The Mechanical and Technological Innovation Centre (CDMIT) of the National Autonomous University of Mexico has a research area focused on the design of upper limb prosthesis. A large number of prosthesis have been developed and tested. This paper presents the analysis made to different proposals of myoelectric hands based on TRIZ. Two TRIZ tools were applied: The Innovation Situation Questionnaire (ISQ) and the Radar of Evolution. The analysis was made in terms of time, space and the user interface. The ISQ helps to better define the scope of the problem through six basic questions; each question provides a different view of the problem. The radar of evolution helps to make a selection of trends of evolution depending on the product or system, as an analogy of a benchmark. The analysis was made considering the state-of-the-art hand prosthesis: i-limb, be-bionic, Michelangelo and Myohand against the prosthesis prototypes developed by the CDMIT. The result of this tool is a diagram that reveals the level and opportunities of evolution. These opportunities imply a strengthening of research areas not only in the CDMIT but around the world. The conclusion achieved is that different design paradigms linked to bio-mimics criteria are needed to design more innovative user-friendly prosthesis.

Objetivo:  Mejorar la comprensión de los cambios generados por los procedimientos restaurativos a través de modelos fotoelásticos. La reconstrucción dental debe fundamentarse en principios de oclusión para no provocar puntos prematuros de contacto durante los procedimientso de preparación y restauración que pueden provocar transtornos como el trauma oclusal, disfuncion de la ATM, o fracturas. En este documento se presenta un metodo didactico para visualizar de forma objetiva las cargas oclusales y su distribución. Materiales y métodos: Se realizaron modelos fotoelasticos de dientes y segmentos maxilares, para visualizar los efectos de las preparaciones dentales y restauraciones, asi como el desgaste de puntos prematuros de contacto. Resultados: Por fotoelasticidad se analizó la dirección, intensidad y distribución de esfuerzos en la corona y soporte óseo. Conclusiones: La tecnica permite visualizar cómo se afectan las estructuras desde la preparación cavitaria, los diferentes esfuerzos con fresas de diamante o carburo, además de observar cómo un punto prematuro de contacto no solo afecta al órgano que lo contiene sino a estructuras aledañas.

This paper presents the literature review on the design criteria for intervertebral disc prosthesis. The design criteria relate to the design features that intervertebral prosthesis must accomplish (i.e. fixation to bones, spine mobility, energy absorption and etcetera). The need to improve the performance has led to changes in the features which reflect in the current design criteria. Currently, the disc prosthesis technology is experiencing a generational change. The first generation was thoroughly studied while the second generation is in the clinical tests stage. During the time the first generation prostheses were applied in patients there was not a clear trend in the clinical results which produced a lack of trust and reliability in the performance of the disc prosthesis. The changes in the design features of one generation compared to the next generation are based in the deepening in the knowledge of the problem and the results obtained with the first generation prostheses. Some design criteria were identified for the first generation. These criteria were not completely characterized since there was not enough information to be used by the designer. This lack of characterization of most design criteria produced many different versions without a clear focus which help to define the basic design features of disc prostheses. This document presents the necessary information to thoroughly characterize the design criteria outlining the missing information for the design criteria found. An analysis is done of the design criteria in the second generation of prosthesis. Finally if the information contained in the design criteria is enough, the clinical results would be better focused to achieve a more repeatable, reproducible and reliable process for a total disc intervertebral prosthesis replacement as now is considered the vertebral fusion, this is a gold standard.