Electro-mechanical studies of skeletal tissues at high resolution

Measurements of the electro-mechanical properties of bone tissues could prove important in the development of models to explain bone remodeling. Two high resolution scanning techniques have been used to obtain acoustic properties and microwave resistivity respectively for specimens of both human cortical and trabecular bone. An Olympus UH3 Scanning Acoustic Microscope (SAM) has been used for the former studies; a newly developed, innovative non-destructive, non-contact Scanning Evanescent Microwave Probe (SEMP) at Case has been used for the latter studies on the same specimens. SAM has been performed at 400 and 600 MHz, with nominal resolutions of 2.5 and 1.7 /spl mu/m respectively. This portion of the studies showed that the lamellar organization of trabecular bone exhibits the same alternation of acoustic impedance in adjacent lamellae as has been observed within the adjacent concentric lamellar structures of secondary osteons (haversian systems). The SEMP generates evanescent microwaves at the tip of a quarter wavelength resonator at 1 GHz and has a resolution of 10 mm. The frequency is now being increased to 10 GHz, yielding a resolution approaching 1 /spl mu/m.