The ultrasonic axial transmission technique, used to assess cortical shells of long bones, is investigated using numerical simulations based on a three-dimensional (3D) finite difference code. We focus our interest the effects 3D bone geometry (curvature, thickness), anisotropy, and microporosity speed sound (SOS) measurements for different frequencies in MHz range. first show that SOS values measured tubular are identical those plates equal thickness. Anisotropy then shown have major impact...

In recent years, quantitative ultrasound (QUS) has played an increasing role in the assessment of bone status. The axial transmission technique allows to investigate skeletal sites such as cortical layer long bones (radius, tibia), inadequate through-transmission techniques. Nevertheless, type propagation involved along specimens not been clearly elucidated. Axial is investigated here by means two-dimensional simulations at 1 MHz. We focus our interest on apparent speed sound (SOS) first...

The axial transmission technique uses a linear arrangement of ultrasonic emitters and receivers placed on same side cortical bone site in contact with the skin, involving propagation along axis bone. velocity waves radiated from has been shown to reflect status. thickness composition soft tissue may vary length bone, between different skeletal sites, or subjects. Hence, accurate estimates require first eliminate effect overlying that is traversed by ultrasound wave. To correct for such bias...

Nonlinear resonant ultrasound spectroscopy (NRUS) is a resonance-based technique exploiting the significant nonlinear behavior of damaged materials. In NRUS, frequency(ies) an object studied as function excitation level. As level increases, elastic nonlinearity manifest by shift in resonance frequency. This study shows feasibility this for application to damage assessment bone. Two samples bovine cortical bone were subjected progressive induced mechanical cycling. Before cycling commenced,...

Abstract The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). Using synchrotron radiation μCT, we investigated, in vitro, relationships between 1-MHz SOS measurements at radius and site-matched C.Th, POR, MIN, vBMD. Introduction: Materials Methods:Using speed sound (SOS) thickness (C.Th), intracortical porosity (POR), tissue mineralization (MIN), volumetric BMD (vBMD). were based on...

This paper reports for the first time on inverse estimation of several bone properties from guided-wave measurements in human samples. Previously, related approaches have focused ultrasonic a single property at time. The method is based two steps: multi-Lamb mode response analyzed using singular value decomposition signal processing recently introduced field, then an identification procedure run to find thickness and anisotropic elastic considered specimen. Prior bone, validated cortical...

The aim is to assess the nonclassical component of material nonlinearity in several classes materials with weak, intermediate, and high nonlinear properties. In this contribution, an optimized resonant ultrasound spectroscopy (NRUS) measuring data processing protocol applied small samples described. used overcome effects environmental condition changes that take place during experiment, may mask intrinsic nonlinearity. External temperature fluctuation identified as a primary source...

Ultrasonic wave propagation in human cortical bone has been investigated vitro using the so-called axial transmission technique. This technique, which relies on velocity measurement of first arriving signal, used earlier investigations to study status during fracture healing or osteoporosis. Two quasi-point-source elements, one transmitter and receiver (central frequency 0.5 MHz), were generate a wide ultrasonic beam, part strikes sample surface at longitudinal critical angle, receive...

200 MHz scanning acoustic microscopy (SAM) and synchrotron radiation μCT (SR-μCT) were used to assess microstructural parameters tissue properties in site-matched regions of interest cortical bone. Anterior postero-lateral ten cross sections from human radius explored. Structural parameters, including diameter number Haversian canals per area (Ca.Dm, N.Ca/Ar) porosity Po assessed with both methods using a custom-developed image fusion analysis software. Acoustic impedance Z degree...

The aim of this work is to evaluate the effect a spatial gradient material properties (mass density and stiffness coefficients) cortical bone on its ultrasonic response obtained with an axial transmission device. Therefore, two-dimensional finite element time-domain method derived model transient wave propagation in three-layer medium composed inhomogeneous transverse isotropic solid layer sandwiched between two acoustic fluid layers excited by linear source located one layer, delivering...

Dynamic acoustoelastic testing provides a more complete insight into the acoustic nonlinearity exhibited by micro-inhomogeneous media like granular and cracked materials. This method consists of measuring time flight energy modulations pulsed ultrasonic waves induced low-frequency standing wave. Here head were employed to assess elastic dissipative nonlinearities in region near surface solid. Synchronization ultrasound pulse sequence with excitation provided instantaneous variations modulus...

Robust signal processing methods adapted to clinical measurements of guided modes are required assess bone properties such as cortical thickness and porosity. Recently, an approach based on the singular value decomposition (SVD) multidimensional signals recorded with axial transmission array emitters receivers has been proposed for materials negligible absorption, see Minonzio et al. [J. Acoust. Soc. Am. 127, 2913–2919 (2010)]. In presence ability extract mode degrades. The objective present...

It was reported in a previous study that simulated guided wave axial transmission velocities on two-dimensional (2D) numerically reproduced geometry of long bones predicted moderately real vitro ultrasound data the same bone samples. also shown fitting velocity with simple analytical model yielded precise estimate (UTh) for true cortical thickness. This current expands 2D into three dimensions (3D). To this end, and UTh were determined from experiments time-domain finite-difference...

Recent in vitro and simulation studies have shown that guided waves measured at low ultrasound frequencies (f=200 kHz) can characterize both material properties geometry of the cortical bone wall. In particular, a method for an accurate thickness estimation from velocity data has been presented. The clinical application remains, however, challenge as impact layer soft tissue on top is not yet well established, this expected to affect dispersion relative intensities modes. present study...

Cortical bone and the surrounding soft tissues are attenuating heterogeneous media, which might affect signals measured with axial transmission devices. This work aims at evaluating effect of acoustic absorption in on ultrasonic response. Therefore, a two-dimensional finite element time-domain method is derived to model transient wave propagation three-layer medium composed an inhomogeneous transverse isotropic viscoelastic solid layer, sandwiched between two viscous fluid layers. The...

Measuring guided waves in cortical bone arouses a growing interest to assess skeletal status. In most studies, model of waveguide is proposed assist the interpretation dispersion curves. all reported investigations, mimicked as with constant thickness, which only approximates irregular geometry bone. this study, mode propagation bone-mimicking wedged plates investigated aim document influence on measured curves varying thickness and propose method overcome measurement limitations induced by...

Finite-difference time domain (FDTD) numerical simulations coupled to real experimental data were used investigate the propagation of 1 MHz pure bulk wave through models cortical bone microstructures. Bone microstructures reconstructed from three-dimensional high resolution synchrotron radiation microcomputed tomography (SR-muCT) sets. Because matrix elastic properties incompletely documented, several assumptions made. Four built-in characterized by four different anisotropy ratios but same...

Human soft tissue is an important factor that influences the assessment of human long bones using quantitative ultrasound techniques. To investigate such influence, a series tissue–bone phantoms (a bone-mimicking plate coated with layer water, glycerol or silicon rubber) were ultrasonically investigated probe multi-emitter and multi-receiver arrays in axial transmission configuration. A singular value decomposition signal processing technique was applied to extract frequency-dependent...

A wide range of ultrasound methods has been proposed to assess the mechanical strength bone. The axial transmission technique, which consists measuring guided elastic modes through cortical shell long bones such as radius or tibia, recently emerged one most promising approaches all bone exploration methods. Determination dispersion curves waves is therefore prime interest because they provide a large set input data required perform inverse process, and hence evaluate properties (elastic...