High efficacy extremely low frequency (ELF) pulsed electromagnetic field (PEMF) device for wound healing promotion

摘要

This research project successfully presents and discusses the design and construction of an extremely low frequency (ELF) PEMF device built on the basis of a Two-Axis (2-Axis) Helmholtz coil system (HCS) that is capable of producing a uniform time varying magnetic field in the frequency range of 2-500Hz and magnetic induction (magnetic flux density) of 0.5mT - 2.5mT. A custom software program was written in order to systematically analyze the induced magnetic field distribution and its region of uniformity within 10%, 1% and 0.1% of the center field, prior to commencing experimentation with the selected biological model systems. The applications of the developed ELF PEMF exposure device have been investigated in terms of the experimental evaluation of ELF PEMF irradiation on protein, i.e. Collagenase enzyme, and gram-positive and gram- negative bacterial cultures of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) respectively. Through this study it was experimentally proved that it is possible to optimize ELF PEMF parameters (frequency, f, and magnetic flux density, B) of the applied irradiation which can modulate (increase or decrease) the biological activity of the studied Collagenase enzyme. Important findings from the conducted experiments showed that the biological activity of Collagenase enzyme is increased by 7-15% and 4-15% upon irradiation at 3Hz and 8Hz for the magnetic flux densities of 0.5-2.5mT. The effects of the applied ELF PEMF exposure system on growth and proliferation of bacterial culture of S. aureus and E. coli have also been experimentally evaluated. All bacterial cultures exposed to ELF PEMF showed a decrease in their growth rate when compared to control samples. For S. aureus, a specific viability pattern “quadrature polynomial” was observed upon ELF PEMF irradiation. The occurrence of the frequency and magnetic flux density “windows” was observed at the higher end of the studied frequencies range and all magnetic flux densities except 1.5mT. Maximum relative decrease of 68.56% was observed at the frequency 300Hz and magnetic flux density 1.5mT. For E. coli, the overall observation is that E. coli bacteria were generally more responsive to the applied irradiation treatment, where the exponential relationship between the colony-forming unit (CFU) values (bacterial growth) and applied exposures was observed. The results obtained clearly demonstrate that the effects of irradiation on bacterial growth are frequency and magnetic flux density dependent. In general, the decrease in bacterial cell viability was achieved at all studied range of frequencies (2-500Hz) and every magnetic flux density (0.5mT, 1mT, 1.5mT, 1.5mT, 2mT and 2.5mT). Minimum and maximum changes in bacterial cells growth for the exposed samples were recorded at 3Hz and 0.5mT, and 500Hz and 2.5mT, respectively. The maximum effect observed at the 500Hz and 2.5mT corresponds to the relative decrease of 77.26 % in bacterial growth. The outcomes of this research project provides evidence based support to the hypothesis that optimal ELF PEMF parameters can induce therapeutic effects in proteins and cells and thereby, ELF PEMF therapies have a great potential for possible treatment of wounds and overall wound healing promotion.