Pressure pulse generator with variable focus - contains focussing and defocussing arrangements for reduced peak pressure

摘要

A generator of acoustic pressure pulses contains a pulse source, a focussing arrangement (10) which focusses the pulses onto a focussing zone and an arrangement (10, 19, 20) for defocussing the pulses. The effect of the defocussing arrangement is less than the effect of the focussing arrangement and is adjustable between a max. and a min. value. The min. value can be null. USE/ADVANTAGE - Calculus locating and destruction patients. Enables peak of pulses in focus zone to be reduced for given acoustic energy per pulse.