Characterisation of frequency modulated wave of NIR photons transport in human lower forearm phantom

Abstract

Free-space broadband frequency modulated near infrared (NIR) photon technique is used to model and characterise the optical behaviour in a lower forearm human phantom. NIR system measures the broadband insertion loss (IL) and the insertion phase (IP). Different penetration depth and path-related modulated photon movement is analysed. The study is divided into two stages. The first stage dedicated to performing broadband IL and IP measurements in a back-scattering method. The second stage dedicates to modelling the photon behaviour in stage 1 using a finite element simulator called as COMSOL. Results in both stages are analysed and compared using a signal processing method to identify the frequency modulated photon stamp associated with different layers and verifies the accuracy of the 3D FE modelling. Error shown to be less than 6% and results gives a clear understanding of how the modulated waves of photons behave when traveling in the human forearms phantom.