sEMG-Based Robust Recognition of Grasping Postures with a Machine Learning Approach for Low-Cost Hand Control.

The design and control of artificial hands remains a challenge in engineering. Popular prostheses are bio-mechanically simple with restricted manipulation capabilities, as advanced devices are pricy or abandoned due to their difficult communication with the hand. For social robots, the interpretation of human intention is key for their integration in daily life. This can be achieved with machine learning (ML) algorithms, which are barely used for grasping posture recognition. This work proposes an ML approach to recognize nine hand postures, representing 90% of the activities of daily living in real time using an sEMG human-robot interface (HRI). Data from 20 subjects wearing a Myo armband (8 sEMG signals) were gathered from the NinaPro DS5 and from experimental tests with the YCB Object Set, and they were used jointly in the development of a simple multi-layer perceptron in MATLAB, with a global percentage success of 73% using only two features. GPU-based implementations were run to select the best architecture, with generalization capabilities, robustness-versus-electrode shift, low memory expense, and real-time performance. This architecture enables the implementation of grasping posture recognition in low-cost devices, aimed at the development of affordable functional prostheses and HRI for social robots.

Design of Virtual Hands for Natural Interaction in the Metaverse.

The emergence of the Metaverse is raising important questions in the field of human-machine interaction that must be addressed for a successful implementation of the new paradigm. Therefore, the exploration and integration of both technology and human interaction within this new framework are needed. This paper describes an innovative and technically viable proposal for virtual shopping in the fashion field. Virtual hands directly scanned from the real world have been integrated, after a retopology process, in a virtual environment created for the Metaverse, and have been integrated with digital nails. Human interaction with the Metaverse has been carried out through the acquisition of the real posture of the user's hands using an infrared-based sensor and mapping it in its virtualized version, achieving natural identification. The technique has been successfully tested in an immersive shopping experience with the Meta Quest 2 headset as a pilot project, where a transactions mechanism based on the blockchain technology (non-fungible tokens, NFTs) has allowed for the development of a feasible solution for massive audiences. The consumers' reactions were extremely positive, with a total of 250 in-person participants and 120 remote accesses to the Metaverse. Very interesting technical guidelines are raised in this project, the resolution of which may be useful for future implementations.

Real-Time Path Planning Based on Harmonic Functions under a Proper Generalized Decomposition-Based Framework.

This paper presents a real-time global path planning method for mobile robots using harmonic functions, such as the Poisson equation, based on the Proper Generalized Decomposition (PGD) of these functions. The main property of the proposed technique is that the computational cost is negligible in real-time, even if the robot is disturbed or the goal is changed. The main idea of the method is the off-line generation, for a given environment, of the whole set of paths from any start and goal configurations of a mobile robot, namely the computational vademecum, derived from a harmonic potential field in order to use it on-line for decision-making purposes. Up until now, the resolution of the Laplace or Poisson equations has been based on traditional numerical techniques unfeasible for real-time calculation. This drawback has prevented the extensive use of harmonic functions in autonomous navigation, despite their powerful properties. The numerical technique that reverses this situation is the Proper Generalized Decomposition. To demonstrate and validate the properties of the PGD-vademecum in a potential-guided path planning framework, both real and simulated implementations have been developed. Simulated scenarios, such as an L-Shaped corridor and a benchmark bug trap, are used, and a real navigation of a LEGO®MINDSTORMS robot running in static environments with variable start and goal configurations is shown. This device has been selected due to its computational and memory-restricted capabilities, and it is a good example of how its properties could help the development of social robots.

A Novel Real-Time MATLAB/Simulink/LEGO EV3 Platform for Academic Use in Robotics and Computer Science.

Over the last years, mobile robot platforms are having a key role in education worldwide. Among others, LEGO Robots and MATLAB/Simulink are being used mainly in universities to improve the teaching experience. Most LEGO systems used in the literature are based on NXT, as the EV3 version is relatively recent. In contrast to the previous versions, the EV3 allows the development of real-time applications for teaching a wide variety of subjects as well as conducting research experiments. The goal of the research presented in this paper was to develop and validate a novel real-time educational platform based on the MATLAB/Simulink package and the LEGO EV3 brick for academic use in the fields of robotics and computer science. The proposed framework is tested here in different university teaching situations and several case studies are presented in the form of interactive projects developed by students. Without loss of generality, the platform is used for testing different robot path planning algorithms. Classical algorithms like rapidly-exploring random trees or artificial potential fields, developed by robotics researchers, are tested by bachelor students, since the code is freely available on the Internet. Furthermore, recent path planning algorithms developed by the authors are also tested in the platform with the aim of detecting the limits of its applicability. The restrictions and advantages of the proposed platform are discussed in order to enlighten future educational applications.

Functional range of motion of the hand joints in activities of the International Classification of Functioning, Disability and Health.

STUDY DESIGN: Cross-sectional research design. INTRODUCTION: Active range of motion (AROM) is used as indicator of hand function. However, functional range of motion (FROM) data are limited, and fail to represent activities of daily living (ADL). PURPOSE OF THE STUDY: To estimate dominant hand FROM in flexion, abduction and palmar arching in people under 50 years of age performing ADL. METHODS: AROMs and hand postures in 24 representative ADL of the International Classification of Functioning, Disability and Health (ICF) were recorded in 12 men and 12 women. FROM data were reported by activity and ICF area, and compared with AROMs. The relationship between ROM measures to gender and hand size was analyzed by correlation. RESULTS: FROM was 5° to 28° less than available AROM depending on the joint and movement performed. DISCUSSION: Joints do not necessarily move through full AROM while performing ADL which has benefits in retaining function despite loss of motion. This may also suggest that ADL alone are insufficient to retain or restore full AROM. CONCLUSIONS: Therapists should consider FROM requirements and normal AROM when defining hand therapy goals, interventions and evaluating the success of treatment. LEVEL OF EVIDENCE: N/A.

Grip force and force sharing in two different manipulation tasks with bottles.

Grip force and force sharing during two activities of daily living were analysed experimentally in 10 right-handed subjects. Four different bottles, filled to two different levels, were manipulated for two tasks: transporting and pouring. Each test subject's hand was instrumented with eight thin wearable force sensors. The grip force and force sharing were significantly different for each bottle model. Increasing the filling level resulted in an increase in grip force, but the ratio of grip force to load force was higher for lighter loads. The task influenced the force sharing but not the mean grip force. The contributions of the thumb and ring finger were higher in the pouring task, whereas the contributions of the palm and the index finger were higher in the transport task. Mean force sharing among fingers was 30% for index, 29% for middle, 22% for ring and 19% for little finger. Practitioner Summary: We analysed grip force and force sharing in two manipulation tasks with bottles: transporting and pouring. The objective was to understand the effects of the bottle features, filling level and task on the contribution of different areas of the hand to the grip force. Force sharing was different for each task and the bottles features affected to both grip force and force sharing.

Grasp modelling with a biomechanical model of the hand.

The use of a biomechanical model for human grasp modelling is presented. A previously validated biomechanical model of the hand has been used. The equilibrium of the grasped object was added to the model through the consideration of a soft contact model. A grasping posture generation algorithm was also incorporated into the model. All the geometry was represented using a spherical extension of polytopes (s-topes) for efficient collision detection. The model was used to simulate an experiment in which a subject was asked to grasp two cylinders of different diameters and weights. Different objective functions were checked to solve the indeterminate problem. The normal finger forces estimated by the model were compared to those experimentally measured. The popular objective function sum of the squared muscle stresses was shown not suitable for the grasping simulation, requiring at least being complemented by task-dependent grasp quality measures.

Tumores intrínsecos de la glándula lagrimal (1976-1996) / Intrinsic tumors of the lachrymal gland

El estudio de 19 pacientes portadores de lesiones tumorales intrínsecas de la glándula lagrimal, atendidos en el Instituto de Oncología y Radiobiología (INOR) en 20 años, reveló que representa el 8,9 por ciento de todas las lesiones tumorales de la órbita. El adenoma pleomórfico (tumor mixto de la glándula) es el más frecuente (42,1 por ciento), seguido de las tumoraciones malignas (36,8 por ciento) y de las lesiones inflamatorias crónicas o dacrioadenitis (21 por ciento). De los pacientes con lesiones malignas, 2 fallecen por progresión de la enfermedad, ambos corresponden al carcinoma adenoideo quístico, lo que reafirma la agresividad de este tipo histológico de tumor. Al analizar los resultados de las técnicas quirúrgicas empleadas encontramos que en 12 pacientes se utilizó orbitotomía superoexterna, craneotomía transfrontal en 6 y la vía transconjuntival en 1, con el 83,3 por ciento, 16,6 por ciento y 100 por ciento, respectivamente, de efectividad (resección total del tumor). En 4 pacientes con adenoma pleomórfico la cirugía seleccionada no fue exerética, donde se observaron recidivas tumorales, 2 de las cuales se transforman en adenocarcinoma, lo que demuestra lo importante de una correcta planificación del tratamietno para reducir los riesgos de recurrencias y transformaciones malignas

Tumores intrínsecos de la glándula lagrimal (1976-1996) / Intrinsic tumors of the lachrymal gland

El estudio de 19 pacientes portadores de lesiones tumorales intrínsecas de la glándula lagrimal, atendidos en el Instituto de Oncología y Radiobiología (INOR) en 20 años, reveló que representa el 8,9 por ciento de todas las lesiones tumorales de la órbita. El adenoma pleomórfico (tumor mixto de la glándula) es el más frecuente (42,1 por ciento), seguido de las tumoraciones malignas (36,8 por ciento) y de las lesiones inflamatorias crónicas o dacrioadenitis (21 por ciento). De los pacientes con lesiones malignas, 2 fallecen por progresión de la enfermedad, ambos corresponden al carcinoma adenoideo quístico, lo que reafirma la agresividad de este tipo histológico de tumor. Al analizar los resultados de las técnicas quirúrgicas empleadas encontramos que en 12 pacientes se utilizó orbitotomía superoexterna, craneotomía transfrontal en 6 y la vía transconjuntival en 1, con el 83,3 por ciento, 16,6 por ciento y 100 por ciento, respectivamente, de efectividad (resección total del tumor). En 4 pacientes con adenoma pleomórfico la cirugía seleccionada no fue exerética, donde se observaron recidivas tumorales, 2 de las cuales se transforman en adenocarcinoma, lo que demuestra lo importante de una correcta planificación del tratamietno para reducir los riesgos de recurrencias y transformaciones malignas(AU)

Reconstrucción total del parpado superior con conservación de su movilidad / Total reconstruction of the upper eyelid preserving its movement

Se presenta la técnica quirúrgica de cirugía funcional del párpado superior en 3 casos en que se le realizó tansectomía total; se incluyó el músculo elevador orbicular y se sustituyó por un injerto cutáneo; se conserva la movilidad de abrirlo y cerrarlo sinérgicamente con el otro ojo(AU)