Shahmohammadi Beni Mehrdad, Yu K N
Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong, Hong Kong.
Biointerphases. 2015 Dec 14;10(4):041003. doi: 10.1116/1.4933107.
A promising application of plasma medicine is to treat living cells and tissues with cold plasma. In cold plasmas, the fraction of neutrals dominates, so the carrier gas could be considered the main component. In many realistic situations, the treated cells are covered by a fluid. The present paper developed models to determine the temperature of the fluid at the positions of the treated cells. Specifically, the authors developed a three-phase-interaction model which was coupled with heat transfer to examine the injection of the helium carrier gas into water and to investigate both the fluid dynamics and heat transfer output variables, such as temperature, in three phases, i.e., air, helium gas, and water. Our objective was to develop a model to perform complete fluid dynamics and heat transfer computations to determine the temperature at the surface of living cells. Different velocities and plasma temperatures were also investigated using finite element method, and the model was built using the comsol multiphysics software. Using the current model to simulate plasma injection into such systems, the authors were able to investigate the temperature distributions in the domain, as well as the surface and bottom boundary of the medium in which cells were cultured. The temperature variations were computed at small time intervals to analyze the temperature increase in cell targets that could be highly temperature sensisitve. Furthermore, the authors were able to investigate the volume of the plasma plume and its effects on the average temperature of the medium layer/domain. Variables such as temperature and velocity at the cell layer could be computed, and the variations due to different plume sizes could be determined. The current models would be very useful for future design of plasma medicine devices and procedures involving cold plasmas.
等离子体医学的一个有前景的应用是用冷等离子体处理活细胞和组织。在冷等离子体中，中性粒子占主导，因此载气可被视为主要成分。在许多实际情况中，被处理的细胞被一种流体覆盖。本文建立了模型来确定在被处理细胞位置处流体的温度。具体而言，作者开发了一个三相相互作用模型，并将其与热传递耦合，以研究氦载气注入水中的情况，并研究气、氦气和水三相中的流体动力学和热传递输出变量，如温度。我们的目标是建立一个模型，以进行完整的流体动力学和热传递计算，从而确定活细胞表面的温度。还使用有限元方法研究了不同的速度和等离子体温度，并使用Comsol Multiphysics软件构建了该模型。利用当前模型模拟等离子体注入此类系统，作者能够研究该区域内的温度分布，以及培养细胞的介质的表面和底部边界。在小时间间隔内计算温度变化，以分析对温度高度敏感的细胞靶点处的温度升高情况。此外，作者能够研究等离子体羽流的体积及其对介质层/区域平均温度的影响。可以计算细胞层处的温度和速度等变量，并确定由于羽流大小不同而产生的变化。当前模型对于未来涉及冷等离子体的等离子体医学设备和程序的设计将非常有用。
