Comparison of A Planar and Finite Difference Time Domain Technique to Simulate the Propagation of Electromagnetic Waves in Biological Tissue

Due to the recent advances in ultra wide-band (UWB) radar technologies, there has been widespread interest in the possible medical applications of UWB microwave radar. Therefore, the development of accurate numerical techniques to predict the propagation of UWB signals in biological tissue is of great interest to researchers as an aid in developing signal processing algorithms. Two techniques for modeling the propagation of electromagnetic (EM) waves in human tissue are presented and compared in this paper: the planar and finite difference time domain (FDTD) technique. A four layer biological model is considered, three layers of normal tissue, and one layer of cancerous soft tissue (sarcoma). The two modeling techniques are used to predict the response of the model to the UWB input signal, with particular focus on the response of the sarcoma layer. Both the Planar technique and the FDTD technique identify the presence of the soft tissue sarcoma quite easily. However the FDTD technique predicts more subtle phenomena such as multiple reflections, albeit at a high computational cost.