Applications of pulsed electromagnetic field (PEMF) therapy have grown steadily over the last 50 years, as clinical evidence of effectiveness for various treatments, e.g. pain relief, bone and tissue (wound) healing etc., has emerged . As an example, in PEMF wound healing therapy, a MHz electrical signal that is amplitude modulated with a low-frequency (e.g. 1 kHz) pulse is applied to a coil that surrounds the perimeter of a wound as shown in Figure 1. The coil produces a time-varying magnetic field that permeates tissue and induces a distribution of electric field and current. These, in turn, stimulate a multitude of biological processes that collectively promote wound healing. However, despite the widespread and growing use of PEMF therapy, relatively few theoretical studies have been reported that ellucidate the field-tissue interaction. In this presentation, we demonstrate computational models to study PEMF tissue therapy. The models predict the coil-driven electromagnetic field and current patterns induced in human tissue taking into account different tissue layers and their individual frequency-dependent electrical properties . We find that the applied stimulation generates a distinct electric current profile, which circulates in the vicinity of targeted wound as shown in Figure 2. The models are implemented using the COMSOL program (www.comsol.com). We discuss typical predicted output including field strength penetration as a function of the drive waveform and coil configurations etc. This analysis enables the rational design of wearable PEMF-based medical devices for wound healing and other applications.
Journal: TechConnect Briefs
Volume: 4, Informatics, Electronics and Microsystems: TechConnect Briefs 2018
Published: May 13, 2018
Pages: 157 - 160
Industry sector: Sensors, MEMS, Electronics
Topic: MEMS & NEMS Devices, Modeling & Applications