K. Takayama, H. Yamamoto, and H. Shimokawa

The chronological development of underwater shock wave researches performed at the Shock Wave Research Center of the Institute of Fluid Science at the Tohoku University is presented. Firstly, the generation of planar underwater shock waves in shock tubes and their visualization by using the conventional shadowgraph and schlieren methods are described. Secondly,  the  generation  of  spherical  underwater  shock  waves  by  exploding  lead  azide  pellets  weighing  from  several  tens of micrograms to 100 mg which were ignited by irradiating with a Q-switched laser beam and their visualization by using double exposure holographic interferometry are presented. The initiation, propagation, reflection, focusing of underwater shock waves, and their interaction with various interfaces, in particular, with air bubbles are visualized quantitatively.  Based  on  such  a  fundamental  underwater  shock  wave  research,  the  collaboration  with  the  School  of  Medicine  at  the  Tohoku  University  was  started  for  developing  a  shock  wave  assisted  therapeutic  device  which  was  named an extracorporeal shock wave lithotripter (ESWL). Miniature shock waves created by irradiation with Q-switched HO:YAG  laser  beams  are  studied,  as  applied  to  damaged  dysfunctional  nerve  cells  in  the  myocardium  in  a  precisely  controlled manner, and are effectively used to design a catheter for curing arrhythmia.
Автор:  Takayama K., Yamamoto H., Shimokawa H.
Ключевые слова:  nderwater shock wave, medical application, water, silicon oil, microexplosion, double exposure holographic interferometry, high-speed video recording, ESWL, soft tissue dissection, arrhythmia
Стр:  905