皮肤软组织重复扩张的生物力学

目的探讨皮肤软组织重复扩张的生物力学规律，为应用和推广皮肤软组织重复扩张术提供理论基础。方法以6只小型猪为实验动物，实验分为正常对照组、常规扩张组、重复扩张组，分别切取皮肤试件，进行应力应变、应力松弛、极限抗拉强度各项生物力学指标的测定。结果常规扩张组和重复扩张组每个试件的应力应变曲线、应力松弛曲线较正常对照组均有偏离，其极限抗拉强度较之也有明显降低；其中重复扩张组的应力应变曲线、应力松弛曲线的偏离最大，其极限抗拉强度的降低也最显著。结论常规扩张的皮肤软组织的黏弹性较正常皮肤软组织有降低的趋势，重复扩张的皮肤软组织的黏弹性较常规扩张的皮肤软组织有进一步降低的趋势。初步明确了皮肤软组织重复扩张的的生物力学特性及其变化规律，对临床工作有一定的参考意义。

Skin biomechanical changes after repeated expansion

Objective To evaluate skin biomechanical properties aft er repeated expansion for its application and popularization. Methods Six little pigs were used as animal models. Three groups were divided: conventional expansion group, repeated expansion group, and blank control group. The stress-strain, stress relaxation, stress strength were measured in each gr oup after samples had been made. Results The stress-strain curves and stress relaxation curves of each sample from conventional expansi on group and repeated expansion group deviated from those of blank control group . And their stress strength decreased as compared with blank control group. The change of stress-strain curves and stress relaxation curves in repeated expan sion group were the most significant, so was the decrease of stress strength in repeated expansion group. Conclusion The viscoelasticity of conventional expanded skin trends to descend as compared with normal skin. The viscoelasticity of repeated expanded skin also trends to descend as compared wit h conventional expanded skin. The understanding of the biomechanical properties and rule of repeated expansion will be helpful in clinic work.