IEEE Trans Ultrason Ferroelectr Freq Control. 2017 Oct;64(10):1583-1590. doi: 10.1109/TUFFC.2017.2724066. Epub 2017 Jul 7.
The acoustoelectric (AE) effect is a basic physical phenomenon, which underlies the changes made in the conductivity of a medium by the application of focused ultrasound. Recently, based on the AE effect, several biomedical imaging techniques have been widely studied, such as ultrasound-modulated electrical impedance tomography and ultrasound current source density imaging. To further investigate the mechanism of the AE effect in tissue and to provide guidance for such techniques, we have modeled the tissue AE effect using the theory of solid mechanics. Both bulk compression and thermal expansion of tissue are considered and discussed. Computation simulation shows that the muscle AE effect result, conductivity change rate, is 3.26×10 with 4.3-MPa peak pressure, satisfying the theoretical value. Bulk compression plays the main role for muscle AE effect, while thermal expansion makes almost no contribution to it. In addition, the AE signals of porcine muscle are measured at different focal positions. With the same magnitude order and the same change trend, the experiment result confirms that the simulation result is effective. Both simulation and experimental results validate that tissue AE effect modeling using solid mechanics theory is feasible, which is of significance for the further development of related biomedical imaging techniques.
声电（AE）效应是一种基本的物理现象，它是通过应用聚焦超声使介质的电导率发生变化的基础。最近，基于 AE 效应，已经广泛研究了几种生物医学成像技术，如超声调制的电阻抗断层成像和超声电流源密度成像。为了进一步研究组织中的 AE 效应机制，并为这些技术提供指导，我们使用固体力学理论对组织 AE 效应进行了建模。本文同时考虑并讨论了组织的体压缩和热膨胀。计算模拟表明，在 4.3MPa 峰值压力下，肌肉的 AE 效应结果，电导率变化率为 3.26×10，满足理论值。体压缩对肌肉 AE 效应起主要作用，而热膨胀几乎没有贡献。此外，在不同的焦点位置测量了猪肌肉的 AE 信号。实验结果与模拟结果具有相同的数量级和相同的变化趋势，这验证了模拟结果的有效性。模拟和实验结果均验证了使用固体力学理论对组织 AE 效应进行建模是可行的，这对相关生物医学成像技术的进一步发展具有重要意义。
