sEMG-Based Gesture Classifier for a Rehabilitation Glove.

Human hand gesture recognition from surface electromyography (sEMG) signals is one of the main paradigms for prosthetic and rehabilitation device control. The accuracy of gesture recognition is correlated with the control mechanism. In this work, a new classifier based on the Bayesian neural network, pattern recognition networks, and layer recurrent network is presented. The online results obtained with this architecture represent a promising solution for hand gesture recognition (98.7% accuracy) in sEMG signal classification. For real time classification performance with rehabilitation devices, a new simple and efficient interface is developed in which users can re-train the classification algorithm with their own sEMG gesture data in a few minutes while enables shape memory alloy-based rehabilitation device connection and control. The position of reference for the rehabilitation device is generated by the algorithm based on the classifier, which is capable of detecting user movement intention in real time. The main aim of this study is to prove that the device control algorithm is adapted to the characteristics and necessities of the user through the proposed classifier with high accuracy in hand gesture recognition.

Two-Stage Shape Memory Alloy Identification Based on the Hammerstein-Wiener Model.

Thanks to characteristics, such as high force and light weight, a good biocompatibility, noiseless operation and simplicity, and relatively low-cost compared with other conventional actuators, actuators based on shape memory alloy are currently one of the most interesting research topics. They have been introduced in applications such robotics, medicine, automation, and so on. For a good actuator integration of these types of applications, proper control is needed, which seems to be a difficult task due to the hysteresis, dilatory response, and non-linear behavior. This work presents a new form of modeling of this type of actuator based on Hammerstein-Wiener model. This has been identified in two stages of the operation. When the activation temperature for the actuator is obtained by the Joule effect, electrically energy is transformed into thermal energy. In the second stage, the thermal energy is transformed into mechanical work. To fulfill this objective, experimental data [e.g., the input signal (pulse-width modulation), temperature signal, and position signal] from the two stages was obtained for a specific shape memory alloy wire and for specific environmental conditions. This data was used in the modeling process. The final model consists of a combination of the models from the two stages, which represent the behavior of the shape memory alloy actuator where the input signal is the pulse-width modulation signal and the output signal are the position of the actuator. Our results indicate that our model has a very similar response to the behavior of the real actuator. This model can be used to tune different control algorithms, simulate the entry system before manufacture and test on real devices.

Hand Exo-Muscular System for Assisting Astronauts During Extravehicular Activities.

Human exploration of the Solar System is one of the most challenging objectives included in the space programs of the most important space agencies in the world. Since the Apollo program, and especially with the construction and operation of the International Space Station, extravehicular activities (EVA) have become an important part of space exploration. This article presents a soft hand exoskeleton designed to address one of the problems that astronauts face during spacewalks: hand fatigue caused by the pressurized EVA gloves. This device will reduce the stiffness of the spacesuit glove by counteracting the force exerted by the pressurized glove. To this end, the system makes use of a set of six flexible actuators, which use a shape memory alloy (SMA) wire as the actuating element. SMAs have been chosen because some of their features, such as low volume and high force-to-weight ratio, make them a suitable choice taking into account the constraints imposed by the use of the device in a spacesuit. Besides describing the different mechanical and electronic subsystems that compose the exoskeleton, this article presents a preliminary assessment of the device; several tests to characterize its nominal operation have been carried out, as well as position and force control tests to study its controllability and evaluate its suitability as a force assistive device.

A High-Level Control Algorithm Based on sEMG Signalling for an Elbow Joint SMA Exoskeleton.

A high-level control algorithm capable of generating position and torque references from surface electromyography signals (sEMG) was designed. It was applied to a shape memory alloy (SMA)-actuated exoskeleton used in active rehabilitation therapies for elbow joints. The sEMG signals are filtered and normalized according to data collected online during the first seconds of a therapy session. The control algorithm uses the sEMG signals to promote active participation of patients during the therapy session. In order to generate the reference position pattern with good precision, the sEMG normalized signal is compared with a pressure sensor signal to detect the intention of each movement. The algorithm was tested in simulations and with healthy people for control of an elbow exoskeleton in flexion⁻extension movements. The results indicate that sEMG signals from elbow muscles, in combination with pressure sensors that measure arm⁻exoskeleton interaction, can be used as inputs for the control algorithm, which adapts the reference for exoskeleton movements according to a patient's intention.

New Design of a Soft Robotics Wearable Elbow Exoskeleton Based on Shape Memory Alloy Wire Actuators.

The elbow joint is a complex articulation composed of the humeroulnar and humeroradial joints (for flexion-extension movement) and the proximal radioulnar articulation (for pronation-supination movement). During the flexion-extension movement of the elbow joint, the rotation center changes and this articulation cannot be truly represented as a simple hinge joint. The main goal of this project is to design and assemble a medical rehabilitation exoskeleton for the elbow with one degree of freedom for flexion-extension, using the rotation center for proper patient elbow joint articulation. Compared with the current solutions, which align the exoskeleton axis with the elbow axis, this offers an ergonomic physical human-robot interface with a comfortable interaction. The exoskeleton is actuated with shape memory alloy wire-based actuators having minimum rigid parts, for guiding the actuators. Thanks to this unusual actuation system, the proposed exoskeleton is lightweight and has low noise in operation with a simple design 3D-printed structure. Using this exoskeleton, these advantages will improve the medical rehabilitation process of patients that suffered stroke and will influence how their lifestyle will change to recover from these diseases and improve their ability with activities of daily living, thanks to brain plasticity. The exoskeleton can also be used to evaluate the real status of a patient, with stroke and even spinal cord injury, thanks to an elbow movement analysis.

Kullback-Leibler Divergence-Based Differential Evolution Markov Chain Filter for Global Localization of Mobile Robots.

One of the most important skills desired for a mobile robot is the ability to obtain its own location even in challenging environments. The information provided by the sensing system is used here to solve the global localization problem. In our previous work, we designed different algorithms founded on evolutionary strategies in order to solve the aforementioned task. The latest developments are presented in this paper. The engine of the localization module is a combination of the Markov chain Monte Carlo sampling technique and the Differential Evolution method, which results in a particle filter based on the minimization of a fitness function. The robot's pose is estimated from a set of possible locations weighted by a cost value. The measurements of the perceptive sensors are used together with the predicted ones in a known map to define a cost function to optimize. Although most localization methods rely on quadratic fitness functions, the sensed information is processed asymmetrically in this filter. The Kullback-Leibler divergence is the basis of a cost function that makes it possible to deal with different types of occlusions. The algorithm performance has been checked in a real map. The results are excellent in environments with dynamic and unmodeled obstacles, a fact that causes occlusions in the sensing area.

Laser treatments on skin enhancing and controlling transdermal delivery of 5-fluorouracil.

BACKGROUND AND OBJECTIVE: Laser ablation of stratum corneum (SC) enhances transdermal delivery of hydrophilic drugs. The influence of the infrared (IR) (lambda = 1,064 nm), visible (lambda = 532 nm), and ultraviolet (UV) (lambda = 355 nm) radiations of a Nd:YAG laser on transdermal delivery of 5-Fluorouracil (5-Fu) across skin was studied in vitro. MATERIALS AND METHODS: Pinna skin of the inner side of rabbit ear, was used for the skin permeation. The light source for laser treatment was a Q-switched Nd:YAG laser (Lotis TII SL-2132). Ablation thresholds were estimated by using a photoacoustic technique. In addition, permeation study, and morphological and structural skin examination by histology and differential scanning calorimetry (DSC) were carried out. RESULTS: A significant increase in the permeation of 5-Fu across skin pre-treatment with the three different wavelengths studied was obtained. Since irradiation at 1,064 nm allows deep penetration of the radiation, collagen fibers were affected [7.7 J/cm(2) (15 Hz)]. Visible radiation of Nd:YAG laser showed the wider range of fluences (3-8.4 J/cm(2) at 15 Hz) to enhance skin delivery of 5-Fu, without risk of skin lesion. UV radiation required minor energy contribution to produce the same effects within a narrower range of fluences [0.3 J/cm(2) (5 Hz)-1.5 J/cm(2) (15 Hz)] so the process is less controlled and this radiation shows greater impact on the lipidic structure than visible and IR radiations. CONCLUSIONS: Use of the visible radiation of a Nd:YAG laser is a good method for improving the efficacy of topical chemotherapy of 5-Fu.

Low doses of lead: effects on reproduction and development in rats.

The effects of exposure to high doses of lead on reproduction and development have been established, but not so those caused by low lead doses or the influence that life stage at which contact with the metal takes place might have. The aim of this work was to study the effects of 200 and 400 ppm lead acetate in drinking water on reproduction and development as well as on renal and hepatic parameters of rats at different life stages, from gestation to 3 mo postweaning. The results indicate a dose-dependent effect on reproduction, with variations in the number of births and in pups' weight. Development was mostly affected at the weaning stage, with hemoglobin levels and erythrocyte numbers significantly decreased. The lead levels in tissues, blood, urine, and feces along with selected renal and hepatic parameters (blood urea nitrogen, creatinine, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase) were determined. There were histological, blood urea nitrogen, alanine aminotransferase, and alkaline phosphatase changes in the first month postweaning. After 3 mo, these changes are no longer evident, possibly because of metabolic adaptation.

Papillomas and atypical papillomas in breast core needle biopsy specimens: risk of carcinoma in subsequent excision.

We sought to define the risk associated with papillomas and atypical papillomas in breast core needle biopsy specimens from a series of approximately 8,500 biopsies performed during 8 years. From a total of 62 papillary lesions (including papillomas and atypical papillomas), 40 (65%) had histologic follow-up. Overall, 15 (38%) of 40 patients had ductal carcinoma in situ (12 cases) or invasive carcinoma at excision (3 cases). Eight cases diagnosed as papilloma had benign follow-up. Slides were available for review in 38 cases and reclassified into benign papilloma with florid hyperplasia and no or minimal atypia (18 cases), papilloma with separate foci of atypical ductal hyperplasia (7 cases), and severely atypical papillomas "suspicious" for papillary carcinoma (13 cases). Carcinoma was identified in 0 (0%), 2 (29%), and 12 (92%) cases, respectively. We conclude that while atypical papillary lesions and papillomas with associated atypical ductal hyperplasia in breast core needle biopsy specimens are associated with a risk of carcinoma, lesions diagnosed as papilloma or papilloma with no or minimal atypia are benign and do not need to be excised.

Anorexia y ciclos de ingestión alimentaria en ratas albinas macho deficientes de cinc / Anorexia and intake cycles in male albino rats with zinc deficiency

Se estudió el efecto de la deficiencia de cinc sobre la cantidad de alimento consumido por día y los patrones de ingestión alimentario enratas albinas macho de 28 días de nacidas. Se formaron 3 grupos experimentales de 12 animales cada uno: grupo control (C), grupo deficiente en cinc (D) y grupo pareja de alimentación (PA). El período experimental fue de 29 días, al término del cual se encontró que los animales del grupo deficiente en cinc consumieron menor cantidad de alimento durante todo el período experimental, siendo además elconsumo de forma irregular con días de máxima y mínima ingesta. La deficiencia de cinc provocó anorexia a partir del tercer o cuarto día de ensayo, lo cual coincidió con un mayor número de ciclos de ingestión alimentaria en estos animales. Se concluye que la deficiencia de cinc afecta de forma adversa la ingestión alimentaria y provoca que ésta se realice de forma cíclica (AU)

Ingestión de zeolita y concentraciones de oligometales en ratas / Zeolite intake and concentrations of trace elements in rats

Se estudió el peso coroporal, el consumo de dieta, la eficacia dietaria *índice de conversión alimentaria) y las concentraciones séricas de Zn, Cu, Fe, Ca y Mg en ratas albinas Wistar adultas, machos, alimentadas con una dieta que contenía 20,0 por ciento de zeolita (Heulandita-Clinoptilolita) durante 40 días. Se encontraron concentraciones séricas más altas de Cu y Mg en el grupo que consumió la zeolita al 20 por ciento en comparación con el grupo control (p < 0,05). Se concluye que la ingestión de zeolita (Heulandita-Clinoptilolita) en las condiciones de este experimento afectó el peso corporal y el índice de conversión alimentaria, y aumentó las concentraciones séricas de Cu y Mg, pero no influyó adversamente sobre el perfil sérico de los 5 metales estudiados (AU)

Ingestión de zeolita y concentraciones de oligometales en ratas / Zeolite intake and concentrations of trace elements in rats

Se estudió el peso coroporal, el consumo de dieta, la eficacia dietaria *índice de conversión alimentaria) y las concentraciones séricas de Zn, Cu, Fe, Ca y Mg en ratas albinas Wistar adultas, machos, alimentadas con una dieta que contenía 20,0 por ciento de zeolita (Heulandita-Clinoptilolita) durante 40 días. Se encontraron concentraciones séricas más altas de Cu y Mg en el grupo que consumió la zeolita al 20 por ciento en comparación con el grupo control (p < 0,05). Se concluye que la ingestión de zeolita (Heulandita-Clinoptilolita) en las condiciones de este experimento afectó el peso corporal y el índice de conversión alimentaria, y aumentó las concentraciones séricas de Cu y Mg, pero no influyó adversamente sobre el perfil sérico de los 5 metales estudiados

Actividad proteolìtica gástrica en ratas tratadas con metronidazol / Gastric proteolytic activity in rats treated with etronidazole

Se estudiaron la actividad proteolítica de homogenezados de mucosa gástrica y las características del perfil de la curva de la referida actividad en ratas que recibieron administración de metronidazol, según esquema de la clínica médica del ser humano. No se encontraron cambios significativos en ninguno de los factores estudiados

Actividad proteolìtica gástrica en ratas tratadas con metronidazol / Gastric proteolytic activity in rats treated with metronidazole

Se estudiaron la actividadad proteolítica de homogenezados de mucosa gástrica y las características del perfil de la curva de la referida actividad en ratas que recibieron administración de metronidazol, según esquema de la clínica médica del ser humano. No se encontraron cambios significativos en ninguno de los factores estudiados