糖尿病病人的足部與輔具之二維有限元素接觸應力分析

Finite Element Contact Stress Analysis of the Diabetic Foot and Orthosis - a Two-Dimensional Analysis

陳文斌(Weng-Pin Chen) ； 謝月雲(Yueh-Yun Hsieh) ； 鄧復旦(Fuk-Tan Tang)

《中華民國復健醫學會雜誌》 25卷2期 (1997/12) Pp. 139-148

摘要

本研究的目的是以有限元素法來評估用於降低糖尿病病人足底壓力所需之足部輔具，比較一般性鞋墊及以三種鞋墊材料所製作的全接觸性足底板對足底壓力分佈之影響。在本研究中分別建立穿著一般性鞋墊及穿著全接觸性足底板之有限元素模型，利用MARC有限元素分析軟體來作接觸應力分析，以便探討穿著全接觸性足底板前後足部壓力分佈之影響。分析中所需之各項材料之材料參數可由Instron材料試驗機所得之資料直接輸入MARC之材料參數程式而決定。足部及輔具各以可變形接觸體來模擬。二維之網格以病人X光片所得之輪廓資料為基礎再利用MARC軟體之自動網格生成模組產生。分析中所給定之負載則以模擬病人走路時步態的重心軌跡所佔整個步態的百分比位置及其在不同位置下所受力之大小來給定。由分析的結果可得知在不同的步態週期下，足底的峰值壓力分別降低了58%、54%、84%、86%、85%。由分析所得之結果可提供足部輔具製作人員在製作足部輔具時之重要參考。

關鍵字

有限元素法 ； 全接觸性足底板 ； 糖尿病 ； 接觸應力 ； 足底壓力

並列摘要

The objective of this research is to utilize the finite element method to analyze the contact stress between a diabetic plantar and the orthosis used in treating ulcers. It is desirable to understand the stress distributions between the plantar and the ordinary insole or the total contact insole made of three different insole materials. In this research, finite element models of the foot in contact with an ordinary insole and with a custom total contact insole were built and a commercial finite element analysis package - MARC was used to investigate the contact pressure distributions at the plantar. Deformable contact bodies were used to simulate the contact behavior between the foot and the orthosis. Five different loading stages in the mid-stance phase were considered and the pressure distributions in the foot-regular insole interface and the foot-total contact insole interface were compared. Results showed that peak stress reduction of 57.78%, 53.57%, 83.70%, 85.79%, and 84.82% were found in each of the loading phases. The results from this research can provide valuable information for orthosis designers and makers for diabetic patients.

並列關鍵字

finite element method ； total contact insole ； diabetes ； contact stress ； plantar pressure