This article reports on a patient who required a cranial protection system. Using additive manufacturing techniques and surgical planning with the help of bio-models, a patient-specific bone implant solution was proposed that allows aesthetic restoration of the affected area and provides an adequate level of protection. In addition, through a comparative analysis with finite elements, the mechanical response to external actions of the medical device, printed with two materials: polymethylmethacrylate (PMMA) and polyether-ether-ketone (PEEK), is simulated. The tested materials have recognized biocompatibility properties, but their costs on the market differ significantly. The results obtained demonstrate the similarities in the responses of both materials. It offers the possibility that low-income people can access these devices, guaranteeing adequate biomechanical safety, considering that PMMA is a much cheaper material than PEEK.

In the present investigation, the mechanical properties of natural polyether-ether-ketone (PEEK), processed by additive manufacturing applying fused deposition modeling (FDM) with three different infill densities, are investigated. Mechanical characterization was performed through destructive testing. Specimens were designed in CAD software and printed with controlled infill densities of $40\%$, $70\%$, and $100\%$, using a rectilinear pattern. The results showed that increased infill density improves mechanical strength and stiffness but reduces ductility and energy absorption capacity. For considered infill densities, maximum stress levels reach values of $107.53\pm 6.29$MPa, $114.32\pm 11.95$MPa, and $63.96\pm 2.39$MPa, respectively, against compression, bending, and tensile loading. These findings offer crucial information for optimizing infill density in manufacturing high-strength components for industrial and biomedical applications. As a result, practical guidelines are provided for the design of medical devices, such as implants, achieving an appropriate balance between mechanical performance and material efficiency.

Background/Objectives: The application of additive manufacturing in medicine, and specifically in personalised medicine, has achieved notable development. This article aims to present the results and benefits of applying a comprehensive methodology to simulate, plan, and manufacture customised three-dimensional medical prosthetic devices for use in surgery to restore bone structures with congenital and acquired malformations. Methods: To digitally reconstruct a bone structure in three dimensions from a medical image, a segmentation process is developed to correlate the anatomical model. Then, this model is filtered using a post-processing step to generate stereolithography (STL) files, which are rendered using specialised software. The segmentation of tomographic images is achieved by the specific intensity selection, facilitating the analysis of compact and soft tissues within the anatomical region of interest. With the help of a thresholding algorithm, a three-dimensional digital model of the anatomical structure is obtained, ready for printing the required structure. Results: The described cases demonstrate that the use of anatomical test models, cutting guides, and customised prostheses reduces surgical time and hospital stay, and achieves better aesthetic and functional results. Using materials such as polylactic acid (PLA) for presurgical models, appropriate resins for cutting guides, and biocompatible materials such as polyether ether ketone (PEEK) or polymethylmethacrylate (PMMA) for prostheses, the described improvements are achieved. Conclusions: The achievements attained demonstrate the feasibility of applying these techniques, their advantages and their accessibility in Ecuador. They also reinforce the ideas of personalised medicine in the search for medical treatments and procedures tailored to the needs of each patient.

The present study analyzes the behavior of connections with flange-web welded plates using the finite element method in tubular columns filled with concrete, and beam, type I. An analytical study of the structural dynamic behavior of a Special Moment Frame (SMF) was carried out, in 5 levels, with HEB structural profiles, for IPE-type columns and beams, according to the requirements established by the AISC-360-16, ANSI-341 standards, and the Ecuadorian standard NEC-2015. The design process of the special frame structure was validated with the help of specialized software. Subsequently, the structural profiles were replaced following the actual construction situation in Ecuador. 3D models of the structural system and the elements of metallic connections were obtained for evaluation through the analysis of finite elements. These models were subjected to virtual tests according to the AISC 341-16 protocols and FEMA 350 standards. The evaluation of the connections showed that they did not meet the flexural strength criterion at 0.04 rad, but they exceeded $80\%$ of the plastic moment at $0.02$ rad. Thus, flange-web welded plate connections can be valid for intermediate moment frames (IMF) in areas with moderate seismicity. In addition, it was observed that the columns filled with concrete optimize the structural elements in terms of dimensions; but do not contribute significantly to soldered connections due to the later development of plastic ball joints.

In the present investigation, the mechanical properties of natural PEEK 450 processed by 1 additive manufacturing and applying fused deposition modeling (FDM) are investigated. Mechanical 2 characterization was performed through destructive testing, following ASTM D638-14, ASTM D695- 3 15 and ASTM D790-10 standards. Specimens were designed in CAD software and printed with 4 controlled infill densities of 40%, 70% and 100%, using a rectilinear pattern. The results showed that 5 an increase in infill density improves mechanical strength and stiffness, but reduces ductility and 6 energy absorption capacity. These findings offer crucial information for optimizing infill density in 7 the manufacturing of high-strength components for industrial and biomedical applications. As a 8 result, practical guidelines are provided for the design of medical devices, such as implants, achieving 9 an appropriate balance between mechanical performance and material efficiency.

This paper describes the results and benefits of applying a comprehensive methodology for simulating and planning surgeries related to the restoration of bone structures damaged by various types of pathologies, through seven clinical success cases. Pre-surgery simulations are performed using 3D printed anatomical test models. In addition, restorations or bone transformations are supported by customised implants manufactured for each case, including customised cutting guides as well. Appropriate polymeric materials are used, and Fused Deposition Modelling (FDM) is applied as the main additive manufacturing technique to obtain the medical devices. The results demonstrate the feasibility of applying such techniques, their advantages and the possibilities of access to them in Ecuador.