An open multi center trial to document the systemic effects and safety of Extremely Low Frequency Electromagnetic Fields (ELF-MF) stimulation on healing of Diabetic Foot Ulcers (DFU). The study will be performed in two sites: Monterrey, Nuevo Leon, with patients from Medical Services of the Autonomous University of Nuevo León, and Cuernavaca, Morelos with patients from Regional General Hospital of Cuernavaca N. 1 IMSS, and Health Services of Morelos.