PROBLEM TO BE SOLVED: To intensify many weak shock waves and use them in medical treatment by composing a convergence system that takes "time development" into consideration since it is not ensured that a convergence point become a shock wave surface unless the entire system satisfies a condition for the time development of a shock wave even if ultrasound is converged due to a phase conjugation system or the like in a medical apparatus that uses the shock wave of ultrasound.SOLUTION: Ultrasound wave has "time development" varied from ultrasound wave, through nonlinear ultrasound wave, to shock wave. The sound speed and the speed of shock wave differs from each other due to the development. The way of their differences is determined by the "initial conditions". By determining appropriate initial conditions and using the absolute value of propagation distance required for the time development of a wave, the wave surface of weak impact wave can be superposed at a convergence point accurately. This makes it possible to obtain a strong impact wave at the target point and to provide a medical means, by virtue of cell destruction or drug delivery systems, which prevents damage to surrounding tissue.COPYRIGHT: (C)2013,JPO&INPIT【課題】 超音波の衝撃波を用いる医療装置で位相共役系等により超音波の収束をしても、システム全体が超音波の「時間発展」の条件を満足していなければ、収束点が衝撃波面になる保証は全く無い。ここでは、「時間発展」を考慮した収束システムを構成し多数の弱い衝撃波を強くして医療に用いる。【解決手段】超音波には、超音波から非線形超音波、そして衝撃波になる「時間発展」がある。該発展のため音速と衝撃波の速度は異なる。異なり方は「初期条件」で決まる。適切な初期条件を決める事と、波の時間発展に必要な伝播距離の絶対値とる事により、弱い衝撃波の波面を収束点で正確に重ね合わせることが可能となる。その結果、目的点で強い衝撃波が得られ、周辺の組織に損傷を与えることのない、細胞破壊、ドラッグデバリーシステムによる医療手段が提供されることになる。【選択図】図6
