire circumference.

7. The shock wave converter (100) according to claim 6, characterized in that said grooves (214) and said protrusions (211-213) are irregularly distributed over the entire circumference of said at least one diffuser (210, 220).

8. The shock wave converter (100) according to claim 6 or 7, characterized in that the body (110) has a central axis (190), and the protrusions (211-213) protrude radially relative to the central axis.

9. The shock wave converter (100) according to any one of the preceding claims, characterized in that said at least one diffuser (210, 220) comprises a polymer material.

10. The shock wave converter (100) according to any one of claims 1 to 9, characterized in that said at least one diffuser (210-220) comprises a metallic shock wave reflecting material.

11. Shock wave converter (100) according to any of the preceding claims, characterized in that said at least one diffuser (210-220) comprises a material having a propagation speed different from the propagation speed of water.

12. The shock wave converter (100) according to any one of the preceding claims, characterized in that the shock wave converter (100) comprises a flat coil or a spherical assembly of piezoelectric elements or a spark gap.

13. The shock wave converter (100) according to any one of the preceding claims, characterized in that said at least one diffuser (210, 220) comprises a shock wave reflecting material.

14. The body (110) comprises a reflector having a central axis; At least one diffuser (210-220) is located at the edge of the reflector; The shock wave converter (100) according to any one of claims 1 to 13, characterized in that the shock wave converter (100) comprises a cylindrical coil whose central axis is arranged on the reflector central axis (190).

15. A medical shock wave device comprising a shock wave converter (100) according to any one of claims 1 to 14.

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