Review
Physics, Multidisciplinary
Juvenal Ormachea, Fernando Zvietcovich
Summary: Various approaches are used for elastography imaging, with the reverberant shear wave elastography (RSWE) showing promise as an alternative method. RSWE has been implemented in ultrasound and optical coherence tomography, demonstrating potential for characterizing the elastic and viscoelastic properties of tissues in various organs.
FRONTIERS IN PHYSICS
(2021)
Article
Chemistry, Analytical
Weirong Ge, Graham Brooker, Ritu Mogra, Jon Hyett
Summary: This study proposes a simulation-based method to resolve the challenges in measuring the nonlinear properties of cervical tissue. The study describes the nonlinear behavior using hyperelastic material models and compares the performance of different models in fitting the elastograms. The use of hyperelastic material models improves the consistency of measurements and has potential applications in clinical settings, but further refinements are needed.
Article
Chemistry, Multidisciplinary
James L. L. Suter, Maxime Vassaux, Peter V. V. Coveney
Summary: Using large-scale classical molecular dynamics simulations, the mechanics of nano-reinforcement of graphene-based nanocomposites are investigated. The simulations show that a significant amount of defect-free, predominantly flat graphene flakes is necessary to enhance the materials properties. The results are in excellent agreement with experimental and proposed continuum shear-lag theories. The optimal critical lengths for enhancement are approximately 500 nm for graphene and 300 nm for graphene oxide (GO). The simulations also suggest that aligned and planar flakes are crucial for optimal reinforcement, as undulations degrade the enhancement of materials properties.
ADVANCED MATERIALS
(2023)
Article
Engineering, Biomedical
Aldo Tecse, Stefano E. Romero, Roozbeh Naemi, Benjamin Castaneda
Summary: This study aimed to develop a validated method for characterizing the viscoelastic properties of soft tissues based on ultrasound elastography data. The viscoelastic parameters were estimated and compared to mechanical test results. The results showed that the fractional-derivative models, especially the FD-KV and FD-Maxwell models, were more effective in simulating the viscoelastic behavior of plantar soft tissue. This study has important implications for assessing the function of soft tissue and can be used as markers for diagnosis or prognosis.
PHYSICS IN MEDICINE AND BIOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Masayuki Uranagase, Shuji Ogata
Summary: A nonequilibrium molecular dynamics method is proposed to produce nonequilibrium states flexibly by constraining coarse-grained physical quantities at virtual points. This method can be applied to constrain coarse-grained kinetic energy and produce a nonuniform temperature field in the system. The temperature profile at a nonequilibrium steady state depends on the method for constructing the shape function matrix.
Article
Engineering, Mechanical
Xin He, Zhong Liu, Lars B. Ripley, Victoria L. Swensen, Isaac J. Griffin-Wiesner, Beatrice R. Gulner, Gabriel R. McAndrews, Raymond J. Wieser, Brian P. Borovsky, Q. Jane Wang, Seong H. Kim
Summary: This study investigates the empirical relationship between frictional shear stress and pressure in macro- and microscale contact and sliding. Two types of friction tests were conducted, with results confirming that interfacial shear stress due to kinetic friction is proportional to average contact pressure, further validating Amontons' law.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Physics, Fluids & Plasmas
A. Cappa, J. Varela, D. Lopez-Bruna, E. Ascasibar, M. Liniers, L. G. Eliseev, J. M. Fontdecaba, J. M. Garcia-Regana, A. Gonzalez-Jerez, N. K. Kharchev, F. Medina, A. V. Melnikov, S. Mulas, M. Ochando, D. Spong, J. L. Velasco
Summary: This paper analyzes the impact of electron cyclotron resonance heating and electron cyclotron current drive on Alfvenic instabilities in the TJ-II stellarator caused by neutral beam injection. An MHD stability analysis is carried out to compare with experimental data, showing that the predicted modes coincide with the observed fluctuations. Despite uncertainties, the code predictions agree reasonably well with experimental results.
Article
Mechanics
Daniel J. O'Shea, Mario M. Attard, David C. Kellermann
Summary: Microscopic imaging techniques for soft biological tissues have advanced understanding of their microstructures, particularly the alignment and dispersion of fibrous constituents. This paper aims to extend hyperelasticity representation for anisotropic bodies using FOSTs to incorporate the effects of fiber dispersion. The framework provides fourteen generalised FOSTs for two-direction preferred hyperelasticity, including dispersed fiber families.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Medicine, General & Internal
Tatiana Costas, Maria de la O. Rodriguez, Mercedes Sanchez-Barba, Juan Luis Alcazar
Summary: This study found that higher shear wave elastography (SWE) measurements in the inner part of the posterior cervix were associated with a higher success rate of labor induction. Additionally, cervical length was also important in predicting the success of induction. Combining these two methods could replace the traditional Bishop Score.
Article
Obstetrics & Gynecology
Jimei Sun, Nan Li, Wei Jian, Dingya Cao, Junying Yang, Min Chen
Summary: This study aims to investigate the predictive effect of cervical shear wave elastography (SWE) on the risk of preterm delivery (PTD) in dichorionic diamniotic (DCDA) twin pregnancy. The results showed a significant negative correlation between cervical stiffness and gestational age, indicating that SWE could be a potential tool for assessing cervical stiffness and predicting PTD in DCDA twin pregnancy.
BMC PREGNANCY AND CHILDBIRTH
(2022)
Article
Materials Science, Ceramics
Yang Su, Bo Yang, Qiang Wei, Ning Hu
Summary: This study investigates the mechanical behaviors of polycrystalline graphene under tensile-shear biaxial strains and high temperature using molecular dynamics simulations. The results reveal that shear strain dominates the failure of polycrystalline graphene when subjected to simultaneous tensile and shear loading. Additionally, the structural destruction of polycrystalline graphene changes from stress-dominated to temperature-dominated as the temperature rises. The study also finds that the ultimate shear stress increases with the increase of grain size, while the ultimate strain has the opposite trend. Furthermore, polycrystalline graphene with a larger grain size exhibits better high temperature resistance.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Luke Geise, Ryan Seifert, Andrew Abbott, Daniel Rapking, Mark Flores
Summary: Shape optimization techniques are utilized to develop an optimal shear specimen for polymer matrix composites, with an expanding array of composite applications making certification and damage tolerance critical design factors. The methodology improves the ease of characterization for challenging material properties, such as shear failure, and numerical simulations using specific mechanical properties were conducted to predict failure in the region of interest. The generated geometry should continue to be explored for its capability to measure the shear modulus and shear strength of a laminate, while the method's ability to tailor sample geometry for desired strain states and failure modes suggests further exploration for other failure modes and materials.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Mechanics
Bhanuday Sharma, Rakesh Kumar, Prateek Gupta, Savitha Pareek, Ashish Singh
Summary: In this work, a study is presented for estimating bulk viscosity using the Green-Kubo method based on equilibrium molecular dynamics. The study explores optimal hyper-parameters for estimating bulk viscosity and investigates the effect of system size, temperature, and pressure. The study reveals that the autocorrelation function for bulk viscosity decays slower than that for shear viscosity, and the required autocorrelation length slightly increases with temperature for bulk viscosity.
Article
Engineering, Chemical
Antonio Rodriguez de Castro, Benoit Goyeau
Summary: Knowledge of pore-scale physics in underground multiphase flows is crucial for efficient soil remediation methods. This study presents numerical simulations investigating the displacement of a contaminant by a shear-thinning fluid and assesses the factors affecting residual pollutant saturation.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Astronomy & Astrophysics
Yan Li, Qian-sheng Zhang, Tao Wu, Jie Su, Xing-hao Chen, Gui-fang Lin, Jian-heng Guo, Jie-ying Liu
Summary: Small-scale magnetic fields are fundamental to solar magnetism and play a crucial role in the structure of the solar atmosphere. Observations and simulations show the existence of tangled small-scale magnetic fields in the solar photosphere, with characteristics consistent with each other.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physiology
Rafael Marques, Juan Melchor, Indalecio Sanchez-Montesinos, Olga Roda, Guillermo Rus, Pedro Hernandez-Cortes
Summary: The Finite Element Method (FEM) models are valuable tools for understanding the behavior of structures. It is necessary to address the complexity of joints, materials, attachment areas, and boundary conditions in biomechanics. Scapholunate instability is a major cause of wrist pain and disability, and a better understanding of its pathomechanics is needed for effective treatments. This study used a 3D model of the proximal carpal row created through DICOM images to provide critical information for biomedical research and surgical reconstructions. Experimental testing successfully validated the linear strength values of the scapholunate ligament.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Acoustics
Ali Aghaei, Nicolas Bochud, Giuseppe Rosi, Quentin Grossman, Davide Ruffoni, Salah Naili
Summary: This paper presents a model-based approach to study the interaction of ultrasound waves with homogeneous and heterogeneous additively manufactured samples, paving the way for characterizing and optimizing multi-material systems that display complex bioinspired features.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Chemistry, Physical
Esraa M. Abdelkader, Jose Manuel Cortes Cortes, Candela Reyes Botella, Khaled Nassar, Guillermo Rus, Salma M. Fathy
Summary: This study investigates a new approach to manufacturing fiber-reinforced composite endodontic posts and evaluates their flexural strength. The results show that posts with a pure GF core and higher PP/GF ratio exhibit superior flexural strength and fiber volume fraction.
Article
Multidisciplinary Sciences
Jorge Torres, Inas H. Faris, Antonio Callejas, Felisa Reyes-Ortega, Juan Melchor, Miguel Gonzalez-Andrades, Guillermo Rus
Summary: This study developed an elastography technique based on torsional waves (TWE) for the cornea and demonstrated its potential for clinical diagnosis by measuring displacements and phase speed to estimate viscoelastic parameters.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Antonio Gomez, Antonio Callejas, Guillermo Rus, Nader Saffari
Summary: This article experimentally validates a wave propagation model for transluminal propagation based on a Kelvin Voigt Fractional Derivative wave equation, which accurately simulates the shear wave propagation in soft tissue.
SCIENTIFIC REPORTS
(2022)
Article
Acoustics
Laura Peralta, Daniele Mazierli, Alberto Gomez, Joseph Hajnal, Piero Tortoli, Alessandro Ramalli
Summary: Coherent multitransducer ultrasound (CoMTUS) utilizes the coherent combination of multiple arrays to create an extended effective aperture, resulting in improved resolution, field-of-view, and sensitivity in images. This study demonstrates the feasibility of implementing CoMTUS in 3-D imaging using a pair of 256-element 2-D sparse spiral arrays, which reduces channel count and data processing. The imaging performance of CoMTUS is investigated using simulations, phantom tests, and experimental free-hand operation, showing significant improvements in spatial resolution, contrast-to-noise ratio, and generalized CNR compared to a single dense array system.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2023)
Article
Physics, Applied
J. Torres, G. Laloy-Borgna, G. Rus, S. Catheline
Summary: In the field of acoustics, the definition of a liquid medium becomes unclear when it contains polymer chains or surfactant aggregates. This study used dynamic elastography to investigate the liquid-solid phase transitions in such viscoelastic liquid media. By comparing the dominant shear modulus, the medium can be classified as solid or liquid. The studied medium, an aqueous solution of xanthan gum, demonstrated liquid-solid-liquid behavior with transition bands. Various rheological models were tested to predict the phase transition frequencies, and the Jeffreys model provided the best fit.
APPLIED PHYSICS LETTERS
(2023)
Article
Acoustics
Jorge Torres, Antonio Callejas, Antonio Gomez, Guillermo Rus
Summary: This study proposed an optical micro-elastography technique using magnetic excitation to generate and track high frequency shear waves. The cutoff frequency of shear wave propagation was found to vary depending on the mechanical properties of the samples. By comparing the low frequency range with the high frequency range, it was observed that the relative errors for the viscosity parameter could reach 60% and could be higher with higher dispersive behavior. The proposed technique has important implications for the mechanical characterization of cell culture media.
Article
Obstetrics & Gynecology
Francisca Sonia Molina, Laura Pardo, Maria D. Munoz, Amaia Aiartzaguena, Amelia Valladolid, Jose E. Blanco, Jorge Burgos, MariaMar Gil
Summary: This study evaluated the reproducibility and usability of a novel medical device, the Fine Birth, for accurately diagnosing threatened preterm labor through objective quantification of cervical consistency in pregnant women. The results showed good intraobserver reproducibility and excellent interobserver reproducibility after adding a lateral microcamera and providing training.
AMERICAN JOURNAL OF OBSTETRICS & GYNECOLOGY MFM
(2023)
Correction
Obstetrics & Gynecology
Alicia Mazer Zumaeta, Maria Mar Gil, Miguel Rodriguez-Fernandez, Pilar Carretero, Jose Hector Ochoa, Maria Cristina Casanova, Francisca Sonia Molina
MATERNAL-FETAL MEDICINE
(2023)
Proceedings Paper
Acoustics
Daniele Mazierli, Laura Peralta, Joseph V. Hajnal, Alessandro Ramalli, Piero Tortoli
Summary: This study evaluates the feasibility of using multiple 2-D sparse array probes to extend high frame rate vector Doppler imaging to a three-dimensional region of interest (ROI) and achieves accurate velocity estimations.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Laura Peralta, Daniele Mazierli, Alberto Gomez, Joseph V. Hajnal, Piero Tortoli, Alessandro Ramalli
Summary: Coherent multi-transducer ultrasound (CoMTUS) creates an extended effective aperture through the coherent combination of multiple arrays. In this study, CoMTUS is experimentally implemented and demonstrated in 3-D using two synchronized ULA-OP 256 systems controlling a pair of 2-D sparse arrays. Results show that the proposed CoMTUS system formed by two 2-D 256-element sparse spiral arrays leads to significant improvements in spatial resolution, in the direction where both arrays are aligned, and higher contrast-to-noise-ratio and generalized contrast-to-noise-ratio.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Laura Peralta, Daniele Mazierli, Joseph V. Hajnal, Piero Tortoli, Alessandro Ramalli
Summary: Coherent multi-transducer ultrasound imaging allows multiple arrays to be combined into one large effective aperture, improving field-of-view, resolution, and SNR. However, this can lead to increased grating and side lobe levels, as well as cross-talk artifacts. This study explores the use of a nonlinear beamforming algorithm, DMAS, to reduce these artifacts and improve contrast in CoMTUS imaging. Results show that DMAS effectively lowers side lobes and noise floor, enhancing the detectability of cystic lesions.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Hossam H. Sultan, Enrico Grisan, Laura Peralta, Sevan Harput
Summary: Cortical bone thickness is a crucial biomarker for assessing bone fragility and fracture risk. However, ultrasound assessment of bone is challenging due to the complex nature of bone and the difference in acoustic impedances between bone and soft tissue. This study aims to estimate cortical bone thickness using spectral analysis, circumventing the limitations of traditional speed of sound measurements. Multi-frequency ultrasound acquisitions and continuous wavelet transformation are utilized to demonstrate the feasibility of the proposed methodology on simulated and ex vivo bone tissue datasets.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Proceedings Paper
Acoustics
Hossam H. Sultan, Enrico Grisan, Laura Peralta, Sevan Harput
Summary: The objective of this study is to develop an accurate ultrasound method using CNN-based regression models to estimate cortical bone thickness, which can be used as a proxy for bone quality. The experimental results demonstrate that the combination of multi-frequency RF signals has the potential for cortical thickness estimation.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Article
Biophysics
Nathan D. Camarillo, Rafael Jimenez-Silva, Frances T. Sheehan
Summary: This article discusses the statistical dependence between multiple measurements from the same participant and provides recommendations for using these measurements when they are not independent.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
J. Huet, A. -S. Boureau, A. Sarcher, C. Cornu, A. Nordez
Summary: Standard compression in freehand 3D ultrasound induces a bias in volume calculations, but minimal compression and gel pad methods have similar results. With a trained examiner and precautions, the bias can be minimized and become acceptable in clinical applications.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
C. Lariviere, A. H. Eskandari, H. Mecheri, F. Ghezelbash, D. Gagnon, A. Shirazi-Adl
Summary: Recent developments in musculoskeletal modeling have focused on model customization. Personalization of the spine profile may affect estimates of spinal loading and stability. This study investigates the biomechanical consequences of changes in the spinal profile and finds that personalizing the spine profile has medium to large effects on trunk muscle forces and negligible to small effects on spinal loading and stability.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Luke T. Mattar, Arash B. Mahboobin, Adam J. Popchak, William J. Anderst, Volker Musahl, James J. Irrgang, Richard E. Debski
Summary: Exercise therapy fails in about 25.0% of cases for individuals with rotator cuff tears, and one reason for this failure may be the inability to strengthen and balance the muscle forces that keep the humeral head in the correct position. This study developed computational musculoskeletal models to compare the net muscle force before and after exercise therapy between successfully and unsuccessfully treated patients. The study found that unsuccessfully treated patients had less inferiorly oriented net muscle forces, which may increase the risk of impingement.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Natsuki Sado, Takeshi Edagawa, Toshihide Fujimori, Shogo Hashimoto, Yoshikazu Okamoto, Takahito Nakajima
Summary: The existing methods for predicting hip and lumbosacral joint centres in Japanese adults are biased and differ between sexes. We propose new regression equations that consider soft-tissue thickness, sex differences, and a height-directional measure, and validate them using leave-one-out cross-validation.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Peimin Yu, Xuanzhen Cen, Qichang Mei, Alan Wang, Yaodong Gu, Justin Fernandez
Summary: This study aimed to explore the intra-foot biomechanical differences among individuals with chronic ankle instability (CAI), copers, and healthy individuals during dynamic tasks. The study found that copers and CAI individuals had smaller dorsiflexion angles and copers presented a more eversion position compared to healthy participants. Copers also had greater dorsiflexion angles in the metatarsophalangeal joint and more inversion moments in the subtalar joint during certain tasks. These findings can help in designing interventions to restore ankle joint functions in CAI individuals.
JOURNAL OF BIOMECHANICS
(2024)
Article
Biophysics
Jon Skovgaard Jensen, Anders Holsgaard-Larsen, Anders Stengaard Sorensen, Per Aagaard, Jens Bojsen-Moller
Summary: This study investigates the biomechanical effects of robot-assisted body weight unloading (BWU) on gait patterns in healthy young adults. The results show that dynamic robot-assisted BWU enables reduced kinetic requirements without distorting biomechanically normal gait patterns during overground walking.
JOURNAL OF BIOMECHANICS
(2024)
