摘要
目的考察三区域复温过程中的应力发展规律。方法实验观察水、土豆、猪肝等生物材料在不同冻结 -复温条件下的裂纹情况 ;采用隐式有限差分法计算三区域复温过程中的温度场和应力场。结果获取三区域复温过程中的瞬态热应力分布并与单纯冻结情况作了对比 ,初步认识复温时生物材料中的裂纹发展特征。结论复温过程与冻结过程中的应力分布方向相反 ,因此紧随冻结后的骤然复温会比单一冻结过程对病变组织造成更大损伤 。
Objective To examine the thermal stress development during cryosurgical three region re warming. Method Several samples such as water, potato and pork liver were utilized to directly observe the crack developed inside them when subjected to a specific freezing or rewarming or a mixed procedure between them. The implicit finite difference method with variable time step was applied to calculate the tissue temperature and the thermal stress fields induced in three region thawing process. Result The transient thermal stress field over the tissue during re warming was obtained and results were compared with that in a simple freezing process.It was found that the stress distributions during the thawing stage are in opposite direction with those of the freezing process.Conclusion Quick re warming immediately following cryosurgical freezing may induce much stronger crack than using only a simple freezing treatment. This may have important value in cryosurgery.
出处
《航天医学与医学工程》
CAS
CSCD
北大核心
2002年第4期291-295,共5页
Space Medicine & Medical Engineering
基金
中国科学院"百人计划"资助项目
关键词
低温
外科复温
热应力
冷冻手术
hypothermia
cryosurgery
thermal stress
freezing
three region rewarming
