Varela Aldas, José
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Varela Aldas, José
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Ambato
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josevarela@uti.edu.ec
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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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Voltammetric Electronic Tongues Applied to Classify Sucrose Samples Through Multivariate Analysis

2021 , Fuentes, E.M. , Varela Aldas, José , Verdú S. , Meló R.G. , Alcañiz M.

The aim of the present study was to classify samples of sugar with different concentrations through a Voltammetric Electronic tongues (VET), with a generic pulse sequence consisted of 22 pulses ranging from –1000 mV to + 1000 mV with a duration of 20 ms/pulse over different samples such as 1.25mM, 2.5mM, 5mM and 10mM, of sucrose concentration, these were measured 4 times each concentration and the test was developed 4 times, giving a total number of 506.880 data supervised learning algorithm using support vector machine was employed, choosing a linear function as a classifying element. In the training, 75% of the data was used to determine the coefficients of the classification function, and the remaining (25%) was used to evaluate the performance of the proposal. The results showed a concordance of more than 80% in the separation of sample, allowing to conclude as acceptable the performance of the classifier and the data acquired through the voltammetric tongue. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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Prototype of a Low Cost Turbine for the Generation of Clean Energy in the Ecuadorian Amazon

2020 , Guáitara B. , Buele, Jorge , Salazar F.W. , Varela Aldas, José

Access to electricity supply in remote areas is limited, despite having wealth of other natural resources such as water. This document presents the design and construction of a scale electric generation system, taking advantage of the hydraulic energy produced by a constant flow of water flow. For this, the turbine design is described, which is based on the principles of Francis and Kaplan. In addition, the structural design made in CAD/CAM software and the actual implementation of the system are shown. To determine the generated electric potential, the electromagnetic analysis is performed based on the Maxwell-Faraday equation and the respective calculations. The validation of this proposal is determined by conducting experimental tests with balanced, unbalanced, series and parallel coils and with their implementation in a home. © 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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IoT-Based User Interface for Remote Control of a Mobile Robot

2023 , Varela Aldas, José , Palacios-Navarro G.

Recent advancements in mobile robot research have resulted in the development of precise robot control tools, while information technology research has focused on the Internet of Things (IoT) in the context of the fourth industrial revolution. This study evaluates a user interface designed for remote control of the Crowbot BOLT robot. This robot utilizes the ESP32 board and is controlled through the M5Stack Core2 kit with a touch screen. The user interface offers two modes of operation: touch-based buttons for movement control and gyroscope control based on the M5Stack’s angular position. Communication between the robot and the user interface is established using the MQTT protocol through the ThingSpeak server, allowing control from any location with a line of sight and internet connectivity. Operation data is collected by recording control orders and measuring sending times, while user acceptance is evaluated using an IoT-based technology acceptance model. The results indicate the need for remote control response time improvement and reveal low scores in perceived usefulness and influence social. In conclusion, the study demonstrates the feasibility of remote control of a mobile robot using the MQTT protocol, providing valuable insights for similar applications and considering user recommendations for future enhancements and system expansion. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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Effects of immersive virtual reality on the heart rate of athlete’s warm-up

2019 , Varela Aldas, José , Palacios-Navarro G. , García-Magariño I. , Fuentes E.M.

An adequate warm-up prior to intensive exercise can bring benefits to athletes, these requirements may vary depending on the physical activity and the training needs. The immersive virtual reality could have benefits in the warm-up and it can be determined by physiological data of the athlete. This work presents a mobile virtual reality application to stimulate the warm-up of an athlete using a standard treadmill, where the developed application is composed of a pleasant and stimulating environment. A Smartphone and the Gear VR are used as an HMD device, and wireless headphones are placed in the users, in addition, the heart rate of the athletes is monitored using a Polar H7 sensor. Experimental results are obtained in athletes with similar characteristics and conditions, identified a direct relation of the virtual environment with the pulsations per minute (ppm), denoting pulsations greater than usual in case of the stimulating environment and lower pulsations for the pleasant environment. Finally, a usability test is performed that shows the level of sociability of the system. © Springer Nature Switzerland AG 2019.

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Temperature control system with hysteresis for drying oven using IoT

2023 , Bucay-Valdiviezo J. , Veronica-Ocana Parra S. , Saa F. , Varela Aldas, José

The fourth industrial revolution (Industry 4.0) spread to the whole world, improving all kinds of industrial processes. Thus, temperature control and monitoring of ovens through the Internet of Things (IoT) is part of this technology, especially in the automotive industry. In this work, the temperature control with hysteresis of a drying oven is carried out incorporating the IoT, with the objective of maintaining the temperature within a certain range in the drying process inside an oven. For this, a thermocouple, heat lamps, couplers and an electronic board are used. The temperature data from the drying oven is sent to the internet via WiFi using a router. The oven temperature data is recorded in the cloud for its respective subsequent analysis using the ThingSpeak services. For the results, the temperature is configured in the range of 50 ° C to 70 ° C that is monitored through a mobile application developed in App Inventor. The tests carried out demonstrate the proper functioning of the system and the high usability of the application. © 2023 IEEE.

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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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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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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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