title: Detection of phase singularities in triangular meshes.
abstract: OBJECTIVE
  Phase singularities have become a key marker in animal and computer models of atrial and ventricular fibrillation. However, existing algorithms for the automatic detection of phase singularities are limited to regular, quadratic mesh grids. We present an algorithm to automatically and exactly detect phase singularities in triangular meshes.
  
  
  METHODS
  For each node an oriented path inscribing the node with one unit of spatial discretization is identified. At each time step the phase information is calculated for all nodes. The so-called topological charge is also computed for each node. A non-zero (+/- 2pi) charge is obtained for all nodes with a path enclosing a phase singularity. Thus all charged nodes belonging to the same phase singularity have to be clustered.
  
  
  RESULTS
  With the use of the developed algorithm, phase singularities can be detected in triangular meshes with an accuracy of below 0.2 mm - independent of the type of membrane kinetics used.
  
  
  CONCLUSIONS
  With the possibility to detect phase singularities automatically and exactly, important quantitative data on cardiac fibrillation can be gained.
authors: Institute of Biomedical Engineering, University for Health Sciences, Medical Informatics and Technology, Eduard-Wallnöfer-Zentrum 1, 6060 Hall in Tirol, Austria. lukas.rantner@umit.at
authors: L J
authors: LJ
authors: Rantner
authors: L
authors: L
authors: Wieser
authors: M C
authors: MC
authors: Stühlinger
authors: F
authors: F
authors: Hintringer
authors: B
authors: B
authors: Tilg
authors: G
authors: G
authors: Fischer
mesh_terms: D000200:Action Potentials; D000465:Algorithms; D001281:Atrial Fibrillation / Q000503:physiopathology*; D003198:Computer Simulation; D006325:Heart Atria / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008962:Models, Theoretical; D010865:Pilot Projects; D014693:Ventricular Fibrillation / Q000503:physiopathology*