Electrical Response and Thermal Damage Assessment of Cutaneous and Subcutaneous Tissues to Noninvasive Radiofrequency Heating: A Computational Modeling Study

A. González-Suárez[1,2], J. N. Jimenez-Lozano[3], W. Franco[1]
[1]Wellman Center for Photomedicine, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA
[2]Biomedical Synergy, Electronic Engineering Department, Universitat Politècnica de València, Valencia, Spain
[3]ZELTIQ Aesthetics, Inc., Pleasanton, CA, USA

Electromagnetic radiofrequency (RF) sources are widely used to heat up cutaneous and subcutaneous tissues. The subcutaneous morphology of tissue consists of a fine, collagenous and fibrous septa network enveloping clusters of adipocyte cells; however, it is commonly regarded as a homogeneous fat layer in computational models. In the present study the objective is to assess the effect of the septa network on the thermal damage during RF heating. Two-dimensional electric, thermal, and thermal damage models of skin, fat and muscle tissues were built and solved numerically using COMSOL Multiphysics®. Our results demonstrate that septa generates more heat and thermal damage than the lipid of adipocyte cells, and the dosimetry in treatments of subcutaneous fat related disorders with RF heating should account for this.