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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Optimal cooperative control of mobile robots based on Pontryagin's Minimum Principle

2022 , Varela Aldas, José

This work presents the cooperative control with optimization for positioning of mobile robots based on Pontryagin's Minimum Principle. The problem to be solved is the minimum energy related to the control actions of the robots. The objective function is subject to the equations of states of the triangular formation of the 3 mobile robots and is restricted to boundary conditions that include the desired form parameters. The mathematical model of the system is based on the kinematic transformation of the position of the robots towards the parameters of the formation. To solve the differential equations obtained, the shooting method is programmed for two initial value problems. The results show the evolution of the robots' positions and the positioning errors that tend to zero, validating this proposal through simulation. In addition, the control actions allow determining the energy index to compare it with a previous work, achieving a lower value. © 2022 IEEE.

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Prototype System of Geolocation Educational Public Transport Through Google Maps API

2020 , Salazar F.W. , Naranjo-Ávalos H. , Buele, Jorge , Pintag M.J. , Buenaño É.R. , Reinoso C. , Urrutia-Urrutia P. , Varela Aldas, José

Urban traffic complications in most underdeveloped countries and congestion in all metropolitan areas has become a daily problem with a difficult solution. Disorganized mobility of drivers and pedestrians along with the increase in travel time, non-compliance with schedules, air pollution and intolerable sound levels, have harmful effects on human health. Therefore, this research describes a geolocation system of urban transport through a mobile application developed on the Xamarin platform. Drivers send the latitude and longitude points when starting a route, this data will be sent to the SQL SERVER online database server, using the SmarterASP.NET platform. By developing the geolocation system in ASP.NET, the coordinates are available to users in an interval of 5 s. The developed interface shows a location map, where the route in real time is presented. It also shows the administration of users, drivers, buses, assignment of routes, assignment of buses and registration of static routes. Being a prototype system, the university transport system has been taken as an object of study to corroborate its correct operation with the respective experimental tests. Satisfaction surveys have also been carried out on a group of 300 people, among students and university teachers and their validation is carried out through the Technological Acceptance Model (TAM). To interpret the results, Kendall Tau-b correlation analysis was used, obtaining positive correlation values with a high significance value. © 2020, Springer Nature Switzerland AG.

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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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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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Virtual Environment for the Mashing and Boiling Process in Craft Beer Production

2023 , Pogo S.I. , Granizo J. , Andaluz V.H. , Varela Aldas, José

Process automation allows to increase production and improve the quality of craft products. This paper presents the implementation of closed-loop control algorithms for a mashing and brewing plant of craft beer. The proposed control scheme is implemented through the HIL technique, for which a virtual environment that simulates the behavior of the industrial process and a control card where the control algorithms are implemented are considered. To represent the behavior of the plant level and temperature processes, the mathematical model of each process is obtained, this model is used for the design of the control algo-rhythms, and the plant is modeled in 3D and incorporated into the graphics engine also has effects of realism together with been 3D in order to increase the level of realism to the process. For user interaction with the environment, an HMI type mantle center is incorporated to visualize and control the process manually, semi-automatically, and automatically, in order to test the control algorithms safely and avoid the risk of instrumentation damage or loss of real materials. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

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Immersive virtual reality app for mild cognitive impairment

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

A characteristic symptom of neurodegenerative diseases is the deterioration of the memory. These problems usually worsen with the progression of the disease, being the cognitive rehabilitation an important tool in order to slow down the progress of the disease in the patient. This work presents the development of a mobile virtual reality application through a serious game to boost the memory by solving mazes in three levels of difficulty. The application uses the Gear VR glasses to provide the user with an immersive experience. The results present the proposed application, showing the components of the virtual environment. © 2019, Associacao Iberica de Sistemas e Tecnologias de Informacao. All rights reserved.

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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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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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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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