Brain-controlled neuromuscular stimulation to drive neural plasticity and functional recovery

There is mounting evidence that appropriately timed neuromuscular stimulation can induce neural plasticity and generate functional recovery from motor disorders. This review addresses the idea that coordinating stimulation with a patient's voluntary effort might further enhance neurorehabilitation. Studies in cell cultures and behaving animals have delineated the rules underlying neural plasticity when single neurons are used as triggers. However, the rules governing more complex stimuli and larger networks are less well understood. We argue that functional recovery might be optimized if stimulation were modulated by a brain machine interface, to match the details of the patient's voluntary intent. The potential of this novel approach highlights the need for a better understanding of the complex rules underlying this form of plasticity.Grant #NS053603 from the National Institute of Neurological Disorder and Stroke. Grant #FP7-PEOPLE-2013-IOF-627384 from the European Commission.Peer reviewe

A neuroprothesis for tremor management

Tremor is the most common movement disorder, affecting ∼ 15 % of people over 50 years old according to some estimates. It appears due to a number of syndromes, being essential tremor and Parkinson's disease the most prevalent among them. None of these conditions is fully understood. Tremor is currently treated through drugs or neurosurgery, but unfortunately, it is not managed effectively in ∼25 % of the patients. Therefore, it constitutes a major cause of loss of independence and quality of life. Various alternative approaches for tremor management are reported in the literature. Among them, those devices that rely on the application of forces to the tremulous segments show a considerable potential. A number of prototypes that exploit this principle are available, spanning fixed devices and orthoses. However, none of them has fulfilled user's expectation for continuous use during daily living. This thesis presents the development and validation of a neuroprosthesis for tremor management. A neuroprosthesis is a system that restores or compensates for a neurological function that is lost. In this case, the neuroprosthesis aims at compensating the functional disability caused by the tremor. To this end, it applies forces to the tremulous limb through the control of muscle contraction, which is modulated according to the characteristics of the tremor. The concept design envisions the device as a textile that is worn on the affected limb, thus meeting the usability requirements defined by the patients. The development of the neuroprosthesis comprised the following tasks: 1. The development of a concept design of the neuroprosthesis, which incorporates state of the art knowledge on tremor, and user's needs. 2. The design and validation of a cognitive interface that parameterizes the tremor in functional contexts. This interface provides the information that the neuroprosthesis uses for tremor suppression. Two versions are developed: a multimodal interface that integrates the recordings of the whole neuromusculoskeletal system, and an interface incorporating only wearable movement sensors. The latter is intended for the functional validation of the neuroprosthesis, while the former is a proof of concept of an optimal interface for this type of applications. 3. The development of a novel approach for tremor suppression through transcutaneous neurostimulation. The approach relies on the modulation of muscle cocontraction as a means of attenuating the tremor without the need of conventional actuators. The experimental validation here provided demonstrates the feasibility and interest of the approach. In parallel with the validation of the neuroprosthesis, I performed a detailed study on the physiology of motoneurons in tremor, given the lack of a complete description of its behavior. The outcome of this study contributes to the interpretation of the results obtained with the neuroprosthesis, and opens new research lines, both related to alternative interventions and basic neuroscience. In summary, the results here presented demonstrate that tremor may be accurately parameterized while the patient performs functional activities, and that this information may be exploited to drive a neuroprosthesis for tremor management. Furthermore, the novel approach for tremor suppression presented in this dissertation constitutes a potential approach for treating upper limb tremor, either alone, or as a complement to pharmacotherapy. These results encourage the validation of the neuroprosthesis in a large cohort of patients, in order to enable its translation to the market. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------El temblor es el trastorno del movimiento más común, afectando, según algunas estimaciones, al ∼15 % de la población de más de 50 años. Existen diversos "síndromes" que causan temblor, siendo el temblor esencial y la enfermedad de Parkinson los que presentan mayor prevalencia. Además, cabe resaltar que no existe una descripción completa de ninguno de ellos. En la actualidad el temblor se trata mediante una serie de fármacos o neurocirugía. A pesar de ello, el ∼ 25 % de los pacientes sufren problemas funcionales debido a su condición. Por tanto, es evidente que el temblor constituye una de las principales causas de dependencia y pérdida de calidad de vida. Realizando una revisión de las publicaciones científicas sobre el temblor, se observa que se ha propuesto un considerable número de tratamientos alternativos. Entre ellos destacan los dispositivos que se fundamentan en la aplicación de fuerzas sobre los segmentos afectados por el temblor, de los que ya se ha evaluado una serie de prototipos. Estos abarcan desde dispositivos fijados a otras estructuras hasta ortesis. Sin embargo, ninguno de ellos satisface las expectativas de los usuarios para su uso durante el día a día. Esta tesis presenta el diseño y validación de una neruoprótesis para el tratamiento del temblor. Una neuroprótesis es un sistema que reemplaza o compensa una función neurológica perdida. En este caso, la neuroprótesis tiene como objetivo compensar la discapacidad motora causada por el temblor. Para ello aplica fuerzas al miembro afectado a través del control del nivel de contracción muscular, que se modula según las características del temblor. El diseño conceptual contempla al dispositivo como un textil que se viste en el brazo afectado, satisfaciendo los requisitos de usabilidad definidos por los pacientes. El desarrollo de la neuroprótesis abarcó las siguientes tareas: 1. El desarrollo del diseño conceptual de la neuroprótesis, que incorpora el conocimiento actual sobre el temblor, y las necesidades de los usuarios. 2. El diseño y validación de una interfaz cognitiva que parametriza el temblor durante tareas funcionales. La información obtenida con esta interfaz es usada por la neuroprótesis para modular la corriente aplicada mediante técnicas de neuroestimulación. Se desarrollan dos versiones de la interfaz cognitiva: una interfaz multimodal que integra información de todo el sistema neuromusculoesquelético, y una interfaz que implementa únicamente sensores vestibles de movimiento. La segunda interfaz fue la que se usó durante la validación funcional de la neuroprótesis, mientras que la primera es una prueba de concepto de una interfaz óptima para este tipo de aplicaciones. 3. El desarrollo de una nueva aproximación para la supresión del temblor mediante neuroestimulación transcutánea. Dicha aproximación se fundamenta en la modulación del grado de co-contracción de los músculos afectados como forma de atenuar el temblor, sin necesidad de usar actuadores convencionales. La evaluación experimental sirvió para demostrar la viabilidad e interés de la intervención. En paralelo a la validación de la neuroprótesis, llevé a cabo un estudio detallado de la fisiología de las motoneuronas en el caso del temblor, dado que no existe una descripción del funcionamiento de las mismas en el caso de este trastorno. Este estudio sirve para ayudar a la interpretación de los resultados de la neuroprótesis, y para abrir una serie de líneas futuras de investigación, tanto sobre nuevas intervenciones para el temblor, como sobre neurociencia básica. En resumen, los resultados que se presentan en esta tesis demuestran que es posible parametrizar de una forma precisa el temblor durante la realización de tareas funcionales, y que esta información sirve para controlar una neuroprótesis para el tratamiento del temblor. Además, la nueva aproximación para la compensación del temblor que se presenta tiene el potencial de convertirse en un tratamiento alternativo para el temblor de miembro superior, ya sea de forma independiente o como complemento a los fármacos. Estos resultados alientan la validación de la neuroprótesis en una cohorte grande de pacientes, con el objetivo de facilitar su transferencia al mercado

Automatic real-time monitoring and assessment of tremor parameters in the upper limb from orientation data

Upper limb tremor is the most prevalent movement disorder and, unfortunately, it is not effectively managed in a large proportion of the patients. Neuroprostheses that stimulate the sensorimotor pathways are one of the most promising alternatives although they are still under development. To enrich the interpretation of data recorded during long-term tremor monitoring and to increase the intelligence of tremor suppression neuroprostheses we need to be aware of the context. Context awareness is a major challenge for neuroprostheses and would allow these devices to react more quickly and appropriately to the changing demands of the user and/or task. Traditionally kinematic features are used to extract context information, with most recently the use of joint angles as highly potential features. In this paper we present two algorithms that enable the robust extraction of joint angle and related features to enable long-term continuous monitoring of tremor with context awareness. First, we describe a novel relative sensor placement identification technique based on orientation data. We focus on relative rather than absolute sensor location, because in many medical applications magnetic and inertial measurement units (MIMU) are used in a chain stretching over adjacent segments, or are always placed on a fixed set of locations. Subsequently we demonstrate how tremor parameters can be extracted from orientation data using an adaptive estimation algorithm. Relative sensor location was detected with an accuracy of 94.12% for the 4 MIMU configuration, and 100% for the 3 MIMU configurations. Kinematic tracking error values with an average deviation of 8% demonstrate our ability to estimate tremor from orientation data. The methods presented in this study constitute an important step toward more user-friendly and context-aware neuroprostheses for tremor suppression and monitoring. © 2014 Lambrecht, Gallego, Rocon and Pons.This work has been funded by the European project NeuroTremor(ICT-2011.5.1-287739)andt he Spanish Consolider project HYPER (CSD2009-00067).Peer Reviewe

Integrating Quality Criteria in a Fuzzy Linguistic Recommender System for Digital Libraries

Recommender systems can be used in an academic environment to assist users in their decision making processes to find relevant information. In the literature we can find proposals based in user’ profile or in item’ profile, however they do not take into account the quality of items. In this work we propose the combination of item’ relevance for a user with its quality in order to generate more profitable and accurate recommendations. The system measures item quality and takes it into account as new factor in the recommendation process. We have developed the system adopting a fuzzy linguistic approach.Projects TIN2010-17876, TIC5299 y TIC-599

PSON: A serialization format for IoT sensor networks

In Many Internet Of Things (Iot) Environments, The Lifetime Of A Sensor Is Linked To Its Power Supply. Sensor Devices Capture External Information And Transmit It. They Also Receive Messages With Control Commands, Which Means That One Of The Largest Computational Overheads Of Sensor Devices Is Spent On Data Serialization And Deserialization Tasks, As Well As Data Transmission. The Simpler The Serialization/Deserialization And The Smaller The Size Of The Information To Be Transmitted, The Longer The Lifetime Of The Sensor Device And, Consequently, The Longer The Service Life. This Paper Presents A New Serialization Format (Pson) For These Environments, Which Simplifies The Serialization/Deserialization Tasks And Minimizes The Messages To Be Sent/Received. The Paper Presents Evaluation Results With The Most Popular Serialization Formats, Demonstrating The Improvement Obtained With The New Pson Format.This work was funded by public research projects of the Spanish Ministry of Economy and Competitivity (MINECO) (MINECO), references TEC2017-88048-C2-2-R, RTC-2016-595-2, RTC-2016-5191-8, and RTC-2016-5059-8, and the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M17) in the context of the V PRICIT (Regional Programme of Research and Technological Innovation) and the CDTI (Centro para el Desarrollo Tecnológico Industrial E.P.E.), CNU/1308/2018, 28 November

Trust Based Fuzzy Linguistic Recommender Systems as Reinforcement for Personalized Education in the Field of Oral Surgery and Implantology

The rapid advances in Web technologies are promoting the development of new pedagogic models based on virtual teaching. In this framework, personalized services are necessary. Recommender systems can be used in an academic environment to assist users in their teaching-learning processes. In this paper, we present a trust based recommender system, adopting a fuzzy linguistic modeling, that provides personalized activities to students in order to reinforce their education, and applied it in the field of oral surgery and implantology. We don’t take into account users with similar ratings history but users in which each user can trust and we provide a method to aggregate the trust information. This system can be used in order to aid professors to provide students with a personalized monitoring of their studies with less effort. The results obtained in the experiments proved to be satisfactory.TIN2016-75850-

Introducing CSP Dataset: A Dataset Optimized for the Study of the Cold Start Problem in Recommender Systems

Recommender systems are tools that help users in the decision-making process of choosing items that may be relevant for them among a vast amount of other items. One of the main problems of recommender systems is the cold start problem, which occurs when either new items or new users are added to the system and, therefore, there is no previous information about them. This article presents a multi-source dataset optimized for the study and the alleviation of the cold start problem. This dataset contains info about the users, the items (movies), and ratings with some contextual information. The article also presents an example user behavior-driven algorithm using the introduced dataset for creating recommendations under the cold start situation. In order to create these recommendations, a mixed method using collaborative filtering and user-item classification has been proposed. The results show recommendations with high accuracy and prove the dataset to be a very good asset for future research in the field of recommender systems in general and with the cold start problem in particular.Spanish Government PID2019-103880RB-I00Andalusian Agency project P20_0067

A risk-aware fuzzy linguistic knowledge-based recommender system for hedge funds

One of the most difficult tasks for hedge funds investors is selecting a proper fund with just the right level level of risk. Often times, the issue is not only quantifying the hedge fund risk, but also the level the investors consider just right. To support this decision, we propose a novel recommender system, which is aware of the risks associated to different hedge funds, considering multiple factors, such as current yields, historic performance, diversification by industry, etc. Our system captures the preferences of the investors (e.g. industries, desired level of risk) applying fuzzy linguistic modeling and provides personalized recommendations for matching hedge funds. To demonstrate how our approach works, we have first profiled more than 4000 top hedge funds based on their composition and performance and second, created different simulated investment profiles and tested our recommendations with them.This paper has been developed with the FEDER financing under Project TIN2016-75850-R

Web platform for learning distributed databases’ queries processing

A distributed database is a collection of data stored in different locations of a distributed system. The processing of queries in distributed databases is quite complex but of great importance for information management. Students who have to learn that process have serious difficulties for understanding them. On this work we present a web platform for helping the students learning the processing and optimization of queries in distributed databases. The novelty of this platform is that as far as we know, there is no similar graphical tool. It allows to visualize step by step the different phases of distributed query processing, showing how are they forming, making it easier for the students to understand these concepts. Moreover, having this web platform available, always and everywhere, indirectly have an impact on other competences like encouraging students’ autonomous work and self-learning, adapting the teaching to its one-time necessities and reinforcing the advantages to apply information techniques in the teaching field. The results of the developed tests to validate the platform's functionalities and student's satisfaction were very positive.This work has been developed thanks to the funding of the project PID46-201617 of the Universidad de Jaén

The Networked Forge: New Environments for Libre Software Development

Libre (free, open source) software forges (sites hosting the development infrastructure for a collection of projects) have been stable in architecture, services and concept since they become popular during the late 1990s. During this time several problems that cannot be solved without dramatic design changes have become evident. To overcome them, we propose a new concept, the “networked forge”, focused on addressing the core characteristics of libre software development and the needs of developers. The key of this proposal is to re-engineer forges as a net of distributed components which can be composed and configured according to the needs of users, using a combination of web 2.0, semantic web and mashup technologies. This approach is flexible enough to accommodate different development processes, while at the same time interoperates with current facilitie