Showing papers in "Medical Engineering & Physics in 2013"

TL;DR: The VascuLuminator is able to decrease failure at first attempt in blood withdrawal in pediatric patients from 10/80 (13%) to 1/45 (2%; P=.05) and the findings with a multispectral imaging system support this theory.

TL;DR: A numerical study of the different mechanisms responsible for the radial force exerted on the aortic annulus by self-expanding and balloon-expandable prostheses indicates that, for both prostheses, the radialforce may vary considerably within the recommended functional range for the valve implantation and is substantially higher at the smallest annular sizes.

TL;DR: Results show that people could effectively navigate a robotic wheelchair using a SSVEP-based BCI with high frequency flickering stimulation, and volunteers expressed neither discomfort nor fatigue due to flickering stimulation.

TL;DR: 3-D fluid-structure interaction is used to provide physiological simulation resulting in modeling with a high level of detail and a comparison of the 3-D simulations to the 1-D model shows good reproduction of the pressure and flow waveforms.

TL;DR: The Optogait system demonstrated high discriminant and concurrent validity with an electronic walkway for the assessment of spatiotemporal gait parameters in orthopedic patients and healthy controls, however, the two measuring instruments cannot be used interchangeably for quantitative gait analysis, and further validation of floor-based photocell technology is warranted.

TL;DR: Results show that gait initiation can be detected timely and accurately, with few errors in the case of within-subject cross-validation and overall good performance in subject-independent cross- validation and gait termination can be predicted in over 80% of trials well before the subject comes to a complete stop.

TL;DR: A patient-specific model is implemented that uses image-based reconstructions of coronary bifurcations and is able to replicate real stenting procedures following clinical indications and the comparison between numerical and image- based post-stenting configurations proved the reliability of such models while replicating stent deployment in coronary arteries.

TL;DR: This study demonstrates that volumetric strain measurements can be obtained successfully using DVC, which may be a useful tool to investigate mechanical behaviour of porous implants.

TL;DR: Calculated spinal loads for different postures and activities at several levels of the thoracolumbar spine for various combinations of body height and weight allow the estimation of the spinal load during activities of daily living on a subject specific basis, if body height is known.

TL;DR: The total variation norm of each subject was used to classify the participants as OSA and non-OSA snorers, and the characteristics of snoring sounds did not vary significantly over time in non-apneic class.

TL;DR: An experimental fretting device was developed in this study to systematically investigate the effect of micromotion and contact pressure on fretting damage in contact situations similar to taper interfaces of modular hip prostheses under cyclic loading representative of in vivo load conditions.

TL;DR: A novel FSI model of the physiological AR simulating its function throughout the entire cardiac cycle is developed and the FSI approach may be worth the extra computational cost when the tackled scenarios are strongly dependent on AV transient dynamics, Valsalva sinuses fluid dynamics in relation to coronary perfusion, or AR fluid dynamic alterations.

TL;DR: Categorizing head-movement artefacts as one distinct class and using support vector machines to automatically detect their presence are presented, and the combination of features extracted from EEG and gyroscope signals is explored in order to design an algorithm which incorporates both physical and physiological signals in accurately detecting artefacts arising from head movements.

TL;DR: In this article, a constant mass flow rate was used to determine the intrinsic permeability of the virtual specimens, and linear relationships were found between permeability and the two physical properties, porosity and bone surface area.

TL;DR: The experimental results demonstrated that the EMD based methods achieved better performance than the conventional digital filters, especially when the signal to noise ratio of the processed signal was low.

TL;DR: Patient-specific hemodynamic simulations offer means of quantitative estimation FD treatment outcomes and showed that FD flow resistance force was higher than dynamic force, indicating that the FD provided sufficient resistance to reduce flow into the aneurysm.

TL;DR: A computational model of the entire cardiovascular system is developed using heterogeneous mathematical representations, which allows hemodynamics analyses of patient-specific arterial district, delivering naturally the appropriate boundary conditions for different cardiovascular scenarios.

TL;DR: The system performed sufficiently well to be considered for clinical use, despite the exclusive use of frequencies not usually considered in clinical interpretation, and has the potential to contribute significantly to the detection of epileptic seizures.

TL;DR: Computational models of AD based on radiological three-dimensional images of a patient at initial presentation and after 4-years of best medical treatment indicate that the reduction of blood pressure in BMT patients lowers pressure and wall shear stress in the thoracic aorta in general, and flattens the pressure distribution on the outer wall of the dissection.

TL;DR: The objectives of this study were to develop a statistical shape and alignment modeling (SSAM) approach to characterize the intersubject variability in bone morphology and alignment for the structures of the knee, to demonstrate the statistical model's ability to describe variability in a training set and to generate realistic instances for use in finite element evaluation of joint mechanics.

TL;DR: The need to optimise tendon repair solutions for specific tendons, and match tendon properties when using grafts in tendon repairs, is highlighted.

TL;DR: This proof of principle study has demonstrated that automated setup of an array stimulator produces results broadly comparable to clinician setup, and may lead to FES becoming more viable for patients who, at present, have difficulty setting up conventional stimulators.

TL;DR: It is demonstrated that the constitutive description of the wall is crucial for AAA wall stress prediction and results obtained using different models should not be mutually compared unless different stress gradients across the wall are not taken into account.

TL;DR: In vivo forces can be estimated from intradiscal pressure values within a certain range and non-model specific correction factors lead to estimation errors of up to 44% when accounting for these limitations.

TL;DR: Evaluating the effect of wheelchair mass, solid vs. pneumatic tires and tire pressure on physical strain and wheelchair propulsion technique found it is important to optimize tire pressure and tire type.

TL;DR: This review aims to provide a foundation for the future creation of advanced simulators to enhance the training of epiduralists, enabling them to comprehensively practice epidural insertion in vitro before training on patients and ultimately reducing the potential risk of harm.

TL;DR: A computational investigation of proximal humeral fracture fixation has been conducted and CFPEEK device simulations predict reduced stresses at the device-bone interface.

TL;DR: A framework for subject-specific FE-models was developed that was able to predict surface strains and bone deformation with good accuracy by using a single density-elasticity relationship, but it was also found that the most appropriate density-Elasticity relationships was specimen-specific.

TL;DR: Compparable strength, along with the heightened pull-out energy and reduced extraction torque, indicates that pedicle screws pre-filled with cement are superior for bone fixation overpedicle screws injected with cement.

TL;DR: The results revealed that minimizing the amount of material of the inner core has a smaller influence than increasing the porosity when the scaffolds are loaded under biomechanical loading.