title: Modeling time resolved light propagation inside a realistic human head model.
abstract: BACKGROUND
  Near infrared spectroscopy imaging is one of the new techniques used for investigating structural and functionality of different body tissues. This is done by injecting light into the medium and measuring the photon intensity at the surface of the tissue.
  
  
  METHODS
  In this paper the different medical applications, various imaging and simulation techniques of NIRS imaging is described. Each method is introduced and discussed. Then, the optimized model is prepared for numerical simulations. In this paper, the finite element method is used for solving the diffusion equation numerically.
  
  
  RESULTS
  Diffusion equation was solved for realistic human head model using finite element approach for a point light source and time resolved case. The photon intensity distribution in different head layers has been shown and the intensity orientation via the CSF layer has been illustrated.
  
  
  CONCLUSIONS
  Simulating the photon transformation inside the tissue is essential for investigating the NIRS imaging technique. The finite element approach is a fast and accurate method for simulating this fact. The time resolved approach of this technique could illustrate the photon migration and intensity orientation in the tissue for time dependent light sources in tissues.
authors.affiliation: Shiraz University of Technology, Shiraz, Iran.
authors.forename: Sh
authors.initials: Sh
authors.lastname: Bazrafkan
authors.affiliation: Shiraz University of Technology, Shiraz, Iran.
authors.forename: K
authors.initials: K
authors.lastname: Kazemi
keywords: Finite element method; Light propagation; Near infrared spectroscopy; Time resolved radiative transfer equation