Applying action research in CAD teaching to improve the learning experience and academic level

A project involving innovation in university education is described in this paper. It was implemented in a Computer-Aided Design (CAD) course on the Bachelor’s Degree in Industrial Design and Product Development Engineering. Several studies have been published about CAD curricula, yet to the best of our knowledge nothing on applying Action Research (AR) to CAD teaching. The project was carried out over a two-year period, after detecting that academic results were not very good even when the course was not very demanding. In the first year, an experiment based on the AR methodology was planned and put into practice. We took the figure of the teacher-researcher as our own, owing to our conviction that teachers themselves must study their own work and reflect on it critically. Encouraged by the good results, throughout the following year, more changes were made in order to further improve the learning experience. The main actions were to develop self-learning material and to use rubrics for assessment, together with an increase in the level of difficulty in some parts of the evaluation. A detailed chronological description of the actions that were carried out, the implied motivations and both the expected results and those actually obtained are presented.The authors are grateful for support from the Unitat de Suport Educatiu of Jaume I University through project Ref: 2793/13 and for the comments made by the reviewers, which were very helpful

Anthropomorphism Index of Mobility for Artificial Hands

The increasing development of anthropomorphic artificial hands makes necessary quick metrics that analyze their anthropomorphism. In this study, a human grasp experiment on the most important grasp types was undertaken in order to obtain an Anthropomorphism Index of Mobility (AIM) for artificial hands. The AIM evaluates the topology of the whole hand, joints and degrees of freedom (DoFs), and the possibility to control these DoFs independently. It uses a set of weighting factors, obtained from analysis of human grasping, depending on the relevance of the different groups of DoFs of the hand. The computation of the index is straightforward, making it a useful tool for analyzing new artificial hands in early stages of the design process and for grading human-likeness of existing artificial hands. Thirteen artificial hands, both prosthetic and robotic, were evaluated and compared using the AIM, highlighting the reasons behind their differences. The AIM was also compared with other indexes in the literature with more cumbersome computation, ranking equally different artificial hands. As the index was primarily proposed for prosthetic hands, normally used as nondominant hands in unilateral amputees, the grasp types selected for the human grasp experiment were the most relevant for the human nondominant hand to reinforce bimanual grasping in activities of daily living. However, it was shown that the effect of using the grasping information from the dominant hand is small, indicating that the index is also valid for evaluating the artificial hand as dominant and so being valid for bilateral amputees or robotic hands

Effects of introducing a parametric Cad in a first year course in engineering degree regarding quality of technical drawings

Comunicació presentada al ICERI 2019 12th annual International Conference of Education, Research and Innovation (Seville, Spain. 11-13 November, 2019).The evolution of teaching in technical drawing during the last years has been addressed towards new paradigms based on 3D modeling. Nevertheless, not only 3D modeling skills are important for an engineer, but the ability to generate quality technical drawings also are part of the learning objectives and should, therefore, be included in the curriculum. For several years, the core subject of technical drawing at Universitat Jaume I has been a common subject during the first course of different Engineering bachelor’s degrees (Mechanical, Industrial Technologies, Electrical, Chemical, and Agrifood/Rural). However, in the last two years, the subject in the case of Agrifood Engineering has been taught independently. This course, aiming for a more intuitive introduction to 3D modeling, the subject has experienced a general methodological change for all the degrees, except for the Agrifood Engineering one. Apart from changing the order of contents with the intention of improving spatial vision, the use of a different commercial CAD software was implemented, this being parametric. In a previous work, the effect of this general methodological change was assessed through the academic performance regarding 3D modeling by comparing the scores before and after implementing the change, as well as through specific questionnaires addressed to students and teachers, obtaining very positive results. Notwithstanding, the effects of the change performed on the obtainment of technical drawings were not analyzed. Taking advantage of having two groups (the one that has experienced the change and the one that did not), they were asked to model and generate the drawing of the same parts in their final exams, with the aim of comparing the scores obtained when assessing their skills of modeling, but also in creating technical drawings (views, sections and dimensioning) and in the quality on technical drawings presentation (title block, line thickness, etc.). Scores were collected and statistical analyses were performed, bringing to light that despite the good results that were obtained in previous studies regarding the 3D modeling, teaching efforts in how to generate technical drawings with quality should be reinforced in future

Dorsal and palmar aspect dimensions of hand anthropometry for designing hand tools and protections

Most hand anthropometric studies are performed on the palmar aspect, while dimensions of the dorsal aspect are also useful in ergonomics and hand modelling. A survey of hand anthropometrics for a Spanish population (69 females, 70 males) is presented. Landmarks were selected to compare lengths from the dorsal and palmar aspects and to be useful for hand modelling and ergonomics design. Ninety-nine dimensions of fingers and thumb of the right hand (41 lengths, 32 depths, 26 breadths) were collected, including thumb breadths and depths. Descriptive statistics of all the dimensions are presented. Lengths were measured from both dorsal and palmar aspects and paired lengths compared through T-tests. Significant differences were found in almost all the lengths, showing that databases should explicitly state the aspect (dorsal or palmar) where dimensions have been measured. The data provided are useful for designing tools and hand protections and developing hand models more accurately

Estudios de caracterización cinemática de la mano sana en actividades de la vida diaria

El aumento de la esperanza de vida ha incrementado la prevalencia de enfermedades que afectan en gran medida a la capacidad manipulativa de la mano y por tanto al desarrollo de actividades de la vida diaria (AVD) necesarias para una vida independiente. Además, existe interés por evaluar más objetivamente la funcionalidad en el desarrollo de AVD, ya que en la práctica, los métodos de evaluación funcional de la mano son altamente subjetivos y poco orientados a las AVD. En esta comunicación se presentan diferentes estudios que desarrolla el grupo de Biomecánica y Ergonomía sobre caracterización cinemática del agarre humano en AVD. En un primer estudio se grabaron tareas representativas de los diferentes ámbitos de la vida personal (aseo, preparar comida, comer, limpieza y orden en casa, conducción, etc.) y se analizó la frecuencia de uso con cada mano de distintos tipos de agarre (de una clasificación con 9 categorías) en los diferentes ámbitos (Vergara et al. 2014). Posteriormente, con la ayuda de guantes instrumentados y goniómetros, en ambiente controlado de laboratorio, se han registrado los movimientos de las articulaciones de la mano y la muñeca en tareas representativas de las AVD, seleccionadas de acuerdo a la Clasificación Internacional de Funcionamiento, Discapacidad y Salud (CIF) de la OMS. Algunas se han realizado, además de con productos estándar, con productos adaptados comerciales. Se pretende además registrar a sujetos con algunas de las patologías de mano más frecuentes. El objetivo final de estos estudios es caracterizar la cinemática de la mano sana durante el desarrollo de AVD en base a patrones posturales, sus rangos y velocidades. Se establecerá una base de datos de ‘normalidad’ y se identificarán los parámetros cinemáticos que permitan evaluar más objetivamente la disfuncionalidad en sujetos lesionados o patológicos.A la Universitat Jaume I por la financiación del proyecto P1·1B2014-10 y al Ministerio de Economía y Competitividad y a la Comunidad Europea (fondos FEDER) por la financiación del proyecto DPI2014-52095-P

Relevance of grasp types to assess functionality for personal autonomy

Study Design Cross-sectional research design. Introduction Current assessment of hand function is not focused on evaluating the real abilities required for autonomy. Purpose of the Study To quantify the relevance of grasp types for autonomy to guide hand recovery and its assessment. Methods Representative tasks of the International Classification of Functioning, Disability and Health activities in which the hands are directly involved were recorded. The videos were analyzed to identify the grasps used with each hand, and their relevance for autonomy was determined by weighting time with the frequency of appearance of each activity in disability and dependency scales. Relevance is provided globally and distinguished by hand (right-left) and bimanual function. Significant differences in relevance are also checked. Results The most relevant grasps are pad-to-pad pinch (31.9%), lumbrical (15.4%), cylindrical (12%), and special pinch (7.3%) together with the nonprehensile (18.6%) use of the hand. Lumbrical grasp has higher relevance for the left hand (19.9% vs 12%) while cylindrical grasp for the right hand (15.3% vs 7.7%). Relevancies are also different depending on bimanual function. Discussion Different relative importance was obtained when considering dependency vs disability scales. Pad-to-pad pinch and nonprehensile grasp are the most relevant grasps for both hands, whereas lumbrical grasp is more relevant for the left hand and cylindrical grasp for the right one. The most significant difference in bimanual function refers to pad-to-pad pinch (more relevant for unimanual actions of the left hand and bimanual actions of the right). Conclusions The relative importance of each grasp type for autonomy and the differences observed between hand and bimanual action should be used in medical and physical decision-making.This research was funded by the Universitat Jaume I through projects P1·1B2013-33 and P1-1B2014-10, and by the Spanish Ministry of Research and Innovation and the European Union (European Regional Development Funds) through project DPI2014-52095-P

Interdependency of the maximum range of flexion–extension of hand metacarpophalangeal joints

Mobility of the fingers metacarpophalangeal (MCP) joints depends on the posture of the adjacent ones. Current Biomechanical hand models consider fixed ranges of movement at joints, regardless of the posture, thus allowing for non-realistic postures, generating wrong results in reach studies and forward dynamic analyses. This study provides data for more realistic hand models. The maximum voluntary extension (MVE) and flexion (MVF) of different combinations of MCP joints were measured covering their range of motion. Dependency of the MVF and MVE on the posture of the adjacent MCP joints was confirmed and mathematical models obtained through regression analyses (RMSE 7.7°).We are grateful to the Spanish Ministry of Economy and Competitiveness for funding through its project DPI2014-52095-P, as well as to the Universitat Jaume I through its project P1-1B2013-33, in which this research is partially included. We also thank the graduate student Lourdes Perez Valiente for her collaboration in data collection

Sharing of hand kinematic synergies across subjects in daily living activities

The motor system is hypothesised to use kinematic synergies to simplify hand control. Recent studies suggest that there is a large set of synergies, sparse in degrees of freedom, shared across subjects, so that each subject performs each action with a sparse combination of synergies. Identifying how synergies are shared across subjects can help in prostheses design, in clinical decision-making or in rehabilitation. Subject-specific synergies of healthy subjects performing a wide number of representative daily living activities were obtained through principal component analysis. To make synergies comparable between subjects and tasks, the hand kinematics data were scaled using normative range of motion data. To obtain synergies sparse in degrees of freedom a rotation method that maximizes the sum of the variances of the squared loadings was applied. Resulting synergies were clustered and each cluster was characterized by a core synergy and different indexes (prevalence, relevance for function and within-cluster synergy similarity), substantiating the sparsity of synergies. The first two core synergies represent finger flexion and were present in all subjects. The remaining core synergies represent coordination of the thumb joints, thumb-index joints, palmar arching or fingers adduction, and were employed by subjects in different combinations, thus revealing different subject-specific strategies

An introductory study of common grasps used by adults during performance of activities of daily living

This paper presents the results of a descriptive survey on human grasps. Sixty-four videos were selected to represent tasks performed in the main areas of activities of daily living (ADL) (personal care, meal preparation, eating, housekeeping, etc.). All the participants were right-handed. Elementary grasps were identified for each hand, and the grasp type (from a 9-type classification), the hands involved, and the duration were registered for each case. The results show that the most commonly used grasps are: pinch, non-prehensile, cylindrical, lateral pinch and lumbrical. The presence of these grasps in the areas of ADL is, however, very different (e.g., pinch is widely used in food preparation and very little in driving). Some grasps were used more frequently with one hand or when both hands were used simultaneously (e.g., special pinch was hardly used by the left hand). Knowing the grasp types most frequently used in ADL is essential to be able to assess grasp rehabilitation processes or hand prostheses development

Diseño asistido por ordenador. Curso práctico de Autocad®

Departament d’Enginyeria Mecànica i Construcció. Codi assignatura: DI101