Piezoelectric device with reduced negative waves, and use of said device for extracorporeal lithotrity or for destroying particular tissues
US5015929A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 1, 1989 |
| Grant date | May 14, 1991 |
| Priority date | — |
| Expiry date | Dec 1, 2009 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2017/22028
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention relates to a device generating ultrasonic waves focused in a ocal point. Said generator device comprises a plurality of transducer elements arranged externally on a support means for focusing into a focal point, such as a circular dome, and is characterized in that the transducer elements are divided into at least two groups of transducer elements, of which the resonance frequency differs in such a way that the principal positive ultrasonic waves produced by each group add up together and the positive and negative secondary ultrasonic waves are at least partly cancelled, thus reducing significantly the negative waves. This device can be advantageously used for extracorporeal lithotripsy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.