低温保存后生物组织微波复温过程的数值分析

Numerical Analysis of Microwave Rewarming for Cryo-Preserved Tissues

在液氮中低温保存的生物组织,使用前需要将其复温到正常温度。而复温过程中的反玻璃化与加热不均匀引起的热应力将对生物组织造成极大的伤害,而采用微波复温能够利用其快速加热的优点减少伤害。本文通过数值方法对麦克斯韦方程和传热方程进行了耦合求解,得到微波复温时组织内温度随时间的变化过程,讨论分析了加热过程中的组织内部温度分布的不均匀性,并提出了一些改善不均匀性的方法。

During the rewarming process of the cryopreserved tissues, vitrified aqueous solutions present in biological systems reorganize into crystalline forms and kill ceils when heating rate is slow. The use of microwave for rewarming offers some significant advantages over conventional methods. However the heating processes require very careful design to achieve the intended outcome and avoid undesired effects. In this paper, a combined solution of Maxell Equations and heat transfer equation is presented to analyze the microwave rewarming process of cryopreserved tissues. The temperature-field inside tissue is determined by solving heat-transfer equations. By calculating the temperature-field, we have also researched the ununfformities of temperature in the tissues during the rewarming process. We found the difference of temperature between the center and edge of tissues. The difference results from thermal run-away and the distribution nonuniformity of microwave power. Some ways to improve the ununiformity, such as hybrid heating or being heated by multi-modes microwave, are advised as well.