本文選題：微血管　切入點(diǎn)：造影劑　出處：《中國(guó)組織工程研究》2016年42期

【摘要】：背景:研究特定超聲激勵(lì)下微血管與內(nèi)部單個(gè)微泡間的非線性聲學(xué)響應(yīng),對(duì)于最大化超聲能量的沉積,促進(jìn)定量成像算法的發(fā)展,揭示損害機(jī)制或評(píng)價(jià)靶向治療的效果,克服傳統(tǒng)方法主要適用于大尺寸血管的局限性、測(cè)量微血管彈性意義重大。目的:構(gòu)建微血管中超聲微泡模型,揭示超聲、微泡與血管、血流間的內(nèi)在機(jī)制。方法:基于有限元分析和集中參數(shù)模型,在Comsol Multiphysics 3.5a平臺(tái)上進(jìn)行微血管中超聲微泡三維模型構(gòu)建和模擬仿真。結(jié)果與結(jié)論:(1)微泡徑向運(yùn)動(dòng)因受近處血管壁面限制,移動(dòng)速度較軸向小;而血管壁因與微泡振動(dòng)耦合,近微泡的中心處位移和應(yīng)力最大;(2)相同聲壓下,激勵(lì)頻率增加會(huì)減弱微血管的縮放且更快趨于穩(wěn)定;在相同頻率下,激勵(lì)聲壓越大血管運(yùn)動(dòng)越強(qiáng)烈,振動(dòng)傳播產(chǎn)生的局部效應(yīng)更持久;(3)微泡振動(dòng)幅度隨微血管壁楊氏模量的增加而降低,近似線性反比關(guān)系;振動(dòng)頻率則隨血管壁楊氏模量的增加而增加;(4)結(jié)果表明,微血管尺寸越小,對(duì)微泡振動(dòng)頻率和幅值的限制越強(qiáng)烈,超聲激勵(lì)頻率的增大會(huì)使微泡振動(dòng)頻率增大、幅值減小;聲壓對(duì)微泡和血管振動(dòng)的影響則相反。此外,研究首次發(fā)現(xiàn),血管壁彈性與微泡振動(dòng)幅度呈近似線性正相關(guān),說明利用微泡測(cè)定血管壁彈性是可能的。
[Abstract]:Background: to study the nonlinear acoustic response between microvessels and internal microbubbles under specific ultrasound excitation, to maximize the deposition of ultrasonic energy, to promote the development of quantitative imaging algorithms, to reveal the mechanism of damage or to evaluate the effectiveness of targeted therapy. To overcome the limitations of traditional methods for large blood vessels, it is of great significance to measure the elasticity of microvessels. Objective: to establish a model of ultrasound microbubbles in microvasculature, and to reveal ultrasound, microbubbles and blood vessels. Methods: based on finite element analysis and lumped parameter model, The three-dimensional model of ultrasonic microbubbles in microvessels was constructed and simulated on the platform of Comsol Multiphysics 3.5a. Results and conclusions: the radial motion of microbubbles is limited by the wall of the near vessels, and the moving speed is smaller than that of the axial ones, and the wall of the microbubbles is coupled with the vibration of the microbubbles. Under the same sound pressure, the increase of excitation frequency will weaken the scaling of the microvessel and stabilize faster, and at the same frequency, the larger the sound pressure, the stronger the blood vessel movement. The vibration amplitude of microbubble decreases with the increase of Young's modulus of microvascular wall, and the vibration frequency increases with the increase of Young's modulus of vascular wall. The smaller the microvessel size, the stronger the limitation on the vibration frequency and amplitude of the microbubble, and the larger the ultrasonic excitation frequency, the larger the vibration frequency and amplitude of the microbubble. The effect of sound pressure on the vibration of microbubble and blood vessel is opposite. There is an approximate linear correlation between the elasticity of vascular wall and the amplitude of vibration of microbubble, which indicates that it is possible to measure the elasticity of vascular wall by using microbubbles.
【作者單位】： 華南理工大學(xué)材料科學(xué)與工程學(xué)院生物醫(yī)學(xué)工程系;
【基金】：國(guó)家自然科學(xué)基金資助項(xiàng)目(31371008,81171179) 廣東省科技計(jì)劃項(xiàng)目(2015A02024006)~~
【分類號(hào)】：R445.1
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本文編號(hào)：1686941