Mario Ortiz

Prof. Mario Ortiz

Brain-Machine Interface Systems Lab, Institute of Research on Engineering of Elche, Miguel Hernández University of Elche, 03202 Elche, Spain
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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2007 in IET Generation, Transmission & Distribution
Verified
Journal Article
Closed access
SVS. Valero
S. Valero
Mario OrtizMario Ortiz
Mario Ortiz
CSC. Senabre
C. Senabre
CAC. Alvarez
C. Alvarez
FFF.J.G. Franco
F.J.G. Franco
AGAntonio Gabaldon
Antonio Gabaldon
Different methodologies are available for clustering and classification purposes. The objective of the research is to prove the capability of self-organising maps (SOMs) to classify customers and their response potential from distributor, commercialiser, or customer electrical demand databases, with the help of load response modelling methodologies as support tools. The search for customer suitability is restricted to day-ahead and real-time products, in which interest is growing in developed countries. Therefore customer demand and response (demand and distributed generation policies) have been tested and compared with price curves. Both steps have been performed through SOMs. The results clearly show the capability of this approach to improve data management and easily to find coherent policies to accomplish cleared-demand offers in different prices scenarios.

10 July 2019 in IEEE Transactions on Education
Verified
Journal Article
Closed access
PMPedro Martínez
Pedro Martínez
FAFrancisco Javier Aguilar
Francisco Javier Aguilar
Mario OrtizMario Ortiz
Mario Ortiz
Contribution: A demonstration of a move from face-to-face to blended learning in an engineering Master's program by adding a parallel online group, which showed the synergy between blended and online approaches in terms of level of interaction, enrollment, student satisfaction, dropout rate, and final grades. Background: Education's transition from traditional face-to-face learning to blended and full online learning can be confronted in different ways. Extensive research has demonstrated that the incorporation of online resources has a positive effect on learning outcomes and can help to assure the continuity of a Master's program. Intended Outcomes: To increase enrollment and student satisfaction, and reduce the dropout rate. Application Design: New equipment and online resources and additional support material allowed students to choose their preferred manner of studying: asynchronous (lecture capture) or synchronous (face-to-face or live broadcast lecture). Findings: The changes increased enrollment and student satisfaction, and lowered the dropout rate. The new methodology significantly improved students' average grades, with no significant differences being found between the blended and online groups. This case study could guide other institutions in the successful implementation of blended and online learning in an engineering Master's degree program.

3 September 2020 in Frontiers in Bioengineering and Biotechnology
Verified
Journal Article
Open access
PDF file
Mario OrtizMario Ortiz
Mario Ortiz
LFLaura Ferrero
Laura Ferrero
EIEduardo Iáñez
Eduardo Iáñez
Jose M. AzorinJose M. Azorin
Jose M. Azorin
JCJosé L. Contreras-Vidal
José L. Contreras-Vidal
Brain-machine interfaces (BMIs) can improve the control of assistance mobility devices making its use more intuitive and natural. In the case of an exoskeleton, they can also help rehabilitation therapies due to the reinforcement of neuro-plasticity through repetitive motor actions and cognitive engagement of the subject. Therefore, the cognitive implication of the user is a key aspect in BMI applications, and it is important to assure that the mental task correlates with the actual motor action. However, the process of walking is usually an autonomous mental task that requires a minimal conscious effort. Consequently, a brain-machine interface focused on the attention to gait could facilitate sensory integration in individuals with neurological impairment through the analysis of voluntary gait will and its repetitive use. This way the combined use of BMI+exoskeleton turns from assistance to restoration. This paper presents a new brain-machine interface based on the decoding of gamma band activity and attention level during motor imagery mental tasks. This work also shows a case study tested in able-bodied subjects prior to a future clinical study, demonstrating that a BMI based on gamma band and attention-level paradigm allows real-time closed-loop control of a Rex exoskeleton.

11 July 2017 in Frontiers in Neuroinformatics
Verified
Journal Article
Open access
MRMarisol Rodríguez-Ugarte
Marisol Rodríguez-Ugarte
Eduardo IáñezEduardo Iáñez
Eduardo Iáñez
Mario OrtizMario Ortiz
Mario Ortiz
Jose M. AzorinJose M. Azorin
Jose M. Azorin
The aim of this work was to design a personalized BCI model to detect pedaling intention through EEG signals. The approach sought to select the best among many possible BCI models for each subject. The choice was between different processing windows, feature extraction algorithms and electrode configurations. Moreover, data was analyzed offline and pseudo-online (in a way suitable for real-time applications), with a preference for the latter case. A process for selecting the best BCI model was described in detail. Results for the pseudo-online processing with the best BCI model of each subject were on average 76.7% of true positive rate, 4.94 false positives per minute and 55.1% of accuracy. The personalized BCI model approach was also found to be significantly advantageous when compared to the typical approach of using a fixed feature extraction algorithm and electrode configuration. The resulting approach could be used to more robustly interface with lower limb exoskeletons in the context of the rehabilitation of stroke patients.

26 March 2021 in IEEE Access
Verified
Journal Article
Open access
LMLaura Ferrero Montes
Laura Ferrero Montes
Mario OrtizMario Ortiz
Mario Ortiz
VQVicente Quiles
Vicente Quiles
Eduardo IáñezEduardo Iáñez
Eduardo Iáñez
Jose M. AzorinJose M. Azorin
Jose M. Azorin
Motor imagery (MI) is one of the most common paradigms used in brain-computer interfaces (BCIs). This mental process is defined as the imagination of movement without any motion. In some lower-limb exoskeletons controlled by BCIs, users have to perform MI continuously in order to move the exoskeleton. This makes it difficult to design a closed-loop control BCI, as it cannot be assured that the analyzed activity is not related to motion instead of imagery. A possible solution would be the employment of virtual reality (VR). During VR training phase, subjects could focus on MI avoiding any distraction. This could help the subject to create a robust model of the BCI classifier that would be used later to control the exoskeleton. This paper analyzes if gait MI can be improved when VR feedback is provided to subjects instead of visual feedback by a screen. Additionally, both types of visual feedback are analyzed while subjects are seated or standing up. From the analysis, visual feedback by VR was related to higher performances in the majority of cases, not being relevant the differences between standing and being seated. The paper also presents a case of study for the closed-loop control of the BCI in a virtual reality environment. Subjects had to perform gait MI or to be in a relaxation state and based on the output of the BCI, the immersive first person view remained static or started to move. Experiments showed an accuracy of issued commands of 91.0± 6.7, being a very satisfactory result.

30 April 2021 in Applied Sciences
Verified
Journal Article
Open access
PDF file
LMLaura Ferrero Montes
Laura Ferrero Montes
VQVicente Quiles
Vicente Quiles
Mario OrtizMario Ortiz
Mario Ortiz
Eduardo IáñezEduardo Iáñez
Eduardo Iáñez
Jose M. AzorinJose M. Azorin
Jose M. Azorin
Lower-limb robotic exoskeletons are wearable devices that can be beneficial for people with lower-extremity motor impairment because they can be valuable in rehabilitation or assistance. These devices can be controlled mentally by means of brain–machine interfaces (BMI). The aim of the present study was the design of a BMI based on motor imagery (MI) to control the gait of a lower-limb exoskeleton. The evaluation is carried out with able-bodied subjects as a preliminary study since potential users are people with motor limitations. The proposed control works as a state machine, i.e., the decoding algorithm is different to start (standing still) and to stop (walking). The BMI combines two different paradigms for reducing the false triggering rate (when the BMI identifies irrelevant brain tasks as MI), one based on motor imagery and another one based on the attention to the gait of the user. Research was divided into two parts. First, during the training phase, results showed an average accuracy of 68.44 ± 8.46% for the MI paradigm and 65.45 ± 5.53% for the attention paradigm. Then, during the test phase, the exoskeleton was controlled by the BMI and the average performance was 64.50 ± 10.66%, with very few false positives. Participants completed various sessions and there was a significant improvement over time. These results indicate that, after several sessions, the developed system may be employed for controlling a lower-limb exoskeleton, which could benefit people with motor impairment as an assistance device and/or as a therapeutic approach with very limited false activations.