E-Book 2nd Congress

  • Application of statistical physics and Nash equilibrium to Prenatal Screening for Down Syndrome
  • Ali Mohammadi Ruzbahani,1,* Abbas Javadian,2
    1. Semnan University
    2. Semnan University


  • Introduction: Screening for a disorder may be carried out by assessing the risk that an individual is affected given the values of variables whose distributions alter when the disorder is present. Currently, our parameters for Down Syndrome (DS) risk prediction include maternal age as well as three biochemical markers and risk calculations for the biochemical markers use a quadratic discriminant function. Analogous problems have been studied for years by physicists extracting macroscopic states of various physical systems by examining microscopic elements and their interactions. In this article, we have checked the values of the evaluated parameters using the methods of statistical physics and the Nash equilibrium equation with the data of a screening program.
  • Methods: we start from a small set of initial findings and proceed by a sequence of hypothesis selection and testing. Due to the statistical nature of the Down syndrome screening results, we are facing a complex statistical system, because the results are checked according to the population ratio and the number of tests, etc., and finally the risk rate is determined according to the statistical classification. Here, by using the combination of Nash equilibrium and statistical physics relations, we were able to establish a relationship between the obtained parameters and previous rates and add error costs to the equation. Finally, using artificial neural networks and a small dataset we had available, we compared the results with current models.
  • Results: By using the models used in statistical physics and also using the Nash equilibrium to compare and categorize the data, we were able to reduce the range of useful predictions with a more accurate probabilistic model and also reduce the standard deviation.
  • Conclusion: In a general statement, it can be said that in addition to the parameters examined in prenatal screening for Down syndrome, other parameters such as defects in the statistical data set should also be considered. The main challenge is to balance the efficiency and predictability of the model against the available data, because even if we achieve a perfect model, due to its statistical nature and dependence on the parameters in the databases, we cannot comment on the success rate of the model.
  • Keywords: statistical physics, Down Syndrome ,Prenatal Screening, Nash equilibrium