Bone Characterization using Piezotransducers as Biomedical Sensors

摘要

This technical note demonstrates the application of piezoelectric ceramic (PZT) transducers for evaluation of structural dynamic parameters of bones. An experimental study conducted on chicken femur is reported. The bone is instrumented with two PZT patches, one serving as an actuator and the other as a sensor. The actuator patch is excited by applying a sinusoidal sweep voltage signal, which in turn excites the bone, the vibrations of which are picked up by the sensor patch. The gain across the sensor patch as a function of frequency serves as the frequency response function (FRF). Structural dynamic parameters of the bone such as modal frequencies and corresponding damping ratios are derived from this FRF. The proposed technique detects changes in the mechanical properties of the bone through changes in the FRF. This technique can be employed in monitoring the healing of critical bones after surgery. It can also aid research related to bone injury, diagnosis of ailments such as osteoporosis and numerous other fields of biomechanics.