In a shock wave generating apparatus, phase shifts contained in echo signals reflected from a calculus are corrected in order to clearly judge whether or not such a calculus is actually present at a focal point or a near region. The shock wave generating apparatus includes: a shock wave producing unit...http://www.google.ca/patents/US5381792?utm_source=gb-gplus-sharePatent US5381792 - Shock wave curing apparatus capable of correcting phase shifts contained in echo signals
