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Ultrasonic Lamb wave has attracted considerable interest to characterize the human cortical bone. Especially, the nonlinear ultrasonic Lamb wave shows great potential to evaluate the micro-damage of cortical bone. However, the quantitatively analysis about the effect of the bone material mechanical properties on the nonlinear Lamb wave are very limited. In this study, a finite-difference time-domain...
Anisotropy of cortical bone is known to be associated with material properties and might thus be relevant for fracture risk assessment. We developed a sensor which is able to measure the velocity of guided waves in different directions simultaneously using bidirectional transmission along the long axis of the sensor and ± 37.5° angled to it. The method was tested on two anisotropic plates by scanning...
The purpose of this work was to study the relationships between quantitative ultrasound (QUS) parameters and the microstructure properties of human proximal femur samples. QUS data acquisition was achieved by means of a custom-developed experimental set-up, which allowed the insonification of excised femoral heads along 30 different directions, each time including both the trabecular region and the...
The longitudinal wave which passes through cancellous bone separates into the fast wave (mainly propagates along trabecular) and slow wave (mainly propagates in bone marrow). This is called two wave phenomenon. However, longitudinal waves passing through the in vivo bone contain circumferential wave which propagates along outer cortical layer. This circumferential wave may influence the two wave phenomenon...
The role of quantitative ultrasound as a diagnostic and monitoring tool in bone pathologies has been widely investigated both experimentally and numerically. Recently, the numerical studies have focused on the exploitation of high-resolution imaging data of bone's microarchitecture in order to develop more realistic computational models of osteoporotic bones. In this work, we present numerical simulations...
Numerical simulations of the piezoelectric effect of bone under ultrasound irradiation were attempted to perform using a three-dimensional (3D) elastic finite-difference time-domain (FDTD) method with piezoelectric constitutive equations (PE-FDTD method). The electric fields in a human femur induced by an ultrasound burst wave at 1 MHz, which was radiated perpendicular to the bone axis, were simulated...
An ultrasonic propagation in cancellous bone is considered using the Biot theory modified by the Johnson et al. Numerical simulations of reflected waves in the time domain are worked out by varying the modified Biot parameters. The sensitivity of different mechanical parameters: Young modulus and the Poisson ratio of the skeletal frame and physical parameters, porosity, tortuosity and viscous characteristic...
Application of ultrasonic axial transmission techniques to assess human elongated cortical bones has gained considerable attention in the area of bone tissue imaging and characterization. The cortical shell of long bones acts as a natural waveguide and supports the propagation of multiple guided modes. In practice, not all guided modes exist. For the existing ones, their energies are absent at high...
Structural decay of bone is not fully assessed by current X-ray methods, and there is an unmet need in identifying women at risk of fracture who should receive a treatment. The last decade has seen the emergence of ultrasound (US) axial transmission (AT) techniques to assess cortical bone. Recent AT techniques exploit the multimode waveguide response of long bones such as the radius. Guided wave (GW)-based...
The subject of the paper is presentation of theoretical and methodological fundamentals for a novel low-frequency ultrasonic method of identification of macroscopic mechanical properties and parameters of macroscopic inhomogeneity of bone tissue. The issue is directly associated with non-invasive assessment of bone fracture risk, being result of the diseases such as osteoporosis, osteomalacia, osteopenia...
In the study, we propose a sparse inverse singular value decomposition (SI-SVD) technique, which combines SVD and a least-squares sparse inversion method to improve the resolution of the ultrasonic (US) guided waves (GW) spectrum of long cortical bones. The method was assessed using synthetic data and experimental signals recorded on a 4-mm thick bone-mimicking plate. The results illustrated that...
The objective of this study is to assess the clinical performance of a novel ultrasound bidirectional axial transmission (BDAT) prototype. The speed of sound of the first arriving signal (VFAS) was measured in the radius and tibia of 58 postmenopausal females. An optimized VFAS measurement protocol was introduced in order to reduce the clinical measurement time and increase the robustness in particular...
The paper present theoretical and experimental issues related to application of Quantitative Ultrasound (QUS) for assessment of cancellous bone quality and prediction of bone fractures. Commonly used for modeling of ultrasonic wave propagation in cancellous bone, the macroscopic Biot's theory is discussed in context of its potential applicability for theoretical prediction of wave parameters: phase...
Osteoporosis is a frequent bone disease that mainly affects women after menopause. It is characterized by a decrease in bone mass and a deterioration of the micro-architecture which can lead to an increased risk of fracture. Ultrasound technologies provide an affordable mean to implement non invasive solutions to diagnostically assess the characteristics of the bone structure. In this work, we are...
The bone healing process involves a sequence of cellular actions and interactions, regulated by biochemical and mechanical signals. Experimental studies have shown that ultrasound accelerates bone solidification and enhances the underlying healing mechanisms. We present a mathematical model for deriving predictions of bone healing under the presence of ultrasound. The model consists of i) partial...
In this study, the acoustic nonlinearity of water was investigated using a variation of the collinear wave mixing method. One single transducer, driven at two different frequencies fa and fb, was used to generate a third frequency component at fa − fb, fa + fb, 2fa and 2fb. Such a configuration allows to cancel out system nonlinearities since no amplification of the signal beyond 10V is needed. Perturbation...
To understand the structure-function relationship of bone and to investigate bone fragility, a precise and practical way to measure cortical bone elasticity is important. Resonant Ultrasound Spectroscopy (RUS) has shown its accuracy and convenience in fully characterizing the stiffness coefficients of anisotropic solid materials. However, it was long believed that the method is not applicable to bone,...
The role of quantitative ultrasound as a diagnostic and monitoring tool in bone pathologies has been widely investigated both experimentally and numerically. Recently, the numerical studies have focused on the exploitation of high-resolution imaging data of bone's microarchitecture in order to develop more realistic computational models of osteoporotic bones. In this work, we present numerical simulations...
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