Visions de Catalunya : Mallorca : Artá y Capdepera : acabament

Abstract not availabl

Visions de Catalunya : Mallorca : Artá y Capdepera

Abstract not availabl

Temporal distribution of sleep onset REM periods and N3 sleep in the MSLT and night polysomnogram of narcolepsy type 1 and other hypersomnias

The presence of $>\geq$2 sleep onset REM periods (SOREMP) in the Multiple Sleep Latency Test (MSLT) and the previous night polysomnogram (PSG) is part of the diagnostic criteria of narcolepsy, with every SOREMP having the same diagnostic value, despite evidence suggesting that time of SOREMP appearance and their preceding sleep stage might be relevant. We studied the temporal distribution of SOREMPs and associated sleep stages in the MSLT of patients with narcolepsy type 1 (NT1) and other hypersomnias (OH).We reviewed consecutive five-nap MSLTs and their preceding PSG from 83 untreated adult patients with hypersomnolence and ?1 SOREMPs. Wake/N1(W/N1)-SOREMPs, N2-SOREMPs, and N3 sleep presence and time of appearance were analyzed.Thirty-nine patients had NT1 and 44 OH. There were 183 (78%) SOREMPs in patients with NT1 and 83 (31%) in OH. Sixty-seven percent of SOREMPs in NT1 were from W/N1, and 20% -none from wake-in OH (p < 0.001). Most patients (94%) with ?2 W/N1-SOREMPs had NT1 (specificity 95%, sensitivity 82%). In patients with NT1 but not in OH, W/N1-SOREMPs decreased throughout the day (from 79% in the 1st nap to 33% in the preceding night, p < 0.001), whereas N2-SOREMPs did not change. N3 sleep frequency in the 5th nap was higher in NT1 than in OH (28% vs. 7%, p:0.009). Nocturnal-SOREMP plus ?4 daytime SOREMPs, Wake-REM transitions, and REM followed by N3 were only seen in NT1.Measuring the sleep stage sequence and temporal distribution of SOREMP helps to identify patients with narcolepsy in the MSLT.Copyright © 2022 Elsevier B.V. All rights reserved

Squash-Box Feasibility Driven Differential Dynamic Programming

Trabajo presentado en la IEEE/RSJ International Conference on Intelligent Robots and System, celebrada en Las Vegas (Estados Unidos), del 25 al 29 de octubre de 2020Recently, Differential Dynamic Programming (DDP) and other similar algorithms have become the solvers of choice when performing non-linear Model Predictive Control (nMPC) with modern robotic devices. The reason is that they have a lower computational cost per iteration when compared with off-the-shelf Non-Linear Programming (NLP) solvers, which enables its online operation. However, they cannot handle constraints, and are known to have poor convergence capabilities. In this paper, we propose a method to solve the optimal control problem with control bounds through a squashing function (i.e., a sigmoid, which is bounded by construction). It has been shown that a naive use of squashing functions damage the convergence rate. To tackle this, we first propose to add a quadratic barrier that avoids the difficulty of the plateau produced by the sigmoid. Second, we add an outer loop that adapts both the sigmoid and the barrier; it makes the optimal control problem with the squashing function converge to the original control-bounded problem. To validate our method, we present simulation results for different types of platforms including a multi-rotor, a biped, a quadruped and a humanoid robot

Borinot: an agile torque-controlled robot for hybrid flying and contact loco-manipulation (workshop version)

This paper introduces Borinot, an open-source flying robotic platform designed to perform hybrid agile locomotion and manipulation. This platform features a compact and powerful hexarotor that can be outfitted with torque-actuated extremities of diverse architecture, allowing for whole-body dynamic control. As a result, Borinot can perform agile tasks such as aggressive or acrobatic maneuvers with the participation of the whole-body dynamics. The extremities attached to Borinot can be utilized in various ways; during contact, they can be used as legs to create contact-based locomotion, or as arms to manipulate objects. In free flight, they can be used as tails to contribute to dynamics, mimicking the movements of many animals. This allows for any hybridization of these dynamic modes, like the jump-flight of chicken and locusts, making Borinot an ideal open-source platform for research on hybrid aerial-contact agile motion. To demonstrate the key capabilities of Borinot, we have fitted a planar 2DoF arm and implemented whole-body torque-level model-predictive-control. The result is a capable and adaptable platform that, we believe, opens up new avenues of research in the field of agile robotics.Comment: 2 pages + references. Workshop on agile robotics, ICRA 202

Full-Body Torque-Level Non-linear Model Predictive Control for Aerial Manipulation

Non-linear model predictive control (nMPC) is a powerful approach to control complex robots (such as humanoids, quadrupeds, or unmanned aerial manipulators (UAMs)) as it brings important advantages over other existing techniques. The full-body dynamics, along with the prediction capability of the optimal control problem (OCP) solved at the core of the controller, allows to actuate the robot in line with its dynamics. This fact enhances the robot capabilities and allows, e.g., to perform intricate maneuvers at high dynamics while optimizing the amount of energy used. Despite the many similarities between humanoids or quadrupeds and UAMs, full-body torque-level nMPC has rarely been applied to UAMs. This paper provides a thorough description of how to use such techniques in the field of aerial manipulation. We give a detailed explanation of the different parts involved in the OCP, from the UAM dynamical model to the residuals in the cost function. We develop and compare three different nMPC controllers: Weighted MPC, Rail MPC, and Carrot MPC, which differ on the structure of their OCPs and on how these are updated at every time step. To validate the proposed framework, we present a wide variety of simulated case studies. First, we evaluate the trajectory generation problem, i.e., optimal control problems solved offline, involving different kinds of motions (e.g., aggressive maneuvers or contact locomotion) for different types of UAMs. Then, we assess the performance of the three nMPC controllers, i.e., closed-loop controllers solved online, through a variety of realistic simulations. For the benefit of the community, we have made available the source code related to this work.Comment: Submitted to Transactions on Robotics. 17 pages, 16 figure

A flexible hardware-in-the-loop architecture for UAVs

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.As robotic technology matures, fully autonomous robots become a realistic possibility, but demand very complex solutions to be rapidly engineered. In order to be able to quickly set up a working autonomous system, and to reduce the gap between simulated and real experiments, we propose a modular, upgradeable and flexible hardware-in-the-loop (HIL) architecture, which hybridizes the simulated and real settings. We take as use case the autonomous exploration of dense forests with UAVs, with the aim of creating useful maps for forest inspection, cataloging, or to compute other metrics such as total wood volume. As the first step in the development of the full system, in this paper we implement a fraction of this architecture, comprising assisted localization, and automatic methods for mapping, planning and motion execution. Specifically we are able to simulate the use of a 3D LIDAR endowed below an actual UAV autonomously navigating among simulated obstacles, thus the platform safety is not compromised. The full system is modular and takes profit of pieces either publicly available or easily programmed. We highlight the flexibility of the proposed HIL architecture to rapidly configure different experimental setups with a UAV in challenging terrain. Moreover, it can be extended to other robotic fields without further design. The HIL system uses the multi-platform ROS capabilities and only needs a motion capture system as external extra hardware, which is becoming standard equipment in all research labs dealing with mobile robots.Peer ReviewedPostprint (author's final draft

Guías y miniplacas personalizadas: un protocolo guiado para cirugía ortognática

ResumenIntroducciónLos avances tecnológicos en planificación e impresión 3D permiten sinterizar productos sanitarios personalizados mediante un flujo de trabajo completamente digital. El objetivo de este trabajo es presentar y evaluar un nuevo sistema posicionador para cirugía ortognática (SPO), basado en el uso de una guía hueso-soportada y una miniplaca personalizada, que permite posicionar el fragmento maxilar sin la necesidad de una férula oclusal intermaxilar.Material y métodosSe trata de un estudio prospectivo observacional sobre 10 casos de cirugía bimaxilar en los que se ha seguido un protocolo de planificación inversa. Tanto la guía como la miniplaca personalizada fueron diseñadas con tecnología computer aided-desing/manufacturing (CAD-CAM) y fabricadas por sinterizado láser de polvo de titanio puro comercial. Para analizar la precisión obtenida, se realizó un estudio comparativo superponiendo la planificación con una tomografía computarizada realizada un mes posterior a la cirugía.ResultadosEl SPO se pudo aplicar con éxito en todos los casos sin observarse fenómenos de intolerancia al material. Permitió simplificar notablemente el procedimiento y reducir los tiempos quirúrgicos, al evitar la fijación intermaxilar, el moldeado de la miniplaca y la necesidad de realizar mediciones intraoperatorias. En el estudio postoperatorio se obtuvo una precisión media del 68,1% ±1mm.ConclusionesLos sistemas de posicionamiento para cirugía ortognática que incluyan sistemas personalizados de osteosíntesis pueden ser una opción de futuro que permita incrementar la precisión y la seguridad del procedimiento, así como reducir los tiempos quirúrgicos.AbstractIntroductionTechnological advances in preoperative planning and 3D printing allow custom-made biomedical devices to be synthesised using a completely digital workflow. The aim of this paper is to present and critically evaluate a new Orthognathic Positioning System (OPS) for Orthognathic Surgery. The OPS used bone-supported guides and a custom mini-plate to allow maxillary fragment positioning and fixation without the need for an inter-maxillary occlusal splint.Materials and methodsA prospective observational study was conducted on 10 cases of bimaxillary surgery using an inverse planning protocol. The guide and the custom-made mini-plate were designed using CAD-CAM software and synthesised by laser from commercially pure titanium powder. Accuracy was evaluated by overlap comparison of the virtual planning and 1-month postoperative CT scan. Operation times, complications, and overall safety profile were analysed.ResultsThe OPS was successfully applied to all cases, and was well tolerated. Operation times were reduced by avoiding inter-maxillary fixation, mini-plate bending, and obviating the need for intra-operative measurements. A mean postoperative accuracy of 1mm was obtained in 68.1% of cases.ConclusionsThe positioning systems for orthognathic surgery that involve custom made systems of osteosynthesis, can be a future option that could increase accuracy and the safety of the procedure, as well as the surgical times. We believe this novel technology is a step forward in optimising and improving the delivery of orthognathic surgery care

Uncalibrated visual servo for unmanned aerial manipulation

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper addresses the problem of autonomous servoing an unmanned redundant aerial manipulator using computer vision. The overactuation of the system is exploited by means of a hierarchical control law, which allows to prioritize several tasks during flight. We propose a safety-related primary task to avoid possible collisions. As a secondary task, we present an uncalibrated image-based visual servo strategy to drive the arm end-effector to a desired position and orientation by using a camera attached to it. In contrast to the previous visual servo approaches, a known value of camera focal length is not strictly required. To further improve flight behavior, we hierarchically add one task to reduce dynamic effects by vertically aligning the arm center of gravity to the multirotor gravitational vector, and another one that keeps the arm close to a desired configuration of high manipulability and avoiding arm joint limits. The performance of the hierarchical control law, with and without activation of each of the tasks, is shown in simulations and in real experiments confirming the viability of such prioritized control scheme for aerial manipulation.Peer ReviewedPostprint (author's final draft