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Brain tissue characterization for determining head injury thresholds
Contusions can develop into massive hemorrhages and are the cause of about 2/3 of Acute Subdural Hematomas. Most brain contusions arise at the base of the frontal and temporal lobes and that the frontal and temporal contusions tend to show a symmetrical distribution after impacts in the sagittal plane. A quasi-static MR study on human volunteers performed at KU Leuven showed that head motion in the sagittal plane results in an up and down motion of the frontal and temporal lobes. The nature of the relative brain-skull motion after occipital head impacts was previously also confirmed by means of cadaver experiments. These findings, in conjunction with data from animal contusion models, indicate that compressive stresses developed in the cortex, secondary to the up and down beating on the skull base, are the causative mechanism for the typical frontotemporal contusions. If tissue level failure criteria were known for the cerebral cortex in terms of critical compressive stress, it could be possible to investigate critical head rotational acceleration levels for different pulse durations and acceleration directions using the head finite element modeling expertise acquired in our previous research. The quality of finite element predictions depends on accurate material definitions used for all components. While the material properties of bone, cerebrospinal fluid and bridging veins were already investigated, the difficulty remains of conflicting data in brain material properties proposed in literature.
Description
This PhD project is part of a Marie-Curie International Training Network, HEADS (Head protection: a European training network for Advanced Designs in Safety), with UC Dublin, KTH Stockholm and KU Leuven as academic partners, and Charles Owen, Lazer Sport and AGV as industrial partners. This PhD will be headquartered at KU Leuven, more specifically in the Head Impact Biomechanics group. This is an interdisciplinary research group at KU Leuven on Head Impact Biomechanics, currently consisting of 10 scientists from the Biomechanics Section of the Mechanical Engineering Department, the Materials Science Department and Neurosurgery Department.
As part of the Marie Curie training experience, the candidate will spend 3 months at University College Dublin, Ireland, and 3 months at Charles Owen, Rhostyllen, UK.
The scientific goal of HEADS is to improve the understanding of head impact injury and to design new helmet standard test methods that recognise the influence of rotational kinematics. This will lead to improved helmets and a reduction in the severity of injuries and the numbers of fatalities. This objective will be achieved through a combination of computational simulations of real-life accidents, experimental and computational investigation of injury thresholds, and design of new helmet certification tests.
In this PhD research specifically, the goal is to establish an experimentally substantiated threshold for head injury, in mechanically quantifiable terms. This threshold can be used in the design requirements of new protective headgear.
Mainly experimental work is foreseen to provide sufficient data to establish a refined constitutive model for brain tissue and to provide input into a head injury threshold. First, experimental assessment of brain mechanical behavior under different loading conditions (compression, tension, and shear) for mature brains and immature brains of different ages will be performed in an animal model. This will be combined with morphological observations made through histological investigations, in order to achieve a complete structural characterization of brain parenchyma. Second, different levels of controlled cortical impacts in terms of indention, velocity and resulting compressive stress will be related to the histopathological findings in terms of contusion occurrence after sacrificing the animals. Third, the results of the two previous tasks will be integrated into a tolerance criterion for cerebral brain contusions. This will yield an improved insight into the mechanogenesis of frontotemporal contusions and maybe into an (age-specific) contusion tolerance criterion provided animals of different ages will be tested.
Nr of positions available : 1
Career Stage
Early stage researcher or 0-4 yrs (Post graduate)
Research Profiles
Not defined
Benefits
The doctoral student is offered a 4 year highly specialised doctoral training, making the candidate an expert in head impact biomechanics and helmet design technologies as well as being aware of commercialisable market opportunities. The doctoral candidate will work in world-class facilities with highly qualified experts, and will benefit from the training scheme developed based on the expertise of academic and industrial partners. This project will reach a new level of understanding of head injury and how head injury should be prevented, with directly applicable results to European industry. It will develop a well-networked group of young engineers and scientists into worldclass researchers and innovators with numerous career paths open to them, who will advance technology for the benefit of society and maintain Europe as a global leader in industrial development.
Comment/web site for additional job details
Reference number BAP-2014-562
Master in Biomedical Engineering, Mechanical Engineering or equivalent, preferably with a biomechanics background. Knowledge of continuum mechanics and material property characterization is considered a plus.
The candidate cannot have resided in Belgium for more than 12 months in the last 3 years prior to the start of the position.
KU Leuven is an equal opportunity employer.
For more information please contact Prof. dr. ir. Jos Vander Sloten, tel.: +32 16 32 70 99, mail: jos.vandersloten@kuleuven.be or Mr. Dries De Kegel, tel.: +32 16 32 00 43, mail: dries.dekegel@kuleuven.be.
You can apply for this job no later than 01/04/2015
Another PhD position on the same project: http://ec.europa.eu/euraxess/index.c...tails/33975038
Contusions can develop into massive hemorrhages and are the cause of about 2/3 of Acute Subdural Hematomas. Most brain contusions arise at the base of the frontal and temporal lobes and that the frontal and temporal contusions tend to show a symmetrical distribution after impacts in the sagittal plane. A quasi-static MR study on human volunteers performed at KU Leuven showed that head motion in the sagittal plane results in an up and down motion of the frontal and temporal lobes. The nature of the relative brain-skull motion after occipital head impacts was previously also confirmed by means of cadaver experiments. These findings, in conjunction with data from animal contusion models, indicate that compressive stresses developed in the cortex, secondary to the up and down beating on the skull base, are the causative mechanism for the typical frontotemporal contusions. If tissue level failure criteria were known for the cerebral cortex in terms of critical compressive stress, it could be possible to investigate critical head rotational acceleration levels for different pulse durations and acceleration directions using the head finite element modeling expertise acquired in our previous research. The quality of finite element predictions depends on accurate material definitions used for all components. While the material properties of bone, cerebrospinal fluid and bridging veins were already investigated, the difficulty remains of conflicting data in brain material properties proposed in literature.
Description
This PhD project is part of a Marie-Curie International Training Network, HEADS (Head protection: a European training network for Advanced Designs in Safety), with UC Dublin, KTH Stockholm and KU Leuven as academic partners, and Charles Owen, Lazer Sport and AGV as industrial partners. This PhD will be headquartered at KU Leuven, more specifically in the Head Impact Biomechanics group. This is an interdisciplinary research group at KU Leuven on Head Impact Biomechanics, currently consisting of 10 scientists from the Biomechanics Section of the Mechanical Engineering Department, the Materials Science Department and Neurosurgery Department.
As part of the Marie Curie training experience, the candidate will spend 3 months at University College Dublin, Ireland, and 3 months at Charles Owen, Rhostyllen, UK.
The scientific goal of HEADS is to improve the understanding of head impact injury and to design new helmet standard test methods that recognise the influence of rotational kinematics. This will lead to improved helmets and a reduction in the severity of injuries and the numbers of fatalities. This objective will be achieved through a combination of computational simulations of real-life accidents, experimental and computational investigation of injury thresholds, and design of new helmet certification tests.
In this PhD research specifically, the goal is to establish an experimentally substantiated threshold for head injury, in mechanically quantifiable terms. This threshold can be used in the design requirements of new protective headgear.
Mainly experimental work is foreseen to provide sufficient data to establish a refined constitutive model for brain tissue and to provide input into a head injury threshold. First, experimental assessment of brain mechanical behavior under different loading conditions (compression, tension, and shear) for mature brains and immature brains of different ages will be performed in an animal model. This will be combined with morphological observations made through histological investigations, in order to achieve a complete structural characterization of brain parenchyma. Second, different levels of controlled cortical impacts in terms of indention, velocity and resulting compressive stress will be related to the histopathological findings in terms of contusion occurrence after sacrificing the animals. Third, the results of the two previous tasks will be integrated into a tolerance criterion for cerebral brain contusions. This will yield an improved insight into the mechanogenesis of frontotemporal contusions and maybe into an (age-specific) contusion tolerance criterion provided animals of different ages will be tested.
Nr of positions available : 1
Career Stage
Early stage researcher or 0-4 yrs (Post graduate)
Research Profiles
Not defined
Benefits
The doctoral student is offered a 4 year highly specialised doctoral training, making the candidate an expert in head impact biomechanics and helmet design technologies as well as being aware of commercialisable market opportunities. The doctoral candidate will work in world-class facilities with highly qualified experts, and will benefit from the training scheme developed based on the expertise of academic and industrial partners. This project will reach a new level of understanding of head injury and how head injury should be prevented, with directly applicable results to European industry. It will develop a well-networked group of young engineers and scientists into worldclass researchers and innovators with numerous career paths open to them, who will advance technology for the benefit of society and maintain Europe as a global leader in industrial development.
Comment/web site for additional job details
Reference number BAP-2014-562
Master in Biomedical Engineering, Mechanical Engineering or equivalent, preferably with a biomechanics background. Knowledge of continuum mechanics and material property characterization is considered a plus.
The candidate cannot have resided in Belgium for more than 12 months in the last 3 years prior to the start of the position.
KU Leuven is an equal opportunity employer.
For more information please contact Prof. dr. ir. Jos Vander Sloten, tel.: +32 16 32 70 99, mail: jos.vandersloten@kuleuven.be or Mr. Dries De Kegel, tel.: +32 16 32 00 43, mail: dries.dekegel@kuleuven.be.
You can apply for this job no later than 01/04/2015
Another PhD position on the same project: http://ec.europa.eu/euraxess/index.c...tails/33975038