Ultrasonics最新文献

{"title":"Optimized Apodizations with Training Simulations (OATS): Learned depth-dependent apodizations via differentiable beamforming for reduced operator tuning","authors":"Di Xiao ,&nbsp;Hassan Nahas ,&nbsp;Misaki Hiroshima ,&nbsp;Aya Kishimoto ,&nbsp;Alfred C.H. Yu","doi":"10.1016/j.ultras.2025.107827","DOIUrl":"10.1016/j.ultras.2025.107827","url":null,"abstract":"<div><div>Ultrasound is a point-of-care imaging modality that allows for real-time operation. While real-time capabilities are advantageous, one potential concern is the operator dependency of the modality as settings selected by the operator can alter the image appearance. Improvement of the B-mode image to necessitate fewer adjustments can reduce the operator dependency. Here, we propose a supervised learning framework (Optimal Apodizations with Training Simulations – OATS) to devise new apodization weights for image quality improvement. Our framework relies on the use of a differentiable beamformer to iteratively optimize apodization weights by comparing differences between simulated ground truth images and the corresponding post-beamformed images (simulated training set of over 200 images). We experimentally verified that these apodization weights resulted in higher quality B-mode images on both simulated and real-world data for focused and unfocused imaging scenarios. In the focused imaging scenario, the OATS-apodized images demonstrated reduced sidelobe artifact, improved lateral resolution (11 %), and improved signal equalization across depth when compared to a conventional Hanning apodization. In the unfocused imaging scenario, we observed reduced sidelobe artifacts and improved tissue-to-lesion contrast by up to 13 dB when compared against fixed F-number beamforming. Additionally, the OATS apodization weights were physically interpretable and learned to emulate image formation parameters such as time-gain compensation, F-number limited aperture, and transmit focus through the supervised learning procedure. Overall, the proposed framework successfully learned generalizable receive apodizations to improve image quality.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107827"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145259294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interpreting material anisotropy through the fractional wave equation","authors":"Ghatu Subhash ,&nbsp;Michael MacIsaac ,&nbsp;Charlie Tran ,&nbsp;Amanda Beck ,&nbsp;Woohyun Eum ,&nbsp;Joel B. Harley","doi":"10.1016/j.ultras.2025.107866","DOIUrl":"10.1016/j.ultras.2025.107866","url":null,"abstract":"<div><div>In the fields of structural health monitoring and non-destructive evaluation (NDE), guided waves are often used for detection of material and structural defects. In this research, we have developed a comprehensive understanding of the generalized superelliptical form of the 2D scalar wave (Helmholtz) equation to predict structural features in anisotropic materials. The exponent of the terms in the superelliptical wave equation was systematically varied, while simultaneously varying the ratio of the wave velocities in two orthogonal directions, to develop 3D maps of wave propagation characteristics in the wavenumber domain as a function of frequency. These wave profiles were then interpreted to reveal structural features and material anisotropy. To validate these predictions, an experimental scheme was designed where a piezoelectric sensor excites a thin specimen, and the ensuing guided wave propagation features were captured on several materials using a laser Doppler vibrometer. The resulting responses in the wavenumber domain were compared against the predicted profiles and a good agreement was observed. Thus, the understanding developed from the superelliptical wave equation and its relationship to a material’s anisotropic structure were experimentally validated on an isotropic material, a uniaxial fiber reinforced composite, and three biaxial composites with different ratios of fiber and matrix stiffnesses. The proposed framework based on guided wave propagation of ultrasonic waves is shown to be a valuable tool to identify structural anisotropy.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107866"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wearable flexible ultrasonic transducers: materials, applications, and challenges","authors":"Lin Guo ,&nbsp;Jing Liu ,&nbsp;Ying Li ,&nbsp;Ruixia Xu ,&nbsp;Guangsheng Song ,&nbsp;Jianan Wu ,&nbsp;Zhihui Qian ,&nbsp;Lei Ren ,&nbsp;Luquan Ren ,&nbsp;Qiang Zhou","doi":"10.1016/j.ultras.2025.107872","DOIUrl":"10.1016/j.ultras.2025.107872","url":null,"abstract":"<div><div>Flexible Ultrasonic Transducers (FUTs) represent a rapidly evolving technology in wearable medical devices, enabling real-time, noninvasive, and continuous physiological monitoring on curved and moving body surfaces. By combining advanced piezoelectric materials with stretchable electrodes and soft encapsulation layers, FUTs overcome the limitations of traditional rigid transducers, including poor conformability, limited wearability, and the potential to cause pressure-induced deformation of the imaging target. This review first summarizes the working principles and typical architectures of FUTs, highlighting key material systems such as flexible substrates and electrodes, high-performance piezoelectric elements, flexible backing and matching layers, and electronic systems. It also summarizes the applications of FUTs in areas such as novel ultrasound diagnostic methods, ultrasonic treatment, advancing healthcare accessibility, and human–machine interaction. Finally, the paper discusses some of the technical challenges faced by FUTs and their corresponding future works, including long-term wearable performance, miniaturization, wireless capability, and the array element localization problem.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107872"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145402069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contrast-Free Super-Resolution microvascular imaging through high frequency ultrasound imaging","authors":"Cheng-Wei Li ,&nbsp;Hsin Huang ,&nbsp;Chih-Yang Lin ,&nbsp;De-Quan Chen ,&nbsp;Yi-Hsiang Chuang ,&nbsp;Chien Chen ,&nbsp;Chih-Chung Huang","doi":"10.1016/j.ultras.2025.107843","DOIUrl":"10.1016/j.ultras.2025.107843","url":null,"abstract":"<div><div>An imaging technique called ultrasound localization microscopy (ULM) has emerged as a means of achieving super-resolution microvascular imaging through localization and tracking of microbubbles (MBs) in blood vessels. However, the use of ULM in preclinical and clinical applications has presented challenges such as prolonged data acquisition times and specific MB injection requirements. To address this drawback, in the present study, erythrocyte ULM (eULM), a contrast-free method for microvascular imaging with a high spatiotemporal resolution that is based on ultra-high-frequency ultrasound (HFUS), was proposed. This technique involves localizing and tracking erythrocytes rather than MBs to achieve super-resolution cerebrovascular imaging. To assess its performance, we conducted two conventional ULM procedures under identical conditions, comparing the image resolution and ability to the measure cerebrovascular hemodynamics of the conventional and proposed ULM procedures. The estimated spatial resolutions for eULM and conventional ULM were 7.3 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span> and approximately 10–13 <span><math><mrow><mi>μ</mi><mi>m</mi></mrow></math></span>, respectively. eULM yielded satisfactory results with just 30-s data accumulation, whereas most ULM techniques typically require 1–10 min for data acquisition. eULM is an in vivo contrast-free ultrasound microvascular imaging method capable of achieving microscopic resolution for live organ imaging. This innovation holds promise as an invaluable diagnostic tool for various diseases that involve changes in microvascular blood flow, making it suitable for both preclinical and clinical applications due to its contrast-free imaging capabilities.</div><div>Keywrods: high frequnecy ultrasound imaging, super-resolution imaging, microvascular imaging, Doppler ultrasound, brain flow imaging.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107843"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145293831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A semi-analytical multimodal Lamb wave imaging algorithm for damage identification in structural health monitoring","authors":"Zhengchen Dai ,&nbsp;Jinxia Liu ,&nbsp;Jianhai Zhang ,&nbsp;Zhiwen Cui ,&nbsp;Tribikram Kundu","doi":"10.1016/j.ultras.2025.107874","DOIUrl":"10.1016/j.ultras.2025.107874","url":null,"abstract":"<div><div>Rapid damage identification in structural health monitoring (SHM) is critical for ensuring structural integrity and safety. Although Lamb waves exhibit high sensitivity to damages, quantitative correlation between multimodal time-of-flight (TOF) differences and damage parameters remains insufficiently explored. In this paper, we proposed an efficient damage identification algorithm based on multimodal Lamb wave TOF differences. The core of the method is a semi-analytical inversion model that reveals the relationship between the multimodal TOF differences and damage parameters. It provides a rapid way to obtain the residual thickness and length of the damage. Moving a transmitter–receiver pair is used to scan the whole detection area. The damage was located at the intersection of abnormal pathways. Dynamic baseline calibration<!--> <!-->through DBSCAN clustering eliminates historical reference dependency while distinguishing damage paths. Tests on aluminum specimens show the range of localization and thickness accuracy. Simulations and experiments confirm its efficacy for identifying corrosion-type damage, demonstrating significant potential for cost-effective SHM deployment in large-scale structures.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107874"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145356052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-precision wavefield simulation and deep learning-based sound speed reconstruction for transcranial ultrasound imaging","authors":"Jing Yang ,&nbsp;Yue Pan ,&nbsp;Yu Qiang ,&nbsp;Xingying Wang ,&nbsp;Zhiqiang Zhang ,&nbsp;Yanyan Yu ,&nbsp;Hairong Zheng ,&nbsp;Weibao Qiu","doi":"10.1016/j.ultras.2025.107860","DOIUrl":"10.1016/j.ultras.2025.107860","url":null,"abstract":"<div><div>Transcranial ultrasound imaging plays an important role in the diagnosis of brain diseases and the monitoring of brain function. However, the quality of transcranial imaging is often impaired by the intricate acoustic properties of the skull. Accurate reconstruction of the skull’s speed of sound (SoS) is critical for effective phase correction and enhanced image quality. In this study, we propose a transcranial SoS local reconstruction framework that integrates high-fidelity 2D numerical simulation with deep learning inversion. A custom wavefield simulation algorithm is developed to generate training datasets that can model spatially varying velocity and attenuation distributions. In the learning framework, we propose WAM-Net, which incorporates a Wavefront Attention Module (WAM) and a gradient-regularized loss function to reconstruct the skull’s SoS accurately. In numerical simulations, the proposed WAM-Net method significantly improves reconstruction speed compared to full-waveform inversion (FWI), and reduces the SoS reconstruction error by 63.52% compared to AutoSoS. In skull-mimicking phantom experiments, the method demonstrates reliable SoS reconstruction across various inclinations and structural designs, with an average Mean Absolute Error (MAE) of 13.4844 m/s in Al₂O₃ phantom and a MAE of 31.3804 m/s in PMMA phantom. In the <em>in-vivo</em> experiments on a crab-eating macaque, the constructed SoS map effectively distinguishes between dense bone and porous bone in anatomically complex regions. These results indicate that the method provides an effective solution for real-time transcranial aberration correction, with high structural fidelity and robustness in heterogeneous cranial environments.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107860"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145356060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the validity of Wood’s law: From bubbly media to liquid foams","authors":"F. Delmotte ,&nbsp;R.-M. Guillermic ,&nbsp;V. Leroy ,&nbsp;T. Brunet","doi":"10.1016/j.ultras.2025.107878","DOIUrl":"10.1016/j.ultras.2025.107878","url":null,"abstract":"<div><div>We report on the acoustic properties of various bubbly gels and foams in order to test the validity of Wood’s law over a very wide range of gas concentration. By using a “double-syringe” technique, we obtain homogeneous mixtures of gas and liquid with controlled gas volume fractions ranging from 0 % to 100 %. The sound speed of acoustic waves propagating in these complex media is extracted from measurements performed at 20 kHz and reveals an excellent agreement with Wood’s prediction. Attenuation measurements also complete the acoustic characterization of these bubbly media and foams.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107878"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145422842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-destructive ultrasonic thermometry for internal temperature field mapping in high-speed aircraft structures","authors":"Yue Cui,&nbsp;Shenshen Liu,&nbsp;Jing Xiang,&nbsp;Youan Shi,&nbsp;Dong Wei,&nbsp;Yanxia Du,&nbsp;Yewei Gui","doi":"10.1016/j.ultras.2025.107888","DOIUrl":"10.1016/j.ultras.2025.107888","url":null,"abstract":"<div><div>A non-destructive ultrasonic-based method is proposed to measure the surface heat flux and internal temperature field of high-speed aircraft structural shells during service. First, a mathematical model for ultrasonic temperature measurement is established, followed by the development of a dedicated measurement system. To meet flight test requirements, the ultrasonic device is upgraded with optimized miniaturization and high-temperature resistance. The experimental scheme is designed, and the ground verification experiment is carried out on the basis of the improved device, and preliminary results validate the reliability of both the ultrasonic method and the measurement instrument. Subsequently, an ultrasonic temperature measurement device is deployed onboard a high-speed aircraft for the first time, enabling real-time determination of one-dimensional temperature distributions along the wall thickness direction and outer wall heat flux at specific measurement points. The results are closely aligned with those obtained from K-type thermocouples. Both ground and flight tests demonstrate that the ultrasonic method effectively captures transient temperature distributions within high-speed aircraft structures, offering a novel, non-invasive solution for thermal parameter measurement and thermal safety assessment.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107888"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145507296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave acoustoelectronic sensor on a diamond substrate for the study of molybdenum oxidation","authors":"B.P. Sorokin ,&nbsp;D.V. Yashin ,&nbsp;N.O. Asafiev ,&nbsp;V.V. Aksenenkov ,&nbsp;N.I. Batova ,&nbsp;K.S. Kravchuk","doi":"10.1016/j.ultras.2025.107842","DOIUrl":"10.1016/j.ultras.2025.107842","url":null,"abstract":"<div><div>For the first time, a method for studying oxidation processes in metal films has been proposed using a microwave acoustoelectronic sensor based on a diamond substrate. The use of microwave operational frequencies guarantees high sensitivity of a sensor. The piezoelectric transducer, which generates a longitudinal bulk acoustic wave as an operational mode, is well protected from external influences. Using the Mo film as an example, we have demonstrated that the changes in the acoustic properties of a chemical sensor caused by Mo oxidation as a result of annealing in air agree well with the phase transformations of Mo studied by other methods, such as XRD, SEM, AFM. It was found that MoO₂, α-MoO₃, and β-MoO₃ were formed at annealing temperatures above 375 °C. Studying a microwave HBAR-based chemical sensor, we obtained changes in the frequency dependencies of the main acoustic parameters at 6.0, 6.5, 13.7, and 16.4 GHz as a result of the annealing process in air at high temperatures up to 500 °C. It should also be noted that a relatively thick film of Mo (∼1 µm) did not completely transform into oxide phases under the given experimental conditions. The increase in the relative frequency shift, Δ<em>f</em>/<em>f</em>, and the <em>Q</em>-factor of overtones at low annealing temperatures up to 300 °C is associated with the compaction of the Mo film, which is a result of a decrease in the average size of the crystallites. In contrast, the decrease in Δ<em>f</em>/<em>f</em> and <em>Q</em> values at annealing temperatures above 375–400 °C is associated with a change in the phase composition of the Mo film. Under these conditions, the main factor contributing to the change in the sign and magnitude of Δ<em>f</em>/<em>f</em> is a significant increase in the total film thickness. It is well known that the higher the <em>Q</em>-factor, the greater the sensitivity of an acoustoelectronic resonant sensor. In our study, we found that the <em>Q</em>-factor decreases as a result of Mo annealing in the range of 300–500 °C. However, it remains at a value of ∼2000, which is quite sufficient for an accurate measurement of Δ<em>f</em>/<em>f</em> values, even at the maximal operational frequency of 16.4 GHz and 500 °C. Because the object under test is placed on a free surface of a diamond substrate, and due to diamond’s high chemical tolerance, the sensor studied can be used multiple times to monitor changes in the chemical composition of substances. It will be possible to do this, at least up to a temperature of 500 °C.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107842"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145222883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wave propagation in highly anisotropic polycrystals: a numerical perspective from an unstructured-mesh-based high-order finite element method","authors":"Shaojie Gong ,&nbsp;Shifeng Guo ,&nbsp;Yi Xiong ,&nbsp;Shiyuan Zhou ,&nbsp;Fangsen Cui ,&nbsp;Menglong Liu","doi":"10.1016/j.ultras.2025.107882","DOIUrl":"10.1016/j.ultras.2025.107882","url":null,"abstract":"<div><div>Ultrasonic non-destructive testing provides an important means to characterize grain size and orientation distribution of polycrystalline materials. Analytical and numerical modeling of ultrasound propagation offer an insight into how ultrasound interacts with polycrystalline materials. However, in highly anisotropic polycrystals, there is still no mature and accurate analytical formulation to describe the strong wave scattering, while the numerical modeling often relies on extremely dense structured meshes to conform to the grain boundary. This study proposes to use a high-order unstructured mesh with added internal nodes to obtain diagonal mass matrices, in order to accurately model wave propagation in strongly anisotropic polycrystals with complex grain boundary. Firstly, polycrystalline geometry was constructed with the Voronoi-based tessellation. Then an explicit dynamics solution was to simulate ultrasonic propagation with the improved element and several typical structured and unstructured elements. The influence of mesh type on calculation accuracy and convergence rate shows that the improved high-order mass-lumped elements, by retaining the true geometry of grain boundaries with unstructured meshes, significantly enhance both computational efficiency and accuracy. Lastly, the simulated results of ultrasonic attenuation and phase velocity in polycrystals show good agreement with both modified analytical models and results obtained with structured meshes. This confirms the effectiveness of the proposed high-order mass-lumped unstructured meshes for accurately simulating wave propagation in polycrystals for the characterization of grain features.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"159 ","pages":"Article 107882"},"PeriodicalIF":4.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145514127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}