Magnetic field strength properties in bone marrow during pulsed electromagnetic stimulation

Hiroyuki Tamaki, Kengo Yotani, Atsumu Yuki, Hikari Kirimoto, Kazuhiro Sugawara, Hideaki Onishi

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DOI: 10.4236/jbise.2010.312150                

Abstract

We clarified the characteristics of pulsed electromagnetic field (PEMF) strength in marrow cavity with bone marrow in long bones based on actual measurements taken during pulsed magnetic stimulation (PMS). Measurements were made under 810 different conditions of stimulation intensity, distance, and position. Significant and strong linear correlations were observed between PEMF strength and stimulation intensity. PEMF strength in marrow cavity during PMS showed an exponential decay depending on coil-sensor distance, with a breaking point at approximately 30 mm. PEMF strength distributions in bone showed geometric differences between 3 types. These findings suggest that PEMF strength in bone depends on stimulation intensity, distance and horizontal position. Our actual measured data could be useful in determining stimulation programs and estimating the in vivo efficacy of PEMF in marrow cavity for research and clinical use.

Keywords

Magnetic Stimulation; Bone Tissue; Focality; Geometry; Intensity

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Yamada S., Guenther H.L., and Fleisch H. (1985) The effect of pulsed electromagnetic fields on bone cell metabolism and calvaria resorption in vitro, and on calcium metabolism in the live rat. International Orthopaedics, 9, 129-134.
[2]	Sakai Y., Patterson T.E., Ibiwoye M.O., Midura R.J., Zborowski M., Grabiner M.D. and Wolfman A. (2006) Exposure of mouse preosteoblasts to pulsed electromagnetic fields reduces the amount of mature, type I collagen in the extracellular matrix. Journal of Orthopaedic Research, 24, 242-253.
[3]	Diniz P., Shomura K., Soejima K. and Ito G. (2002) Effects of pulsed electromagnetic field (PEMF) stimulation on bone tissue like formation are dependent on the maturation stages of the osteoblasts. Bioelectromagnetics, 23, 398-405.
[4]	Thielscher A. and Kammer T. 2004. Electric field properties of two commercial figure-8 coils in TMS: calculation of focality and efficiency. Clinical Neurophysiology, 115, 1697-708.
[5]	Tamaki H., Yotani K., Yuki A., Kirimoto H., Sugawara K., Jigami H., Tsubaki A., Onishi H. and Ogita F. (2010) Characterization of magnetic field strength in long bone during pulsed electromagnetic stimulation. Advances in Exercise and Sports Physiology, 15, 77.
[6]	Takano-Yamamoto T., Kawakami M. and Sakuda M. (1992) Effect of a pulsing electromagnetic field on demineralized bone-matrix-induced bone formation in a bony defect in the premaxilla of rats. Journal of Dental Research, 71, 1920-1925.
[7]	Shen W.W. and Zhao J.H. (2010) Pulsed electromagnetic fields stimulation affects BMD and local factor production of rats with disuse osteoporosis. Bioelectromagnetics, 31, 113-119.
[8]	Tamaki H., Yotani K., Yuki A., Nishizawa T., Tomori K., Kirimoto H., Onishi H., Ogita F. and Takekura H. (2010) Effects of pulsed electromagnetic fields stimulation on gene expression related to bone formation in spontaneously hypertensive rats. 32nd Annual Meeting of American Society for Bone and Mineral Research, Toronto, 16, 56.
[9]	Lingwood M.D., Siaw T.A., Sailasuta N., Ross B.D., Bhattacharya P. and Han S. (2010) Continuous flow Overhauser dynamic nuclear polarization of water in the fringe field of a clinical magnetic resonance imaging system for authentic image contrast. Journal of Magnetic Resonance, 205, 247-254.
[10]	Bland J. M. and Altman D.J. (1986) Regression analysis. Lancet, 1, 908-909.
[11]	Marquez-Gamino S., Sotelo F., Sosa M., Caudillo C., Holguin G., Ramos M., Mesa F., Bernal J. and Cordova T. (2008) Pulsed electromagnetic fields induced femoral metaphyseal bone thickness changes in the rat. Bioelectromagnetics, 29, 406-409.
[12]	Martino C.F., Perea H., Hopfner U., Ferguson V.L. and Wintermantel E. (2010) Effects of weak static magnetic fields on endothelial cells. Bioelectromagnetics, 31, 296-301.