一体化小腿假肢在不同步态时相的应力分布  

The Stress Distribution in Transtibial Monolimb at Various Typical Subphases of Stance

作　　者：刘展[1] 樊瑜波[1] 张明[2] 

机构地区：[1]四川大学生物力学工程实验室,四川成都610065 [2]香港理工大学赛马会复康科技中心

出　　处：《四川大学学报（工程科学版）》2004年第5期25-29,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(30370376);四川省杰出青年基金资助项目

摘　　要：在典型步态时相对一体化假肢进行应力分析,为一体化假肢的设计提供参考。采用一实验阶段的内骨架一体化小腿假肢的真实几何构型,并考虑残端软组织和骨,建立三维有限元模型,分别施加HeelStrike、FootFlat、Mid Stance、HeelOff和ToeOff5个典型步态时相的载荷,计算假肢内的应力分布,采用VonMises应力为分析指标。结果表明:一体化假肢和软组织各区域的应力在HeelOff步态时相均为最大,假腿、接受腔、交界区域的最大VonMises应力分别为30MPa、18MPa、32.1MPa,软组织表面最大正应力为703.8kPa。HeelOff为步态周期中最不利的步态时相,一体化假肢的设计应该重点考虑满足该步态时相的强度要求。Analyzing the stress distributions in monolimb under the typical subphases of stance as a guide for the designing of monolimb,a three-dimensional finite element model including the soft tissue and bone of stump is established based on a real geometry of an endoskeletal transtibial monolimb. The loads corresponding to five typical subphases of the stance of Heel Strike, Foot Flat, Mid-Stance, Heel Off and Toe Off are applied to the model respectively to obtain the stress distributions in monolimb. Von Mises stress is used for analysis.The stresses in the monolimb and soft tissue at Heel Off are the highest of all. At Heel Off, the maximal Von Mises stresses in prosthetic shank, socket and the border section are 30 MPa, 18 MPa and 32.1 MPa respectively, and the maximal normal stress on the surface of soft tissue is 703.8 kPa.Heel Off is the most disadvantageous subphase of stance for transtibial monolimb. So it's necessary for monolimb structure to meet the requirement of intensity at Heel Off subphase.

关 键 词：一体化小腿假肢 步态周期 步态时相 有限元应力分析 

分 类 号：R318.01[医药卫生—生物医学工程]