To see the other types of publications on this topic, follow the link: Torso.
Dissertations / Theses on the topic 'Torso'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Torso.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Masterson, Richard Garrett. "Torso as ceramic vessel." PDXScholar, 1990. https://pdxscholar.library.pdx.edu/open_access_etds/4141.
Full textAbstract:
The ceramic forms in this thesis project represent a study of the sculptural and figurative qualities of the ceramic process. This study includes a search for a personal form language, development of the slab construction technique, and development of a glazed surface appropriate to the work. The subject of the work is the human torso, with the vessel-like forms focusing on the core of the body as a metaphor for the core of the human spirit.
2
Demirkol, Onur Ali. "Segmentation Of Torso Ct Images." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607431/index.pdf.
Full textAbstract:
Medical imaging modalities provide effective information for anatomic or
metabolic activity of tissues and organs in the body. Therefore, medical
imaging technology is a critical component in diagnosis and treatment of
various illnesses. Medical image segmentation plays an important role in
converting medical images into anatomically, functionally or surgically
identifiable structures, and is used in various applications. In this study,
some of the major medical image segmentation methods are examined and
applied to 2D CT images of upper torso for segmentation of heart, lungs,
bones, and muscle and fat tissues. The implemented medical image
segmentation methods are thresholding, region growing, watershed
transformation, deformable models and a hybrid methodwatershed transformation and region merging. Moreover, a comparative analysis is performed among these methods to obtain the most efficient segmentation method for each tissue and organ in torso. Some improvements are proposed for increasing accuracy of some image segmentation methods.
3
Renner, Michael Robert. "Machine Learning Simulation: Torso Dynamics of Robotic Biped." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/34602.
Full textAbstract:
Military, Medical, Exploratory, and Commercial robots have much to gain from exchanging wheels for legs. However, the equations of motion of dynamic bipedal walker models are highly coupled and non-linear, making the selection of an appropriate control scheme difficult. A temporal difference reinforcement learning method known as Q-learning develops complex control policies through environmental exploration and exploitation. As a proof of concept, Q-learning was applied through simulation to a benchmark single pendulum swing-up/balance task; the value function was first approximated with a look-up table, and then an artificial neural network. We then applied Evolutionary Function Approximation for Reinforcement Learning to effectively control the swing-leg and torso of a 3 degree of freedom active dynamic bipedal walker in simulation. The model began each episode in a stationary vertical configuration. At each time-step the learning agent was rewarded for horizontal hip displacement scaled by torso altitude--which promoted faster walking while maintaining an upright posture--and one of six coupled torque activations were applied through two first-order filters. Over the course of 23 generations, an approximation of the value function was evolved which enabled walking at an average speed of 0.36 m/s. The agent oscillated the torso forward then backward at each step, driving the walker forward for forty-two steps in thirty seconds without falling over. This work represents the foundation for improvements in anthropomorphic bipedal robots, exoskeleton mechanisms to assist in walking, and smart prosthetics.Master of Science
4
Ziraknejad, Nima. "Torso-mounted visual servoing of an outdoor robotic manipulator." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/47171.
Full textAbstract:
In the majority of vision applications, sensor calibration is a prerequisite to proper use of the sensor for both measurement and control. The objective in camera calibration is to estimate a set of parameters to construct a mapping between the 3D position of a target point and its 2D image coordinates. This thesis presents an autonomous stereo camera calibration technique based on a pinhole camera model with applications in industrial outdoor visual servoing systems. An efficient iterative least-squares parameter estimation algorithm is used to estimate the camera model parameters. The obtained stereo camera model is used to estimate the pose of the target object during the robot servoing process. The heavy-duty stereo camera rig is installed on the torso of an outdoor 3DOF robotic manipulator.
The stereo camera calibration is entirely an autonomous process as the robot moves the calibration tool within its workspace and the stereo camera model is produced after the data collection process. The stereo cameras are treated as a single unit and a single transformation is obtained for the stereo camera pair in the system. The calibration process is fast, efficient and no human interaction is required during the process.
The developed vision system is capable of detecting the 3D positions of the objects within the robot workspace with an average error of 1.93cm (maximum error of 7.6cm) for a region equal and smaller than the region in which the camera calibration is performed. The errors are comprised of errors in camera calibration, robot positioning and image processing. The maximum error represents an error of 2.1% of the total robot workspace reach. The visual servoing tasks are being performed with an update rate of 29ms.
The complete visual servo system, used for pipe handling, has been implemented on a combined platform with two main processing units and a fully integrated 3DOF torso-mounted robotic manipulator. The processing units include an industrial PC104 embedded system with 900MHz Pentium III CPU for vision related tasks and an industrial Programmable Logic Control (PLC) unit for low level control of the robot.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
5
Vigano, Lorenzo C. "Modeling torso imaging via time-domain diffuse correlation spectroscopy." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/123122.
Full textAbstract:
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 50-52).
Medical imaging is vital to the timely diagnosis of internal hemorrhaging and the prevention of fatalities. This thesis aims to contribute to this field by examining the efficacy of time-domain diffuse correlation spectroscopy (TD-DCS) as a means of imaging bleeding within the torso. TD-DCS is a new, powerful imaging technique with primary application of measuring blood flow in the brain. Here we show both how this novel imaging technique can be expanded for use in other regions beyond the brain as well as how we hypothesized and modeled the technique's ability to detect internal bleeding consistent with the trauma-related injury of non-compressible torso hemorrhaging (NCTH). In the constructed models, blood thickness changes from four to six millimeters were detectable at the hepatic vein region within the liver. By using Monte Carlo models, trillions of photons were simulated to approximate results taken across a multi-second measurement. The results show promise for the technique and recommend the construction of a testbed for further testing.
by Lorenzo C. Vigano.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
6
Wood, Jacqueline Mary. "A Study of Carasaurus' (Dinosaura: Sauropodomorph) Torso and its Biomechanical Implications." ScholarWorks@UNO, 2006. http://scholarworks.uno.edu/td/369.
Full textAbstract:
Physical examination of the articulations between the dorsal vertebrae and the dorsal ribs of the sauropod dinosaur Camarasaurus (Upper Cretaceous, Wyoming or whatever) shows that the dorsal vertebral column has a slight double curve and the torso is more narrow and volumetrically smaller than previously reconstructed. The shape of the dorsal vertebrae series was based upon the position of the zygopophyses and centrum spacing. The dorsal ribs were placed on the vertebrae based upon the position of tuberculum/diapophysis, capitulum/parapophysis, and the lateral edge of the rib head. Comparisons between the articulated torso of Camarasaurus and extant relatives allowed for the first attempt in reconstructing the three intercostal muscle groups. The newly defined torso shape in combination with the presence of scapular facets on the ribs allowed the scapulocoracoid to be placed upon the torso at an angle of 20-30°.
7
Montgomery, Trevor Colin. "The effects of sagittal plane postures on trunk rotation range of motion a thesis submitted to Auckland University of Technology in partial fulfillment of the requirements for the degree of Master of Health Science (MHSc), 2008." Click here to access this resource online, 2008. http://hdl.handle.net/10292/392.
Full textAbstract:
Thesis (MHSc--Health Science) -- AUT University, 2008.Includes bibliographical references. Also held in print (xv, 121 leaves : col. ill. ; 30 cm.) in the Archive at the City Campus (T 612.76 MON)
8
Oz, Sinan. "Implement Of Three Segmentation Algorithms For Ct Images Of Torso." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612866/index.pdf.
Full textAbstract:
Many practical applications in the field of medical image processing require valid and reliable segmentation of images. In this dissertation, we propose three different semi-automatic segmentation frameworks for 2D-upper torso medical images to
construct 3D geometric model of the torso structures. In the first framework, an extended version of the Otsu&rsquos method for three level thresholding and a recursive connected component algorithm are combined. The segmentation process is accomplished by first using Extended Otsu&rsquo
s method and then labeling in each consecutive slice. Since there is no information about pixel positions in the outcome of Extended Otsu&rsquo
s method, we perform some processing after labeling to connect pixels belonging with the same tissue. In the second framework, Chan-Vese (CV) method, which is an example of active contour models, and a recursive connected component algorithm are used together. The segmentation process is achieved using CV method without egde information as stopping criteria. In the third and last framework, the combination of watershed transformation and K-means are used as the segmentation method. After segmentation operation, the labeling is performed for the determination of the medical structures. In addition, segmentation and labeling operation is realized for each consecutive slice in each framework. The results of each framework are compared quantitatively with manual segmentation results to evaluate their performances.
9
Pinochet, Briones Mercedes. "Equipamiento de hidratación y regulación de la temperatura del torso." Tesis, Universidad de Chile, 2015. http://repositorio.uchile.cl/handle/2250/141189.
Full textAbstract:
Memoria para optar al título de Diseñador IndustrialChile es un país atractivo turísticamente y pocos chilenos se dedican a recorrerlo. Es por esto que el SERNATUR creó un programa llamado “Chile es tuyo” que contiene varias rutas, entre éstas se encuentra la ruta del desierto que fue escogida por ser un lugar inhóspito para recorrerlo a pie. Objetivo general Generar un equipamiento que ayude a hidratar y a regular la temperatura del torso de una persona en una situación de senderismo en altas temperaturas. Objetivos específicos - Establecer el perfil del usuario en las condiciones a estudiar. - Realizar un análisis de las zonas corporales posibles de intervención en el contexto de uso. - Realizar un estudio de la acción de caminar en situación de senderismo, con especial atención de las zonas involucradas El usuario es un hombre de clase social media alta, independiente, de 24 - 34 años, que viaja solo o acompañado por alguien. Para esto, se desarrollaron diferentes propuestas de diseño. La primera consistió en una mochila que poseía diferentes compartimientos y una bolsa de hidratación incluida. La segunda, un equipamiento de hidratación para la zona del torso. Y por último, se desarrolló un equipamiento de hidratación y regulación de la temperatura del torso. Se optó por escoger la última, ya que cumple de mejor manera con mantener hidratado al usuario. Para esto, se realizó un estudio del caminar de las personas que realizan senderismo para determinar cómo movilizar el agua para que su calentamiento fuese más lento. Se experimentó con el polietileno para desarrollar la bolsa de hidratación, presentándose diferentes desafíos. Primero, se experimentó con el ancho adecuado para la conexión entre los diferentes compartimientos de la bolsa, resultando el de 30 mm el más adecuado. Se modificó el prototipo, sin embargo no se movilizó el agua, ya que seguía doblándose. Por lo que se optó por ubicar tubos que mantuviesen abierta la conexión para que no se doblase. Para que el agua subiera a los compartimientos superiores, se elaboró un equipamiento que comprimiese la zona baja del torso. Como el agua no logró llegar a la parte donde se accionaba el movimiento de éste, se suprimió momentáneamente. Por último, se realizó una prueba de validación con el usuario para determinar si la temperatura del torso cambiaba utilizando el equipamiento. Sólo un sensor mostró mejoras, sin embargo se repetirá la prueba, ya que se agregó un elemento ajeno al equipamiento, para lograr que el agua subiese a los compartimientos superiores de la bolsa, que puede haber modificado los resultados.
marzo 2018
10
Margossian, Christa M. (Christa Marie). "Vibrotactile pattern recognition on the torso : effects of concurrent activities." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40454.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaf 25).
Vibrotactile displays have been created to aid vision or hearing through the sense of touch. These displays communicate with the user to provide information. The focus of this thesis was to determine how concurrent activity affects vibrotactile signal recognition. An overall accuracy recognition rate of 90% or greater was desired from each of the signals in the each of the tasks. The first experiment asked subjects to wear the tactile display and walk while responding to signals. The results indicated that most of the subjects were able to recognize the patterns. The overall mean correct response rate was 92% and then when the subjects were asked to jog, they correctly identified the patterns 91% of the time. After determining the success rates from the first experiment, a second set of subjects were asked to concentrate on an internet game while responding to signals. The data from this experiment had an overall mean correct response rate of 93%. The results from this experiment further indicate that subjects can still receive communications while participating in other activities. The results also lead to specific conclusions about the patterns used and their ability to be identified with concurrent activity where some patterns are more easily received than others. By understanding how these patterns are recognized by humans, we can better develop patterns to communicate through tactile devices.
by Christa M. Margossian.
S.B.
11
Nakamura, Mealani 1978. "A torso haptic display based on shape memory alloy actuators." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89927.
Full text
12
Monat, Heath Barnhart. "Lumbar Skin Profile Prediction from Anterior and Lateral Torso Measurements." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343062090.
Full text
13
Rioux, Myriam. "Numerical Computations of Action Potentials for the Heart-torso Coupling Problem." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20533.
Full textAbstract:
The work developed in this thesis focusses on the electrical activity of the heart, from the modeling of the action potential originating from cardiac cells and propagating through the heart, as well as its electrical manifestation at the body surface. The study is divided in two main parts: modeling the action potential, and numerical simulations.
For modeling the action potential a dimensional and asymptotic analysis is done. The key advance in this part of the work is that this analysis gives the steps to reliably control the action potential. It allows predicting the time/space scales and speed of any action potential that is to say the shape of the action potential and its propagation. This can be done as the explicit relations on all the physiological constants are defined precisely. This method facilitates the integrative modeling of a complete human heart with tissue-specific ionic models. It even proves that using a single model for the cardiac action potential is enough in many situations.
For efficient numerical simulations, a numerical method for solving the heart-torso coupling problem is explored according to a level set description of the domains. This is done in the perspective of using directly medical images for building computational domains. A finite element method is then developed to manage meshes not adapted to internal interfaces. Finally, an anisotropic adaptive remeshing methods for unstructured finite element meshes is used to efficiently capture propagating action potentials within complex, realistic two dimensional geometries.
14
Tanaka, Martin L. "Biodynamic Analysis of Human Torso Stability using Finite Time Lyapunov Exponents." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/26580.
Full textAbstract:
Low back pain is a common medical problem around the world afflicting 80% of the population some time in their life. Low back injury can result from a loss of torso stability causing excessive strain in soft tissue. This investigation seeks to apply existing methods to new applications and to develop new methods to assess torso stability. First, the time series averaged finite time Lyapunov exponent is calculated from data obtained during seated stability experiments. The Lyapunov exponent is found to increase with increasing task difficulty. Second, a new metric for evaluating torso stability is introduced, the threshold of stability. This parameter is defined as the maximum task difficulty in which dynamic stability can be maintained for the test duration. The threshold of stability effectively differentiates torso stability at two levels of visual feedback. Third, the state space distribution of the finite time Lyapunov exponent (FTLE) field is evaluated for deterministic and stochastic systems. Two new methods are developed to generate the FTLE field from time series data. Using these methods, Lagrangian coherent structures (LCS) are found for an inverted pendulum, the Acrobot, and planar wobble chair models. The LCS are ridges in the FTLE field that separate two inherently different types of motion when applied to rigid-body dynamic systems. As a result, LCS can be used to identify the boundaries of the basin of stability. Finally, these new methods are used to find the basin of stability from time series data collected from torso stability experiments. The LCS and basins of stability provide a richer understanding into the system dynamics when compared to existing methods.
By gaining a better understanding of torso stability, it is hoped this knowledge can be used to prevent low back injury and pain in the future. These new methods may also be useful in evaluating other biodynamic systems such as standing postural sway, knee stability, or hip stability as well as time series applications outside the area of biomechanics.Ph. D.
15
Perez, Miguel A. "Empirical Evaluation of Models Used to Predict Torso Muscle Recruitment Patterns." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/35381.
Full textAbstract:
For years, the human back has puzzled researchers with the complex behaviors it presents. Principally, the internal forces produced by back muscles have not been determined accurately. Two different approaches have historically been taken to predict muscle forces. The first relies on electromyography (EMG), while the second attempts to predict muscle responses using mathematical models. Three such predictive models are compared here. The models are Sum of Cubed Intensities, Artificial Neural Networks, and Distributed Moment Histogram. These three models were adapted to run using recently published descriptions of the lower back anatomy. To evaluate their effectiveness, the models were compared in terms of their fit to a muscle activation database including 14 different muscles. The database was collected as part of this experiment, and included 8 participants (4 male and 4 female) with similar height and weight. The participants resisted loads applied to their torso via a harness. Results showed the models performed poorly (average R2's in the 0.40's), indicating that further improvements are needed in our current low back muscle activation modeling techniques. Considerable discrepancies were found between internal moments (at L3/L4) determined empirically and measured with a force plate, indicating that the maximum muscle stress selected and/or the anatomy used were faulty. The activation pattern database collected also fills a gap in the literature by considering static loading patterns that had not been systematically varied before.Master of Science
16
Ferrer, Albero Ana. "Three-dimensional Multiscale Modelling and Simulation of Atria and Torso Electrophysiology." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/88402.
Full textAbstract:
A better understanding of the electrical activity of the heart under physiological and pathological conditions has always been key for clinicians and researchers. Over the last years, the information in the P-wave signals has been extensively analysed to un-cover the mechanisms underlying atrial arrhythmias by localizing ectopic foci or high-frequency rotors. However, the relationship between the activation of the different areas of the atria and the characteristics of the P-wave signals or body surface poten-tial maps are still far from being completely understood. Multiscale anatomical and functional models of the heart are a new technological framework that can enable the investigation of the heart as a complex system.
This thesis is centred in the construction of a multiscale framework that allows the realistic simulation of atrial and torso electrophysiology and integrates all the anatom-ical and functional descriptions described in the literature. The construction of such model involves the development of heterogeneous cellular and tissue electrophysiolo-gy models fitted to empirical data. It also requires an accurate 3D representation of the atrial anatomy, including tissue fibre arrangement, and preferential conduction axes. This multiscale model aims to reproduce faithfully the activation of the atria under physiological and pathological conditions. We use the model for two main applica-tions. First, to study the relationship between atrial activation and surface signals in sinus rhythm. This study should reveal the best places for recording P-waves signals in the torso, and which are the regions of the atria that make the most significant contri-bution to the body surface potential maps and determine the main P-wave characteris-tics. Second, to spatially cluster and classify ectopic atrial foci into clearly differenti-ated atrial regions by using the body surface P-wave integral map (BSPiM) as a bi-omarker. We develop a machine-learning pipeline trained from simulations obtained from the atria-torso model aiming to validate whether ectopic foci with similar BSPiM naturally cluster into differentiated non-intersected atrial regions, and whether new BSPiM could be correctly classified with high accuracy.En la actualidad, una mejor compresión de la actividad eléctrica del corazón en condi-ciones fisiológicas y patológicas es clave para médicos e investigadores. A lo largo de los últimos años, la información derivada de la onda P se ha utilizado para intentar descubrir los mecanismos subyacentes a las arritmias auriculares mediante la localiza-ción de focos ectópicos y rotores de alta frecuencia. Sin embargo, la relación entre la activación de distintas regiones auriculares y las características tanto de las ondas P como de la distribución de potencial en la superficie del torso está lejos de entenderse completamente. Los modelos cardíacos funcionales y anatómicos son una nueva he-rramienta que puede facilitar la investigación relativa al corazón entendido como sis-tema complejo. La presente tesis se centra en la construcción de un modelo multiescala para la simula-ción realista de la electrofisiología cardíaca tanto a nivel auricular como de torso, integrando toda la información anatómica y funcional disponible en la literatura. La construcción de este modelo implica el desarrollo, en base a datos experimentales, de modelos electrofisiológicos heterogéneos tanto celulares como tisulares. Así mismo, es imprescindible una representación tridimensional precisa de la anatomía auricular, incluyendo la dirección de fibras y los haces de conducción preferentes. Este modelo multiescala busca reproducir fielmente la activación auricular en condiciones fisiológi-cas y patológicas. Su uso se ha centrado fundamentalmente en dos aplicaciones. En primer lugar, estudiar la relación entre la activación auricular en ritmo sinusal y las señales en la superficie del torso. Este estudio busca definir la mejor ubicación para el registro de las ondas P en el torso así como determinar aquellas regiones auriculares que contribuyen fundamentalmente a la formación y distribución de potenciales super-ficiales así como a las características de las ondas P. En segundo lugar, agrupar y cla-sificar espacialmente los focos ectópicos en regiones auriculares claramente diferen-ciables empleando como biomarcador los mapas superficiales de integral de la onda P (BSPiM). Se ha desarrollado para ello una metodología de aprendizaje automático en la que las simulaciones obtenidas con el modelo multiescala aurícula-torso sirven de entrenamiento, permitiendo validar si los focos ectópicos cuyos BSPiMs son similares se agrupan de forma natural en regiones auriculares no intersectadas y si BSPiMs nue-vos podrían ser clasificados prospectivamente con gran precisión.
Avui en dia, una millor comprenssió de l'activitat elèctrica del cor en condicions fisio-lògiques i patològiques és clau per a metges i investigadors. Al llarg dels últims anys, la informació derivada de l'ona P s'ha utilitzat per intentar descobrir els mecanismes subjacents a les arítmies auriculars mitjançant la localització de focus ectòpics i rotors d'alta freqüència. No obstant això, la relació entre l'activació de diferents regions auri-culars i les característiques tant de les ones P com de la distribució de potencial en la superfície del tors està lluny d'entendre's completament. Els models cardíacs funcionals i anatòmics són una nova eina que pot facilitar la recerca relativa al cor entès com a sistema complex. La present tesi es centra en la construcció d'un model multiescala per a la simulació realista de la electrofisiologia cardíaca tant a nivell auricular com de tors, integrant tota la informació anatòmica i funcional disponible en la literatura. La construcció d'aquest model implica el desenvolupament, sobre la base de dades experimentals, de models electrofisiològics heterogenis, tant cel·lulars com tissulars. Així mateix, és imprescindible una representació tridimensional precisa de l'anatomia auricular, in-cloent la direcció de fibres i els feixos de conducció preferents. Aquest model multies-cala busca reproduir fidelment l'activació auricular en condicions fisiològiques i pa-tològiques. El seu ús s'ha centrat fonamentalment en dues aplicacions. En primer lloc, estudiar la relació entre l'activació auricular en ritme sinusal i els senyals en la superfí-cie del tors. A més a més, amb aquest estudi també es busca definir la millor ubicació per al registre de les ones P en el tors, així com, determinar aquelles regions auriculars que contribueixen fonamentalment a la formació i distribució de potencials superfi-cials a l'hora que es caracteritzen les ones P. En segon lloc, agrupar i classificar espa-cialment els focus ectòpics en regions auriculars clarament diferenciables emprant com a biomarcador els mapes superficials d'integral de l'ona P (BSPiM). És per això que s'ha desenvolupat una metodologia d'aprenentatge automàtic en la qual les simulacions obtingudes amb el model multiescala aurícula-tors serveixen d'entrenament, la qual cosa permet validar si els focus ectòpics, llurs BSPiMs són similars, s'agrupen de for-ma natural en regions auriculars no intersectades i si BSPiMs nous podrien ser classifi-cats de manera prospectiva amb precisió.
Ferrer Albero, A. (2017). Three-dimensional Multiscale Modelling and Simulation of Atria and Torso Electrophysiology [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/88402
TESIS
17
Schaeffer, Valérie. "Rôle de Bicoid chez la drosophile : intercations avec Hunchback et Torso." Montpellier 2, 1999. http://www.theses.fr/1999MON20102.
Full textAbstract:
Lors du developpement precoce de la drosophile, le plan de l'embryon est defini par quatre systemes maternels. La molecule-cle du systeme anterieur est bicoid, facteur de transcription a homeodomaine. Il a ete montre que bicoid etait aide par un autre morphogene anterieur, hunchback. Bod et hb sont capables d'agir en synergie pour organiser un developpement anterieur correct. Le mecanisme moleculaire propose pour cette synergie fait intervenir des facteurs specifiques de la machinerie generale de transcription, les tafs. Dans un premier temps, nous avons ete amenes a tester la signification biologique des ces resultats in vivo. Des mouches transgeniques portant des deletions de la proteine bicoid ont montre que les domaines putatifs d'activation de la transcription de bicoid etaient dispensables pour son activite in vivo. Ceci suggere que les interactions observees in vitro avec des composants specifiques de la machinerie generale de transcription ne sont pas essentiels pour un developpement anterieur correct. Le systeme terminal anterieur a longtemps ete implique dans la modification de l'activite de bcd. A l'extremite la plus anterieure, tor est connu pour avoir une fonction negative sur l'activite de bcd (retraction des genes cibles de bcd) tandis que dans les regions posterieures de la tete presomptive, tor semble plutot augmenter la fonction de bcd. Dans une deuxieme partie, nous montrons que de multiples copies de bcd sont capables de restaurer le phenotype anterieur des mutants du systeme terminal. Ceci signifie que le seul role de tor dans l'anterieur est d'aider bcd a effectuer sa fonction. Nous avons aussi montres que tor n'agit pas sur bcd mais qu'il existe deux voies d'activation differentes des genes cibles de tor et bcd. Ces observations sont consistantes avec l'hypothese de l'apparition recente d'un centre morphogenetique anterieur (bcd et anterieur tor) chez les dipteres superieurs.
18
Paar, Maja. "Design of the Trunk and Torso of a Lower-Limb Exoskeleton." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1624988804573986.
Full text
19
Sutherland, Alistair James. "A torso driven walking algorithm for dynamically balanced variable speed biped robots." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0049.
Full textAbstract:
As a contribution toward the objective of developing useful walking machines, this dissertation considers solutions to some of the problems involved with bipedal robot development. The main area of focus involves control system design and implementation for dynamically balanced walking robots. A new algorithm “Torso Driven Walking” is presented, which reduces the complexity of the control problem to that of balancing the robot’s torso. All other aspects of the system are indirectly controlled by the changing robot state resulting from direct control of the robot’s torso. The result is literally a “top-down” approach to control, where the control system actively balances the top-most component of the robot’s body, leaving the control of the lower limbs to a passive “state-driven” system designed to ensure the robot always keeps at least one leg between the torso and the ground. A series of low-cost robots and simulation systems have been constructed as experimental platforms for testing the proposed new control system. The robots have been designed to balance on “point” feet, and so the control system must be able to dynamically maintain balance, while moving at a variable velocity. The Torso Driven Walking control system achieves a fully dynamic, variable speed walking behaviour that does not rely on maintaining a stable supporting polygon for balance. In addition, the system exhibits a high degree of tolerance for low frequency “bias” or “drift” errors. These measurement errors are commonly encountered when using sensors for detecting torso inclination.
20
Lam, Amy R. (Amy Rebecca). "Vibrotactile pattern recognition on the torso with one and two dimensional displays." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36738.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (leaves 27-28).
This research focused on the evaluation of a tactile display that is used for navigation and communication. In the first experiment, a four by four array of vibrating motors (tactors) was mounted on the torso while the subject wore an Interceptor Body Armor (IBA) vest. Subjects were required to identify which of eight patterns was presented. The results indicated that subjects could recognize the patterns presented with perfect accuracy, which indicates that wearing heavy body armor over the display does not affect the ability to perceive tactile inputs. A second set of experiments involved a one-dimension tactile array of eight tactors worn around the waist. The results indicated that the subjects could recognize the six circumferential patterns presented with an accuracy of 98-100% correct. A further experiment confirmed that the linear tactile display could be used to provide cues about the location of an event in the environment. These experiments showed that identification of the vibrotactile patterns was slightly superior on the two-dimension tactile array on the torso as compared to the one-dimension tactile array around the waist.
(cont.) When subjects were required to identify the location of an individual vibrating motor using the one-dimensional array they achieved an accuracy of 94-100% correct. This suggests that a linear tactile array can be used to present navigational cues.
by Amy R. Lam.
S.B.
21
Sutherland, Alistair James. "A torso driven walking algorithm for dynamically balanced variable speed biped robots /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0049.
Full text
22
Gallagher, Sean. "Effects of torso flexion on fatigue failure of the human lumbosacral spine." Connect to this title online, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1070310033.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2003.Title from first page of PDF file. Document formatted into pages; contains xvii, 238 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: William S. Marras, Dept. of Industrial and Systems Engineering. Includes bibliographical references (p. 204-238).
23
Sierra, Romero Adriana Estefania, and Romero Adriana Estefania Sierra. "La Tauromaquia y el mito de llegar a ser figura del toreo. Caso Manuel Rodríguez Manolete." Tesis de Licenciatura, Universidad Autónoma del Estado de México, 2015. http://hdl.handle.net/20.500.11799/65813.
Full textAbstract:
El presente trabajo de investigación, tiene como objetivo en primer instancia dar a conocer
brevemente un panomara general de la tauraquia y la manera en la cual la sociedad, el
torero y el toro en conjunto, son a la vez una estructura sólida que sistematiza a la fiesta de
los toros, explicando con ello el poder que las estructuras simbolicas, que junto con los
medios de comunicación ejercen sobre la sociedad para la creación de los mitos.
Pero, ¿qué es la tauromaquía? ¿el toreo? ¿qué es una corrida de toros? ¿qué es un torero?, y
más importante: ¿qué es una “figura del toreo”? ¿qué es lo que hace que un toreo sea una
“figura del toreo”?, así como la manera en la cual los medios hablan del toro y del torero a
tal punto de convertirlos en mitos.
El origen de las corridas de toros no solo debe remontarse a la antigua España, sino que la
relación hombre-bestia debe tomarse en cuenta desde la aparición del hombre sobre la
tierra. Es por ello, que la tauromaquia más allá de verse como un espectáculo que entretiene
a las personas, se debe de conocer su significado técnico y el valor simbólico que trae
consigo.
Menciona Juan Carlos Fernández Truhán (s/a) que existen un sinnúmero de escritos
relacionados y especializados sobre la tauromaquia y que sería una gran osadía querer
aportar algo nuevo sobre dicho tema; así, que concordando con él, lo que se realizará en la
presente investigación será recopilar aquellos datos históricos de más importancia sobre la
tauromaquia, la importancia del toro de lidia y la biografía de uno de de los toreros más
relevantes en la historia taurina, que servirá para analizar a las llamadas Figuras del toreo,
que en este caso la biografía de Manuel Rodríguez Manolete.
24
Torres, Edgar S. M. Massachusetts Institute of Technology. "Dynamics of the human head and torso during activities that require stable vision." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40941.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaf 44).
The dynamics of the head and torso during activities that require clear vision is a topic that has previously been studied. These studies have examined the relationships between the angular velocities of the head in pitch and yaw in activities that either require clear vision or do not. However, many of these studies have been performed in artificial settings and so have required the subject to perform uncommon activities. The present study attempts to overcome the limitations of studying head and torso dynamics in artificial settings and determine whether the relationships found in previous studies apply during more natural activities where subjects move freely and track moving targets. Equipment was developed to measure the movements of the head and torso. This equipment used several different sensors to measure both the rotational velocities and linear accelerations of all degrees of freedom for both the head and torso. Several experiments were conducted using this equipment with subjects who were required to catch a ball. The subjects in this experiment walked with no visual task portion, ran with no visual task, and also ran while trying to catch a ball. It was found that during these activities, the yaw of the head was stabilized when clear vision was required. The pitch of the head however, became less stable when completing activities that required clear vision. These findings are consistent with previous studies in the field of head and torso dynamics.
by Edgar Torres.
S.B.
25
Gottipati, Pranitha. "Experimental and Simulation Based Dynamic Assessment of Flexion and Extension Movements of Torso." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/40426.
Full textAbstract:
Low back disorders (LBDs) comprise one of the major health issues in the United States. Previous research used isometric studies to understand the mechanisms that cause LBDs. Occupational tasks involving dynamic trunk movements, muscle fatigue, and spinal instability are identified as major risk factors for developing low back pain. Dynamic stability and muscle forces during trunk flexion-extension movements are studied in this dissertation.
Torso muscle fatigue is known to affect the neuromuscular muscle recruitment that influences spinal stability. The first part of this dissertation investigates the effect of muscle fatigue on the stability of dynamic trunk flexion-extension movements. Participants with no self-reported low back pain history performed repetitive trunk flexion-extension exercises before and after extensor muscle fatigue. The extensor muscles were fatigued to 60% of their unfatigued isometric maximum voluntary exertion force. The maximum finite-time Lyapunov exponent, λMax, was used to quantify the dynamic stability. Values of λMax increased with fatigue, suggesting dynamic stability of the torso decreases with muscle fatigue. Fatigue-by-task asymmetry interactions did not influence spinal stability.
The purpose of the second part of this dissertation was to predict time-dependent muscle forces and spinal loads during symmetric flexion-extension movements. A 2-dimensional sagittal plane, lumped parameter model was built with one thorax and five lumbar vertebrae stacked upon a stationary pelvis. Kinematics driven optimization was used to estimate time-dependent muscle forces. Muscle forces were determined by minimizing the metabolic power while satisfying the equations of motion. Spinal loads were calculated as the vector sum of the muscle forces and the trunk weight. Abdominal activity was observed at the onset of flexion and at the end of extension. The multifidus and psoas muscles played a major role in the spine dynamics. The compressive spinal loads were found to reach highest values at the onset of flexion, while the shear loads reached the highest values at large flexion angles.Ph. D.
26
Whyte, T. "Adequacy of test standards in evaluating blast overpressure (BOP) protection for the torso." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/10993.
Full textAbstract:
The blast wave emanating from an explosion produces an almost instantaneous rise in pressure which can then cause Blast Overpressure (BOP) injuries to nearby persons. BOP injury criteria are specified in test standards to relate BOP measurements in a testing environment to a risk of BOP injury. This study considered the adequacy of test standards in evaluating BOP protection concepts for the torso.
Four potential BOP injury scenarios were studied to determine the likelihood of injury and the adequacy of test standards for appropriate protection concepts. In the case of vehicle blast, BOP injury is unlikely and test standards are adequate. In the scenario involving an explosive charge detonated within a vehicle, and the close proximity to a hand grenade scenario, test standards are not available. The demining scenario was identified as of importance as test standards are available, but do not mandate the evaluation of BOP protection.
A prototype South African Torso Surrogate (SATS) was developed to explore this scenario further. The SATS was required to be relatively inexpensive and robust. The SATS was cast from silicone (selected to represent body tissue characteristics) using a torso mould containing a steel frame and instrumented with chest face-on pressure transducer and accelerometer. The SATS was subjected to an Anti-Personnel (AP) mine test and the Chest Wall Velocity Predictor and Viscous Criterion were used to predict that BOP injuries would occur in a typical demining scenario. This result was confirmed by applying the injury criteria to empirical blast predictions from the Blast Effects Calculator Version 4 (BECV4).
Although limitations exist in the ability of injury criteria and measurement methods to accurately predict BOP injuries, generally a conservative approach should be taken. Thus, it is recommended that the risk of BOP injuries should be evaluated in demining personal protective equipment test standards.
27
Mineo, Alessandro. "Mechanisms of restricted activation of the Torso receptor: from the eggshell to the embryo." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/402625.
Full textAbstract:
The establishment of the embryonic axis in the Drosophila embryo relies on four maternal systems. Anterior and posterior axes rely on morphogens located at the poles that will generate a gradient of activity along the embryo. In contrast, terminal and dorsoventral system rely on cues that are generated by follicle cells in the egg chamber to induce the restricted activation of their receptors, Torso and Toll respectively. In the case of the terminal signaling, the torso (tor) gene encodes for a tyrosine kinase receptor uniformly localised all around the membrane of the embryo but exclusively activated at the poles upon the activity of the Torso-like (Tsl) protein. Restricted activation of the Torso receptor at the embryonic poles relies on the tsl gene. Indeed, Tsl is expressed at the poles of the egg chamber during oogenesis and, in embryogenesis, accumulates at both poles of the inner side of the vitelline membrane, the innermost eggshell layer, by means of three protein encoded by the Nasrat (f(s) N), Polehole (f(s) Ph) and Closca (clos) genes. f(s) N, f(s) Ph and clos encode for proteins that localise in the vitelline membrane and are involved in the crosslinking of the vitelline membrane converting the eggshell into a stiff and insoluble layer. Indeed, females bearing mutations in any of
these genes produce collapsed eggs due to defects in their eggshell. fs(1)N12, fs(1)ph1901 and clos1
are the only point mutation alleles which do not abolish the integrity of the vitelline membrane but cause the lack of terminal structures.
The main objective of this work was to shed light on the role of Tsl, Nasrat, Polehole and Closca in ensuring restricted of Tor activation at the embryonic poles.
In the case of Tsl, we found that, during oogenesis, it accumulates at the vitelline membrane while, in embryogenesis it localises at both ends of the embryonic plasma membrane probably at egg activation. These results suggest a a mechanism to transfer the Tsl from the egg chamber to the early embryo. This mechanism relies on the initial anchoring of Tsl at the vitelline membrane as it is secreted by the follicle cells, followed by its later translocation to the egg plasma membrane.
In the case of Nasrat, Polehole and Closca,we found that embryo laid by fs(1)N12, fs(1)ph1901 and
clos1 mutant females display defects in dorsoventral patterning specification besides their terminal phenotype. Nasrat, Polehole and Closca, are required for proper anchorage and activity of Nudel, a protease acting both in embryonic dorsoventral patterning and vitelline membrane integrity, thus providing a mechanism for the role of Nasrat, Polehole and Closca in vitelline membrane cross linking and dorsoventral patterning. Therefore, the dorsoventral and terminal systems, hitherto considered independent, share a common extracellular mechanism constituted by the Nasrat, Polehole and Closca proteins. Moreover, we found that these proteins have a new Tsl-independent role in terminal signaling. In the embryonic terminal system, Tor is activated only at the poles by its ligand
Trunk while, in Drosophila larvae, Tor is also expressed and activated by another ligand called Prothoracicotropic hormone (PTTH) in the Prothoracic Gland. Ectopic expression of PTTH in the embryo is able to activate Tor ectopically even in the absence of Tsl but requires Nasrat, Polehole and Closca.
From these results, we propose that a Nasrat/Polehole/Closca complex acts as a multifunctional hub to anchor various proteins synthesized at oogenesis, ensuring their spatial and temporal restricted function. These findings shed light on the eggshell not just as protective layer but as a specialised extracellular matrix that regulates the spatial and temporal control of early embryonic developmental processes.El eje antero-posterior del embrión de Drosophila se especifica por acción de tres sistemas maternos: el sistema anterior, el sistema posterior y el sistema terminal. En el sistema terminal el receptor tirosina quinasa Torso (Tor) está localizado uniformemente en la membrana del embrión temprano pero se activa sólo en los polos por acción de la proteína Torso-like (Tsl). Aunque el papel de Tsl en la activación de Tor no está del todo claro, se ha descrito que Tsl es la única proteína de todo el sistema terminal localizada en los polos. De hecho, Tsl se acumula en la cara interna de la membrana vitelina (MV), anclado a las proteínas Nasrat, Polehole y Closca. El papel molecular de estas proteínas es poco conocido, pero análisis genéticos han demostrado que se necesitan para una correcta estructura de la MV y también para la activación de Tor. En esta tesis, nos hemos focalizado en la función de las proteínas Tsl, Nasrat, Polehole y Closca y su papel en la activación de Tor en los polos. Respecto a Tsl, descubrimos que esta proteína se acumula en la MV durante la oogénesis y, al principio de la embriogénesis, transloca de la MV a la membrana plasmática del embrión. En cuanto a Nasrat, Polehole y Closca descubrimos que estas proteínas se necesitan también para la correcta localización y función de Nudel, una proteína involucrada en la especificación del eje dorso ventral del embrión. Además encontramos que Nasrat, Polehole y Closca tienen una función adicional en el sistema terminal independiente de Tsl. De los resultados aquí descritos proponemos que un complejo formado por las proteínas Nasrat, Polehole y Closca podría funcionar en la MV como un centro multifuncional para anclar proteínas importantes por la especificación de los ejes del embrión.
28
Glaser, Ivan [Verfasser]. "Warum "Das Kapital" ein Torso blieb : historische und systematische Studien [[Elektronische Ressource]] / Ivan Glaser." Konstanz : Bibliothek der Universität Konstanz, 2012. http://d-nb.info/1079554750/34.
Full text
29
Anderson, Kimberly Rose. "Computational fluid dynamics (CFD) study investigating the effects of torso geometry simplification on aspiration efficiency." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/774.
Full textAbstract:
In previous studies truncated models were found to underestimate the air's upward velocity when compared to wind tunnel velocity studies, which may affect particle aspiration estimates. This work compared aspiration efficiencies using three torso geometries: 1) a simplified truncated cylinder; 2) a non-truncated cylinder; and 3) an anthropometrically realistic humanoid body. The primary aim of this work was to (1) quantify the errors introduced by using a simplified geometry and (2) determine the required level of detail to adequately represent a human form in CFD studies of aspiration efficiency. Fluid simulations used the standard k-epsilon turbulence models, with freestream velocities at 0.2 and 0.4 m s-1 and breathing velocities at 1.81 and 12.11 m s-1 to represent at-rest and heavy breathing rates, respectively. Laminar particle trajectory simulations were used to determine the upstream area where particles would be inhaled. These areas were used to compute aspiration efficiencies for facing the wind. Significant differences were found in vertical velocity and location of the critical area between the three models. However, differences in aspiration efficiencies between the three forms was less than 6% over all particle sizes, indicating that there is little difference in aspiration efficiency between torso models.
30
Martin, Jean-René, and Daniel Blangy. "Mutagenese insertionnnelle a l'element p et caracterisation moleculaire du locus torso-like : clonage du gene torso-like et de la sous-unite beta du gene de la proteine kinase calcium/calmoduline-dependante, chez la drosophile." Paris 6, 1993. http://www.theses.fr/1993PA066605.
Full textAbstract:
Ce travail se divise en trois parties. Premierement, nous avons effectue une mutagenese par insertion du transposon p pour constituer une collection d'environ 1500 mutants. Nous avons repertorie les mutations a effet maternel ou zygotique qui alterent la morphologie de l'embryon. Nous avons identifie 40 mutations dont 20 sont de nouveaux loci. La localisation de ces nouvelles mutations a ete effectuee par recombinaison genetique et par hybridation in-situ sur chromosome. Deuxiemement, nous avons etudie la mutation a effet maternel torso-like (tsl). Ce gene est implique dans une cascade d'activation aboutissant a induire les parties terminales de l'embryon. L'expression de tsl est localisee dans les cellules folliculaires migrantes et polaires. Ce gene code pour une nouvelle proteine qui contient un peptide signal, suggerant qu'elle est secretee. L'utilisation d'anticorps polyclonaux montre qu'au stade blastoderme la proteine tsl forme un gradient de concentration symetrique aux deux poles de l'embryon. A partir de lignee transgeniques, nous avons montre que l'expression ubiquitaire de tsl dans des femelles tsl mutantes induit les elements du pattern terminal et supprime la formation de l'abdomen. Ces resultats suggerent que tsl est le ligand qui se lie au recepteur torso. Troisiemement, nous avons mis en evidence un gene voisin, codant pour la sous unite beta de la proteine kinase calcium/calmoduline-dependante. Ce gene tres grand est exprime dans le systeme nerveux durant l'embryogenese, la vie larvaire et pupale. Quoique sa sequence en acides amines soit moderement conservee entre le rat et la drosophile, sa fonction dans la regulation de la transcription est bien conservee
31
Kurt, Arda. "Boundary Element Method Formulation And Its Solution In Forward Problem Of Electrocardiography By Using A Realistic Torso Model." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607232/index.pdf.
Full textAbstract:
The electrical currents generated in the heart propagate to the outward direction
of the body by means of conductive tissues and these currents yield a potential
distribution on the body surface. This potential distribution is recorded
and analyzed by a tool called electrocardiogram. It is not a problem, if this process
continues normallyhowever, when it is distorted by some abnormalities, the results will be fatal. Electrocardiography (ECG) is the technique dealing with the acquisition and interpretation of the electrical potentials recorded at the body surface due to the electrical activity of the heart. This can be realized by using one of the two approaches utilized in ECG namely
forward and inverse problems. The former one entails the calculation potentials on the body surface from known electrical activity of the heart and the latter one does the reverse. In this thesis, we will construct the body surface potentials in a realistic torso model starting from the epicardial potentials. In order to solve the forward problem, one needs a geometric model that includes the torso and the heart surfaces, as well as the intermediate surfaces or the intervening volume, and some assumptions about the electrical conductivity inside the enclosed volume. A realistic torso model has a complex geometry and this complexity makes it impossible to solve the forward problem analytically. In this study, Boundary Element Method (BEM) will be applied to solve the forward problem numerically. Furthermore, the effect of torso inhomogeneities such as lungs, muscles and skin to the body surface potentials will be analyzed numerically.
32
Bhaghavathula, N. V. S. Kapeesh. "Protection of occupants in car side impact crashes with an external inflatable upper torso restraint system." Thesis, Wichita State University, 2008. http://hdl.handle.net/10057/2086.
Full textAbstract:
Passenger vehicles in today’s world are more crashworthy than they used to be. Significant improvements have been done in the recent years to improve protection for occupants in the passenger vehicle; most of it was done in frontal crashes and only a small amount of improvement has been observed in side impact crashes. Thus, making it necessary, to do significant research on side impact crashes. Side impact standard FMVSS 214 was established to be used as a base for studying injury parameters during side impacts. But, this standard does not take into account the severities of Neck injury. Neck injuries, used to associate with front and rear side crashes can be life altering. Neck injuries are even given lowest ratings on the Abbreviated Injury Scale (AIS) 1. Recent studies show the importance of neck injury during side impacts, leading to need for immediate need to study the effect of neck injuries on occupants in passenger vehicles.
In this study, to address the above concern effort has been made to improve neck injury
protection during side impacts, using FMVSS 214 standard as the basis to study the effect of airbag on restraint system in improving occupant protection from neck injuries. Two different dummy models US-DoT SID (according to FMVSS 214 standard) and Hybrid III 50% dummy have been used for the study, and the results show improvement in Neck Injury Criterion (NIC) commonly used to assess neck injuries along with improvement in Head injury criterion (HIC) commonly used to evaluate head injuries with the use of airbag on restraint system.Wichita State University, College of Engineering, Dept. of Mechanical Engineering
Includes bibliographic references (leaves 93-95)
33
Davey, Sarah. "The effect of varying torso skin temperatures on thermal perceptions during moderate exercise in the heat." Thesis, University of Portsmouth, 2010. https://researchportal.port.ac.uk/portal/en/theses/the-effect-of-varying-torso-skin-temperatures-on-thermal-perceptions-during-moderate-exercise-in-the-heat(9629ae33-375f-44f6-90fb-e4f829597b38).html.
Full textAbstract:
Personal cooling garnents (peGs) are designed to relieve thermal stress in occupations that require the use of personal protective clothing (e.g. fire fighter, military personnel). The cooling source in peGs is usually delivered continuously, which over long periods requires a large battery source. Intermittent cooling has been found to be as effective as continuous cooling at maintaining thermal balance. Based on the observation that larger improvements in thermal perceptions are associated with rapid changes in skin temperature, it was hypothesised that intermittent cooling could also enhance thennal perceptions (i.e. temperature sensation and thennal comfort). The overall aim of the studies presented in this thesis was to test this hypothesis. In order to detect differences between intermittent and continuous cooling on thermal perceptions, it was important to use a reliable measurement tool to assess perceptual responses in conditions where a PCG would be utilised. The first study described in this thesis assessed the reliability of a graphic visual analogue scale (VAS) against a Likert scale (LS) for validity and reproducibility in the measurement of thennal perceptions in non-uniform, dynamic thermal environments. The study involved three identical conditions in which thermal perceptions were measured by both the V AS and LS in response to changes in the torso microclimate. During the condition, participants walked (Skm.hr-] , 2% incline) in a warm environment (3S0C, SO% relative humidity [RH]) and wore clothing (I.2 clo) that covered 88% of the body. The torso microclimate was manipulated by ventilating air of different temperatures and relative humidity through an air-perfused vest (APV). These thermal conditions were similar across all the studies presented in this thesis. The V AS were found to be slightly more reproducible for local thermal perceptions than the LS , and had greater validity during both stable and non-uniform, dynamic thermal environments. Therefore the use of the graphic VAS was adopted in all subsequent studies. To develop the intermittent cooling profiles that were assessed for their ability to enhance thermal perceptions, the second study involved ventilating different air temperatures (-15- 26°C) through the APV to determine what type of flu ctuations in skin temperatures are required to enhance thermal perceptions. The results suggested that the rate of change in mean skin temperature (f'sk) and torso skin temperatures (T sktorso) had a greater influence on thermal perceptions than absolute changes in Tsk and T sktorso. The results also confirmed the results from the first study, that increasing evaporative heat loss at the skin surface was the most effective method to manipulate the rate of change of skin temperatures, and consequently, thermal perceptions. To compare the capability of intermittent and continuous cooling profiles to enhance thermal perceptions, whilst maintaining thermal balance, the final study involved ventilating the APV with either fluctuating or continuous air velocities during both exercise and rest Three different intermittent cooling profiles were used; sinusoidal, sawtooth and step-change. Upon completion of the experiment, participants stated their preferred cooling profile. Based on the results it was concluded that intermittent cooling, which had 50% less air flow than continuous, maintained both thermal balance and thennal comfort when compared to continuous cooling. Out of the intennittent cooling profiles, the sinusoidal profile produced significantly cooler sensations and was 4111 participants' preferred choice. The results suggest that the presence of a significantly higher torso relative humidity (RH1orso) in the intennittent cooling profiles, compared to continuous profile, may have confounded their capability to enhance thennal perceptions over time. In addition, the cooling profi le that was perceived to the 'coolest' and/or the most ' stable' was generally the participants' preferred choice. This suggests that large fluctuations in skin temperature are not always perceived favourably. Based on the studies conducted as part of this thesis, it is concluded that in order to minimise high levels of RHtorso and provide smoother transitions in temperature sensation, an optimal cooling profile should consist of: 1) a sinusoidal pattern with a frequency greater tban 0.000139 Hz, 2) have a ratio of 2:1 ON/OFF periods, 3) OFF periods no longer tban 3 minutes, 4) highest flow rate not to exceed 255 L.min-], 5) provide a rate of change in f sk and t sklOISO of -{).29°C.min-1 and O. 78°C.min-], respectively, and 6) the incorporation of a drying agent into the design of an APV.
34
Jorgensen, Michael J. "Quantification and modeling of the lumbar erector spinae as a function of sagittal plane torso flexion /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486398195326904.
Full text
35
Bhaghavathula, N. V. S. Kapeesh Lankarani Hamid M. "Protection of occupants in car side impact crashes with an external inflatable upper torso restraint system." A link to full text of this thesis in SOAR, 2008. http://hdl.handle.net/10057/2086.
Full textAbstract:
Wichita State University, College of Engineering, Dept. of Mechanical Engineering.Copyright 2008 by N V S Kapeesh Bhaghavathula. All Rights Reserved. Includes bibliographical references (leaves 93-95).
36
DiLorenzo, Paul Carmen. "Breathing, laughing, sneezing, coughing model and control of an anatomically inspired, physically-based human torso simulation /." Diss., [Riverside, Calif.] : University of California, Riverside, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3350078.
Full textAbstract:
Thesis (Ph. D.)--University of California, Riverside, 2009.Includes abstract. Title from first page of PDF file (viewed January 28, 2010). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 100-106).
37
Heiman, Christopher James. "LAKESIDE: AN INDEPENDENT STUDENT FILM." Kent State University Honors College / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1313072280.
Full text
38
Voinier, Steven. "Passive Stiffness Characteristics of the Scoliotic Lumbar Torso in Trunk Flexion, Extension, Lateral bending, and Axial Rotation." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/52241.
Full textAbstract:
As the average American age increases, there is a need to study the spine biomechanics of adults with scoliosis. Most studies examining the mechanics of scoliosis have focused on in vitro testing or computer simulations, but in vivo testing of the mechanical response of a scoliotic spine has not yet been reported. The purpose of this study was to quantitatively define the passive stiffness properties of the in vivo scoliotic spine in three principle anatomical motions and identify differences relative to healthy controls.
Scoliotic (n=14) and control (n=17) participants with no history of spondylolisthesis, spinal fracture, or spinal surgery participated in three different tests (torso lateral side bending, torso axial rotation, and torso flexion/extension) that isolated mobility to the in vivo lumbar spine. Scoliotic individuals with Cobb angles ranging 15-75 degrees were accepted. Applied torque was measured using a uni-directional load cell, and inertial measurement units (IMU) recorded angular displacement of the upper torso relative to the pelvis and lower extremities. Torque-rotational displacement data were fit using a double sigmoid function, resulting in excellent overall fit (R2 > 0.901). The neutral zone (NZ) width, or the range of motion where there is minimal internal resistance, was then calculated. Stiffnesses within the NZ and outside of the NZ were also calculated. Stiffness asymmetries were also computed within each trial. These parameters were statistically compared between factor of population and within factor of direction.
There was an interaction effect between populations when comparing axial twist NZ width and lateral bend NZ width. The lateral bend NZ width magnitude was significantly smaller in scoliotic patients. NZ stiffness in the all three directions was greater in the scoliotic population. There was no significant difference in asymmetrical stiffness between populations.
The present study is the first investigation to quantify the in vivo neutral zone and related mechanics of the scoliotic lumbar spine. Future research is needed to determine if the measured lumbar spine mechanical characteristics can help explain progression of scoliosis and complement scoliosis classification systems.Master of Science
39
Sherman, Brian Randall. "The effect of a commercially available abdominal support belt on torso posture, lift strength, and spinal compression." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-01102009-063900/.
Full text
40
Tayba, Ahmad. "Amélioration de la partie supérieure du robot HYDROïD pour les tâches bi-manuelles et la manipulation." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV102/document.
Full textAbstract:
Ma thèse vise à contribuer au développement et l’amélioration de la cinématique de la partie supérieure du robot HYDROïD pour des tâches bi-manuelles, tout en basant sur une étude biomécanique de cette partie chez l’être humain.Pour atteindre notre objectif majeur, ce travail adopte dans un premier temps une nouvelle structure hybride de 4 degrés de liberté (ddl) pour le torse du robot, distribués en 3 ddl au niveau lombaire et un ddl au niveau thoracique. Cette structure était identifiée après une analyse de l’espace de travail d’un modèle multi-corps simulant la colonne vertébrale d’un être humain, et une étude d’optimisation de ce modèle permettant la synthèse de la structure envisagée.Dans un second temps, une amélioration de la cinématique du bras du robot a été mise en place, en introduisant la notion de l’épaule complexe au présente structure. Le choix de ce nouveau degré de liberté était le fruit d’une approche systématique pour augmenter l’anthropomorphisme géométrie du bras souhaité vers un bras humain de la même taille.Les 2 structures proposées ont passé par la suite par la phase de conception mécanique tout en respectant les contraintes géométriques et en se basant sur l’énergie hydraulique comme étant l’énergie d’ actionnement de ces systèmes. Enfin, le Modèle Géometrique Inverse (MGI) pour la solution générique du torse a été établi et son adaptation à notre cas particulier a été identifiée. Une solution optimisée pour ce mécanisme basée sur 2 différents critères a ensuite été donnéeMy thesis aims at contributing to the development and improvement of the upper body of HYDROïD robot for bi-manual tasks, while basing on a bio-mechanical study of this part of the human being. To reach our major goal, this work adopts, at first, a novel hybrid structure of 4 degrees of freedom (DOF) for the trunk of the robot, distributed in three DOF at the lumbar level and one DOF at the thoracic level. This structure was identified after an analysis of the work-space of a multi-body model feigning the vertebral column of a human being, and an optimization study of that model allowing the synthesis of the envisaged structure. Secondly, an improvement of the kinematics of the robor arm was organized, by introducing the notion of the shoulder complex in the present structure. The choice of this new degree of freedom was the fruit of a systematic approach to increase the anthropomorphism geometry of the arm wished towards a humanitarian arm of the same size.The two proposed structures crossed afterward by the mechanical design phase while respecting all the geometrical constraints and by using the hydraulic energy as being the type of actuation of these systems. Finally, the Inverse Geometrical Model (IGM) for the generic solution of the trunk was established and its adaptation to our particular case was identified. An optimized solution for this mechanism based on 2 various criteria was then given
41
Jardim, Marília Hernandes. "O corset na moda ocidental: um estudo sociossemiótico sobre a constrição do torso feminino do século XVIII ao XXI." Pontifícia Universidade Católica de São Paulo, 2014. https://tede2.pucsp.br/handle/handle/4658.
Full textAbstract:
Made available in DSpace on 2016-04-26T18:14:44Z (GMT). No. of bitstreams: 1
Marilia Hernandes Jardim.pdf: 54375032 bytes, checksum: 754a2bce65f2359960e8f42da67f083a (MD5)
Previous issue date: 2014-12-03Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This study investigates the feminine torso constriction obtained through the corset use, which presents a fundamental role on the feminine body conformation, and a pronounced function of transforming the social logic. Also, the silhouette configurations by him realized significantly alter the interaction between constricted bodies and other subjects. It is possible to postulate thus that the corset is an interactive subject, whose role is part of the social logic shaping, and not its reflex. From this point, the studied problem is the identification of the relation between the conformation of the silhouette and a consequent social interaction determination, arisen from the apprehension modes that surface from the body plastic endowed by the garment. Far from constituting a historical fashion problem, the use of constrictive lingerie present as a hodiernal topic, especially on the West, where significant efforts are devoted on the development of shaping objects, consumed by women from all ethnicities and social backgrounds. In order to understand the meanings that emerge from this complex and risky interaction between corset and body, it is necessary to seek the phenomenon origins on 18thcentury western fashion, when the corset use as an undergarment began. From this use, we purpose the identification of emblematic moments of such practice, as well as the ruptures on its continuity, designing to recognize, in those fractures, the specific roles assumed by corset and body, to categorize the transits between corset use continuity and discontinuity. For such, the study call on an extensive research corpus, formed by corset, crinoline and gown images collected from museum collections, as well as virtual stores lingerie photographs and images that can help on reconstructing the studied body tendencies, as advertising and painting reproductions. In the light of Landowski's socio-semiotic, Greimas's semiotic theory and Floch's and Oliveira's visual semiotics, we investigated the uses and apparel configurations, isolating the relations of complementarity between the roles played by the actors corset and body, which underlies the dominance of the first as body's addresser, as well as other relations between those two roles, which reveal a body leadership, important former of fashion and social surroundings passages
Esta pesquisa investiga a constrição do torso feminino praticada pelo uso do corset, que apresenta um papel fundamental na conformação do corpo feminino e uma marcada função na transformação da lógica social, uma vez que as configurações de corpo por ele realizadas alteram significativamente a interação entre os corpos constritos e os demais sujeitos formadores deste entorno social. É possível postular que o corset pode ser abordado como um sujeito da interação, cujo papel aparece como parte da formação das lógicas sociais, e não como um reflexo destes contextos. A partir daí, o problema abordado é a identificação da relação entre a conformação da silhueta e uma consequente determinação da interação social, advinda dos modos de apreensão que emergem da plástica conferida ao corpo pelo traje. Longe de constituir uma problemática pertinente ao estudo da moda de época, o uso de lingeries constritoras apresenta-se como um temário extremamente atual, sobretudo no Ocidente, onde grandes esforços são empregados pela indústria na produção de objetos constritivos, difundidos entre mulheres de todas as etnias e classes sociais. Para entender os sentidos que emergem desta complexa e arriscada interação entre corset e corpo, se faz necessária a busca das origens deste fenômeno na moda ocidental do século XVIII, quando consolidou-se o uso do corset como roupa interior. A partir deste uso, buscamos identificar momentos emblemáticos desta prática, bem como as rupturas em sua continuidade, com o objetivo de localizar nestas fraturas os papéis específicos assumidos, nas interações, pelo corset e pelo corpo, para categorizar, a partir deles, os trânsitos entre continuidade e descontinuidade do uso do corset. Para tal, este estudo recorre a um extenso corpus de pesquisa, formado por imagens de corsets, crinolinas e trajes colhidas de acervos de museus, bem como fotografias de lingeries comercializadas em lojas virtuais, além de imagens que auxiliam na recontrução das tendências de corpo estudadas, como publicidades e reproduções de pinturas. À luz da sociossemiótica de Landowski, da teoria semiótica de Greimas e da semiótica visual de Floch e Oliveira, conduzimos uma investigação destes usos e configurações vestimentares, que nos possibilitou isolar as relações de complementaridade entre os papéis dos atores corset e corpo na narrativa vestimentar, que embasam a dominância do primeiro como destinador do corpo, além das demais relações entre estes dois papéis, reveladoras de um maior protagonismo do corpo, importante formador das passagens da moda e do entorno social que a engloba
42
Yassierli, Yassierli. "Muscle Fatigue during Isometric and Dynamic Efforts in Shoulder Abduction and Torso Extension: Age Effects and Alternative Electromyographic Measures." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29509.
Full textAbstract:
Aging has been associated with numerous changes in the neuromuscular system. Age effects on muscular performance, however, have been addressed only in limited contexts in earlier research. The present work was conducted primarily to investigate age-related effects on muscle capacity (fatigue and endurance) during isometric and dynamic efforts. This work was also motivated by current theories on muscle fatigue as a potential risk factor for musculoskeletal disorders and recent demographic projections indicating a substantial increase of older adults in the working population. Four main experiments were conducted to investigate development of muscle fatigue during isometric and intermittent efforts in shoulder abduction and torso extension at different contraction levels. Two age groups were involved (n=24 in each), representing the beginning and end of working life. Findings from this study demonstrated that the older group exhibited slower progressions of fatigue, though the age effect was more consistent for the shoulder than the torso muscles. This implied a muscle dependency of the influence of age on fatigue. Several interaction effects of age and effort level were also observed, suggesting that both task and individual factors should be considered simultaneously in job design.
The present investigation also sought to develop alternative electromyography (EMG)-based fatigue parameters for low-level isometric and dynamic contractions, two areas in which improvements are needed in the sensitivity and reliability of existing EMG indices. Several alternative EMG indices were introduced, derived from logarithmic transformation of EMG power spectra, fractal analysis, and parameter estimation based on a Poisson distribution. Potential utility of several of these alternative measures was demonstrated for assessment of muscle fatigue.Ph. D.
43
Muller, Matthew David. "The influence of interval vs. continuous exercise on thermoregulation, torso hemodynamics, and finger dexterity in the cold (5°C)." Kent State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=kent1255294775.
Full text
44
Lavender, Steven Alan. "The role of cognitive functions and biomechanical preparatory responses in maintaining spinal stability during sudden loading of the torso /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487685204967361.
Full text
45
Muller, Matthew D. "The influence of interval vs. continuous exercise on thermoregulation, torso hemodynamics, and finger dexterity in the cold (5°C)." [Kent, Ohio] : Kent State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1255294775.
Full textAbstract:
Thesis (Ph.D.)--Kent State University, 2009.Title from PDF t.p. (viewed April 14, 2010). Advisor: Ellen Glickman. Keywords: cold; exercise; dexterity; temperature; blood flow; homeostasis. Includes bibliographical references (p. 83-98).
46
Benali, Khairidine. "Commande d'un système robotisé de type torse humanoïde pour le transport de colis de taille variable." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMLH22.
Full textAbstract:
Dans les entrepôts logistiques, les moyens robotiques sont de plus en plus fréquemment utilisés pour réduire les temps non productifs, déplacer des charges lourdes, limiter les risques d'erreurs pendant les opérations de préparation de commandes (picking, de/palettisation,...), faire des inventaires (drones,...) et améliorer les conditions de travail des opérateurs humains. Bien que l'homme reste incontournable pour les tâches de préparation de commande à cause de son adresse et de son aptitude à s'adapter à des tâches toujours différentes, l'augmentation de la productivité est souvent synonyme d'augmentation de la pénibilité au travail (troubles musculo-squelettiques,...). Les travaux de recherche présentés dans cette thèse sont une contribution à la robotisation des opérations de dé/palettisation pour des colis de taille variable qui exigent une grande polyvalence du système de préhension. La solution innovante que nous proposons consiste à utiliser un torse humanoïde équipé de deux bras manipulateurs munis de préhenseurs adaptés à la saisie d'objets de taille et de masse différentes. La principale contribution porte sur la conception d'une loi de commande hybride Force/Position-Position avec commutations, estimation du glissement de l'objet, prise en compte de la compliance et correction de la force de serrage pendant la manipulation. Cette solution suppose d'assurer la collaboration entre les deux bras manipulateurs et de s'adapter à l'environnement matériel et humain (cobotique)In logistics warehouses, automation in the sense of robotization is frequently being employed to cut down production times by efficiently managing the processes of picking heavy loads, place, pack and palletize, while reducing the risks and errors to improve the working conditions of human operators along the way. The flexibility of human is fundamental for order preparation owing to adaptive skills for task variation, but at the same time increasing productivity is complemented with fatigue (musculoskeletal disorders). In this context the research presented in this thesis is a contribution in the robotization of palletization operations requiring exceptional versatility of manipulation and gripping. We have proposed an innovative solution of utilizing a humanoid torso equipped with two manipulator arms with adaptive grippers to grasp and hold the objects of variable size and mass. The main contribution of research is the development of a hybrid Force / Position-Position control law with commutation and estimation of the object surface slip, while taking into account the compliance and correction of the clamping force during handling. The execution of the control involves the collaboration of the two arms for coordinated manipulation and adaptation to the material and the human environment (cobotics)
47
Rackwitz, Christian [Verfasser]. "Validierung eines neu entwickelten, durchströmten Torso-Modells zur Evaluation der Wärmeentwicklung epikardialer und endokardialer Herzschrittmacher-Elektroden im 1,5-Tesla-MRT / Christian Rackwitz." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2020. http://d-nb.info/1218077611/34.
Full text
48
Janody, Florence. "Etude de l'interaction entre Torso et Bicoid au cours du développement précoce de l'embryon de drosophile : Approche du mécanisme moléculaire et analyse du rôle biologique." Aix-Marseille 2, 1999. http://www.theses.fr/1999AIX22072.
Full text
49
Martínez, Mateu Laura. "Mapping of the electrical activity of human atria. Multiscale modelling and simulations." Doctoral thesis, Universitat Politècnica de València, 2018. http://hdl.handle.net/10251/104604.
Full textAbstract:
La fibrilación auricular es una de las arritmias cardíacas más comunes observadas en la práctica clínica. Por lo tanto, es de vital importancia desarrollar nuevas tecnologías destinadas a diagnosticar y acabar con este tipo de arritmia, para mejorar la calidad de vida de los pacientes y reducir los costes de los sistemas nacionales de salud.
En los últimos años ha aumentado el uso de las nuevas técnicas de mapeo auricular, basadas en sistemas multi-electrodo para mapear la actividad eléctrica en humanos. Dichas técnicas permiten localizar y ablacionar los impulsores de la fibrilación auricular, como son las fuentes focales o los rotores. Sin embargo, todavía existe incertidumbre sobre su precisión y los procedimientos experimentales para su análisis están limitados debido a su carácter invasivo. Por lo tanto, las simulaciones computacionales son una herramienta muy útil para superar estas limitaciones, al permitir reproducir con fidelidad las observaciones experimentales, dividir el problema bajo estudio en sub-estudios más simples, y realizar investigaciones preliminares imposibles de llevar a cabo en el práctica clínica.
Esta tesis doctoral se centra en el análisis de la precisión de los sistemas de mapeo multi-electrodo a través de modelos y simulaciones computacionales. Para ello, desarrollamos modelos realistas multi-escala con el objetivo de simular actividad eléctrica auricular reentrante, en primer lugar en una lámina de tejido auricular, y en segundo lugar en las aurículas completas. Posteriormente, analizamos los efectos de las configuraciones geométricas multi-electrodo en la precisión de la localización de los rotores, mediante el uso de agrupaciones multi-electrodo con distancias inter-electrodo equidistantes, así como a través de catéteres de tipo basket con distancias inter-electrodo no equidistantes. Después de calcular los electrogramas unipolares intracavitarios, realizamos mapas de fase, detecciones de singularidad de fase para rastrear los rotores, y mapas de frecuencia dominantes. Finalmente, descubrimos que la precisión de los sistemas de mapeo multi-electrodo depende de su posición dentro de la cavidad auricular, de la distancia entre los electrodos y el tejido, de la distancia inter-electrodo, y de la contribución de las fuentes de campo lejano. Además, como consecuencia de estos factores que pueden afectar a la precisión de los sistemas de mapeo multi-electrodo, observamos la aparición de rotores falsos que podrían contribuir al fracaso de los procesos de ablación de la fibrilación auricular.Atrial fibrillation is one of the most common cardiac arrhythmias seen in clinical practice. Therefore, it is of vital importance to develop new technologies aimed at diagnosing and terminating this kind of arrhythmia, to improve the quality of life of patients and to reduce costs to national health systems. In the last years, new atrial mapping techniques based on multi-electrode systems are increasingly being used to map the atrial electrical activity in humans and localise and target atrial fibrillation drivers in the form of focal sources or rotors. However, significant concerns remain about their accuracy and experimental approaches to analyse them are limited due to their invasive character. Therefore, computer simulations are a helpful tool to overcome these limitations since they can reproduce with fidelity experimental observations, permit to split the problem to treat into more simple substudies, and allow the possibility of performing preliminary investigations impossible to carry out in the clinical practice. This PhD thesis is focused on the analysis for accuracy of the multielectrode mapping systems through computational models and simulations. For this purpose, we developed realistic multiscale models in order to simulate atrial electrical reentrant activity, first in a sheet of atrial tissue and, then, in the whole atria. Then, we analysed the effects of the multi-electrode geometrical configurations on the accuracy of localizing rotors, by using multi-electrode arrays with equidistant inter-electrode distances, as well as multi-electrode basket catheters with non-equidistant inter-electrode distances. After computing the intracavitary unipolar electrograms, we performed phase maps, phase singularity detections to track rotors, and dominant frequency maps. We finally found out that the accuracy of multi-electrode mapping systems depends on their position inside the atrial cavity, the electrode-to-tissue distance, the inter-electrode distance, and the contribution of far field sources. Furthermore, as a consequence of these factors, false rotors might appear and could contribute to failure of atrial fibrillation ablation procedures.
La fibril·lació auricular és una de les arítmies cardíaques més comuns observades en la pràctica clínica. Per tant, és de vital importància desenvolupar noves tecnologies destinades a diagnosticar i acabar amb aquest tipus d'arítmia, per tal de millorar la qualitat de vida dels pacients i reduir els costos dels sistemes nacionals de salut. En els últims anys, ha augmentat l'ús de les noves tècniques de mapeig auricular, basades en sistemes multielèctrode per a mapejar l'activitat elèctrica auricular en humans. Aquestes tècniques permeten localitzar i ablacionar els impulsors de la fibril·lació auricular, com són les fonts focals o els rotors. No obstant això, encara hi ha incertesa sobre la seua precisió i els procediments experimentals per al seu anàlisi estan limitats a causa del seu caràcter invasiu. Per tant, les simulacions computacionals són una eina molt útil per a superar aquestes limitacions, en permetre reproduir amb fidelitat les observacions experimentals, dividir el problema sota estudi en subestudis més simples, i realitzar investigacions preliminars impossibles de dur a terme en el pràctica clínica. Aquesta tesi doctoral es centra en l'anàlisi de la precisió del sistemes de mapeig multielèctrode mitjançant els models i les simulacions computacionals. Per a això, desenvolupàrem models realistes multiescala per tal de simular activitat elèctrica auricular reentrant, en primer lloc en una làmina de teixit auricular, i en segon lloc a les aurícules completes. Posteriorment, analitzàrem els efectes de les configuracions geomètriques multielèctrode en la precisió de la localització dels rotors, mitjançant l'ús d'agrupacions multielèctrode amb distàncies interelèctrode equidistants, així com catèters de tipus basket amb distàncies interelèctrode no equidistants. Després de calcular els electrogrames unipolars intracavitaris, vam realitzar mapes de fase, deteccions de singularitat de fase per a rastrejar els rotors, i mapes de freqüència dominants. Finalment, vam descobrir que la precisió dels sistemes de mapeig multielèctrode depèn de la seua posició dins de la cavitat auricular, de la distància entre els elèctrodes i el teixit, de la distància interelèctrode, i de la contribució de les fonts de camp llunyà. A més, com a conseqüència d'aquests factors, es va observar l'aparició de rotors falsos que podrien contribuir al fracàs de l'ablació de la fibril·lació auricular.
Martínez Mateu, L. (2018). Mapping of the electrical activity of human atria. Multiscale modelling and simulations [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/104604
TESIS
50
Andrade, Daniela da Costa Maia de. "Efeito em curto prazo da corrente interferencial associado a cinesioterapia no tronco de paciente com acidente vascular encefálico." Pós-Graduação em Ciências da Saúde, 2018. http://ri.ufs.br/jspui/handle/riufs/8553.
Full textAbstract:
Introduction: Among the main causes of disability associated with stroke, are: impairment of voluntary movements, spasticity, pain and loss of selective activity of muscles responsible for trunk control. The use of interferential current (IFC) in stroke patients has been recently reported in the literature for managing pain and spasticity. Aims: 1. to identify the evidence from studies evaluating the effects of IFC in patients with central neurological diseases (a systematic review); 2. To determine the short-term effect of IF associated with kinesiotherapy on pain of stroke patients; 3. To investigate the short term effects of IFC associated with kinesiotherapy on motor performance and functional gains of the trunk of patients with stroke. Methods: 1) A systematic review of clinical trials on 8 databases (Medline, Scopus, Science Direct, Web of Science, CINAHL, Scielo, Cochrane Central Register and PEDro) was conducted by two investigators by using the following key-words: interferential current OR interferential current therapy OR interferential electrical stimulation OR interferential electrical stimulation therapy OR interferential therapy OR interferential stimulation. The Cochrane collaboration tool was used for methodological quality analysis. 2 and 3) A randomized, double-blinded, placebo-controlled, crossover-type clinical trial was performed. 36 stroke patients were recruited and randomly included in one of two groups: active IFC group (IFC application + kinesiotherapy of trunk) and placebo IFC group (30 minutes of placebo IFC + kinesiotherapy of trunk). Both groups received 10 session of treatment, twice a week, for 60 minutes, with 05 sessions at each treatment group and a washout period of one week between treatments. Results: 1) 2004 studies were found, but only two were included based on the proposed inclusion criteria. After one single session, IFC was effective in reducing pain and spasticity and at improving balance, gait and range of motion of stroke patients. 2 and 3) there was improvement in pain during movement, pain catastrophizing and reaching of the affected member, when comparing pre and post treatment averages. There was no change in fatigue, self-esteem, motivation, trunk control, posture, flexibility and muscle tone in both groups. Conclusion: IFC might have influenced the improvements in trunk control and motor performance of stroke patients when associated with kinesiotherapy. It is recommended that new studies with a higher number of sessions be conducted to better clarify the effects of IFC associated with kinesiotherapy.Introdução: Entre as principais causas de incapacidades do AVE podemos citar: o comprometimento dos movimentos voluntários, a espasticidade, a dor e a perda da atividade seletiva dos músculos responsáveis pelo controle do tronco. O uso da corrente interferencial (CI) em pacientes com AVE tem sido reportado recentemente na literatura científica, na prática isolada, no tratamento da dor e na espasticidade. Objetivos: 1. Identificar a evidência dos estudos que avaliaram os efeitos da CI em pacientes com doenças neurológicas centrais (revisão sistemática); 2. Determinar o efeito da CI associado a cinesioterapia na dor dos pacientes com AVE; 3. Investigar a performance motora e ganhos funcionais do tronco dos pacientes com AVE após aplicação de CI associado a cinesioterapia. Método: 1) busca sistemática de estudos em 8 bases de dados (Medline, Scopus, Science Direct, Web of Science, CINAHL, Scielo, Cochrane Central Register e PEDro) realizada por dois investigadores, através dos descritores interferential current OR interferential current therapy OR interferential electrical stimulation OR interferential electrical stimulation therapy OR interferential therapy OR interferential stimulation. Para avaliação metodológica desses estudos, foi utilizada a ferramenta da Colaboração Cochrane. 2 e 3) Ensaio clínico randomizado, controlado por placebo e duplamente encoberto, do tipo crossover. Foram recrutados 36 pacientes com AVE, que foram aleatoriamente incluídos em um dos dois grupos de estudo: grupo CI Ativa (aplicação de CI por 30 minutos + cinesioterapia de tronco) e grupo CI Placebo (placebo da CI + cinesioterapia de tronco). Ambos os grupos receberam intervenção por 10 sessões, duas vezes por semana, 60 minutos, sendo 05 sessões para cada forma de tratamento e um período de washout de uma semana. Resultados: 1) Foram encontrados 2004 estudos, porém apenas dois artigos foram incluídos por seguirem os critérios de inclusão propostos. Após administração única, a CI mostrou-se eficaz na redução da dor, da espasticidade e na melhora do equilíbrio, da marcha e da amplitude de movimento de ombro de pacientes pós AVE. 2 e 3). Houve melhora na dor em movimento, catastrofização da dor e no alcance para o lado acometido quando comparadas as médias pré e pós-tratamento. Não houve alteração da fadiga, da autoestima, da motivação, do controle de tronco, da postura, da flexibilidade e do tônus em ambos os grupos. Conclusão: A CI pode ter influenciado a melhora do tronco e performance motora de pacientes pós AVE associado a cinesioterapia. Recomenda-se, assim, a realização de novos estudos com um maior número de sessões para melhor esclarecer os efeitos da CI associada a cinesioterapia.
São Cristóvão, SE