Pressure pulse/shock wave apparatus for generating waves having plane, nearly plane, convergent off target or divergent characteristics
An apparatus for generating pressure pulse/shock waves (PP/SWs) is disclosed which comprises a pressure pulse/shock wave (PP/SW) source, a housing enclosing said PP/SW source, and an exit window from which wave fronts of waves generated by said PP/SW source emanate. The wave fronts have plane, nearly plane, convergent off target or divergent characteristics. In one embodiment, an extracorporeal shock wave system provides a planar wave for the treatment of tissue. A parabolic reflector is provided in order to propagate the planar wave through a membrane and to the tissue of a human subject. A piezoelectric, electrohydraulic or electromagnetic source may be used to develop the wave.
1. Apparatus for generating pressure pulse/shock waves comprising:
a pressure pulse/shock wave (PP/SW) source;
a housing enclosing said PP/SW source; and
an exit window from which shock wave fronts of waves generated by said PP/SW source emanate, wherein said shock wave fronts have plane, nearly plane, convergent off target or divergent characteristics wherein the apparatus is shaped and dimensioned to provide the shock wave fronts having a power density level to produce a tissue reaction in a subject to which the wave is administered and wherein the waves have a power density in the range of approximately 0.01 mJ/mm 2 up to 1.0 mJ/mm 2 to stimulate a living tissue while avoiding tissue damage.
2. The apparatus of claim 1 , wherein said PP/SW source comprises:
a pressure pulse/shock wave generating element for generating pressure pulses/shock waves;
a focusing element for focusing said waves into a focus volume outside the focusing element;
said apparatus further comprising a movable elongated mechanical element having a longitudinal axis;
wherein said focus volume is situated on or at said longitudinal axis; and
wherein said movable elongated mechanical element is movable to extend to or beyond said focus volume so that shock wave fronts with divergent characteristics emanate from said exit window.
3. The apparatus of claim 2 , wherein said movable elongated element is part of said housing and said exit window is a window of the housing.
4. The apparatus of claim 2 , wherein said focusing element is an acoustic lens, a reflector or a combination thereof.
5. The apparatus of claim 1 , wherein said PP/SW source comprises a pressure pulse/shock wave generating element for generating pressure pulses/shock waves, and wherein said waves emanate from said exit window without being focused by a focusing element.
6. Apparatus of claim 1 , wherein said PP/SW source comprises an electro hydraulic pressure pulse/shock wave generating element.
7. The apparatus according to claim 6 , wherein said electro hydraulic pressure pulse/shock wave generating element comprising at least two electrodes, said PP/SW source further comprising a generalized paraboloid according to the formula y n =2px, wherein—x and y are carthesian coordinates, —p/2 is a focal point measured from an apex of the generalized paraboloid, and—n is about 1.2<2 or 2<about 2.8, with n≠2,
said electrodes being positioned within said generalized paraboloid, and wherein a spark between tips of said electrodes is, with about +/−5 mm of variance, generated at the focal point p/2 of the generalized paraboloid.
8. The apparatus of claim 7 , wherein burn down of the electrode tips (z) is compensated by the selection of (p+/−z) and n so that the resulting generalized paraboloid has a configuration between a paraboloid defined by formula y 2 =2(p+z)x and a paraboloid defined by formula y 2 =2(p−z)x.
9. The apparatus of claim 7 , wherein at least one of said electrodes is adjustable.
10. Apparatus of claim 1 , wherein said PP/SW source comprises an electromagnetic pressure pulse/shock wave generating element.
11. Apparatus of claim 10 , wherein said electromagnetic pressure pulse/shock wave generating element is an electromagnetic flat or curved emitter emitting waves having nearly plane or divergent characteristics, and wherein said waves emanate from said exit window without being modified by a lens.
12. Apparatus of claim 10 , wherein said electromagnetic pressure pulse/shock wave generating element is an electromagnetic flat emitter emitting waves having nearly plane characteristics, and wherein said PP/SW source further comprises a lens for focusing said waves in a first focal point, wherein divergent waves are created behind said focal point emanate from said exit window.
13. Apparatus of claim 10 , wherein said electromagnetic pressure pulse/shock wave generating element is an electromagnetic flat emitter emitting waves having nearly plane characteristics and wherein said PP/SW source further comprises a lens for de-focusing said waves so that waves with divergent wave characteristics emanate from said exit window.
14. Apparatus of claim 10 , wherein said electromagnetic pressure pulse/shock wave generating element is an electromagnetic cylindrical emitter and wherein said PP/SW source further comprises at least one reflecting element and/or at least one lens.
15. Apparatus of claim 1 , wherein said PP/SW source comprises a piezoceramic pressure pulse/shock wave generating element.
16. Apparatus of claim 15 , wherein said piezoceramic pressure pulse/shock wave generating element is a piezoceramic flat or curved emitter emitting waves having nearly plane or divergent characteristics, and wherein said waves emanate from said exit window without being modified by a lens.
17. Apparatus of claim 15 , wherein said piezoceramic pressure pulse/shock wave generating element is a piezoceramic flat emitter emitting waves having nearly plane characteristics, and wherein said PP/SW source further comprises a lens for focusing said waves in a first focal point, wherein divergent waves generated behind said first focal point emanate at said exit window.
18. Apparatus of claim 15 , wherein said piezoceramic pressure pulse/shock wave generating element is a piezoceramic flat emitter emitting waves having nearly plane characteristics and wherein said PP/SW source further comprises a lens for de-focusing said waves so that waves with divergent wave characteristics emanate from said exit window.
19. Apparatus of claim 15 , wherein said piezoceramic pressure pulse/shock wave generating element is a piezoceramic cylindrical emitter and wherein said PP/SW source further comprises at least one reflecting element and/or at least one lens.
20. A therapeutic device for administering a shock wave to produce a living tissue reaction in a subject comprising:
a housing;
a shock wave source disposed in the housing;
wave directing and shaping structure in the housing responsive to the shock wave for causing a planar shock wave to be emitted from the housing and transferred to a living tissue;
structure for coupling the shock wave to the subject; and
wherein the device is shaped and dimensioned to provide the planar shock wave having a power density level to produce a tissue reaction in a subject to which the wave is administered and wherein the shock wave has a power density in the range of approximately 0.01 mJ/mm 2 up to 1.0 mJ/mm 2 to stimulate the living tissue while avoiding tissue damage.
21. The therapeutic device of claim 20 wherein the wave directing and shaping structure includes a parabolic reflector.
22. The therapeutic device of claim 20 wherein the housing includes an opening and the coupling structure includes a membrane disposed across the opening.
23. The therapeutic device of claim 22 wherein the wave directing and shaping structure is disposed in a cavity having the opening.
24. The therapeutic device of claim 20 wherein the shock wave source includes an electrode that develops a spark.