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Experimental Studies on Laser Induced Underwater Converging Shock Waves Based Generated by Pseudo Phase Conjugate Method

伪相位共轭法产生激光诱导水下汇聚冲击波的实验研究

基本信息

批准号：
17560146
负责人：
SUZUKI Shinichi
金额：
$ 2.24万
依托单位：
Toyohashi University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

Underwater shock waves are utilized for the medical treatment of kidney stones, extracorporeal shock wave lithotripsy (ESWL). In ESWL, spherical converging shock waves are generated outside the human body, and propagate into the human body toward the kidney stones. The shock waves break the kidney stones into many smaller fragments, and then the fragments are excreted with urine. The treatment by ESWL is said to be a method with smaller physical strain, however it is also said that the effective fragmentation of kidney stones has not been realized yet.The speed of sound is not uniform in a human body, thus, different parts of a shock wave arrive at the kidney stone at different times. As the result, the impact force applied to the kidney stone is smaller than the impact force that is applied to the kidney stone when all the parts of a shock wave arrive at the kidney stone simultaneously. This is the reason why the effective fragmentation of kidney stones has not been realized yet by ES … More WL.In order to solve the above mentioned problem, the present study carried out the experiments on laser induced underwater shock waves, and obtained the following results.(1) The method of pulsed laser induced shock waves can generate the pseudo phase conjugate shock waves in the field of non-uniform speed of sound which consists of water and PMMA.(2) The pseudo phase conjugate shock wave focuses on a point even in the field of non-uniform speed of sound.(3) It is possible to change the pressure waveform of the shock wave at the focal point by changing the shape of the wave front of the shock wave. The result suggests that it may be possible to reduce the negative pressure that appears just behind the shock wave with positive pressure and that is thought to give damage to organs in a human body.(4) The numerical results given by the method of Green's function is qualitatively in agreement with the experimental ones. The present study is based on the idea that applies the phenomena of crack bifurcation to the treatment of kidney stones by ESWL. Accordingly, the following studies on crack bifurcation is also published.(5) When a solid material breaks under strong impact force, fast propagating cracks appears. A fast propagating crack bifurcates into two cracks or more when the crack speed is high enough, and the energy release rate is continuous across the bifurcation. Less

水下冲击波用于肾结石的医疗治疗，体外冲击波碎石术（ESWL）。在ESWL中，球形会聚冲击波在人体外产生，并且朝向肾结石传播到人体内。冲击波将肾结石破碎成许多更小的碎片，然后这些碎片随尿液排出体外。据说ESWL治疗是一种物理负荷较小的方法，但也有人说，肾结石的有效破碎尚未实现。声音在人体内的速度是不均匀的，因此冲击波的不同部分在不同的时间到达肾结石。结果，施加到肾结石的冲击力小于当冲击波的所有部分同时到达肾结石时施加到肾结石的冲击力。这也是ES至今未能有效粉碎肾结石的原因 ...更多信息为了解决上述问题，本文开展了激光水下冲击波的实验研究，得到了以下结果。(1)利用脉冲激光诱导激波的方法，可以在水和有机玻璃组成的非均匀声速场中产生赝相位共轭激波。(2)即使在非均匀声速场中，赝相位共轭激波也能聚焦于一点。(3)可以通过改变冲击波的波前形状来改变冲击波在焦点处的压力波形。该结果表明，可以通过正压来减少冲击波后面出现的负压，该负压被认为会对人体器官造成损害。(4)用绿色函数法计算的结果与实验结果定性地一致。本研究是基于将裂纹分叉现象应用于ESWL治疗肾结石的思路。相应地，还发表了以下关于裂纹分叉的研究。(5)当固体材料在强冲击力下断裂时，会出现快速扩展的裂纹。当裂纹速度足够大时，快速扩展裂纹分叉为两条或多条裂纹，且能量释放率在分叉处是连续的。少

项目成果

期刊论文数量（33）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

光干渉法を用いた分岐直前における高速進展き裂先端応力場の測定

使用光学干涉测量法测量分叉前快速生长裂纹尖端的应力场

DOI：
发表时间：
2006
期刊：
日本機械学会M＆M2006材料力学カンファレンス講演論文集 No.06-4
影响因子：
0
作者：
鈴木新一;岩永和也
通讯作者：
岩永和也

Measurement of Crack Speed and Energy Release Rate of Rapidly Bifurcating Crack in Araldite B

Araldite B 快速分叉裂纹的裂纹速度和能量释放率的测量

DOI：
发表时间：
2006
期刊：
Proceedings of the 2006 Annual Meeting of the JSME/MMD No.06-4
影响因子：
0
作者：
Shinichi Suzuki;Kazuya Iwanaga
通讯作者：
Kazuya Iwanaga

Kenichi Sakaue and Kazuya Iwanaga Measurement of Energy Release Rate and Energy Flux of Rapidly Bifurcating Crack in Homalite 100 and Araldite B by High-Speed Holographic Microscopy

Kenichi Sakaue 和 Kazuya Iwanaga 通过高速全息显微镜测量 Homalite 100 和 Araldite B 中快速分叉裂纹的能量释放率和能量通量

DOI：
发表时间：
2007
期刊：
The 13^<th> International Conference on Experimental Mechanics Vol.55
影响因子：
0
作者：
Shinichi Suzuki;Toru Yamaguchi;Takashi Kobayashi;Toshiaki Taki;Shinichi Suzuki
通讯作者：
Shinichi Suzuki

Measurement of Stress Field around Bifurcated Notch by Moire Interferometry

莫尔干涉测量分叉缺口周围应力场