Lithotrity apparatus having a missed-shot preventive function
US5215091A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 30, 1991 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | May 30, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/2256
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A lithotrity apparatus of this invention sends a low-pressure wave into a body continuously, at an interval shorter than an irradiating interval predetermined as an irradiating rate of an impulse from an impulse source. The low-pressure wave serves to discriminate coincidence and non-coincidence of a position of a focal point and that of a stone. When the intensity of the impulse received by a piezocrystal is at a predetermined threshold or higher, it is determined that the focal point coincides with the stone, and an impulse is radiated. Radiation of the impulse and a low-pressure wave is stopped during a time period corresponding to the predetermined radiation interval starting from the moment of impulse radiation. More specifically, the apparatus uses a piezocrystal as the impulse source. The piezocrystal is driven by a pulse generator and and a low-power supply when a low-pressure wave of a interval shorter than the predetermined irradiating interval is generated. The echo of the low-pressure wave is received. When a comparing circuit determines that the echo intensity is a threshold or more, the piezocrystal is switched to a high-power supply and is driven by a high-power puls…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.