Quantification of intervertebral efforts using a multibody dynamics approach : application to scoliosis

Spine surgery planning involves many decisions for which the surgeon has not enough information, and for which biomechanical models might be helpful. Research studies show a high variability in decision making in the planning of scoliosis surgery by experienced groups of surgeons. That variability is problematic because it may cause complications for the patient, such as revision surgery or an increased limitation in spine mobility. Therefore, a biomechanical model for spine surgery planning may be useful in providing the surgeon the information needed to propose the best treatment. In this context, intervertebral efforts represent an essential input in assisting diagnosis and subsequently guiding the surgical planning of scoliosis. The long-term motivation of this thesis consists in assisting surgeons in obtaining quantitative - kinematic and dynamical - information that will allow them to improve the surgical planning of scoliosis, by specifying the set of vertebrae to be fused, while preserving the spinal mobility. In regards to this final motivation, the thesis seeks to develop a clinical protocol based on experimental data and on a multibody model of the upper body, to quantify the intervertebral efforts for idiopathic scoliotic adolescents in standing up position (statics) and during moderate gait (dynamics). The estimation of intervertebral efforts is based upon four interwoven topics: patient physiology, spine geometry, spine and pelvis kinematics, as well as muscular forces. In line with this, if this work’s final objective is to be met, three targeted contributions must be achieved: -The elaboration of a clinical protocol focusing on assessment of the scoliotic patient’s parameters: necessary anthropomorphic data, spine shape and kinematics, and muscle force calibration; -The development of a physiologically-based multibody model of the upper body, able to predict the spine’s kinematics and dynamics during gait; -In terms of internal efforts, using the multibody model and experimental input conjointly should allow exploration and discussion of plausible solutions, thanks to the high potentials offered by both models and computer simulations.(FSA - Sciences de l'ingénieur) -- UCL, 201

Simulación de una Montaña Rusa usando teorías multicuerpo

Mechanical system simulations have become a very important tool in the development of new technologies. In this thesis, a simulation of a roller coaster using the Multibody Systems method was developed. Multibody systems are groups of bodies joined by articulations that can allow rotation and/or translation between the bodies. This thesis concentrates on the construction of a valid wheel/rail contact model that is necessary to perform a simulation.Las simulaciones de sistemas mecánicos se han convertido en una herramienta muy importante para el desarrollo de nuevas tecnologías. En esta tesis se realizó una simulación de una montaña rusa a través del método de los Sistemas Multicuerpo. Un sistema multicuerpo es un conjunto de cuerpos rígidos unidos entre sí por medio de articulaciones que pueden permitir ya sea rotación y/o traslación entre estos. En esta tesis se puso énfasis en la construcción de un modelo de contacto válido entre la rueda y el riel de la montaña rusa, un ingrediente fundamental al momento de hacer simulaciones

Intervertebral force computation: a non invasive computation method

INTRODUCTION : Spine surgery planning involves many decisions for which the surgeon has not enough information, and for which a dynamic model can be helpful. Research studies show a high variability in decision making in the planning of scoliosis surgery by experienced surgeons (Robitaille et al. 2007). That variability is problematic because this lack of information may cause complications for the patient, such as revision surgery or an increased limitation in spine mobility. Therefore, a biomechanical model for spine surgery planning can be useful in providing the surgeon with the information needed to propose the best treatment. In this context, intervertebral efforts represent an essential input in assisting diagnosis and subsequently guiding the surgical planning of scoliosis. [...

Intervertebral efforts quantification using a multibody dynamics approach: application to scoliosis

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Quantification of Intervertebral Efforts Using a Multibody Dynamics Approach: Application to Scoliosis

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Customized MBD models to contribute to answering clinical questions about the spine in motion

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MULTIBODY SIMULATION OF A CRASH TEST ATTENUATOR MADE OF RECYCLED MATERIALS

A multibody system (MBS) model of a scaled experimental attenuator is being developed, the aim being to design a new kind of truck-mounted attenuator (TMA) made of recycled materials. In this work, we implement the elasto-plastic behavior of the recycled material modules as a constitutive law of a MBS model which also includes the impacting vehicle, in order to simulate the collision. The simulation results aim at predicting the potential risk for the occupants, referring to the Acceleration Severity Index (ASI), and for the road workers by considering the truck displacement. The envisaged collisions consider a vehicle weighting from 1 ton (at 100 km/h) up to 13 tons (at 70 km/h)