916 resultados para map-matching
Resumo:
Atrial flutter in the donor part of orthotopic heart transplants has been reported and successfully treated by radiofrequency ablation of the cavotricuspid isthmus, but mapping and ablation of atypical flutter circuits may be challenging.(1) Entrainment mapping has been used in combination with activation mapping to define the mechanism of atypical atrial flutter. Here, we report a case where colour-coded three-dimensional (3D) entrainment mapping allowed us to accurately determine and visualize the 3D location of the reentrant circuit and to plan the ablation of a left atrial flutter without the need for activation mapping.
Resumo:
This paper presents a kernel density correlation based nonrigid point set matching method and shows its application in statistical model based 2D/3D reconstruction of a scaled, patient-specific model from an un-calibrated x-ray radiograph. In this method, both the reference point set and the floating point set are first represented using kernel density estimates. A correlation measure between these two kernel density estimates is then optimized to find a displacement field such that the floating point set is moved to the reference point set. Regularizations based on the overall deformation energy and the motion smoothness energy are used to constraint the displacement field for a robust point set matching. Incorporating this non-rigid point set matching method into a statistical model based 2D/3D reconstruction framework, we can reconstruct a scaled, patient-specific model from noisy edge points that are extracted directly from the x-ray radiograph by an edge detector. Our experiment conducted on datasets of two patients and six cadavers demonstrates a mean reconstruction error of 1.9 mm
Resumo:
The function of the coronary collateral circulation in heart transplant patients has not been investigated in a controlled fashion. Since it partly belongs to the microcirculation, which is affected by transplant vasculopathy, the hypothesis was tested that the coronary collateral circulation in heart transplant recipients is less developed than in coronary artery disease (CAD) patients.