The Effect of High Voltage, High Frequency Pulsed Electromagnetic Field on Slain Ovine Cortical Bone

Abstract

 

Background: This study is the first research investigating the possible effect of pulsed power signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to pulsed power.

Methods: A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behaviour of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation.

Results:The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 hours of high power pulsed electromagnetic field  compared to  the control samples.

Conclusions:These results can suggest that the pulse power stimulation has influenced the arrangement or the quality of collagen fibrils with no significant effect on bone mineral content. The results also confirm that the indirect application of high power pulsed electromagnetic field at 500 V and 10 kHz through capacitive coupling method did not destroy the bone structure.