EEG Windowed statitical wavelet deviation for estimation of muscular artifacts

Electroencephalographic (EEG) recordings are, most of the times, corrupted by spurious artifacts, which should be rejected or cleaned by the practitioner. As human scalp EEG screening is error-prone, automatic artifact detection is an issue of capital importance, to ensure objective and reliable results. In this paper we propose a new approach for discrimination of muscular activity in the human scalp quantitative EEG (QEEG), based on the time-frequency shape analysis. The impact of the muscular activity on the EEG can be evaluated from this methodology. We present an application of this scoring as a preprocessing step for EEG signal analysis, in order to evaluate the amount of muscular activity for two set of EEG recordings for dementia patients with early stage of Alzheimer’s disease and control age-matched subjects.

La coordinación muscular del cuádriceps en pacientes con el síndrome del dolor femoropatelar.

Introducción: el síndrome del dolor femoropatelar es un conjunto de signos y síntomas común entre adolescentes y adultos jóvenes caracterizada por un dolor retropatelar o peripatelar en actividades tales como subir o bajar escaleras. Su etiología y métodos de tratamiento han sido ampliamente estudiados en la literatura. Se piensa que es una patología multifactorial y el tratamiento que más se prescribe es la terapia física haciendo hincapié en el fortalecimiento del cuádriceps, aunque su eficacia es aún confusa. Objetivos: esta revisión tiene como objetivo obtener información sobre la posible relación del cuádriceps como causa o consecuencia del síndrome femoropatelar y evidenciar si el tratamiento basado en el fortalecimiento de dicho músculo es efectivo para reducir los síntomas en pacientes con esta patología. Metodología: en la búsqueda bibliográfica se han revisado las bases de datos Pubmed, Cochrane y ScienceDirect de las cuales se han extraído un total de veintiún artículos siguiendo los criterios de inclusión y exclusión. Las palabras clave han sido en inglés y no han sido aceptados artículos con fecha de publicación anterior al año 2003. Resultados: se han encontrado diversidad de resultados donde el trabajo del cuádriceps y sus modalidades siguen sin estar claras respecto a sus beneficios en pacientes con síndrome del dolor femoropatelar. Aun así en la literatura revisada se observa cómo hay autores que apoyan totalmente el trabajo del cuádriceps basándose en la reducción del dolor y mejora de la funcionalidad y otros, en cambio, discrepan en algunos resultados. Conclusiones: el retardo en la activación del vasto medial oblicuo respecto al vasto lateral y la posible atrofia del vasto medial son apoyados en la literatura revisada aunque aún faltan estudios para averiguar si son causa o consecuencia del síndrome del dolor femoropatelar. La terapia física y el fortalecimiento del cuádriceps sigue siendo el tratamiento de elección para este síndrome. Respecto a las modalidades de ejercicios, tanto los ejercicios en CCC y en CCA son mencionados como beneficios para esta patología aunque no existen estudios concisos que hagan decantarse por uno de ellos. En cambio, en la realización de los ejercicios con carga o sin carga se observa que losdos tipos de ejercicios son igual de beneficiosos aunque los ejercicios con carga provocan un mayor reclutamiento en el vasto medial oblicuo.

Evaluación de la efectividad de las Técnicas de Activación Muscular® en la resolución de la fasciosis plantar en corredores habituales: ensayo clínico aleatorizado.

Pregunta clínica de investigación: ¿es efectiva la Técnica de Activación Muscular® (MAT®) en la resolución de la fasciosis plantar (FP) en personas corredoras habituales? Objetivo: determinar si la terapia combinada mediante ejercicios de MAT® mejora los resultados obtenidos con el procedimiento convencional en el tratamiento de la FP en personas deportistas en la ciudad de Lleida. Metodología: En este ensayo clínico experimental ha participado un total de 264 pacientes, corredores habituales con FP de más de un mes y menos de un año de evolución, que han sido derivados por sus médicos de atención primaria. La muestra se ha dividido de forma aleatoria en dos grupos, uno control que sigue un protocolo convencional (educación sanitaria, AINEs y estiramietos) y el grupo experimental, al que se le ha aplicado la intervención de MAT®. La duración del estudio es de dos años, y cada intervención dura 4 semanas con un seguimiento a 6 y 12 meses. Un analista externo es el encargado del análisis de la información mediante el programa SPSS 15.0. Los resultados se miden mediante las variables de: dolor a la presión, grosor de la aponeurosis, percepción del estado de los pies, rango de movimiento articular (RMA) de tobillo y 1era metetarsofalángica (MTF) y tiempo de vuelta a la carrera entre otras.

Neck Muscle Function and Adolescent Headache

Muscular function of the neck region may be of importance for the etiology of headache, especially of tension-type headache. However, very few data exist on the association of neck muscle function with different types of headache in adolescents. The main aim of the study was to examine the association of neck muscle function with adolescent headache. The associations between leisure time activities, endurance strength of the upper extremities (UE endurance) and mobility of the neck-shoulder region and adolescent headache were studied. In addition, the associations of force production, EMG/force ratio, co-activation and fatigue characteristics, and cross-sectional area (CSA) of neck muscles with adolescent headache were studied. The study is part of a population-based cohort study of 12-year-old children with and without headache. The study had five phases (years 1998-2003). At the age of 13 years, a sample of 183 adolescents (183/311) participated in endurance strength and mobility measurements of the neck-shoulder region. In addition, the type and level of physical and other leisure activity were elicited with open and structured questions. At the age of 17 years, a random sample of 89 adolescents (89/202) participated in force and EMG measurements of the neck-shoulder muscles. In addition, at the age of 17 years, a sample of 65 adolescents (65/89) participated in CSA measurements of the neck muscles. At the age of 13 years, intensive participation in overall sports activity was associated with migraine. Frequent computer use was associated both with migraine and tension-type headache. The type of sports or other leisure activity classified them on the basis of body loading was not associated with headache type. In girls, low UE endurance of both sides, and low cervical rotation of the dominant side, were associated with tension-type headache, and low UE endurance of non-dominant side with migraine. In boys, no associations occurred between UE endurance and mobility variables and headache types. At the age of 17 years, in girls, high EMG/force ratios between the EMG of the left agonist sternocleidomastoid muscle (SCM) and maximal neck flexion and neck rotation force to the right side as well as high co-activation of right antagonist cervical erector spinae (CES) muscles during maximal neck flexion force were associated with migraine-type headache. In girls, neck force production was not associated with headache types but low left shoulder flexion force was associated with tension-type headache. In boys, no associations were found between EMG and force variables and headache. Increased SCM muscles fatigue of both sides was associated with tension-type headache. In boys, the small CSA of the right SCM muscle and, in girls, of combined right SCM and scalenus muscles was associated with tension-type headache. Similarly, in boys, the large CSA of the right SCM muscle, of the combined right SCM and scalenus muscles, of the left semispinalis capitis muscle, of the combined left semispinalis and splenius muscles was associated with migraine. No other differences in the CSA of neck flexion or extension muscles were found. Differences in the neuromucular function of the neck-shoulder muscles were associated with adolescent headache, especially in girls. Differences in the cross-sectional area of unilateral neck muscles were associated with headache, especially in boys. Differences in the neuromuscular function and in the cross-sectional area of the neck muscles also occurred between different types of headache. It remains to be established whether the findings are primary or secondary to adolescent migraine and tension headache. Keywords: adolescent, cross-sectional area, electromyography, endurance strength, fatigue, force, headache, leisure time activity, migraine, mobility, neck muscles, tension-type headache

Monitoring Fatigue Status with HRV Measures in Elite Athletes : An Avenue Beyond RMSSD?

Among the tools proposed to assess the athlete's "fatigue," the analysis of heart rate variability (HRV) provides an indirect evaluation of the settings of autonomic control of heart activity. HRV analysis is performed through assessment of time-domain indices, the square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals (RMSSD) measured during short (5 min) recordings in supine position upon awakening in the morning and particularly the logarithm of RMSSD (LnRMSSD) has been proposed as the most useful resting HRV indicator. However, if RMSSD can help the practitioner to identify a global "fatigue" level, it does not allow discriminating different types of fatigue. Recent results using spectral HRV analysis highlighted firstly that HRV profiles assessed in supine and standing positions are independent and complementary; and secondly that using these postural profiles allows the clustering of distinct sub-categories of "fatigue." Since, cardiovascular control settings are different in standing and lying posture, using the HRV figures of both postures to cluster fatigue state embeds information on the dynamics of control responses. Such, HRV spectral analysis appears more sensitive and enlightening than time-domain HRV indices. The wealthier information provided by this spectral analysis should improve the monitoring of the adaptive training-recovery process in athletes.

Assessment of meshing techniques for fatigue analysis of load carrying welded joints using the effective notch approach

The effective notch stress approach for the fatigue strength assessment of welded structures as included in the Fatigue Design Recommendation of the IIW requires the numerical analysis of the elastic notch stress in the weld toe and weld root which is fictitiously rounded with a radius of 1mm. The goal of this thesis work was to consider alternate meshing strategies when using the effective notch stress approach to assess the fatigue strength of load carrying partial penetration fillet-welded cruciform joints. In order to establish guidelines for modeling the joint and evaluating the results, various two-dimensional (2D) finite element analyses were carried out by systematically varying the thickness of the plates, the weld throat thickness, the degree of bending, and the shape and location of the modeled effective notch. To extend the scope of this work, studies were also carried out on the influence of

Monitoring Fatigue Status with HRV Measures in Elite Athletes: An Avenue Beyond RMSSD?

Among the tools proposed to assess the athlete's "fatigue," the analysis of heart rate variability (HRV) provides an indirect evaluation of the settings of autonomic control of heart activity. HRV analysis is performed through assessment of time-domain indices, the square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals (RMSSD) measured during short (5 min) recordings in supine position upon awakening in the morning and particularly the logarithm of RMSSD (LnRMSSD) has been proposed as the most useful resting HRV indicator. However, if RMSSD can help the practitioner to identify a global "fatigue" level, it does not allow discriminating different types of fatigue. Recent results using spectral HRV analysis highlighted firstly that HRV profiles assessed in supine and standing positions are independent and complementary; and secondly that using these postural profiles allows the clustering of distinct sub-categories of "fatigue." Since, cardiovascular control settings are different in standing and lying posture, using the HRV figures of both postures to cluster fatigue state embeds information on the dynamics of control responses. Such, HRV spectral analysis appears more sensitive and enlightening than time-domain HRV indices. The wealthier information provided by this spectral analysis should improve the monitoring of the adaptive training-recovery process in athletes.

Typology of "Fatigue" by Heart Rate Variability Analysis in Elite Nordic-skiers.

This study investigated changes in heart rate variability (HRV) in elite Nordic-skiers to characterize different types of "fatigue" in 27 men and 30 women surveyed from 2004 to 2008. R-R intervals were recorded at rest during 8 min supine (SU) followed by 7 min standing (ST). HRV parameters analysed were powers of low (LF), high (HF) frequencies, (LF+HF) (ms(2)) and heart rate (HR, bpm). In the 1 063 HRV tests performed, 172 corresponded to a "fatigue" state and the first were considered for analysis. 4 types of "fatigue" (F) were identified: 1. F(HF(-)LF(-))SU_ST for 42 tests: decrease in LFSU (- 46%), HFSU (- 70%), LFST (- 43%), HFST (- 53%) and increase in HRSU (+ 15%), HRST (+ 14%). 2. F(LF(+) SULF(-) ST) for 8 tests: increase in LFSU (+ 190%) decrease in LFST (- 84%) and increase in HRST (+ 21%). 3. F(HF(-) SUHF(+) ST) for 6 tests: decrease in HFSU (- 72%) and increase in HFST (+ 501%). 4. F(HF(+) SU) for only 1 test with an increase in HFSU (+ 2161%) and decrease in HRSU (- 15%). Supine and standing HRV patterns were independently modified by "fatigue". 4 "fatigue"-shifted HRV patterns were statistically sorted according to differently paired changes in the 2 postures. This characterization might be useful for further understanding autonomic rearrangements in different "fatigue" conditions.

Hospitalisation du proche : fatigue et coping du proche aidant à l'occasion de cette transition

Le processus de vieillissement entraîne une augmentation et une complexification des besoins de soins. Or, la proportion de personnes vieillissantes dans le monde et en Suisse s'accroit. Les professionnels de la santé ne disposent pas des moyens économiques et humains pour couvrir l'ensemble des besoins de soins. Les proches aidants contribuent de manière importante à la couverture des besoins. Cette contribution devient un élément central de la politique du maintien à domicile. Cependant, l'engagement à long terme des proches aidants auprès de leur parent peut influencer négativement leur état de santé. Pour une même classe d'âge, la population des proches aidants déclare un niveau de fatigue plus élevée que le reste de la population. Dans ce contexte, la fatigue est définie comme le résultat de l'ambivalence entre la demande en soins et les ressources dont dispose le proche aidant. L'hospitalisation du parent, qu'elle soit ou non liée à la fatigue, constitue un moment de crise pour le proche aidant. Face à cette crise, l'aidant mettra en oeuvre des stratégies de coping telles que conceptualisées dans la théorie transactionnelle du stress. Dans le cadre de la théorique intermédiaire de la transition de Meleis, le coping est un indicateur de processus de la transition qui doit permettre d'appréhender la transition vécue par l'aidant à l'occasion de l'hospitalisation du parent. Avec un devis corrélationnel descriptif, cette étude décrit les caractéristiques de l'échantillon de proches aidants, et du rôle qu'ils assument. Elle décrit le degré de fatigue et les styles de coping utilisés, et explore la relation entre la fatigue et le coping du proche aidant à l'occasion de l'hospitalisation du parent. Deux questionnaires auto-administrés ont été complétés par 33 participants. Cette étude a permis de dégager les résultats suivants : le score moyen de fatigue dans cet échantillon indique une fatigue légère selon la classification établie par Piper. Les participants mettent en avant l'influence du rôle d'aidant sur leur fatigue, ainsi que l'influence de leur propre santé et des contraintes économicoprofessionnelles. Le score moyen de fatigue varie en fonction de la nature de l'aide fournie. Il est significativement plus élevé lorsque le proche aidant soutient son parent dans les activités de la vie quotidienne (AVQ). Le style de coping mobilisé préférentiellement dans cet échantillon est le coping centré sur le problème, suivi du coping centré sur la recherche du soutien social, et enfin le coping centré sur l'émotion. Les aidants soutenant leur proche dans les AVQ mobilisent plus le coping centré sur l'émotion que ceux qui n'offrent pas ce type d'aide. Les principales sources de stress nommées par les participants sont l'état de santé du parent, son hospitalisation, et la rencontre avec le système de santé. Dans cet échantillon, nous n'avons pas observé de corrélation entre le degré de fatigue et les trois styles de coping. Des limites liées à la petite taille de l'échantillon amènent à la prudence quant à la généralisation des résultats de cette étude.

Syndrome de fatigue chronique [Chronic fatigue syndrome].

Le syndrome de fatigue chronique (SFC) est une pathologie invalidante, moins rare qu'on ne le pense (prévalence de l'ordre de 0,3-0,9 %), qui associe un épuisement physique persistant et inexpliqué à des douleurs diffuses, des troubles du sommeil, des troubles neurocognitifs et neurovégétatifs. Sa physiopathologie est controversée, mais les pistes de recherche actuelles convergent vers une atteinte dysimmunitaire, dans laquelle le stress oxydatif et un dysfonctionnement des mitochondries semblent jouer un rôle. Il n'existe pas de médication ayant démontré une efficacité spécifique pour le traitement du SFC. La prise en charge consiste à limiter les investigations superflues et à encourager le patient vers un reconditionnement à l'effort très progressif, dans le cadre d'un counselling empathique visant à prévenir les pensées négatives. Chronic fatigue syndrome (CFS) is a debilitating disorder, characterized by a severe, persistant and unexplained fatigue, which can be associated with diffuse pain, sleep difficulties, neurocognitive and neurovegetative troubles. Its prevalence has been estimated between 0.3 and 0.9%. Though its physiopathology remains controversial, evidence is growing that dysimmunity, oxidative stress and mitochondrial dysfunction are involved in its pathogeny. No medication has demonstrated specifc efficacy in the CFS. The management of CFS involves limiting unnecessary investigations, promoting graded exercice therapy, and providing empathic counselling in order to prevent negative thoughts.

Fatigue resistance of denture teeth

AIMS: There is no standard test to determine the fatigue resistance of denture teeth. With the increasing number of patients with implant-retained dentures the mechanical strength of the denture teeth requires more attention and valid laboratory test set-ups. The purpose of the present study was to determine the fatigue resistance of various denture teeth using a dynamic load testing machine. METHODS: Four denture teeth were used: Bonartic II (Candulor), Physiodens (Vita), SR Phonares II (Ivoclar Vivadent) and Trubyte (Dentsply). For dynamic load testing, first upper molars with a similar shape and cusp inclination were selected. The molar teeth were embedded in cylindrical steel molds with denture base material (ProBase, Ivoclar Vivadent). Dynamic fatigue loading was carried out on the mesio-buccal cusp at a 45° angle using dynamic testing machines and 2,000,000 cycles at 2Hz in water (37°C). Three specimens per group and load were submitted to decreasing load levels (at least 4) until all the three specimens no longer showed any failures. All the specimens were evaluated under a stereo microscope (20× magnification). The number of cycles reached before observing a failure, and its dependence on the load and on the material, has been modeled using a parametric survival regression model with a lognormal distribution. This allowed to estimate the fatigue resistance for a given material as the maximal load for which one would observe less than 1% failure after 2,000,000 cycles. RESULTS: The failure pattern was similar for all denture teeth, showing a large chipping of the loaded mesio-buccal cusp. In our regression model, there were statistically significant differences among the different materials, with SR Phonares II and Bonartic II showing a higher resistance than Physiodens and Trubyte, the fatigue resistance being estimated at around 110N for the former two, and at about 60N for the latter two materials. CONCLUSION: The fatigue resistance may be a useful parameter to assess and to compare the clinical risk of chipping and fracture of denture tooth materials.