Suitable task allocation in intelligent systems for assistive environments

The growing need of technological assistance to provide support to people with special needs demands for systems more and more efficient and with better performances. With this aim, this work tries to advance in a multirobot platform that allows the coordinated control of different agents and other elements in the environment to achieve an autonomous behavior based on the user’s needs or will. Therefore, this environment is structured according to the potentiality of each agent and elements of this environment and of the dynamic context, to generate the adequate actuation plans and the coordination of their execution.Peer ReviewedPostprint (author's final draft

Event-based control for sit-to-stand transition using a wearable exoskeleton

Sit-to-stand transition is an essential step in a lower limb rehabilitation therapy, mainly for assisting the patient to transit from wheel chair to the next level of therapy. A mixed stiffness-damping control adaptation is proposed for this task which will help in reaching the final position with a constant velocity. A combination of control model is proposed to ensure the initiation and the final stage of the transition, such as to ensure stability and to maintain the equilibrium. The combined control model helps in reaching the goal position with equal participation from the user. For patient studies, such as with paraplegic patients, a combinational control model with muscle stimulation can be included to provide a complete assistance. The role of muscle stimulation and joint movement assistance is also considered in this control model. Further, final stage of this transition must ensure keeping or helping the user to maintain the upright position.Peer ReviewedPostprint (author's final draft

Retaining or excising the supraspinatus tendon in complex proximal humeral fractures treated with reverse prosthesis: a biomechanical analysis in two different designs

Purpose: We aimed to biomechanically evaluate the effect of the supraspinatus tendon on tuberosity stability using two different reverse shoulder arthroplasty (RSA) models for complex proximal humeral fractures (PHFs) Methods: Four-part proximal humeral fractures were simulated in 20 cadaveric shoulders. Two different RSA designs were implemented: a glenosphere-medialized model and a glenosphere-lateralized model. Tuberosities were reconstructed, and displacement of bony fragments was measured (mm) by placing three sensors: in the humeral diaphysis (D), in the greater tuberosity (GT), and in the lesser tuberosity (LT). Axial forces were induced and measured in Newton (N). The test was performed twice in each specimen, with and without the supraspinatus tendon. The regression line (RL) was measured in mm/N. Results: In the medialized model, the GT–D displacement was greater in the supraspinatus preserving model than that in the tendon excision model (p<0.001), as well as for the LT–D displacement (p<0.001). In the lateralized model, GT–D displacement and GT–LT distance were greater in the preserving model than that in the excision model (p<0.001, p=0.04). Conclusion: The supraspinatus tendon resection leads to a more biomechanically stable tuberosity construct when performing RSA for PHFs, while the rest of the rotator cuff tendons (infraspinatus and teres minor) are retained in the greater tuberosity.Peer ReviewedPostprint (author's final draft

Plataforma para un entorno asistencial inteligente heterogéneo

La creciente demanda de soporte tecnológico para la asistencia a personas con necesidades especiales obliga a avanzar tecnológi-camente hacia sistemas más eficientes y con más prestaciones. En esta íinea, en este artículo se describen los avances en el desarrollo de una plataforma que permite el control coordinado de diferentes agentes y otros elementos del entorno para conseguir un comporta-miento autónomo en base a las necesidades o deseos del usuario. Para ello se estructura este entorno en base a la potencialidad de cada agente y elemento del entorno, así como del contexto dinámico, para generar los adecuados planes de actuación y la coordinación en su ejecuciónPeer ReviewedPostprint (published version

Control de robots en neurorehabilitación: desde sensores neurales a sensores portables

Las interfaces BCI tienen ya un cierto grado de desarrollo en el ámbito del diagnóstico y de la interacción persona-computador, sin embargo su aplicación al control de dispositivos robóticos está todavía muy limitado debido a la dificultad de interpretación dinámica. Es por ello que actualmente el control BCI queda muy limitado a órdenes elementales y para el control de robots la información proporcionada por esta interfaz debe complementarse con otros tipos de sensores y estrategias. Este artículo describe las diferentes líneas de trabajo que se llevan a cabo en control volitivo y cooperativo de robots asistenciales en el grupo de investigación de Robótica Inteligente y Sistemas (GRINS) del Centro de investigación en Ingeniería Biomédica (CREB) de la UPC.Peer ReviewedPreprin

Anticipating human activities from object interaction cues

A real time approach to the recognition of human activity based on the interaction with objects in domestic settings is presented. It is based on capturing partial images where the activity takes place using a color camera, and processing the images to recognize the present objects and their location changes. For object description and recognition, a histogram on a normalized chromaticity space has been selected. The interaction with the objects is classified as four types of possible actions regarding change in location (add, remove, move or unchanged). Activities are defined as receipts, where objects plays the role of ingredients, tools or substitutes. Sensed objects and actions are then used to analyze in real time the probability of the human activity that is being performed at the moment in a continuous activity sequence. Tests are carried on a automated kitchen scenario where proactive assistance wants to be implemented taking into account the early recognition user activity.Peer Reviewe

Anticipating human activities from object interaction cues

A real time approach to the recognition of human activity based on the interaction with objects in domestic settings is presented. It is based on capturing partial images where the activity takes place using a color camera, and processing the images to recognize the present objects and their location changes. For object description and recognition, a histogram on a normalized chromaticity space has been selected. The interaction with the objects is classified as four types of possible actions regarding change in location (add, remove, move or unchanged). Activities are defined as receipts, where objects plays the role of ingredients, tools or substitutes. Sensed objects and actions are then used to analyze in real time the probability of the human activity that is being performed at the moment in a continuous activity sequence. Tests are carried on a automated kitchen scenario where proactive assistance wants to be implemented taking into account the early recognition user activity.Peer Reviewe

A new relational geometric feature for human action recognition

Pose-based features have demonstrated to outperform low-levelappearance features in human action recognition. New RGB-D cameras provide locations of human joints with which geometric correspondences can be easily calculated. In this article, a new geometric correspondence between joints called Trisarea feature is presented. It is defined as the area of the triangle formed by three joints. Relevant triangles describing human pose are identified and it is shown how the variation over time of the selected Trisarea features constitutes a descriptor of human action. Experimental results show a comparison with other methods and demonstrate how this Trisarea-based representation can be applied to human action recognition.Peer ReviewedPostprint (published version

An interactive robotic system for human assistance in domestic environments

This work introduces an interactive robotic system for assistance, conceived to tackle some of the challenges that domestic environments impose. The system is organized into a network of heterogeneous components that share both physical and logical functions to perform complex tasks. It consists of several robots for object manipulation, an advanced vision system that supplies in-formation about objects in the scene and human activity, and a spatial augmented reality interface that constitutes a comfortable means for interacting with the system. A first analysis based on users’ experiences confirms the importance of having a friendly user interface. The inclusion of context awareness from visual perception enriches this interface allowing the robotic system to become a flexible and proactive assistant.Peer Reviewe

Event-based control for sit-to-stand transition using a wearable exoskeleton

Sit-to-stand transition is an essential step in a lower limb rehabilitation therapy, mainly for assisting the patient to transit from wheel chair to the next level of therapy. A mixed stiffness-damping control adaptation is proposed for this task which will help in reaching the final position with a constant velocity. A combination of control model is proposed to ensure the initiation and the final stage of the transition, such as to ensure stability and to maintain the equilibrium. The combined control model helps in reaching the goal position with equal participation from the user. For patient studies, such as with paraplegic patients, a combinational control model with muscle stimulation can be included to provide a complete assistance. The role of muscle stimulation and joint movement assistance is also considered in this control model. Further, final stage of this transition must ensure keeping or helping the user to maintain the upright position.Peer Reviewe