41 research outputs found
Cardiovascular autonomic dysfunction in insomnia patients with objective short sleep duration.
Two phenotypes have been proposed: insomnia with objective near-normal sleep duration, related to increased psychological symptoms, and insomnia with objective short sleep duration, associated with cardiometabolic morbidity. Reduced heart rate variability has also been implicated in the pathophysiology of cardiometabolic disease; however, there are little data on whether cardiovascular function differs between patients with objective short sleep duration and near-normal sleep duration. Participants (Mage = 49.9 ± 11.3 years; 62.8% female) were 180 adults with chronic insomnia (Mduration = 15.7 ± 13.6). Objective sleep duration was based on total sleep time averaged across two consecutive nights of polysomnography and subjective sleep duration was based on 2-week sleep diaries. The sample was divided into two groups, with sleep duration shorter (polysomnography-total sleep time: n = 46; sleep diary: n = 95) or equal/longer (polysomnography-total sleep time: n = 134; sleep diary: n = 85) than 6 hr. Electrocardiogram data derived from polysomnography were used to obtain heart rate and heart rate variability during stage 2 (N2) and rapid eye movement sleep. Heart rate variability measures included absolute and normalized high-frequency component, an index of parasympathetic activation, and the ratio of low- to high-frequency (LF/HF ratio), an index of sympathovagal balance. After controlling for covariates (e.g., co-morbidity), patients with objective short sleep duration had reduced high-frequency (p < .05) and elevated low-frequency/high-frequency ratio (p = .036) and heart rate (p = .051) compared with patients with near-normal sleep duration. No differences were observed between phenotypes when subjective sleep duration was used. Insomnia patients with objective short sleep duration showed significantly dampened parasympathetic activation and increased sympathovagal imbalance relative to their counterparts with near-normal sleep duration. These findings highlight the importance of treating insomnia, as treatment may reduce the risk of cardiovascular disease
Apports conjoints de l’ergonome et de l’ergothérapeute pour la conception d’aides techniques
L’objectif de cet article est de dĂ©montrer l’intĂ©rĂŞt d’une conception centrĂ©e sur les restrictions physiques et cognitives des utilisateurs d’aides techniques. Également, la plus-value d’une recherche effectuĂ©e par un binĂ´me de recherche ergonome-ergothĂ©rapeute sera exposĂ©e. Ă€ partir de situations rĂ©ellement vĂ©cues dans le cadre de notre Ă©tude, les bĂ©nĂ©fices de cette dĂ©marche seront exposĂ©s ainsi que la nĂ©cessitĂ© d’adaptation que celle-ci impose par rapport Ă un mode de conception « classique ». En effet, donner de la voix aux personnes en situation de handicap Ă la fois sur les Ă©lĂ©ments constitutifs de l’interface et sur les directions que doit prendre le dĂ©veloppement nĂ©cessite de s’adapter Ă leur rythme, Ă leur environnement et Ă leur grand niveau de fatigabilitĂ©.The objective of this article is to demonstrate the potential of design focused on the physical and cognitive restrictions of those who use technical aids. The advantages of research conducted by an ergonomist and an occupational therapist will be described. Using real-life situations as a starting point, we outline the benefits of this approach, as well as the need for adaptation that it imposes compared to a "classic" design mode. Indeed, giving voice to people with disabilities on both the elements of the interface but also on the directions that must take development, requires that we adjust to their rhythms, their environments and their great level of fatigability.El objetivo del articule es de demonstrar los interĂ©s de un concepciĂłn centrada en la restricciones fĂsicas et cognitivas de los utilizadores de los ayudas tĂ©cnicas. Igualmente, el valor agregado de una bĂşsqueda efectuada por un binomio de investigaciĂłn “ergnono-ergoterapeuta” será presentado. A partir de situaciones realmente vividas en el cuadro de nuestro estudio, los beneficios de ese enfoque serán esposados tambiĂ©n asĂ como la necesidad de adaptaciĂłn que ella impone en comparaciĂłn a une modo de concepciĂłn más “clásico”. En efecto, dar de la voz a las personas en situaciĂłn de discapacidad Ă la vez sobre les elementos constitutivos de la interfaz pero tambiĂ©n sobre la direcciones que debe tomar el desarrollo, necesidad de adaptarse a su ritmo, al medio ambiente et al gran nivel de cansancio
Examination of psychological risk factors for chronic pain following cardiac surgery: protocol for a prospective observational study
© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. INTRODUCTION: Approximately 400 000 Americans and 36 000 Canadians undergo cardiac surgery annually, and up to 56% will develop chronic postsurgical pain (CPSP). The primary aim of this study is to explore the association of pain-related beliefs and gender-based pain expectations on the development of CPSP. Secondary goals are to: (A) explore risk factors for poor functional status and patient-level cost of illness from a societal perspective up to 12 months following cardiac surgery; and (B) determine the impact of CPSP on quality-adjusted life years (QALYs) borne by cardiac surgery, in addition to the incremental cost for one additional QALY gained, among those who develop CPSP compared with those who do not. METHODS AND ANALYSES: In this prospective cohort study, 1250 adults undergoing cardiac surgery, including coronary artery bypass grafting and open-heart procedures, will be recruited over a 3-year period. Putative risk factors for CPSP will be captured prior to surgery, at postoperative day 3 (in hospital) and day 30 (at home). Outcome data will be collected via telephone interview at 6-month and 12-month follow-up. We will employ generalised estimating equations to model the primary (CPSP) and secondary outcomes (function and cost) while adjusting for prespecified model covariates. QALYs will be estimated by converting data from the Short Form-12 (version 2) to a utility score. ETHICS AND DISSEMINATION: This protocol has been approved by the responsible bodies at each of the hospital sites, and study enrolment began May 2015. We will disseminate our results through CardiacPain.Net, a web-based knowledge dissemination platform, presentation at international conferences and publications in scientific journals. TRIAL REGISTRATION NUMBER: NCT01842568
Le dioxyde de titane : un matériau nouveau pour la photonique à 1.55 µm et à 2 µm
In the next decades, the limits of current optical communication systems will be reached unless new solutions are adopted. On of them is the use of a new spectral range around 2 µm enabled by the emergence of thulium-doped fiber amplifiers. In this thesis, we will focus on it in the context of very short distances transmissions on photonic chips. Various materials, mainly titanium dioxide (TiO2), will be explored.This thesis work has two main objectives. On the one hand, it aims to demonstrate that a material relatively unexplored, titanium dioxide, is promising for telecom applications by comparing it to more mature plateforms. On the other hand, it tends to introduce the spectral band around 2 µm as a solution to be considered for next-generation communications.More precisely, the first part of this thesis aims to develop a technique to efficiently couple light in TiO2 structures. For the first time, a configuration using a buried metallic grating was evaluated numerically and then characterized experimentally. The second part presents error-free high-speed (10 Gbit/s) telecom transmissions around 2 µm carried out in subwavelength or multimode waveguides in titanium dioxide, silicon or silicon-germanium. Finally, nonlinear functions are explored on the photonic chips. Thus, it has been demonstrated a wavelength conversion at 2 µm reaching -10dB on a silicon waveguide or the first supercontinuum generation spreading from visible to 2 µm wavelength in a TiO2 waveguide.Dans les prochaines décennies, les limites des systèmes de communications optiques actuels seront atteintes à moins d'adopter de nouvelles solutions. L'une d'elles est l'utilisation d'une nouvelle plage spectrale autour de 2 µm stimulée par l'apparition des amplificateurs fibrés dopés thulium. Dans ce manuscrit, nous nous y intéresserons dans le cadre de transmissions très courtes distances sur puces photoniques. Divers matériaux, dont le dioxyde de titane, seront ainsi explorés.Ce travail de thèse a deux principaux objectifs. D'une part, il vise à démontrer que le dioxyde de titane (TiO2), matériau encore peu exploré, est prometteur pour des applications télécoms en le comparant à des plateformes plus matures. D'autre part, il tend à introduire la bande spectrale autour de 2 µm comme une solution à envisager pour les télécommunications de nouvelle génération.Plus précisément, la première partie de cette thèse a pour but de développer une technique pour coupler efficacement la lumière dans les structures en TiO2). Pour la première fois, une configuration faisant appel à un réseau métallique enterré a été évaluée numériquement avant d'être caractérisée expérimentalement. La seconde partie présente des transmissions télécoms haut-débit (10 Gbit/s) autour de µm réalisées sans erreurs dans des guides d'ondes sub-longueur d'onde ou multimodes en dioxyde de titane, silicium ou silicium-germanium. Pour terminer, des fonctions non-linéaires sont explorées sur ces puces photoniques. Il a été ainsi démontré une conversion en longueurs d'onde à 2 µm atteignant -10dB sur silicium ou la génération du premier supercontinuum s'étalant du visible à 2 µm dans un guide d'onde en TiO2
Titanium dioxide a new material for 1.55 µm and 2 µm photonics
Dans les prochaines décennies, les limites des systèmes de communications optiques actuels seront atteintes à moins d'adopter de nouvelles solutions. L'une d'elles est l'utilisation d'une nouvelle plage spectrale autour de 2 µm stimulée par l'apparition des amplificateurs fibrés dopés thulium. Dans ce manuscrit, nous nous y intéresserons dans le cadre de transmissions très courtes distances sur puces photoniques. Divers matériaux, dont le dioxyde de titane, seront ainsi explorés.Ce travail de thèse a deux principaux objectifs. D'une part, il vise à démontrer que le dioxyde de titane (TiO2), matériau encore peu exploré, est prometteur pour des applications télécoms en le comparant à des plateformes plus matures. D'autre part, il tend à introduire la bande spectrale autour de 2 µm comme une solution à envisager pour les télécommunications de nouvelle génération.Plus précisément, la première partie de cette thèse a pour but de développer une technique pour coupler efficacement la lumière dans les structures en TiO2). Pour la première fois, une configuration faisant appel à un réseau métallique enterré a été évaluée numériquement avant d'être caractérisée expérimentalement. La seconde partie présente des transmissions télécoms haut-débit (10 Gbit/s) autour de µm réalisées sans erreurs dans des guides d'ondes sub-longueur d'onde ou multimodes en dioxyde de titane, silicium ou silicium-germanium. Pour terminer, des fonctions non-linéaires sont explorées sur ces puces photoniques. Il a été ainsi démontré une conversion en longueurs d'onde à 2 µm atteignant -10dB sur silicium ou la génération du premier supercontinuum s'étalant du visible à 2 µm dans un guide d'onde en TiO2.In the next decades, the limits of current optical communication systems will be reached unless new solutions are adopted. On of them is the use of a new spectral range around 2 µm enabled by the emergence of thulium-doped fiber amplifiers. In this thesis, we will focus on it in the context of very short distances transmissions on photonic chips. Various materials, mainly titanium dioxide (TiO2), will be explored.This thesis work has two main objectives. On the one hand, it aims to demonstrate that a material relatively unexplored, titanium dioxide, is promising for telecom applications by comparing it to more mature plateforms. On the other hand, it tends to introduce the spectral band around 2 µm as a solution to be considered for next-generation communications.More precisely, the first part of this thesis aims to develop a technique to efficiently couple light in TiO2 structures. For the first time, a configuration using a buried metallic grating was evaluated numerically and then characterized experimentally. The second part presents error-free high-speed (10 Gbit/s) telecom transmissions around 2 µm carried out in subwavelength or multimode waveguides in titanium dioxide, silicon or silicon-germanium. Finally, nonlinear functions are explored on the photonic chips. Thus, it has been demonstrated a wavelength conversion at 2 µm reaching -10dB on a silicon waveguide or the first supercontinuum generation spreading from visible to 2 µm wavelength in a TiO2 waveguide
Nonlinear spectral compression in fibre as a power limiting device
International audienc
Broadband etching-free metal grating couplers embedded in titanium dioxide waveguides
International audienceEmbedded metal grating couplers into titanium dioxide layer are proposed. A coupling efficiency better than 20 % is experimentally demonstrated with a 3-dB bandwidth of 86 nm in agreement with simulation results. This allowed us to perform error-free transmissions of 10 Gbit/s wavelength multiplexed signals in the C-band
Réseaux métalliques pour le couplage dans des guides en dioxyde de titane
National audienceNous montrons la fabrication de réseaux métalliques enterrés entre deux couches de dioxyde de titane. En utilisant un supercontinuum, nous démontrons expérimentalement une efficacité de couplage supérieure à -8 dB pour une bande passante à 3 dB supérieure à 80 nm
Exploring titanium dioxide as a new photonic platform
International audienceWe report the development of titanium dioxide-based waveguides for applications in the near-and mid-infrared. Thanks to embedded metal grating couplers, we demonstrate error free 10 Gbit/s optical transmissions at 1.55 and 2 µm. We also demonstrate octave-spanning supercontinuum in cm-long waveguides. We explore the way to improve such waveguides through optimized fabrication process
Titanium Dioxide Waveguides for Data Transmissions at 1.55 µm and 1.98 µm
International audienceWe demonstrate error free transmissions of 10 Gbps signals in titanium dioxide waveguides at wavelengths of 1.55 or 2 µm. An efficient coupling of light is achieved thanks to metal grating couplers and we have checked that the component could be used with standard CWDM SFP+ devices