Abstract
Previous studies have shown that the overall porosity of bone has a significant effect on the mechanical strength of bone. In a comprehensive review on porosity of bone, Martin [1] described that small changes in porosity would lead to significant changes in the stiffness and strength of both compact and spongy bone. In a recently study, McCalden [2], reported that the porosity of bone has a significant effect to absorb energy during fracture. Since changes in numbers and sizes of these natural cavities are directly related to the remodeling processes and biomechanical properties of bone, a direct sensing technique to detect such changes in bone has been long wanted.