Quantitative Ultrasound Measurement For The Assessment Of Bone Density Based On Leteral Wave

In recent years, quantitative ultrasound (QUS) measurement has played a growing role in the assessment of skeletal status. Compared to conventional X-ray absorptiometric techniques, QUS is inexpensive, noninvasive, non-radioactive and easy to use. It has gained applications in the clinical assessment of osteoporosis for the past 20 years. Currently available technologies are mostly based on measurements in transmission of the slope of the frequency-dependent attenuation and the speed of sound at peripheral skeletal sites. The objective of this research is to improve ultrasonic techniques to better estimate bone's density and provide diagnostic means for the earlier investigations to study bone density during osteoporosis.The thesis compares the advantages and disadvantages of several normal techniques applied to diagnose osteoporosis, also introduces the properties of ultrasound used in this area. We put emphasis on lateral wave which only exists under specific condition. Basing on physical modeling of the lateral wave theory, we introduce the axial transmission technique for the measurement of bone mineral density. Ultrasonic wave propagation in human cortical bone has been investigated in vitro using the so-called axial transmission technique. This technique, which relies on velocity...