Análise de viabilidade de fabricação de um pé SACH por impressão 3D e comparação de seu custo de fabricação com o preço de compra do pé SACH convencional do Sistema Único de Saúde

Abstract

The SACH (Solid Ankle-Cushion Heel) foot, which is a solid ankle foot and cushioned heel, without mechanical articulation in the prosthetic ankle foot region, is a foot with interesting characteristics and is still widely used, especially by Unified health system (SUS), as it is a functional, simple and inexpensive foot. Despite being a passive foot that does not return energy for propulsion, it is designed to provide impact absorption and ankle action with equivalent characteristics to a normal ankle, without the use of a joint. In addition to impact absorption, it also simulates a slight plantar flexion allowing the user of this device to walk in a normal and balanced way despite the fact that passive prostheses do not reproduce the gait adequately in relation to the responses of the human body member. Although the SACH foot presents a simple design, whose fabrication is not complex, flaws in its construction, modeling, and prosthetic installation can occur, causing early structural damage and limiting the individual's functionality. In this context, the present study aims to present the feasibility of manufacturing by 3D printing a SACH foot with finite element simulations to analyze stress and displacement in different situations in the main materials used (ABS, PETG and PLA) and with easier access, as well as the type of technology used to manufacture FDM (Fused Deposition Modeling) with satisfactory results for these 3 materials. A study was also made to compare the weight and cost of the virtual model with the traditional model of SACH foot, with results of a 50% reduction in cost for the 3 materials and an increase in weight of 100% for 2 materials and 50% for 1 material. However it does not makes the proposal of the project unfeasible since the proposed solutions can improve these results. Therefore, a study is needed to develop a custom-made SACH foot, manufactured by 3D printing, with the advantages of being low cost, customized considering biomechanical aspects, and its customization.