摘要
针对低频超声透皮给药过程中声场和流场的促渗机理问题,基于压电方程、声压方程以及湍流k-ε模型,利用COMSOL有限元软件建立了其声-压电-流耦合仿真计算模型。通过理论分析和Franz体外透皮实验分别获得了给药系统中的声场与流场的大小及分布,以及体外实验的超声促渗后的渗透量。仿真计算与实验结果表明:离体皮肤在超声作用下渗透量更大,皮肤上产生更多褶皱与空化穴,这说明存在空化效应与交变载荷,而后者可能是流场流动或涡流引起的;药液中流场沿超声换能器的辐射面下方流动到辐射面侧面,形成搅拌作用,且辐射面正下方的流速最大,当输入电功率为5.5 W时,可达0.55m/s,皮肤上方伴有较强涡流;流场在超声促渗中起搅拌与扩张皮肤通道的作用,对促渗起辅助作用。
In order to analyse the mechanism of acoustic and flow coupled fields in the low frequency sonophoresis (LFS) process, an acoustic-piezoelectric-fluid model was built based on the piezoelectric equation, acoustic equation, and turbulence k-Ε model, by using the finite element software COMSOL. The amplitudes and distributions of acoustic and flow fields in LFS were calculated, and the drug permeation of an in vitro transdermal experiment was measured after 90 minutes of ultrasonic radiation. The simulated and experimental results showed that there was a large amount of cavitation and folding on the skin of LFS, which suggested that the acoustic cavitation effect and alternating load occur on the epidermis, and that the folds may have been caused by water flow or vortex flow field. Further, the flow began on the sound radiation surface in an ultrasonic transducer and circulated to the transducer's horn profile, contributing to the stirring effect; the largest value of flow velocity happened under the radiation face and reached 0.55 m/s when the input electrical power was 5.5 W, accompanied with eddy currents above the skin; and acoustic field helps promote permeability in LFS, and the flow field can mix drug solution and expand permeation channels role to support the promotion. © 2016, Editorial Department of JVMD. All right reserved.
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2016年第6期1109-1115,共7页
Journal of Vibration,Measurement & Diagnosis
基金
国家自然科学基金青年基金资助项目(51405224)
江苏省科技计划青年基金资助项目(BK20140818)
中央高校基本科研业务费专项资金资助项目(NJ20160003)
江苏省大学生创新创业训练计划资助项目(201510287010Y)
关键词
低频超声
透皮给药
超声换能器
流场
有限元
Acoustic fields
Cavitation
Eddy currents
Flow fields
Flow of water
Flow velocity
Piezoelectricity
Transducers
Ultrasonic transducers
Vortex flow
