  Osteoporosis is a well recognized problem affecting millions of individuals
worldwide. Consequently, the need to effectively, efficiently, and affordably
diagnose and identify those at risk is essential; moreover, site-specific
assessment of bone quality is necessary, not only in the process of risk
assessment, but may also be desirable for other applications. The present study
evaluated a new one-dimensional granular crystal sensor, composed of a tightly
packed chain of beads under Hertzian contact interaction, representing the most
suitable fundamental component for solitary wave generation and propagation.
First, the sensitivity of the novel sensor was tested using densities of rigid
polyurethane foam, representing clinical bone quality ranging from healthy, to
severely osteoporotic. Once the relationship between the signal response and
known densities was established, the sensor was used to measure several sites
located in the proximal femur of ten human cadaveric specimens. The accuracy of
the model was then further investigated, using measurements of bone quality
from the same cadaveric specimens, independently, using DEXA. The results
indicate not only that the novel technique is capable of detecting differences
in bone quality, but that the ability to measure site-specific properties
without exposure to radiation, has the potential to be further developed for
clinical applications.
