胸腰椎骨之表面應變量測與分析

Surface Strain Measurement and Analysis of the ThoracoLumbar Vertebrae Body

蔡源泉(Yuan-Chuan Tsai)

指導教授 ： 王兆麟

國立臺灣大學/工學院/醫學工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.01732

摘要

摘要
背景：脊椎傷害的形成，取決於外在負載的形式、作用位置以及脊椎各元件對負
載的生物力學反應。當軸向衝擊力作用於脊椎時，椎骨的各個位置會產生大小不
同的應變量，而最大的應力可能集中在椎根。探討應變的大小與發生的位置，將
有助於瞭解脊椎傷害的發生機制。
目標：觀察胸腰椎骨在潛變及動態測試下的微觀力學特性。
方法：以10 個胸腰椎的二節脊椎運動單元(三個脊椎骨和二個椎間盤)為試樣，
在試樣不同位置施予衝擊載荷後，量測椎骨的表面應變。應變由三軸應變規量
測，應變規的黏貼位置在脊骨前緣和椎根。
設計：為了研究豬試樣的生物力學反應，選擇衝擊及連續式負載，量測在不同壓
縮力合併彎矩下，脊椎骨表面的應變分佈。連續式衝擊的負載頻率為5Hz，總計
9 萬次，衝擊載荷能量為1.2 焦耳。
結果：研究結果顯示三個主要現象，第一，當脊椎受到來自上方的垂直載荷時，
會產生壓縮變形；第二，當負載點在運動單元中央時，產生的應變最小；第三，
當負載點在運動節的棘突上方時，會產生方向朝脊椎腔的拉伸變形。第一個現象
可以解釋壓迫性骨折的發生機制，而第三個現象則可以解釋爆烈性骨折的發生機
制。另一個重要的力學指標是應變能密度，主要的產生來源是扭轉所造成的應變
能，脊椎在不同受力點的應變能密度分佈可以當作治療及預防壓迫性骨折的參考。

關鍵字

應變 ； 應變能密度 ； 脊椎骨 ； 應力

並列摘要

Abstract
Background Study. The mechanisms of vertebral injuries depend on the external
loading condition. It is hence important to find the relationship of bony strain of
vertebral body with respect to the corresponding external loading condition.
Objectives. To investigate the micro mechanical response of thoracolumbar vertebral
body during the eccentric impact and creep loading.
Methods. Ten thoracolumbar porcine two-motion segment specimens were subjected
to 1.2 J compressive eccentric impact loading and 14 specimens were tested at cyclic
loading at 5 Hz for 5 hours. Surface strain of vertebral body was measured with
three-axis strain gauges rosette attached to the base of the pedicles and anterior wall
of vertebral body.
Results. Three major phenomena were observed in the current study: First,
compressive strain was measured when the impact force was applied on the top of
anterior vertebral bodies. Second, the strain of vertebral body was minimal when the
impact force was applied on the center of motion segments. Third, the tensile strain
occurred and directed towards spinal cannel when the impact force applied on top of
posterior process. The first phenomenon may explain the mechanism of compressive
fracture, while the third may explain the burst fracture.

並列關鍵字

strain energy density ； stress ； strain ； vertebrae body

參考文獻

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