Wrist model for the whole human hand

A hand with 25 degrees of freedom (DOF) was proposed with forward and inverse kinematics for all fingers, with a realistic virtual simulation. However, the wrist is not in the model. Today, several authors have proposed in the literature that the wrist has a relative movement between the two rows of bones with eight bones. Some authors discuss a comparison of four joint coordinate systems previously described in the literature. Others propose a helical movement of wrist bones in distal movements. Objective: A new design the hand model of 25 DOF adding a movement of two rows and eight bones of the wrist. Methods: Once we locate a new coordinates system in the end of the radius close to the scaphoid, we apply Denavit-Hartenberg for all joints. Forward and inverse kinematics are applied. We include ten ligaments to apply restrictions in the wrist movement, which affects fingertip position. Results: A new model of a virtual human hand with more accuracy is presented and validated with a Cyberglove™ and Leap Motion. Conclusions: This new model that includes wrist movement yields a more accurate virtual human hand. New DOFs are added to the 25-DOF hand model.This work was partially supported for Spanish government by the project PID2020-114819GB-I00.Peer ReviewedPostprint (published version

Human simulation in stroke patients rehabilitation

Different types of neurological deficits and sequels in the upper extremities that affect the activities of daily living in patients who have undergone stroke, have been analyzed from a subjective clinical point of view. Prognosis recovery after stroke depends on many factors, among which are included individualized program of rehabilitation and cooperation of patients. Simulation patients in the beginning of stroke. The aim of this work is to show a novel environment to simulate the initial improvement upper limb functions a few days after stroke and simulate the functional recovery of patients under a rehabilitation program. Twenty-nine patients in the first four days post stroke were selected. Inclusion criteria were: over eighteen years of age, collaborative patients, and neurological deficits in upper extremities post stroke without a previous history of stroke of motor sequelae second to other neurological or osteoarticular diseases that might identify pre-existing disability. Assessments were performed with 3-4 days and 7 days and 1, and 3 months post stroke recording the following variables: demographics, stroke type, stroke classification according to the Oxford scale, neurological deficit determined by the NIHSS, disability measures (Barthel’s Index, Rankin Scale), assessment of the motor dysfunction of the upper extremities according to the Fugl-Meyer Scale as well as muscle tone (Ashworth’s Scale) and muscle balance of the upper extremities. We measured the deficits of angles, lengths and range of motion for the arm and hand affected. These measures were implemented in a virtual environment with 29 DOF for each arm and hand. The different types of deficit and sequelae seen in the upper extremities of stroke patients impairing their activities of daily living have been analysed from a subjective clinical standpoint based on clinical and functional assessments. The prognosis for recovery of each patient very much depends on many factors, which can be found in the rehabilitation program and individual goals together with the collaboration afforded by the patients themselves while they are unaware a priori of the objective outcome of the rehabilitation process.Postprint (published version

Preface: a special selection on biomechanical applications in medical science - Part II

Electronic version of an article published as Journal of Mechanics in Medicine and Biology, Volume 21, Issue 10, 2021, 2102003:1-7, DOI 10.1142/S0219519421020036 © 2021 World Scientific Publishing Company https://www.worldscientific.com/doi/10.1142/S0219519421020036This special selection on Biomechanical Applications in Medical Science presents the ongoing and active research in the Biomechanics area. The overall goal is to summarize recent discoveries and groundbreaking studies that will account for new challenge research in the broad and relevant area of Biomechanics used for medical science.Peer ReviewedPostprint (published version

Preface: a special selection on biomechanical applications in medical science - Part I

This special selection on Biomechanical Applications in Medical Science presents the ongoing and active research in Biomechanics area. The overall goal is to summarize recent discoveries and groundbreaking studies that will account for new challenge research in the broad and relevant area of Biomechanics used for medical science.Peer ReviewedPostprint (published version

Classification models of action research arm test activities in post-stroke patients based on human hand motion

The Action Research Arm Test (ARAT) presents a ceiling effect that prevents the detection of improvements produced with rehabilitation treatments in stroke patients with mild finger joint impairments. The aim of this study was to develop classification models to predict whether activities with similar ARAT scores were performed by a healthy subject or by a subject post-stroke using the extension and flexion angles of 11 finger joints as features. For this purpose, we used three algorithms: Support Vector Machine (SVM), Random Forest (RF), and K-Nearest Neighbors (KNN). The dataset presented class imbalance, and the classification models presented a low recall, especially in the stroke class. Therefore, we implemented class balance using Borderline-SMOTE. After data balancing the classification models showed significantly higher accuracy, recall, f1-score, and AUC. However, after data balancing, the SVM classifier showed a higher performance with a precision of 98%, a recall of 97.5%, and an AUC of 0.996. The results showed that classification models based on human hand motion features in combination with the oversampling algorithm Borderline-SMOTE achieve higher performance. Furthermore, our study suggests that there are differences in ARAT activities performed between healthy and post-stroke individuals that are not detected by the ARAT scoring process.Peer ReviewedPostprint (published version

Preface: a special selection on biomechanics in medical application - Part II

Electronic version of an article published as Journal of Mechanics in Medicine and Biology, Volume 19, Issue 8, 2019, 1902004:1-8 DOI 10.1142/S0219519419020044 © 2019 World Scientific Publishing Company https://www.worldscientific.com/doi/abs/10.1142/S0219519419020044Part II of this special issue sums up the selections focusing on the Applications of Biomechanics in Medicine.Postprint (author's final draft

Preface: a special selection on biomechanics in medical applications - Part I

Electronic version of an article published as Journal of Mechanics in Medicine and Biology, Volume 19, Issue 7, 2019, 1902003:1-8, DOI 10.1142/S0219519419020032 © 2019 World Scientific Publishing Company https://www.worldscientific.com/doi/10.1142/S0219519419020032Part I of this special issue sums up the selections focusing on the Applications of Biomechanics in Medicine.Peer ReviewedPostprint (author's final draft

Valoración del daño corporal en personas afectadas de secuelas neurológicas

Objetivo: Mostrar un nuevo sistema para simular la recuperación inicial de las funciones de la extremidad superior los primeros días después del ictus y simular la recuperación funcional de los pacientes bajo los programas de rehabilitación. Pacientes y metodología: Seleccionamos 29 pacientes en los primeros cuatro días después de padecer un ictus, valorados a los tres y siete días y uno, tres y seis meses, recogiendo tipo de ictus, clasificación (escala de Oxford), déficit neurológico (escala de NIHSS), medidas de discapacidad, valoración de la función motora de la extremidad superior (escala de Fugl-Meyer), tono muscular y balance muscular de la extremidad superior. Resultados: Los pacientes que presentaron un tono muscular disminuido tuvieron más dificultad en mejorar el control motor de las articulaciones de la extremidad superior. Los pacientes TACI presentaron mayor déficit neurológico, mientras que los tipos de ictus POCI y LACI tenían una función motora mejor con mayor independencia para el desarrollo de sus actividades de la vida diaria. Conclusión: La simulación virtual del brazo y la mano en pacientes afectados por un ictus proporciona a los médicos y fisioterapeutas una nueva herramienta que permite simular la evolución de los déficits en algunos pacientes.Postprint (published version

Spin off Urbiòtica, SL

Conté: Dispositivo de accionamiento para una mano discapacitada (Exoesqueleto) / Esteban Peña Pitarch. Spin off Urbiòtica, SL / Antoni Brey RodríguezAquest llibre recull les dues candidatures guanyadores de les diferents modalitats d’aquesta 9a edició del Premi: 1. La patent Dispositivo de accionamiento para una mano discapacitada (Exoesqueleto), del grup de recerca SIR-Robòtica Industrial i de Servei, dirigit pel professor Esteban Peña Pitarch, del departament d’Enginyeria Mecànica que va guanyar el Premi a la millor patent per la seva aplicació al mercat. El jurat va valorar el fet que aplica una solució tecnològica basada en la biomecànica a un àmbit cada vegada més sensible com es la discapacitat de les persones, en concret la mobilitat de les mans i el mercat potencial que pot suposar, tenint en compte l’envelliment de la població i les necessitats associades a les dolences de la gent gran en aquests aspectes de mobilitat. 2. L’ spin-off Urbiotica, vinculada al grup de recerca ANTENNALAB-grup d’Antennes i Sistemes Radio, del Departament de Teoria del Senyal i Comunicacions que va ser la guanyadora del Premi a la millor empresa de base tecnològica o spin-off. En aquest cas, el jurat va valorar de manera paral·lela, la seva trajectòria i el caràcter global del seu negoci, així com la capacitat tecnològica per integrar diferents tecnologies TIC per tal d’oferir solucions avançades, innovadores i d’alt potencial de creixement, enfocades al sector de les smart cities.Peer ReviewedAward-winningPostprint (published version

Hot working behaviour and processing maps of duplex cast steel

In this paper the hot working behaviour of medium carbon duplex cast steel is studied using uniaxial hot compression tests over a temperature range varying from 700 °C to 1 000 °C and at different strain rates ranging from 10–4 to 10–1 s–1. A model based on a variant of a dynamic materials model was employed to construct processing maps. These maps delineate the safe and unsafe domains. The safe domains, associated with dynamic recrystallization and dynamic recovery, can be chosen to optimize the hot workability of the studied material. Whereas, the unsafe domain is to be avoided because it is associated with plastic deformation instabilities. The domain associated with dynamic recrystallization is centred at 1000 °C and 10–4 s–1 with a peak energy dissipation efficiency of about 40%, while the domain associated with dynamic recovery is centred at 700 °C and 10–4 s–1 with a peak energy dissipation efficiency of about 27%. The unsafe hot working domain, spread over the entire temperature range and moderate to high strain rates, predicts the appearance of flow instabilities, in the form of shear bands and intergranular cracks. To validate the obtained results, microstructural observations corresponding to different processing conditions are presented.The authors are grateful for the financial support received from the CICYT (Spain) through the research project DPI2016-80077-R.Peer ReviewedPostprint (published version