Apparatus for generating acoustic rarefaction pulses
AssigneeSiemens Aktiengesellschaft
InventorsDietrich Hassler, Helmut Reichenberger, Hubert Schwark, Georg Koehler
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Abstract
An apparatus for generating acoustic rarefaction pulses, i.e., a negative pressure pulse, has a pressure pulse source and reflector having a negative reflection factor, and an acoustic propagation medium filling the space between the pressure pulse source and the reflector. The reflector has a boundary surface facing toward the pressure pulse source, consisting of a medium which is acoustically soft in comparison to the acoustic propagation medium. The boundary surface medium is separated from the acoustic propagation medium by a wall which is impenetrable by the acoustic propagation medium.
Claims13
A medical therapy apparatus for generating rarefaction pulses comprising:
- a housing;
- means for generating shockwave pulses disposed in said housing;
- reflector means, disposed in said housing spaced from said means for generating shockwave pulses, having a negative reflection factor for converting said shockwave pulses into rarefaction pulses;
- an acoustic propagation medium filling the space in said housing between said means for generating shockwave pulses and said reflector means;
- and
- said reflector means containing an acoustically soft medium having a boundary surface at which reflection of said shockwave pulses occurs facing said acoustic propagation medium and said means for generating shockwave pulses, said acoustically soft medium being acoustically soft relative to said acoustic propagation medium, and said reflector means having a wall consisting of material impenetrable by said acoustic propagation medium, said wall disposed between said acoustic propagation medium and said boundary surface of said acoustically soft medium.
An apparatus for generating rarefaction pulses comprising:
- a housing;
- means disposed in said housing for generating shockwave pulses in a propagation direction and having a wavelength;
- reflector means, spaced in said housing from said means for generating shockwave pulses, having a negative reflection factor for converting said shockwave pulses into rarefaction pulses;
- an acoustic propagation medium filling the space in said housing between said means for generating shockwave pulses and said reflector means;
- said reflector means containing an acoustically soft medium at which reflection of said shockwave pulses occurs having a boundary surface facing said acoustic propagation medium and said means for generating pressure pulses, said acoustically soft medium being acoustically soft relative to said acoustic propagation medium;
- and
- means disposed between said boundary surface of said acoustically soft medium and said acoustic propagation medium for separating said boundary surface from said acoustic propagation medium, consisting of material impenetrable by said acoustic propagation medium and which is acoustically hard in comparison to said acoustic propagation medium and which has a thickness which is small in comparison to the wavelength of said shockwave pulses in said material of said means for separating.
An apparatus for generating rarefaction pulses comprising:
- a housing;
- means disposed in said housing for generating shockwave pulses in a propagation direction and having a wavelength;
- an acoustic propagation medium disposed in said housing in contact with said means for generating shockwave pulses and following said means for generating shockwave pulses in said propagation direction;
- and
- reflector means, disposed in said housing spaced from said means for generating shockwave pulses and in contact with said acoustic propagation medium, having a negative reflection factor for converting said shockwave pulses into rarefaction pulses, said reflector means being a one-piece component consisting of expanded polymeric material having a boundary surface at which reflection of said shockwave pulses occurs and a layer of non-expanded polymeric material, said layer of non-expanded polymeric material being acoustically hard in comparison to said acoustic propagation medium and having a thickness in said propagation direction which is small in comparison to the wavelength of said shockwave pulses in said layer of non-expanded polymeric material, said layer of non-expanded polymeric material being disposed between said boundary surface and said acoustic propagation medium and being impenetrable by said acoustic propagation medium.
Dependencies are inferred from the claim text.