title: Thermoregulation in premature infants: A mathematical model.
abstract: OBJECTIVE
  In 2010, approximately 14.9 million babies (11.1%) were born preterm. Because preterm infants suffer from an immature thermoregulatory system they have difficulty maintaining their core body temperature at a constant level. Therefore, it is essential to maintain their temperature at, ideally, around 37°C. For this, mathematical models can provide detailed insight into heat transfer processes and body-environment interactions for clinical applications.
  
  
  METHODS
  A new multi-node mathematical model of the thermoregulatory system of newborn infants is presented. It comprises seven compartments, one spherical and six cylindrical, which represent the head, thorax, abdomen, arms and legs, respectively. The model is customizable, i.e. it meets individual characteristics of the neonate (e.g. gestational age, postnatal age, weight and length) which play an important role in heat transfer mechanisms. The model was validated during thermal neutrality and in a transient thermal environment.
  
  
  RESULTS
  During thermal neutrality the model accurately predicted skin and core temperatures. The difference in mean core temperature between measurements and simulations averaged 0.25±0.21°C and that of skin temperature averaged 0.36±0.36°C. During transient thermal conditions, our approach simulated the thermoregulatory dynamics/responses. Here, for all infants, the mean absolute error between core temperatures averaged 0.12±0.11°C and that of skin temperatures hovered around 0.30°C.
  
  
  CONCLUSIONS
  The mathematical model appears able to predict core and skin temperatures during thermal neutrality and in case of a transient thermal conditions.
authors.affiliation: Chair for Medical Information Technology, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany. Electronic address: pereira@hia.rwth-aachen.de.
authors.forename: Carina Barbosa
authors.initials: CB
authors.lastname: Pereira
authors.affiliation: Department of Neonatology, University Children's Hospital, University Hospital RWTH Aachen, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Heimann
authors.affiliation: Department of Anesthesiology, University Hospital RWTH Aachen, Aachen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Czaplik
authors.affiliation: Chair for Medical Information Technology, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany; Czech Institute of Informatics, Robotics and Cybernetics (CIIRC), CTU Prague, Prague, Czech Republic.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Blazek
authors.affiliation: Chair for Medical Information Technology, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany.
authors.forename: Boudewijn
authors.initials: B
authors.lastname: Venema
authors.affiliation: Chair for Medical Information Technology, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Leonhardt
mesh_terms: D001833:Body Temperature Regulation; D003198:Computer Simulation; D004777:Environment; D005865:Gestational Age; D006358:Hot Temperature; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D008954:Models, Biological; D047928:Premature Birth / Q000503:physiopathology*; D012881:Skin Temperature; D013696:Temperature; D013814:Thermal Conductivity
keywords: Bioheat model; Computer simulation; Physiological processes; Premature infants; Thermoregulation