Yang Wenting, Wang Dongmei, Lei Zhoujixin, Wang Chunhui, Chen Shanguang
School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P.R.China.
School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240,
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2017 Dec 1;34(6):857-862. doi: 10.7507/1001-5515.201609051.
Astronauts who are exposed to weightless environment in long-term spaceflight might encounter bone density and mass loss for the mechanical stimulus is smaller than normal value. This study built a three dimensional model of human femur to simulate the remodeling process of human femur during bed rest experiment based on finite element analysis (FEA). The remodeling parameters of this finite element model was validated after comparing experimental and numerical results. Then, the remodeling process of human femur in weightless environment was simulated, and the remodeling function of time was derived. The loading magnitude and loading cycle on human femur during weightless environment were increased to simulate the exercise against bone loss. Simulation results showed that increasing loading magnitude is more effective in diminishing bone loss than increasing loading cycles, which demonstrated that exercise of certain intensity could help resist bone loss during long-term spaceflight. At the end, this study simulated the bone recovery process after spaceflight. It was found that the bone absorption rate is larger than bone formation rate. We advise that astronauts should take exercise during spaceflight to resist bone loss.
长期太空飞行中处于失重环境的宇航员可能会遭遇骨密度和骨量流失，因为机械刺激小于正常值。本研究基于有限元分析（FEA）构建了人体股骨的三维模型，以模拟卧床实验期间人体股骨的重塑过程。在比较实验结果和数值结果后，验证了该有限元模型的重塑参数。然后，模拟了失重环境下人体股骨的重塑过程，并推导了时间的重塑函数。增加了失重环境下人体股骨的加载幅度和加载周期，以模拟对抗骨质流失的运动。模拟结果表明，增加加载幅度在减少骨质流失方面比增加加载周期更有效，这表明一定强度的运动有助于抵抗长期太空飞行期间的骨质流失。最后，本研究模拟了太空飞行后的骨骼恢复过程。发现骨吸收速率大于骨形成速率。我们建议宇航员在太空飞行期间应进行运动以抵抗骨质流失。
