title: Catastrophe theory model for decelerations of fetal heart rate.
abstract: BACKGROUND
  Decelerations of fetal heart rate (FHR) are the results of many pathophysiological factors that modulate the intrinsic rate of the heart. FHR change is a complex phenomenon and can be viewed as a type of nonlinear dynamic system. This paper presents a qualitative model of FHR decelerations based on catastrophe theory, especially to account for abrupt heart rate changes seen in variable decelerations.
  
  
  METHODS
  One of the elementary catastrophes, the cusp catastrophe, was used to model FHR changes seen in variable, late, and early decelerations.
  
  
  RESULTS
  Catastrophe theory describes typical variable decelerations as an abrupt response to a slowly changing force of attack (uterine contraction) and physiological defense. Because of its three-dimensionality and topological features, the cusp catastrophe model provides a qualitatively satisfying description of FHR decelerations.
  
  
  CONCLUSIONS
  The organized complexity of living systems offers the best hope for the application of catastrophe theory. The nature of the elementary catastrophes will be essential knowledge in the mathematical analysis of biology.
authors.affiliation: Department of Obstetrics, Center for Perinatal Medicine, Nagano Children's Hospital, Nagano, Japan. dr-kiku@yj8.so-net.ne.jp
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Nobuya
authors.initials: N
authors.lastname: Unno
authors.forename: Tsuguhiro
authors.initials: T
authors.lastname: Horikoshi
authors.forename: Shiro
authors.initials: S
authors.lastname: Kozuma
authors.forename: Yuji
authors.initials: Y
authors.lastname: Taketani
mesh_terms: D005260:Female; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D008432:Mathematical Computing; D008954:Models, Biological; D017711:Nonlinear Dynamics; D011247:Pregnancy