Automated System Design to Modify the CAD Models of Residual Limbs

• Main Authors: Chih-Wei Chien, 簡志緯
• Other Authors: Lai-Hsing Hsu
• Format: Others
• Language: en_US
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/j4s7aq

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 90 === The traditional fabricating procedure of the prosthetic socket for a specific amputee includes marking pressure-tolerant (PT) and pressure-relief (PR) areas, wrapping plaster cast, duplicating plaster model, rectifying plaster model, and fabricating socket etc. This procedure is time-consuming, complicated, labor-intensive, and non-reproductive. Consequently, this thesis presents a novel procedure that employs reverse engineering techniques and improves computer-aided systems to develop an automated system that intends to replace the traditional method for producing prosthetic socket. This prototype system includes scanning amputee stump, PT/PR areas recognition, surface model construction of stump, and surface model modification etc. In order that contact pressure transformed amputee weight via socket would be uniformly distributed, an experienced prosthetist has to mark the PT/PR areas on an amputee stump and rectify them. The proposed algorithm in the automated system aims to modify the PT/PR areas of stump using the theory of NURBS surface, techniques of application programming, and functions of computer graphic. NURBS surface is used to reposition the control points and change the weights to modify the surface model. Using techniques of application programming and functions of computer graphic would allow the user either manipulating the dialog box to input required information or dragging the control points. The “user-friendly” interface therefore helps display the modified results immediately. The demonstrated case study has verified the prototype system for modifying surface model of stump. Difference analysis indicates that the proposed algorithm can adjust the PT/PR areas within a desired accuracy. Additionally, the modified surface model can be converted into IGES format for further research such as contact stress evaluation.