Rehabilitation and prevention biomechanics
- Biomechanical modelling of head impacts using finite elements, finite volumes and smooth particle hydrodynamics.
- Vibration analysis of human head. Experimental and analytical approach.
- Dynamic biomechanical analysis of the musculo-skeletal system of the lower extremities
- The mechanical interaction between human body and sleeping system
- The use of vibration analysis to measure the fixation of enodies implant
- Biomechanics of hind foot pathologies
- Design of intelligent bedding systems towards optimal sleep ergonomics
- Pressure distribution for Easy Sleep Project
- Multiparameter analysis to objectify, optimize and automate sleeping quality
- Real time intra-articular pressure measurements of the hind foot
Biomechanical modelling of head impacts using finite elements, finite volumes and smooth particle hydrodynamics.
There is a need for a reliable numerical head model that accurately simulates the biomechanical response of the head after an impact to support the study of head protection, to test different hypotheses and to carry out parameter studies. There are already different numerical head models available but each of them without a good representation of the cerebrospinal fluid (CSF). This CSF however, has a large influence on the movement of the brain relative to the skull and consequently also on the different injury mechanisms.
Therefore the main goal of this PhD is to improve the representation of the CSF and the interaction between fluid and structure (CSF and brain). For this improvement, a combination of finite elements and finite volumes will be used together with a new technique, called smooth particle hydrodynamics. Finally this PhD will result in a new numerical head model that can be used for helmet optimization and to define new head injury criteria.
Vibration analysis of human head. Experimental and analytical approach.
Vibration in structures occurs mostly due to dynamic loadings. Considering the human head a mechanical structure this will also vibrate to some extend. We hypothesis that a direct impact on the head, due to for example a traffic collision, will generate high vibration at the skull, which in turn can be damaging on the brain. Therefore the main focus of this work is to quantify the vibrations of the skull and head due to impacts by means of experimental modal analysis and to investigate the link between these vibrations and brain injuries. An underlying goal of this thesis is to develop a finite element model to simulate the vibration response of the human head to impacts.
Dynamic biomechanical analysis of the musculo-skeletal system of the lower extremities
Orthopaedic physicians and physiotherapists are required to analyze a variety of movements related to the knee joint and the foot-ankle complex. Currently, a motion capturing device to reconstruct bone motion in the rear foot is developed. A biomechanical model of the ankle joint, combined with a video raster stereography (VRS) measurement of the upper foot surface will allow to reconstruct approximate bone motion without skin artefacts. The new developed technique will be validated with our custom designed and custom built gait simulator during several cadaveric studies. The device can be used as a diagnostic tool for foot surgeons and podiatrists, and can help in future biomechanical research to explore the cause and effect of several foot pathologies.
Related project: FWO-project, Chair Baron J.-P. Berghmans
The mechanical interaction between human body and sleeping system
We spend approximately one third of our lives in bed, while our inactive body depends on the sleeping system (i.e. mattress + supporting structure + head cushion) we are lying and relying on. Biomechanical research points out that the mechanical characteristics of mattresses and mattress support structures have a major influence on the position of the spine in both a lateral and a supine sleeping position. Through numerical simulations and precise anthropometric modeling, the influence of individual body characteristics and sleeping system properties on the position and the shape of the spine can be predicted. Validation of these simulations is situated on two levels. On the one hand, spinal deformations of persons on different sleeping systems can be determined by white light raster line triangulation (WLRT) measurements. On the other hand, it is of utmost importance to carry out actual sleep experiments in which the influence of biomechanical parameters on sleep quality, as determined through polysomnographic readings, can be established.
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Simulation and validation of the spinal deformation for a person lying in lateral sleeping posture on a specific sleeping system |
The use of vibration analysis to measure the fixation of enodies implant
The main goals of my thesis research are to etablish a fundamental insight in the connection between contact and stress conditions at the interface between a prosthesis and the host bone and a intraoperative measurable quantity (FRF) in a generic way and the developement of intraoperative protocols based on this insight. This will allow the surgeon to assess the initial stability of a prosthesis during an operation in an absolute way. This initial stability is crucial for the long term performance of a prosthesis as it limits the amount of micromotion, which is a conditio sine qua non for osseointegration. Lack of initial stability is one of the main factors leading to a failure of the prosthesis. A range of protocols will be developed for a broad spectrum of prostheses that will allow the surgeon to reach an optimal fixation during operation and ensure a better long-term outcome of the prosthesis.
Biomechanics of hind foot pathologies
The aim of this study is to investigate the action of the muscle force on the foot during gait. We perform measurements on cadaver feet, using a gait simulator, a motion analysis system and a pressure platform to examine the effect of isolated muscle perturbations on foot kinematics and plantar pressure. This gives us the possibility to determine the etiology of several foot pathologies. The obtained experimental results will be used for the validation of a biomechanical foot-ankle model. Besides that, these results will be used to evaluate in vivo measurements with (non-invasive) skin markers.
Chair Baron J.-P. Berghmans-Dereymaeker
Design of intelligent bedding systems towards optimal sleep ergonomics
Although sleep comprises nearly one third of our life time, it is surprising to find out how little research focuses on proper body support during the night. Optimal support is highly individual and influenced by both the body contours and the adopted posture. Ideally, our sleep system should adapt to these changes by optimizing its stiffness distribution. A new approach in the development of state-of-the-art sleep systems consists of continuously monitoring the mattress indentation due to the sleeper’s weight. The main goal of this project is to develop a control algorithm that uses these indentation measurements to optimize the stiffness distribution of the mattress. This will lead to optimal body support and/or pressure distribution for every person, and during the entire night. Validation of the sleep system will focus on (i) preventing and decreasing back pain and (ii) the development of pressure ulcers in bedridden individuals.
Pressure distribution for Easy Sleep Project
During sleeping, differnt body weights and shapes, different sleeping positions, and different bed materials can cause various interface pressure between body and material surfaces. Therefore, interface pressure distribution can be used to differentiate the relationship of interface pressure for each location, each bed material, each sleeping position, etc. The aim of this project is to find how relationships of sleep positions and/or height-levels of mattress do affect on pressure distribution to develop customized mattress for better sleep.
Multiparameter analysis to objectify, optimize and automate sleeping quality
During various projects, a lot of sleep measurement data was and is still being collected. Voluntary test subjects sleep up to 6 different nights in a sleep laboratory (each night a different environmental condition). During the first part of this thesis, a thorough analysis will be performed on the data collected up till now, in order to find significant differences between the different environmental conditions. A second part of this thesis consists in an attempt to objectify the subjective concept 'sleep quality', in order to find ways to optimize it. In a last part, an attempt will be made to derive the polysomnographic scoring from data which is obtained in a stand-alone way. This means that only data can be used that was obtained from sources directly measured in the bed itself, without the patient having to wear any sensors himself. This would enable raw sleep analysis without any personal interference during a very long period, e.g. to be used in the healthcare and revalidation sector.
Real time intra-articular pressure measurements of the hind foot
The human foot is a complicated structure that needs to be as flexible as rigid, depending on the situation. Moreover, it is a structure that should withstand huge amounts of loads in order to enable humans perform a series of movements. The goal of this project is to investigate the magnitude and pattern of the developed pressures in the intra-articular areas inside the human foot. This will lead to a better understanding of how several different movements or pathologies can affect the endurance of the ankle, while at the same time it will allow the development of better total ankle prostheses.
Chair Baron J.-P. Berghmans-Dereymaeker
