人工椎間盤之設計與力學分析

Design and mechanical study of artificial disc

蘇建融(Chien-Jung Su)

指導教授 ： 蘇侃

國立臺灣大學/工學院/機械工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.02226

摘要

摘要
本文研究人工椎間盤之設計與最佳化的外形。
現今人工椎間盤的研發相當盛行，以球和托座所組成的關節機構最為接近人體椎間盤的活動範圍。但是，這類人工椎間盤無法有效的限制扭轉範圍，將使小面關節在椎間盤去除後承受更大的外力。故本研究將人工椎間盤分為上盤、核心和下盤三個元件，以限制扭轉角度為考量，設計出一個符合脊椎活動範圍的人工椎間盤。
本研究以有限元素法求出人工椎間盤在正向壓力的施加下之最低應力及極限負載，以三個階段循序漸進的分析：(1)以人工椎間盤之元件曲率半徑不同作比較(2)以人工椎間盤之核心曲率半徑不同作比較(3)求出人工椎間盤之極限負載。
經有限元素法分析比較後得知，接觸面的曲率半徑愈大，所受之應力愈小;若接觸之兩曲面的曲率半徑愈接近，所受之應力亦愈小。以核心大小觀之，核心愈厚，核心所受之應力愈小。最終之最佳化人工椎間盤模型所能承受的最大正向壓力為2375N。
本研究所設計之人工椎間盤的扭轉範圍是完全限制的，與人體椎間盤平均可扭轉角度為2°比較，仍然有些釭漁t異。

關鍵字

扭轉 ； 小面關節 ； 人工椎間盤

並列摘要

Abstract
The design and optimum shape of the artificial disc were studied in this research.
The joint mechanism of an artificial disc was composed by a ball and a socket, which was similar to activities of the ball of the vertebral disc. But the artificial disc of this type could not restrain the sphere from rotation with effect. The artificial disc of this type would make the facet joint support the more external force after the vertebral disc has cut. So this research divided the artificial disc into three components that were the upper plate, the core, and the lower plate. This designed artificial disc has conformed to activities of the ball of the vertebral disc and is thought about the rotation of sphere was restrained.
The finite element method was used to analyze the lowest contact stress and the ultimate load at normal pressure acting on the artificial disc. This research used three stages to analyze in proper sequence:(1)To compare with the different radius of curvature of the component of the artificial disc.(2)To compare with the different radius of curvature of the core of the artificial disc.(3)To calculate the ultimate load of the artificial disc.
After analyzed and compared, we obtained that the bigger the radii of curvatures of the contact surfaces were, the smaller was the contact stresses. When the radii of curvatures of two contact surfaces approached each other, the contact stresses decreased. As the thickness of the core was increased, the contact stresses decreased. The optimum artificial disc could support a maximum load of 2375N.
The rotation of the ball of the artificial disc designed was restrained completely. It was different to the vertebral disc its possible rotation is 2°.

並列關鍵字

artificial disc ； rotation ； facet joint

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