發(fā)布時(shí)間：2019-07-09 07:00

【摘要】：目的探討聚焦超聲輻照仿組織體模過程中沸騰氣泡和空化氣泡的演變及其對(duì)損傷的影響。方法以聚焦超聲輻照仿組織體模30 s。采用連接在體視顯微鏡上的高速攝影機(jī)實(shí)時(shí)監(jiān)控輻照過程中的氣泡活動(dòng)和損傷演變,同時(shí)進(jìn)行被動(dòng)空化檢測(cè)。在相同條件下分別重復(fù)8次實(shí)驗(yàn)。結(jié)果在沸騰氣泡產(chǎn)生前,未見寬帶噪聲增加,損傷同時(shí)向聲源方向和遠(yuǎn)離聲源方向呈"雪茄"狀線性增長(zhǎng);毫米級(jí)沸騰氣泡瞬時(shí)產(chǎn)生后,迅速破裂成大量微米級(jí)氣泡,而后寬帶噪聲出現(xiàn)階躍性增強(qiáng)并持續(xù)至輻照結(jié)束,同時(shí)損傷范圍快速增大并向聲源方向發(fā)展,形狀由"雪茄"狀變?yōu)?蝌蚪"狀;沸騰氣泡完全破裂時(shí)間[(9.79±1.86)s]與3~7 MHz寬帶噪聲出現(xiàn)階躍性增強(qiáng)的時(shí)間[(9.75±2.84)s]差異無統(tǒng)計(jì)學(xué)意義(P0.05)。結(jié)論毫米級(jí)沸騰氣泡破裂成大量微米級(jí)氣泡后為空化提供了空化核,也成為損傷向聲源方向前移、范圍快速非線性增大及損傷形狀由"雪茄"狀變?yōu)?蝌蚪"狀的原因。
[Abstract]:Objective to investigate the evolution of boiling bubbles and cavitation bubbles and their effect on damage during focused ultrasound irradiation of tissue-like phantom. Methods the tissue phantom was irradiated by focused ultrasound for 30 s. A high speed camera connected to stereoscopic microscope is used to monitor bubble activity and damage evolution in real time during irradiation, and passive cavitation detection is carried out at the same time. Eight experiments were repeated under the same conditions. Results before the generation of boiling bubbles, there was no increase in broadband noise, and the damage increased linearly in the direction of sound source and away from the sound source at the same time. After the instantaneous generation of millimeter boiling bubble, it burst into a large number of micron bubbles, and then the broadband noise increased step by step and lasted until the end of irradiation, at the same time, the damage range increased rapidly and developed in the direction of sound source, and the shape changed from "cigar" to "tadpole". There was no significant difference between the complete rupture time of boiling bubbles [(9.79 鹵1.86) s] and the time of step enhancement of 3 鈮，

本文編號(hào)：2511952