Summary: | 碩士 === 國立成功大學 === 機械工程學系專班 === 98 === This research focused on the design and fabrication of a vacuum forming tool to produce below-knee stump model that is the basis of using rapid prototyping (RP) technology to fabricate a transtibial socket. The uncertainty of the shape of stump models either created by manual skill or directly scanning stump using a hand-held scanner is to be improved by the prototype of vacuum forming tool proposed in this thesis.
The proposed vacuum forming tool is composed of a vacuum pump, a latex chamber with plastic filling, a latex sleeve, a mandrel, a stack of silicon sand and a set of flexible tubes for the connection of the whole system. The steps of using the vacuum forming tool to produce a stump model include: inserting the below-knee stump into a latex chamber; vacuuming the internal air of the latex chamber under a pressure that the amputee can tolerate and the latex chamber can be solified; a cavity mold of stump shape created by extracting the stump; the negative mold filled with silicon sand and the mandrel inserted; sealing the latex sleeve containing mandrel and sand; connecting the flexible tubes to the mandrel; and then sucking the remaining air in the sleeve. A stump model is then created for the use of scanning process.
The stability and consistency of using this proposed vacuum forming tool to generate the stump model of a specific amputee has been verified by the function of registration of a CAD system. The stump model of a volunteer amputee generated by the vacuum forming tool has been employed to easily design a socket. The socket is then fabricated by using an RP machine and the experiments of motion analysis and trial use of the socket have been implemented.
This study demonstrated that the stable and consistent stump model generated by the vacuum forming tool can be employed to design a socket shape without complicated modification. This result will enhance the applicability of using RP technology in the production of prosthetic devices.
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