Diseño y construcción de una prótesis ergonómica de antebrazo y mano derecha por medio de tecnologías de escaneo 3D, modelado CAD e impresión 3D

Abstract

The present technological proposal suggested promoting the association of the academy and society, with the design and construction of an ergonomic prosthesis of forearm and right hand through technologies of 3D scanning, CAD modeling and 3D printing, for a real case study at the IESS (Ecuadorian Social Security Institute) in the city of Latacunga, Cotopaxi province. The dimensions of the prosthesis were obtained by means of an anthropometric analysis of the patient; the 3D model of the stump was acquired by scanning 3D, the CAD modeling was used to design phalanges, palm of the hand, forearm and coupling that make up the prosthesis; Finally, the 3D printing of each component constitutes the design and construction methodology of the present project. The mechanical system of the prosthesis is composed of servomotors whose movement is communicated to the fingers of the hand by means of nylon conductive wires due to its high tensile strength, moderate cost and the elasticity that it possesses. The prosthesis obtained is functional with 15 degrees of freedom for the fingers and wrist that simulate the movement of a normal joint; it is aesthetic with a smooth texture and skin color that resembles the characteristics of the human being; is ergonomic because it fits the patient’s anthropometric dimensions (length: 32 cm and stump diameter: 22 cm) and has a total prosthesis weight of (492, 54 grams); it is secure and fits perfectly to the stump due to the coupling with fastening straps that it has; it is not hermetic so it is recommended not to submerge it in liquids; it is built on a biodegradable material (PLA) so it is not toxic to the patient’s health, the static analysis performed allowed to work on fasteners to 12 pounds in grip and transport. Before the employment of the prosthesis, it is recommended to train the patient on the proper use of it through the prepared user manual.