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The following topics are dealt with: medical signal processing; medical image processing; biomedical imaging; biosensors; chemical sensors; biomedical measurement; cardiology; haemodynamics; breathing; brain-computer interfaces; tissue engineering; medical robotics; and health care.
The pulstile components of photoplethysmography (PPG) contain valuable information about a subject's cardiovascular and metabolic systems. Pulse rate is one of the most significant vital signs that can be extracted from PPG signals. However, patient movement, especially movement at the measurement sites, such as fingers, can disturb the PPG's light path significantly, resulting in corrupted measurements...
The paper proposes a novel Extensible Markup Language (XML) based format called ART-ML that aims at supporting the interoperability and the reuse of models of blood flow, mass transport and plaque formation, exported by ARTool. ARTool is a platform for the automatic processing of various image modalities of coronary and carotid arteries. The images and their content are fused to develop morphological...
Brain's functional response can be studied by observing the spatiotemporal dynamics of functional and structural changes in cerebral vasculature. However, very few studies explore detailed changes at the level of individual microvessels while revealing the simultaneous wide field view of microcirculation responses to functional stimulation. Here we use a high spatiotemporal resolution laser speckle...
In this paper we use the modified and integrated version of the balloon model in the analysis of fMRI data. We propose a new state space model realization for this balloon model and represent it with the standard A,B,C and D matrices widely used in system theory. A second order Padé approximation with equal numerator and denominator degree is used for the time delay approximation in the modeling...
Numerous phantoms for human organs are commercially available or designed for scientific purposes. None of these combine the imaging possibility with color Doppler ultrasound (CDU) and computer tomography (CT) while providing vessel branches with bifurcations as natural landmarks. We designed, built and evaluated a flow model with vessel tree which can be imaged with CDU and CT. It aims at development...
Hemodynamically induced stress plays an important role in the progression and rupture of cerebral aneurysms. The current work describes computational fluid dynamics (CFD) simulations in anatomically realistic models of cerebral aneurysms. Twenty lateral aneurysms models were investigated. The models were obtained from three-dimensional rotational angiographic imaging data and CFD were studied under...
Hemodynamic Response Function (HRF) estimation in functional Magnetic Resonance Imaging (fMRI) experiments is an important issue in functional neuroimages analysis. Indeed, when modeling each brain region as a stationary linear system characterized by its impulse response, the HRF describes the temporal dynamic of the brain region response during activations. Using the mixed-effects model, a new algorithm...
Stanford type B aortic dissections (TB-AD), which split the descending aorta in a true and false lumen, have better in-hospital survival than type A dissections affecting the ascending aorta. However, short-term and long-term prognosis for the individual patient remains challenging, with one in four patients not surviving after 3 years. Towards a better understanding of the influence of tear location...
The carotid artery bifurcation is a common site of atherosclerosis which is a major leading cause of ischemic stroke. The impact of stenosis in the atherosclerotic carotid artery is to disturb the flow pattern and produce regions with high shear rate, turbulence, and recirculation, which are key hemodynamic factors associated with plaque rupture, clot formation, and embolism. In order to characterize...
Atherosclerotic plaques form at specific sites of the arterial tree, an observation that has led to the "geometric risk factor" hypothesis for atherogenesis. It is accepted that the location of atherosclerotic plaques is correlated with sites subjected to low abnormal values of wall shear stress (WSS), which is in turn determined by the specific geometry of the arterial segment. In particular,...
The geometry of conduits derived from in vivo image data is subject to acquisition and reconstruction errors. This results in a degree of uncertainty in defining the bounding geometry for a patient-specific anatomical conduit. The impact of the conduit geometry uncertainty should be considered with respect to haemodynamic clinically relevant measures that may alter the perception and evaluation of...
This paper proposes a new approach for the selection of a biophysical model describing the haemodynamic response function (HRF) measured in BOLD-fMRI data, based on model falsification techniques. Specifically, the novel method of Multiple Model Set-Valued Observers (MMSVOs) is introduced. The observers consider that the initial state lives in a set, the linear time-varying dynamic system obtained...
Equilibrium radionuclide angiography images (ERNA) has been established as a useful modality for clinical evaluation of the ventricular function. Tomographic acquisition of ERNA (SPECT-ERNA) improves the quantification of ventricular function with planar ERNA, avoiding both the overlap of structures and the need of defining the best septal view which can be difficult in dilated ventricles. In this...
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