Varela Aldas, José
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Varela Aldas, José
Main Affiliation
Ambato
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josevarela@uti.edu.ec
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Scopus Author ID
57192546163

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Effects of a dual intervention (motor and virtual reality-based cognitive) on cognition in patients with mild cognitive impairment: a single-blind, randomized controlled trial

2024 , Buele, Jorge , Avilés-Castillo, Fátima , Carolina Del-Valle-Soto , Varela Aldas, José , Guillermo Palacios-Navarro

Abstract Background The increase in cases of mild cognitive impairment (MCI) underlines the urgency of finding effective methods to slow its progression. Given the limited effectiveness of current pharmacological options to prevent or treat the early stages of this deterioration, non-pharmacological alternatives are especially relevant. Objective To assess the effectiveness of a cognitive-motor intervention based on immersive virtual reality (VR) that simulates an activity of daily living (ADL) on cognitive functions and its impact on depression and the ability to perform such activities in patients with MCI. Methods Thirty-four older adults (men, women) with MCI were randomized to the experimental group (n = 17; 75.41 ± 5.76) or control (n = 17; 77.35 ± 6.75) group. Both groups received motor training, through aerobic, balance and resistance activities in group. Subsequently, the experimental group received cognitive training based on VR, while the control group received traditional cognitive training. Cognitive functions, depression, and the ability to perform activities of daily living (ADLs) were assessed using the Spanish versions of the Montreal Cognitive Assessment (MoCA-S), the Short Geriatric Depression Scale (SGDS-S), and the of Instrumental Activities of Daily Living (IADL-S) before and after 6-week intervention (a total of twelve 40-minutes sessions). Results Between groups comparison did not reveal significant differences in either cognitive function or geriatric depression. The intragroup effect of cognitive function and geriatric depression was significant in both groups (p < 0.001), with large effect sizes. There was no statistically significant improvement in any of the groups when evaluating their performance in ADLs (control, p = 0.28; experimental, p = 0.46) as expected. The completion rate in the experimental group was higher (82.35%) compared to the control group (70.59%). Likewise, participants in the experimental group reached a higher level of difficulty in the application and needed less time to complete the task at each level. Conclusions The application of a dual intervention, through motor training prior to a cognitive task based on Immersive VR was shown to be a beneficial non-pharmacological strategy to improve cognitive functions and reduce depression in patients with MCI. Similarly, the control group benefited from such dual intervention with statistically significant improvements. Trial registration ClinicalTrials.gov NCT06313931; https://clinicaltrials.gov/study/NCT06313931.

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Teleoperation of a mobile manipulator with feedback forces for evasion of obstacles [Teleoperación de un manipulador móvil con retroalimentación de fuerzas para evasión de obstáculos]

2019 , Andaluz V.H. , Varela Aldas, José , Chicaiza F.A. , Quevedo W.X. , Ruales, María Belén

This work develops the teleoperation of a mobile manipulator using a kinematic and dynamic control. In addition, the operator receives feedback forces through a haptic device to evade obstacles. The experiments were performed in a local wireless communication network and using the AKASHA robot. The results show an adequate following of the references of control, speed errors are corrected with minimum communication delays. © 2019, Associacao Iberica de Sistemas e Tecnologias de Informacao. All rights reserved.

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Inverse kinematics of a redundant manipulator robot using constrained optimization

2020 , Varela Aldas, José , Ayala-Chauvin, Manuel Ignacio , Andaluz, V.H. , Santamaría, M.

Redundant manipulative robots are characterized by greater manipulability improving performance but complicating inverse kinematics, on the other hand, optimization techniques allow solving complex problems in robotics applications with greater efficiency. This paper presents the inverse kinematics of a redundant manipulative robot with four degrees of freedom to track a desired trajectory, and considering constraint in manipulability. The optimization problem is proposed using the quadratic position errors of the operative end and the constraint is established by a manipulability index, for this the kinematic model of the robot is determined. The results show the points of singularity of the robot and the performance of the proposal implemented, observing the positional errors and the manipulability for each point of the trajectory. In addition, the optimization is evaluated for two desired manipulability values. Finally, it is concluded that the implemented method optimizes the inverse kinematics to track the desired path while constraining the manipulability. © Springer Nature Switzerland AG 2020.

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Electric Monitoring System for Residential Customers Using Wireless Technology

2022 , Buele, Jorge , Morales-Sánchez J.C. , Varela Aldas, José , Palacios-Navarro G. , Ayala-Chauvin, Manuel Ignacio

Power grids continue to develop and it is increasingly difficult to guarantee the quality of service offered to the user. In several developing countries, consumption is calculated on the basis of visual inspection, which is prone to errors. Consequently, this document outlines the construction of electrical consumption telemetering equipment. This is designed to reduce human error through manual measures and have a web backup that can be accessed from anywhere. To develop the prototype voltage and current sensors are used, and the signal is conditioned for the control stage. The processing unit is the Arduino Mega embedded board, which incorporates a GPRS Shield (General Packet Radio Services) that handles communication with a LAMP server (Linux, Apache, MySQL, PHP) connected to the Internet. It also incorporates a block of connection and disconnection of the electrical service that would leave the whole house without service. Two functionalities are used to present the data, one is local on the LCD display of the equipment installed in the home (user) and the second is remote access to a website (server). The results show that in comparison with a standard voltage device it presents an error of 0.28% and 4.12% in current. In this way, the use of this prototype for real-time monitoring of electricity consumption is validated, since it works similarly to a conventional one. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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Construction of a WBGT index meter using low cost devices

2020 , Varela Aldas, José , Fuentes, E.M. , Ruales, María Belén , Ichina, C.

Appropriate working conditions can improve the working performance of an employee on a company, one of the main concerns nowadays is the thermal stress, due to the affection not only to the productivity of an employee but also for the risk of affections to his health, in this sense, WBGT (Wet-Bulb Globe Temperature) index is widely proved to define thermal discomfort and thermal stress but in some cases is out of reach due to its cost or availability on a certain region of the world, so this work explains the construction of a low cost device WBGT meter built by an Arduino pro mini, three lm35 temperature sensors and an LCD to install the electronic system; Globe temperature and wet bulb temperature was achieved using a matte black sphere and moistened fabric, respectively. After testing the dispositive, the collected information was sent to a computer through serial communication for further analysis which showed acceptable errors on the measurement of the WBGT index taken indoors and outdoors thru the device and compared to the data obtained by a commercial WBGT meter. © Springer Nature Switzerland AG 2020.

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Virtual System for Industrial Processes: Distillation Towers

2021 , Jacome E.M. , Toaquiza J.F. , Mullo G.M. , Andaluz V.H. , Varela Aldas, José

In this paper a realistic and intuitive virtual environment of a distillation tower system is developed. The three-dimensional model of the system is based on a real system, which is replicated in Blender software to be later implemented in Unity, in order to simulate its behavior. By showing the evolution of the system, control and monitoring maneuvers are implemented, so that the virtual animation is similar to a real process. The application developed is intended to provide support in the learning process of an operator in the work area. © 2021, Springer Nature Switzerland AG.

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3D Object Reconstruction Using Concatenated Matrices with MS Kinect: A Contribution to Interiors Architecture

2020 , Buele, Jorge , Varela Aldas, José , Castellanos E.X. , Jadán Guerrero, Janio , Barberán J.

Interior architecture is part of the individual, social and business life of the human being; it allows structuring the spaces to inhabit, study or work. This document presents the design and implementation of a system that allows the three-dimensional reconstruction of objects with a reduced economic investment. The image acquisition process and treatment of the information with mathematical support that it entails are described. The system involves an MS Kinect as a tool to create a radar that operates with the structured light principle to capture objects at a distance of less than 2 meters. The development of the scripts is done in the MATLAB software and in the same way the graphical interface that is presented to the user. As part of the initial tests of this prototype, the digitization of geometric shape structures has been performed with an accuracy of over 98%. This validates its efficient operation, which serves as the basis for the development of modeling in interior architecture for future work. © 2020, Springer Nature Switzerland AG.

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Development of Behavior Profile of Users with Visual Impairment

2020 , Guevara Maldonado, César Byron , Arias Flores, Hugo Patricio , Varela Aldas, José , Castillo Salazar, David Ricardo , Borja M. , Fierro-Saltos W. , Rivera R. , Hidalgo-Guijarro J. , Yandún-Velasteguí M.

The interaction of the user with visual impairment with assistive technologies, and in particular with screen readers, generates a group of actions and events during their navigation. These interactions are defined as behavioral patterns, which have a sequence that occurs at specific time slot. Understanding user behavior by analyzing their interaction with applications, in addition, details the characteristics, relationships, structures and functions of the sequence of actions in a specific application domain. The objective of this document is to find activity patterns from a set of commands used by the user, combining data mining and a Bayesian model. This model calculates the probability of the functions used with the screen reader and generates a behavior profile to improve the user experience. For this study, the screen reader JAWS version 2018, the Open Journal Systems platform version 3.0.1 and a computer with Windows 10 operating system were used. During the first phase, command history used by the user by interacting with the Open Journal Systems platform were collected. The result is that the accessibility of users with visual impairment to interact with the computer and its applications has been improved by applying this model. © Springer Nature Switzerland AG 2020.

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Control of an Arm-Hand Prosthesis by Mental Commands and Blinking

2020 , Varela Aldas, José , Castillo Salazar, David Ricardo , Borja Galeas, Carlos , Guevara Maldonado, César Byron , Arias Flores, Hugo Patricio , Fierro-Saltos, W. , Rivera, R. , Hidalgo-Guijarro, J. , Yandún-Velasteguí, M.

Patients who lack upper and lower extremities have difficulties in carrying out their daily activities. The new technological advances have allowed the development of robotic applications to support people with disabilities, also, portable electroencephalographic (EEG) sensors are increasingly accessible and allow the development of new proposals which involve the mental control of electronic systems. This work presents the control by mental orders of an arm-hand prosthesis using low-cost devices, the objective is to command the arm using the user’s attention and blinking, where the components are a brain signal sensor, a prosthesis, an Arduino board, six servomotors, and a computer. The developed program in Matlab allows controlling the arm by means of an attention level y blinking. The results show the functioning of the system through experimental tests and a usability test is applied, finally, the conclusions establish adequate coordination in the movements of the prosthesis and the patient indicate satisfaction with the proposal. © Springer Nature Switzerland AG 2020.

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Modeling and Control of Omnidirectional Robots with Displaced Center of Mass

2022 , Gallo L.V. , Paste B.D. , Varela Aldas, José , Andaluz, Víctor H.

This work focuses on the design and implementation of a control algorithm for tracking trajectories of an omnidirectional robotic platform. The design is based on a dynamic model that considers the center of mass displaced; this model is obtained by formulating Euler–Lagrange considering the kinetic energy that acts on the robotic system. This type of model is used for when robots carry loads and these are not located in the center of the robot directly affecting the dynamics of the robotic platform; validation of the obtained model is carried out experimentally with an identification algorithm using the robotic platform built. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

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