An impact body for a pressure wave device and a method for manufacturing such an impact body

Abstract

An impact body (30) being configured for a pressure wave device (10), which is intended to treat biological tissue, comprising: - a contact side (34), being configured to be, in operation, in contact with the treated biological tissue, and - an interface side (32) being configured for connecting the impact body (30) to the pressure wave device (10) such that the impact body (30) introduce, along a treatment direction (TD) and into the treated biological tissue, being in contact with said contact side in operation, a pressure wave (16) resulting from the interface side (32) being impacted by a projectile (28), when operating the pressure wave device (10), the interface side (32) and the contact side (34) being opposite to each other, wherein the impact body (30) comprises at least a cavity (20) between the contact side (34) and the interface side (32).

Description

[0001] FERTON HOLDING S.A. MSP Ref: 47662 PT-WO PM / SK

[0002] An impact body for a pressure wave device and a method for manufacturing such an impact body

[0003] The present invention refers to an impact body for a pressure wave device and a method for manufacturing such an impact body.

[0004] Such pressure wave devices are intended to treat humans or animals by using pressure waves, the pressure waves being generated by the impact of an accelerated projectile on an impact body and are well known from the prior art. For example, EP 2 529 792 A1 and EP 2 381 864 B1 describe such pressure wave devices.

[0005] Typically, the pressure wave device has a pneumatic drive element for accelerating the projectile. In particular, the pneumatic drive element is intended to accelerate the projectile, which, in turn, hits the impact body, being in contact or close to the surface of the tissue, which should be treated. The pressure wave, generated in the impact body, is transferred into the tissue of a patient by entering the body of the patient via the surface or skin, which is close to the impact body or is in contact with the impact body.

[0006] In the context of the above-discussed state of the art, it was an objective technical problem to improve pressure wave devices such that they more effectively transfer energy into the tissue to improve the effectiveness of the treatment.

[0007] The problem is solved by an impact body according to claim 1 and a method according to claim 14. Advantages and preferred embodiments of the invention are discussed in the dependent claims, the description, and the figures. 47662 PT-WO PM / SK ©

[0008] According to the first aspect an impact body is provided, the impact body being configured for a pressure wave device, which is intended to treat biological tissue, comprising:

[0009] - a contact side, being configured to be, in operation, in contact with the treated biological tissue, and

[0010] - an interface side being configured for connecting the impact body to the pressure wave device such that the impact body introduces, along a treatment direction and into the treated biological tissue, being in contact with said contact side in operation, a pressure wave resulting from the interface side being impacted by a projectile when operating the pressure wave device, the interface side and the contact side being opposite to each other, wherein the impact body comprises a cavity between the contact side and the interface side.

[0011] Preferably, the impact body is configured and determined for the use with a pressure wave device. In a preferred embodiment, the contact side, is outwardly curved.

[0012] Preferably, the contact side is at least partially outwardly dome-shaped and has an axis of symmetry.

[0013] Contrary to the prior art, the present invention suggests incorporating the cavity into the impact body. It turned out that by introducing the cavity into the impact body it is possible to modify the deformation of the impact body when it is hit by the projectile in operation. As a result, the output, i.e. the created pressure wave, can be manipulated or adapted. Especially, it turned out that it was possible to increase the output energy of the created pressure wave by incorporating the cavity. Furthermore, it is of benefit to introduce the cavity into this impact body, since the material amount of the impact body is reduced. This advantageously reduces the material amount needed to create the impact body on the one hand and decreases the weight of the pressure wave device, into which the impact body is incorporated in operation. As a result, the handling of the pressure wave device is 47662 PT-WO PM / SK © simplified for the operator. For the sake of completeness, it is noted that the present invention also refers to a pressure wave device having an impact body according to the invention. The benefits and specification of the impact body applies analogically for the pressure wave device and vice versa.

[0014] In particular, it is provided that the contact side protrudes outwardly, i. e. into a direction facing in operation to the biological tissue. Due to its outwardly curved shape or outwardly dome-shape, the center of the contact side is the first part to touch the biological tissue when the shock wave device is applied. Furthermore, the impact body is configured and determined to be accelerated as whole part inside the shock wave apparatus. Preferably, the contact side is shaped or formed convex and more preferably does not include any recess or recesses, i. e. is free of a recess. In particular the cavity is no part of the contact side. There is preferably a distance between the cavity and the contact side, being more preferably determined by the side wall forming the contact side on the outer side and an inner side of the cavity on the opposite side of the side wall. In other words: the cavity does not form a part of the outer side of the impact body. Instead the cavity is incorporated inside the impact body. Preferably the impact body is single-pieced, i. e. you cannot further divide the impact body without destroying the impact body. Preferably, the convex or outwardly curved or outwardly dome-shaped contact side is free from a recess or concave segment depression. Preferably it is provided that the contact side contacts the biologic tissue over an area being greater than 1 cm2, more preferably greater than 2 cm2and most preferably greater than 3 cm2.

[0015] Preferably it is provided that between the contact side and the interface side, a center section is arranged. The center section has mainly a cylindrical shape and extends from the contact side, which faces the biological tissue in operation, to an annular rim or collar, which defines one end of the interface side. The interface side is adapted, for example by a tapered or conical shape, such that it can be inserted into a pressure wave device. The annular rim / collar, which extends along a circumference direction and protrudes perpendicular to the treatment direction, is 47662 PT-WO PM / SK © intended to guarantee that the impact body does not leave the pressure wave device when it is hit by the projectile in operation. In the assembled state the annular rim is included in the handpiece and you can only see the center section and the contact side of the impact body if the handpiece is not made from transparent material.

[0016] Measured along a direction parallel to the treatment direction, an extension of the center section is 1.4 to 20 times, preferably 1.4 to 10 times, and most preferably 1 .4 to 8 times larger than an extension of the contact side and / or the interface side. The deformation of the impact body in operation proceeds along the treatment direction from the interface side to the contact side, bypassing the center section.

[0017] Preferably, it is provided that a single cavity is incorporated into the impact body. Creating only a single impact body simplifies a manufacturing process and especially allows easy manufacturing a homogenous cavity, which is necessary to create a homogenous material distribution of the impact body. As a result of this homogenous distribution of the material, the pressure wave can be created along a determined direction, being parallel to the treatment direction, which in turn allows an optimized and idealized handling of the operator, since they can determine the direction of the pressure wave more exactly. Furthermore, it is of advantage for the lifetime of the impact body, since the deformation of the impact body, especially of the side walls, is also homogenous.

[0018] Furthermore, it is provided that a volume of the cavity represents 10 % to 90 % of the volume of the impact body, preferably 20 % to 70 % and most preferably 35 % to 55 % or even 45 %. Especially, it turned out to be of benefit to create a comparably large cavity, as is indicated by the mentioned high values for the volume of the cavity. As a consequence, all porous materials having small cavities inside the impact body are not meant. It is intended to create a comparably large dimensioned cavity, which in turn decreases the wall thickness of the wall section surrounding the cavity in case of the same dimension for the impact body. This has a strong influence on the deformation characteristics, which turned out to be of 47662 PT-WO PM / SK © benefit in case of energy transfer from the projectile to the generated pressure wave.

[0019] Preferably, it is provided that the impact body has an axis of symmetry, each cavity being symmetrically distributed around this axis. As a consequence of this symmetry, it is possible to control the deformations of the impact body during the operation in a more controlled manner, especially such that the generated pressure wave is directed in a well-defined direction, preferably parallel to the treatment direction.

[0020] Preferably, the cavity presents an ogival or conical shape. Due to this shape, the wall section surrounding the cavity extends slanted to the treatment direction. Therefore, the comparably small impact surface of the interface side, which experiences the impact of the projectile during the operation, transfers the energy and the deformation not only parallel to the treatment direction but also in a direction slanted to the treatment section. This allows the transfer of the deformation to the cylindrical-shaped center section such that the deformation, being created, increases its cross section perpendicular to the treatment direction in comparison to the comparably small impact surface of the interface side.

[0021] Preferably, it is provided that the cavity is surrounded by a wall section, the wall section comprising at least one slit, opening the cavity to an exterior of the impact body. The cavity of the impact body is connected to the exterior by incorporating at least one slit into the side wall, especially in the section assigned to the center section of the impact body. This allows for further influencing the deformation characteristics of the impact body. It turned out to be a benefit to have at least one slit, preferably a plurality of slits. Most preferably the wall section, which surrounds the cavity has at least four slits.

[0022] Preferably, it is provided that a ratio of the width of the at least one slit to a length of the at least one slit is between 0,01 and 0,3, preferably between 0,05 and 0,2 and most preferably between 0,05 and 0,15. The length of the at least one slit is 47662 PT-WO PM / SK © measured along the treatment direction and the width is measured in a direction perpendicular to the treatment direction.

[0023] Preferably, the slits, including the at least one slit, extend or the at least one slit extends along the treatment direction. Furthermore, it is conceivable that the slits extend along the treatment direction at least 70%, preferably at least 80% and most preferably at least 90% of the length being assigned to the center section of the impact body. Preferably, the location of the at least one slit is limited to the center region and the at least one slit does not extend into the interface section. The center section of the impact body extends from the contact side to the annular rim of the interface section. Furthermore, it is provided that the interface side extends from the annular rim, protruding from the impact body, especially along a direction perpendicular to the treatment direction, to an impact surface being configured to be impacted by the projectile.

[0024] Furthermore, it is provided that the cavity extends at least partially into the interface side. Preferably, the main part of the cavity is arranged inside the center section of the impact body. However, it turned out to be a benefit to extend the cavity into the interface section to remove also material from the interface side, especially in the section, in which the deformation forces are split or spread such that they are distributed to the wall section of the center side.

[0025] Furthermore, it is provided that the contact side is dome-shaped, configured for being in contact with a treated biological tissue, wherein the contact section has a maximum thickness being measured in a direction parallel to the treatment direction, wherein the maximum thickness is between 1 mm and 10 mm, preferably between 1.2 and 5 mm and most preferably between 1.5 mm and 3.5 mm. In particular, the minimum thickness is at least 1 mm. It turned out that it is sufficient to create a wall thickness of this dimension to make the contact side stable for operation, especially during the transfer to the biological tissue. Furthermore, it is provided that the dome-shaped contact side is prolongated by a cylindrical wall section, forming preferably the center section. 47662 PT-WO PM / SK ©

[0026] Preferably, it is provided that the impact body has a weight smaller than 300 g, more preferably smaller than 200 g, and most preferably between 50 g and 150 g. It turned out that by increasing the size of the cavity, it is possible to significantly decrease the weight of the impact body and still have a reasonable impact body, which can transfer and create pressure waves in the biological tissue being treated.

[0027] Another subject matter of the present invention concerns a pressure wave device including an impact body, according to the present invention, comprising.

[0028] - a handpiece,

[0029] - a pneumatic drive device accelerating a projectile and

[0030] - the impact body is connected to the pressure wave device by the interface side.

[0031] All specifications being discussed in contact with the impact body apply analogically to the pressure wave device and vice versa.

[0032] Another subject matter of the present invention is a method to manufacture an impact body, according to the present invention, wherein the impact body having a cavity is generated. The specifications and benefits being discussed in contact with the impact body apply analogously for the method to manufacture the impact body and vice versa. Especially, it turned out that it is of benefit to create the impact body by a selective laser sintering method and / or by machining two or more parts followed by a brazing / welding or another possible conventional assembly method. In other words, it turned out that it is easier to create the cavity during the formation of the impact body and not to remove the material from a massive block, being handled previously and shaped previously to create the shape of the impact body.

[0033] Wherever not already described explicitly, individual embodiments or their aspects and features can be combined or exchanged with one another without limiting or 47662 PT-WO PM / SK © widening the scope of the described invention, whenever such a combination or exchange is meaningful and in the sense of this invention. Advantages which are described concerning one embodiment of the present invention are, wherever applicable, also advantageous to other embodiments of the present invention.

[0034] In the drawings:

[0035] Fig. 1 shows a pressure wave device

[0036] Fig. 2a and 2b show an impact body according to the state of the art (figure 2a) and according to one exemplary embodiment of the present invention (figure 2b)

[0037] Fig. 3 shows a picture of an exemplary embodiment of an impact body according to the present invention.

[0038] Fig. 4 provides information about an experimental setup to determine

[0039] In Figure 1 a pressure wave device 10 is shown. Such a pressure wave device 10 is intended to treat tissue of a human body or an animal by generating a pressure wave 16, which acts on the tissue of the body. In particular, it is provided that the pressure wave device 10 is located on the skin of the human or animal body and the pressure wave 16 enters the human or animal body through the skin and acts on tissue inside of the human or animal body. Thereby, the pressure wave device 10 includes an impact body 30, which is in contact with the skin of the human or animal during the treatment. For generating pressure wave 16, the pressure wave device 10 includes projectile 28, which is accelerated in pipe 26 for guiding the projectile 28. The accelerated projectile 28 hits the impact body 30, generating the pressure wave 16 being emitted by the pressure wave device 10. In particular, the pressure wave device 10 has a handpiece 12, including at least a pipe 26 for accelerating the projectile 28, and a pneumatic drive element 14, which provides pressurized gas to accelerate the projectile 28 inside the pipe 26, in which the pro- 47662 PT-WO PM / SK © jectile 28 is accelerated. Furthermore, it is conceivable that the pressure wave device 10 has a regulation unit 19 and an activation switch 25. By actuating the regulation unit 19 it is possible to define parameters of operation of the pressure wave device 10, whereas the activation switches 25 triggers the generation of the pressure wave 16.

[0040] The transfer of the pressure wave 16 is established by the impact body 30 being impacted especially by an accelerated projectile 28. The impact body 30 is configured for a pressure wave device 10, which is intended to treat a biological tissue, and comprises

[0041] - a contact side 34, being configured to be, in operation, in contact with a treated biological tissue and

[0042] - an interface side 32, being configured for connecting the impact body 30 to the pressure wave device 10 such that the impact body 30 introduces a pressure wave 16, along a treatment direction TD and into the treated biological tissue, being in contact with said contact side 34 in operation. In particular, the interface side 32 and the contact side 34 are opposite to each other.

[0043] In Figure 2a a detailed cross-sectional view of an impact body 30’ according to the prior art is illustrated. In particular the impact body 30’ has on the one hand an interface side 32, which is impacted by projectile 28. Especially, the interface side 32 includes an impact surface 31 , which is impacted by the projectile 28. Preferably, the interface side 32 extends from this impact surface 31 to an annular rim 36 protruding along a direction being perpendicular to the treatment direction TD. In addition to the contact side 34 and the interface side 32, there is a cylindric- shaped centre section 35. This specific geometry of the impact body 30 is used to transfer effectively the pressure wave 16 into the biological tissue. According to the prior art, the impact body 30’ is completely massive, i. e. the impact body 30’ is formed from the metal block by just shaping its outside geometry.

[0044] In Figure 2b an impact body 30 according to an exemplary embodiment of the present invention is illustrated. Contrary to the prior art approach of the impact 47662 PT-WO PM / SK © body 30’, the impact body 30 according to this exemplary embodiment of the present invention includes a cavity 20, being incorporated into the impact body 30. It turned out that by removing material from the inner side of the impact body 30, in particular from the center section 35 of the impact body 30, it is possible to even increase the output of the pressure wave 16. Increasing the output of pressure wave 16 and its strength is helpful for the treatment. It turned out that introducing at least one cavity 20 into the impact body 30 allows to modify the deformation characteristics of the impact body 30 when impacted by the projectile 28 in operation. As illustrated, cavity 20 extends mainly symmetrical to an axial symmetry axis of the impact body 30 and / or especially extends mainly in the center section 35 and in particular extends into the section of the interface side 32. As a result, it is possible to create a comparably large cavity 20, being incorporated into the impact body 30, such that the cavity 20 is mainly surrounded by a wall section 38.

[0045] Further, it turned out that it is even possible to modify the deformation by inserting at least one slit 22 into the wall section 38 surrounding the cavity 20. The slit 22 forms an opening of the impact body 30 connecting the inner side of the impact body 30, i. e. cavity 20, with its exterior. Preferably, the impact body 30 comprises a plurality of slits 22.

[0046] For example, the impact body 30 includes slits 22 being arranged opposite to each other. Preferably, the slits 22 are distributed in an equidistant distanced manner along a circumference direction. In particular, slits 22 are localized in the center section 35, which is localized between the interface side 32 and the contact side 34. Preferably, the slits 22 extend along the treatment direction TD, in particular parallel to the treatment direction TD. Measured along this treatment direction TD, at least one slit 22 has at least a length of 50% of the length of the centre section 35 of the impact body 30 measured in the same direction. Preferably, the at least one slit 22 extends about at least 70 % or more preferably at least more than 80% of the length of the centre section 35. Preferably, the centre section 35 is defined by the distance between the annular rim 36 and the end of the cavity 20 at the contact side 34 or the wall section 38 forming the contact side 34 of the impact body 30, the distance being considered along a direction being parallel to the 47662 PT-WO PM / SK © treatment direction TD. Furthermore, the centre section 35 comprises, preferably directly adjacent to the annular rim 36, a groove 37 extending circumferentially around the impact body 30. It is conceivable that the slits 22 have all the same length along a direction parallel to the treatment direction TD. However, it is also conceivable that the slits 22 differ in length.

[0047] The contact side 34 is mainly formed by a dome shaped wall section 38 at the front side of the impact body 30 facing in operation to the tissue. The wall section 38 at the contact side 34 has a maximum thickness D, being between 1 mm and 10 mm, preferably between 1.2 and 5 mm and most preferably between 1.5 mm and 3.5 mm. Thereby, it is conceivable that the thickness of this wall section 38 at the contact side 34 modulates or is constant along a direction, being perpendicular to the treatment direction TD. The interface side 32, which extends from the annular rim 36 to the impact surface 31 , which is in contact with the projectile 28 during the impact event, tapers from the annular rim 36 to an impact surface 31 .

[0048] Figure 3 shows a picture of an impact body 30 illustrating a three-dimensional view of this impact body 30. In particular, it is shown here that two slits 22 are localized opposite to each other, such that you can view through the impact body 30. As a consequence, you can see the cavity 20 from outside.

[0049] Figure 4 shows an experimental set up to determine an energy flux density of different impact bodies 30. Pressure and energy outputs are done with the hydrophone method, described various studies characterizing pressure wave devices 10. The measurement method uses a hydrophone (FOPH 2000) to record pressure data generated by the device at different positions of the sensor relative to the applicator centre. The measurement tool used is the FOPH 2000 from RP acoustics, which comprises a 0.1 mm diameter optical fiber immersed into water of a water tank 51 and constituting the sensing device, i. e. as sensor 53.

[0050] A laser light is emitted by a stable laser diode 42 and the reflected light is measured by a photodetector 45. Due to the change in refraction index Nwater as a function of pressure, the light signal shifts, when a pressure wave 16 passes through 47662 PT-WO PM / SK © the fiber surface. For handling the detected signals, a photodetector 45, a fiber coupler 41 , a sensor 53, an amplifier 46 and an oscilloscope 52 are used. Figure 4 shows a test shock wave 55 being recorded.

[0051] Further details can be found in the FOPH 2000 user manual, or on the manufacturer’s website. The handpiece 12 is put on the surface of a water tank 51 , with the applicator immersed. A 3-axis motorised table is used to move the sensing part of the FOPH 2000 in positions of interest, and the signal is recorded through an oscilloscope 52. Key parameters extracted from these measurements are described in IEC 63045. For this study, a focus is made on peak positive pressure and EFD+, which will be used to compare the parameters.

[0052] Once the measurements have been acquired, the pressure signal is post-treated to extract required values. The Energy Flux Density (EFD) is computed following the equation with Z_H2O=1 .5e6 Rayl, P(t) being the pressure signal. The typical limit used for integration is the 1st positive peak to calculate the EFD+.

[0053] The results of this experiment are listed below for an impact body 30 as illustrated in figure 2a (first column) on the one hand and an impact body 30 according to an embodiment in consistency with the embodiment shown in figure 2b (second column). It turned out that advantageously energy flux density can be significantly decreased for the impact body 30 having a cavity 20 inside. As a result, the experimental setup and experiments show that incorporating cavity 20, while having the same geometry for the outer shape of the impact body, results in an increase of the created shock wave 16. 47662 PT-WO PM / SK ©

[0054] Reference numbers:

[0055] 10 pressure wave device

[0056] 12 handpiece

[0057] 16 pressure wave

[0058] 19 regulator

[0059] 20 cavity

[0060] 22 slit

[0061] 25 activation button

[0062] 26 guide tube

[0063] 28 projectile

[0064] 30 impact body

[0065] 30’ impact body of the prior art

[0066] 31 impact surface

[0067] 32 interface side

[0068] 34 contact side

[0069] 35 center section

[0070] 36 annular rim I collar

[0071] 37 groove

[0072] 41 fiber coupler

[0073] 42 laser diode

[0074] 45 photodetector

[0075] 46 amplifier

[0076] 51 water tank

[0077] 52 oscilloscope

[0078] 53 sensor

[0079] 55 test shock wave

[0080] TD treatment direction

[0081] D maximum thickness

Claims

47662 PT-WO PM / SK ©Claims1 . An impact body (30) being configured and determined for use with a pressure wave device (10), which is intended to treat biological tissue, comprising:- a contact side (34), being configured to be, in operation, in contact with the treated biological tissue, and being outwardly curved and- an interface side (32) being configured for connecting the impact body (30) to the pressure wave device (10) such that the impact body (30) introduce, along a treatment direction (TD) and into the treated biological tissue, being in contact with said contact side in operation, a pressure wave (16) resulting from the interface side (32) being impacted by a projectile (28), when operating the pressure wave device (10), the interface side (32) and the contact side (34) being opposite to each other, wherein the impact body (30) comprises a cavity (20) between the contact side (34) and the interface side (32).

2. The impact body (30) according to one of the preceding claims, wherein a single cavity (20) is incorporated into the impact body (30).

3. The impact body according to one of the preceding claims, wherein the impact body is single pieced.

4. The impact body (30) according to one of the preceding claims, wherein a volume of the cavity (20) or the cavities represents at least 10 % to 90 % of the volume of the impact body (30), preferably 20 % to 70 % and most preferably 35 % to 55 %5. The impact body (30) according to one of the preceding claims, wherein the impact body (30) has an axis of symmetry, the cavity (20) or cavities being symmetrically distributed around this axis.

6. The impact body (30) according to claim 4, wherein the cavity (20) presents an ogival or conical shape.

7. The impact body (30) according to one of the preceding claims, wherein the cavity (20) is surrounded by a wall section (38), the wall section (38) comprising at least one slit (22) opening the cavity (20) of the impact body (30) to an exterior.

8. The impact body (30) according to claim 6, wherein the at least one slit (22) extends along the treatment direction (TD).

9. The impact body (30) according to one of the preceding claims, wherein the interface side (32) extends from an annular rim (36), protruding from impact body (30), to an impact surface (31 ) being configured to be impacted by the projectile (28).

10. The impact body (30) according to claim 8, wherein the cavity (20) extends at least partially into the interface side (32).11 . The impact body (30) according to one of the preceding claims, wherein the contact side (34) is at least partially dome-shaped, configured for being in contact with the treated biological tissues, wherein the contact side (34) has a maximum thickness (D), being measured in a direction parallel to the treatment direction (TD), wherein the maximum thickness (D) is between 1 mm and 10 mm, preferably between 1.2 and 5 mm and most preferably between 1.5 mm and 3.5 mm.

12. The impact body (30) according to claim 11 , wherein the dome-shaped contact side (34) is prolongated by a cylindrical wall section (38).47662 PT-WO PM / SK ©13. The impact body (30) according to one of the preceding claims, wherein a weight of the impact body (30) is s smaller than 300 g, more preferably smaller than 200 g, and most preferably between 50 g and 150 g.

14. A pressure wave device (10) including an impact body (30) according to one of the preceding claims, comprising- a handpiece (12),- a pneumatic drive device accelerating a projectile (28) and- the impact body (30), being connected to the pressure wave device (10.) by the interface side.

15. A method to manufacture an impact body (30) according to one of the claims 1 to 13, wherein an impact body (30) having a cavity (20) is generated.- 17 / 18 -

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