Piezoelectric transducer for destruction of concretions inside the body
First Claim
1. In a piezoelectric transducer for destruction of concretions inside a body, said transducer comprising a cap having an inner surface with a partially-spherical curvature with a given radius from a point, said cap having a back surface, a plurality of piezoelectric ceramic elements for producing sonic pulses being mounted on the inner surface to form a mosaic of elements with the output of the sonic pulses from said mosaic of elements being focussed at said point, the improvements comprising the cap being of a metal with an wave impact resistance of the metal corresponding at least substantially to the wave impact resistance of the material of the ceramic elements, and the cap having means for scattering sonic pulses entering into the cap from the elements to prevent the back surface of the cap from reflecting a focussed wave of sonic pulses at said point.
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Accused Products
Abstract
A piezoelectric transducer for destruction of concretions inside the body. The transducer essentially comprises a spheroidal cap having piezoelectric ceramic elements situated at its radially inner front side. To prevent overpressure pulses radiated at the front side of the transducer being followed by underpressure pulse reflected from the rear side of the cap, the cap is produced from metal, preferably from a copper alloy. The impact wave resistances of the cap metal and of the ceramic material should largely correspond. Furthermore, the rear-side surface of the rear wall of the cap is so shaped geometrically and/or provided with a coating, that the sonic waves reflected therefrom are no longer focussed.
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Citations
7 Claims
- 1. In a piezoelectric transducer for destruction of concretions inside a body, said transducer comprising a cap having an inner surface with a partially-spherical curvature with a given radius from a point, said cap having a back surface, a plurality of piezoelectric ceramic elements for producing sonic pulses being mounted on the inner surface to form a mosaic of elements with the output of the sonic pulses from said mosaic of elements being focussed at said point, the improvements comprising the cap being of a metal with an wave impact resistance of the metal corresponding at least substantially to the wave impact resistance of the material of the ceramic elements, and the cap having means for scattering sonic pulses entering into the cap from the elements to prevent the back surface of the cap from reflecting a focussed wave of sonic pulses at said point.
Specification