...
首页> 外文期刊>Physics in medicine and biology. >In vivo bubble nucleation probability in sheep brain tissue.
【24h】

In vivo bubble nucleation probability in sheep brain tissue.

机译:体内泡沫脑组织中的体内成核概率。

获取原文
获取原文并翻译 | 示例
           

摘要

Gas nuclei exist naturally in living bodies. Their activation initiates cavitation activity, and is possible using short ultrasonic excitations of high amplitude. However, little is known about the nuclei population in vivo, and therefore about the rarefaction pressure required to form bubbles in tissue. A novel method dedicated to in vivo investigations was used here that combines passive and active cavitation detection with a multi-element linear ultrasound probe (4-7 MHz). Experiments were performed in vivo on the brain of trepanated sheep. Bubble nucleation was induced using a focused single-element transducer (central frequency 660 kHz, f-number = 1) driven by a high power (up to 5 kW) electric burst of two cycles. Successive passive recording and ultrafast active imaging were shown to allow detection of a single nucleation event in brain tissue in vivo. Experiments carried out on eight sheep allowed statistical studies of the bubble nucleation process. The nucleation probability was evaluated as a function of the peak negative pressure. No nucleation event could be detected with a peak negative pressure weaker than -12.7 MPa, i.e. one order of magnitude higher than the recommendations based on the mechanical index. Below this threshold, bubble nucleation in vivo in brain tissues is a random phenomenon.
机译:气体核自然存在于活体中。它们的激活引发了空化活动,并且可以使用高振幅的短超声波激发。然而,对于体内核群而言,对核群具有很少,因此关于在组织中形成泡沫所需的稀疏压力。这里使用了专用于体内调查的新方法,将被动和主动空化检测与多元素线性超声探头(4-7MHz)相结合。在荚膜绵羊的脑内进行实验。气泡成核是使用聚焦通过高功率驱动(高达5千瓦)单元素换能器(中心频率660千赫,f数= 1)两个循环的电动突发诱导。显示连续的被动记录和超快主动成像,以允许在体内脑组织中检测单个成核事件。在八只羊允许泡沫成核过程中进行的实验。评估成核概率作为峰值负压的函数。没有比-12.7 MPa越弱的峰值负压检测到核切割事件,即高于基于机械指数的建议的一个数量级。低于该阈值,脑组织体内的泡沫成核是随机现象。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号