侧卧角度对骶尾部软组织压力的有限元分析

A finite element analysis on sacrococcygeal soft tissue pressure at different lateral positioning angles

[目的]构建不同侧卧角度骶尾部三维有限元模型并进行力学分析,探讨预防深部压力性损伤的最佳侧卧翻身角度。[方法]选取健康成年男性志愿者俯卧位骶尾部CT数据,构建0°、15°、30°、45°侧卧翻身角度下包含皮肤脂肪组织、肌肉组织、骨骼支撑垫的三维有限元模型,设定边界条件、施加载荷,分析骶尾部深部组织压力性损伤模型Von Mises应力、剪切应力及分布特征。[结果]皮肤脂肪组织的Von Mises应力由小至大依次为:30°组<15°组<0°组<45°组,差异有统计学意义[(5.1±0.1) kPa,(5.6±0.2) kPa,(6.1±0.1) k Pa,(12.7±1.2) kPa, P<0.001]。肌肉组织中Von Mises应力由小至大依次为:30°组<45°组<15°组<0°组,差异有统计学意义[(17.6±0.8) k Pa,(19.3±1.4) kPa,(20.6±0.5) kPa,(22.6±1.4) kPa, P<0.001]。皮肤脂肪组织剪切应力由小至大依次为:30°组<15°组<0°组<45°组,差异有统计学意义[(0.8±0.2) kPa,(0.9±0.1) kPa,(1.3±0.2) kPa,(2.6±0.8) kPa, P<0.001]。肌肉组织剪切应力由小至大依次为:30°组<15°组<45°组<0°组,差异有统计学意义[(4.4±0.2) kPa,(4.4±0.2) kPa,(4.7±0.5)kPa,(5.1±0.3) kPa, P=0.02]。4种侧卧角度下,肌肉组织Von Mises应力和剪切应力均显著大于皮肤脂肪组织,差异有统计学意义(P<0.05)。[结论]侧卧角度为30°时骶尾部深部组织所受Von Mises应力及剪切应力最小,建议采用30°侧卧翻身角度预防深部组织压力性损伤。

[Objective] To explore the best lateral positioning angle to prevent deep pressure injury by a mechanical analysis with the three-dimensional finite element sacrococcygeal model at different lateral positioning angles. [Methods] The sacrococcygeal CT data of a healthy adult male volunteers in prone position were used to construct a three-dimensional finite element model, including skin adipose tissue, muscle tissue and bone at 0°, 15°, 30° and 45° lateral positioning angles. As boundary conditions were set and loads were applied, the Von Mises stress, shear stress and distribution characteristics of pressure to damage the sacrococcygeal soft tissues were measured. [Results] The Von Mises stress on the skin and adipose tissue were ranked in ascending order of 30° group <15° group <0° group <45 ° group with a statistically significant difference among them [(5.1±0.1) k Pa,(5.6±0.2) kPa,(6.1 ± 0.1) kPa,(12.7±1.2) kPa, P<0.001], whereas the Von Mises stress on muscle tissue were down-up in order of 30° group <45° group <15° group <0° group, which was statistically significant[(17.6±0.8) kPa,(19.3±1.4) kPa,(20.6±0.5) k Pa,(22.6±1.4) k Pa, P<0.001]. In addition, the shear stress on the skin and adipose tissue was in acending order as 30° group <15° group <0° group <45 ° group, which was statistically significant [(0.8±0.2) kPa,(0.9±0.1) kPa,(1.3±0.2) k Pa,(2.6±0.8) kPa, P<0.001], however, the shear stress on muscle tissue was ranked as 30° group < 15° group < 45° group < 0 ° group with a statistically significant difference [(4.4±0.2) k Pa,(4.4±0.2) kPa,(4.7±0.5) kPa,(5.1±0.3) kPa, P=0.02]. By comparison between tissues, both Von Mises stress and shear stress on the muscle tissue were significantly higher than those on the skin and adipose tissue under the 4 lateral positioning angles(P<0.05). [Conclusion] The Von Mises stress and shear stress on the sacrococcygeal soft tissue are the least at the lateral positioning angle of 30°, so it is recommended to use the lateral decubitus position at 30° to prevent the stress injury in the deep tissue.