AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task... more AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task of manually annotating ECG's. Several algorithms have been developed to segment the ECG automatically. We first review several of such methods, and then present a new ...
AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task... more AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task of manually annotating ECG's. Several algorithms have been developed to segment the ECG automatically. We first review several of such methods, and then present a new ...
... a value jt x , , for every stream nj 1 and for every time-tick t 1, 2,., SPIRIT works as foll... more ... a value jt x , , for every stream nj 1 and for every time-tick t 1, 2,., SPIRIT works as follows: a) Adapts the number k of hidden variables necessary to explain/summarise the main trends in the collection; b) Adapts the participation weights ji w , of ... A. Zifan, P. Liatsis, and R. Bayford ...
2012 IEEE International Conference on Imaging Systems and Techniques Proceedings, 2012
ABSTRACT In this paper we present a new pipeline for the fast and accurate segmentation of impeda... more ABSTRACT In this paper we present a new pipeline for the fast and accurate segmentation of impedance images of the lungs using Electrical Impedance Tomography (EIT). EIT is an emerging promising non-invasive imaging modality, which produces real-time poor-spatial but high temporal resolution images of impedance inside a body. Recovering impedance itself constitutes a non-linear ill-posed inverse problem, therefore the problem is usually linearized which produces impedance-change images rather than static impedance, and the images are highly blurry and fuzzy along the object boundaries. We provide a mathematical reasoning behind the high suitability of the Kalman filter when it comes to segmenting and tracking conductivity changes in EIT lung images. Next, we use a two-fold approach to tackle the segmentation problem. First, we construct a global lung shape to restrict the search region of the Kalman filter. Next, we proceed by augmenting the Kalman filter by incorporating an adaptive foreground detection system to provide the boundary contours for the Kalman filter to carry out the tracking of the conductivity changes as the lungs undergo deformation in a respiratory cycle.
ABSTRACT We present a new method for the fully automatic 3D reconstruction of the coronary artery... more ABSTRACT We present a new method for the fully automatic 3D reconstruction of the coronary artery centerlines, using two X-ray angiogram projection images from a single rotating monoplane acquisition system. During the first stage, the input images are smoothed using curve evolution techniques. Next, a simple yet efficient multiscale method, based on the information of the Hessian matrix, for the enhancement of the vascular structure is introduced. Hysteresis thresholding using different image quantiles, is used to threshold ...
This study aimed at investigating the effect of myocardial motion on pulsating blood flow distrib... more This study aimed at investigating the effect of myocardial motion on pulsating blood flow distribution of the left anterior descending coronary artery in the presence of atheromatous stenosis. The moving 3D arterial tree geometry has been obtained from conventional x-ray angiograms obtained during the heart cycle and includes a number of major branches. The geometry reconstruction model has been validated against projection data from a virtual phantom arterial tree as well as with CT-based reconstruction data for the same patient investigated. Reconstructions have been obtained for a number of temporal points while linear interpolation has been used for all intermediate instances. Blood has been considered as a non-Newtonian fluid. Results have been obtained using the same pulse for the inlet blood flow rate but with fixed arterial tree geometry as well as under steady-state conditions corresponding to the mean flow rate. Predictions indicate that myocardial motion has only a minor ...
AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task... more AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task of manually annotating ECG's. Several algorithms have been developed to segment the ECG automatically. We first review several of such methods, and then present a new ...
AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task... more AbstractElectrocardiogram (ECG) segmentation is necessary to help reduce the time consuming task of manually annotating ECG's. Several algorithms have been developed to segment the ECG automatically. We first review several of such methods, and then present a new ...
... a value jt x , , for every stream nj 1 and for every time-tick t 1, 2,., SPIRIT works as foll... more ... a value jt x , , for every stream nj 1 and for every time-tick t 1, 2,., SPIRIT works as follows: a) Adapts the number k of hidden variables necessary to explain/summarise the main trends in the collection; b) Adapts the participation weights ji w , of ... A. Zifan, P. Liatsis, and R. Bayford ...
2012 IEEE International Conference on Imaging Systems and Techniques Proceedings, 2012
ABSTRACT In this paper we present a new pipeline for the fast and accurate segmentation of impeda... more ABSTRACT In this paper we present a new pipeline for the fast and accurate segmentation of impedance images of the lungs using Electrical Impedance Tomography (EIT). EIT is an emerging promising non-invasive imaging modality, which produces real-time poor-spatial but high temporal resolution images of impedance inside a body. Recovering impedance itself constitutes a non-linear ill-posed inverse problem, therefore the problem is usually linearized which produces impedance-change images rather than static impedance, and the images are highly blurry and fuzzy along the object boundaries. We provide a mathematical reasoning behind the high suitability of the Kalman filter when it comes to segmenting and tracking conductivity changes in EIT lung images. Next, we use a two-fold approach to tackle the segmentation problem. First, we construct a global lung shape to restrict the search region of the Kalman filter. Next, we proceed by augmenting the Kalman filter by incorporating an adaptive foreground detection system to provide the boundary contours for the Kalman filter to carry out the tracking of the conductivity changes as the lungs undergo deformation in a respiratory cycle.
ABSTRACT We present a new method for the fully automatic 3D reconstruction of the coronary artery... more ABSTRACT We present a new method for the fully automatic 3D reconstruction of the coronary artery centerlines, using two X-ray angiogram projection images from a single rotating monoplane acquisition system. During the first stage, the input images are smoothed using curve evolution techniques. Next, a simple yet efficient multiscale method, based on the information of the Hessian matrix, for the enhancement of the vascular structure is introduced. Hysteresis thresholding using different image quantiles, is used to threshold ...
This study aimed at investigating the effect of myocardial motion on pulsating blood flow distrib... more This study aimed at investigating the effect of myocardial motion on pulsating blood flow distribution of the left anterior descending coronary artery in the presence of atheromatous stenosis. The moving 3D arterial tree geometry has been obtained from conventional x-ray angiograms obtained during the heart cycle and includes a number of major branches. The geometry reconstruction model has been validated against projection data from a virtual phantom arterial tree as well as with CT-based reconstruction data for the same patient investigated. Reconstructions have been obtained for a number of temporal points while linear interpolation has been used for all intermediate instances. Blood has been considered as a non-Newtonian fluid. Results have been obtained using the same pulse for the inlet blood flow rate but with fixed arterial tree geometry as well as under steady-state conditions corresponding to the mean flow rate. Predictions indicate that myocardial motion has only a minor ...
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Papers by Dr Ali Zifan