Guided wave phased arrays, which use multiple sensors in compact patterns to perform damage imaging through phase delays, have garnered significant interest for the rapid inspection of large composite panels. Previous phased arrays typically used large, wired ultrasonic transducers attached to composites, limiting array reconfigurability and preventing contactless inspection from a distance. This study presents a fully noncontact guided wave phased array imaging approach, which utilizes a dual laser-based guided wave generation and sensing system, namely a pulsed laser-scanning laser Doppler vibrometer (PL-SLDV) system, along with synthetic phased array beamforming and wavefield analysis. The PL-SLDV system employs a Q-switched PL module to generate nanosecond laser pulses that excite ultrasonic guided waves through the thermoelastic effect. To ensure consistent laser-to-ultrasound energy conversion across different composites and prevent potential thermal damage to composites, the laser pulses are directed onto a thin aluminum patch bonded on the composite. The SLDV acquires guided wave signals based on the Doppler effect, and its integrated galvo mirrors can quickly steer laser beam directions to scan a composite plate, thereby acquiring guided wave signals at various array points. Time/phase delays are then applied to the acquired signals through post-processing for synthetic phased array beamforming. To generate inspection images using the acquired wave signals, an improved delay-and-sum (DAS) imaging algorithm is introduced. It uses adaptive weighting factors and incorporates phase delay and back-propagation phase shift, accounting for the frequency- and direction-dependent dispersion relation, to overcome the dispersion effect and directional dependency of waves in anisotropic materials. Moreover, the fusion of phased array imaging and a wavefield analysis approach, which can extract frequency-wavenumber dispersion relations from experimental wavefields, enables our phased array method to perform damage imaging without requiring prior knowledge of composite properties, such as mechanical properties or theoretical dispersion curves. Additionally, the noncontact wave generation/acquisition feature of our PL-SLDV system allows for inspecting composites from a distance and easily constructing phased arrays with different patterns. Proof-of-concept experiments demonstrate that multiple defects in different directions can be successfully detected. Additionally, this study reveals that PL-generated guided waves can contain multiple modes, such as A0, S0, SH0, A1, S1, and SH1 modes, offering valuable insights for researchers interested in using PL-generated guided waves.
{"title":"Noncontact pulsed laser-scanning laser Doppler vibrometer (PL-SLDV) phased array imaging for damage detection in composites.","authors":"Bowen Cai, Luyu Bo, Andrew Campbell, Jiali Li, Chongpeng Qiu, Hongye Liu, Lingyu Yu, Zhenhua Tian","doi":"10.1016/j.ultras.2025.107787","DOIUrl":"10.1016/j.ultras.2025.107787","url":null,"abstract":"<p><p>Guided wave phased arrays, which use multiple sensors in compact patterns to perform damage imaging through phase delays, have garnered significant interest for the rapid inspection of large composite panels. Previous phased arrays typically used large, wired ultrasonic transducers attached to composites, limiting array reconfigurability and preventing contactless inspection from a distance. This study presents a fully noncontact guided wave phased array imaging approach, which utilizes a dual laser-based guided wave generation and sensing system, namely a pulsed laser-scanning laser Doppler vibrometer (PL-SLDV) system, along with synthetic phased array beamforming and wavefield analysis. The PL-SLDV system employs a Q-switched PL module to generate nanosecond laser pulses that excite ultrasonic guided waves through the thermoelastic effect. To ensure consistent laser-to-ultrasound energy conversion across different composites and prevent potential thermal damage to composites, the laser pulses are directed onto a thin aluminum patch bonded on the composite. The SLDV acquires guided wave signals based on the Doppler effect, and its integrated galvo mirrors can quickly steer laser beam directions to scan a composite plate, thereby acquiring guided wave signals at various array points. Time/phase delays are then applied to the acquired signals through post-processing for synthetic phased array beamforming. To generate inspection images using the acquired wave signals, an improved delay-and-sum (DAS) imaging algorithm is introduced. It uses adaptive weighting factors and incorporates phase delay and back-propagation phase shift, accounting for the frequency- and direction-dependent dispersion relation, to overcome the dispersion effect and directional dependency of waves in anisotropic materials. Moreover, the fusion of phased array imaging and a wavefield analysis approach, which can extract frequency-wavenumber dispersion relations from experimental wavefields, enables our phased array method to perform damage imaging without requiring prior knowledge of composite properties, such as mechanical properties or theoretical dispersion curves. Additionally, the noncontact wave generation/acquisition feature of our PL-SLDV system allows for inspecting composites from a distance and easily constructing phased arrays with different patterns. Proof-of-concept experiments demonstrate that multiple defects in different directions can be successfully detected. Additionally, this study reveals that PL-generated guided waves can contain multiple modes, such as A<sub>0</sub>, S<sub>0</sub>, SH<sub>0</sub>, A<sub>1</sub>, S<sub>1</sub>, and SH<sub>1</sub> modes, offering valuable insights for researchers interested in using PL-generated guided waves.</p>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"157 ","pages":"107787"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144817594","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}
Pub Date : 2025-12-29DOI: 10.1016/j.ultras.2025.107948
Hak Hyun Moon, Ga Yeong Lee, Gil Su Kim, Gyu Li Ra, Jong Seob Jeong
Non-contact ultrasound imaging provides a valuable alternative for patients in whom direct skin contact is difficult or undesirable, such as those with burns or a high risk of infection. However, clinical adoption has been limited by the lack of a practical air-coupled transducer. In this study, we present a MHz-band air-coupled ultrasound transducer (ACUT) designed specifically for medical use, enabling bidirectional, contact-free imaging of the skin. The device features a compact 7 mm × 7 mm aperture and a 2 MHz center frequency, and incorporates a porous matching layer together with an optimized piezocomposite structure to overcome the severe acoustic impedance mismatch with air. These design choices result in improved transmission efficiency and stable operation at low drive voltages (tens of volts), delivering sufficient acoustic energy for both brightness-mode (B-mode) and acoustic radiation force impulse (ARFI) imaging. To assess performance, tissue-mimicking agar phantoms with different stiffness levels were fabricated, and fully air-coupled B-mode and ARFI imaging were performed. Both reflected intensity and ARFI-induced displacement clearly distinguished stiffness differences. Additionally, temperature measurements during insonification indicated that measurable acoustic energy reached the target surface, consistent with the observed ARFI displacements. Experiments on ex vivo porcine skin with varying degrees of thermal damage further showed that superficial intensity and displacement responses varied consistently with tissue condition. These findings demonstrate that the proposed approach enables simultaneous acquisition of anatomical and biomechanical information from the skin surface without physical contact, offering a promising tool for safe, efficient, and quantitative assessment of skin integrity.
非接触式超声成像为难以或不希望直接接触皮肤的患者（如烧伤或感染风险高的患者）提供了一种有价值的替代方法。然而，由于缺乏实用的空气耦合换能器，临床应用受到限制。在这项研究中，我们提出了一种专门为医疗用途设计的mhz波段空气耦合超声换能器（ACUT），可实现皮肤的双向无接触成像。该器件具有紧凑的7 mm × 7 mm孔径和2 MHz中心频率，并将多孔匹配层与优化的压电复合材料结构结合在一起，以克服与空气的严重声阻抗失配。这些设计选择提高了传输效率，并在低驱动电压（数十伏）下稳定运行，为亮度模式（b模式）和声辐射力脉冲（ARFI）成像提供了足够的声能。为了评估性能，制作了不同刚度水平的组织模拟琼脂模型，并进行了完全空气耦合b模式和ARFI成像。无论是反映强度还是arfi引起的位移，都清楚地区分了刚度差异。此外，失谐过程中的温度测量表明，可测量的声能到达目标表面，与观察到的ARFI位移一致。对不同程度热损伤的离体猪皮肤的实验进一步表明，表面强度和位移响应随组织状态的变化一致。这些研究结果表明，该方法可以在没有物理接触的情况下同时从皮肤表面获取解剖和生物力学信息，为安全、有效和定量评估皮肤完整性提供了一种有前途的工具。
{"title":"Bidirectional non-contact ultrasound imaging using MHz-band air-coupled ultrasound transducer for skin assessment: A feasibility study","authors":"Hak Hyun Moon, Ga Yeong Lee, Gil Su Kim, Gyu Li Ra, Jong Seob Jeong","doi":"10.1016/j.ultras.2025.107948","DOIUrl":"10.1016/j.ultras.2025.107948","url":null,"abstract":"<div><div>Non-contact ultrasound imaging provides a valuable alternative for patients in whom direct skin contact is difficult or undesirable, such as those with burns or a high risk of infection. However, clinical adoption has been limited by the lack of a practical air-coupled transducer. In this study, we present a MHz-band air-coupled ultrasound transducer (ACUT) designed specifically for medical use, enabling bidirectional, contact-free imaging of the skin. The device features a compact 7 mm × 7 mm aperture and a 2 MHz center frequency, and incorporates a porous matching layer together with an optimized piezocomposite structure to overcome the severe acoustic impedance mismatch with air. These design choices result in improved transmission efficiency and stable operation at low drive voltages (tens of volts), delivering sufficient acoustic energy for both brightness-mode (B-mode) and acoustic radiation force impulse (ARFI) imaging. To assess performance, tissue-mimicking agar phantoms with different stiffness levels were fabricated, and fully air-coupled B-mode and ARFI imaging were performed. Both reflected intensity and ARFI-induced displacement clearly distinguished stiffness differences. Additionally, temperature measurements during insonification indicated that measurable acoustic energy reached the target surface, consistent with the observed ARFI displacements. Experiments on ex vivo porcine skin with varying degrees of thermal damage further showed that superficial intensity and displacement responses varied consistently with tissue condition. These findings demonstrate that the proposed approach enables simultaneous acquisition of anatomical and biomechanical information from the skin surface without physical contact, offering a promising tool for safe, efficient, and quantitative assessment of skin integrity.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107948"},"PeriodicalIF":4.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145900951","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}
When a longitudinal ultrasound pulse impinges on a particle suspension with the particle diameter on the order of the wavelength, resonant scattering of the ultrasound occurs, resulting in an inherent frequency dependence of ultrasound attenuation. Since ultrasound is an elastic wave that transmits deformation of material, the attenuation coefficient and phase velocity are strongly correlated with the mechanical properties of the particles. It is known that a peak is observed in the frequency spectrum of the attenuation coefficient, from which the elastic modulus and viscous loss of the particles can be quantified at a single particle level. This method may be applicable not only for uniform spherical particles with uniform density, but also for particle assemblies called supraballs or supraparticles. Among the various factors, the packing fraction of particle and the connectivity between particles may contribute to the stiffness of supraball. The packing factor was then determined from the sedimentation velocity and density obtained by dynamic ultrasound scattering measurements, while particle elasticity was evaluated from the peak of the frequency spectrum of the attenuation coefficient obtained by ultrasonic spectroscopy measurements. To validate the ultrasonic elasticity analysis, an indentation analysis of a single dried particle was performed using a commercially available dynamic hardness tester.
{"title":"Shear elasticity analysis of supraball by resonant scattering using longitudinal ultrasonic pulses","authors":"Mayu Hiromoto , Mayuko Hirano , Valentin Leroy , Tomohisa Norisuye","doi":"10.1016/j.ultras.2025.107946","DOIUrl":"10.1016/j.ultras.2025.107946","url":null,"abstract":"<div><div>When a longitudinal ultrasound pulse impinges on a particle suspension with the particle diameter on the order of the wavelength, resonant scattering of the ultrasound occurs, resulting in an inherent frequency dependence of ultrasound attenuation. Since ultrasound is an elastic wave that transmits deformation of material, the attenuation coefficient and phase velocity are strongly correlated with the mechanical properties of the particles. It is known that a peak is observed in the frequency spectrum of the attenuation coefficient, from which the elastic modulus and viscous loss of the particles can be quantified at a single particle level. This method may be applicable not only for uniform spherical particles with uniform density, but also for particle assemblies called supraballs or supraparticles. Among the various factors, the packing fraction of particle and the connectivity between particles may contribute to the stiffness of supraball. The packing factor was then determined from the sedimentation velocity and density obtained by dynamic ultrasound scattering measurements, while particle elasticity was evaluated from the peak of the frequency spectrum of the attenuation coefficient obtained by ultrasonic spectroscopy measurements. To validate the ultrasonic elasticity analysis, an indentation analysis of a single dried particle was performed using a commercially available dynamic hardness tester.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107946"},"PeriodicalIF":4.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885626","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}
Pub Date : 2025-12-28DOI: 10.1016/j.ultras.2025.107934
Yong Li, Bin Lin, Zaiwei Liu, Haiyuan Jia, Wenxing Chen, Xiaokang Ma, Yangfan Wan
Surface acoustic wave (SAW)-based ultrasonic inspection has emerged as a promising technique for non-destructive evaluation (NDE) of machined surfaces of hard and brittle materials. However, accurately simulating SAW propagation and its interaction with crack remains challenging. In this study, an efficient multiscale ultrasound peridynamic (PD) modeling framework is developed to address these limitations. A strategy for developing a low-scattering model with smooth SAW transmission is introduced by introducing a transition PD horizon and combining with a convergence analysis of the wavelength-to-particle-spacing ratio. Furthermore, a customizable local damage matrix mapping method is implemented, significantly enhancing modeling flexibility and computational efficiency. The proposed approach is applied to simulate SAW propagation in polysilicon, investigating the influence of transverse cracks, longitudinal cracks, and cracks with different growth stages. Numerical results clearly capture the SAW evolution under varying damage scenarios. Moreover, by extracting the Rayleigh ellipse characteristics from the surface receiving point trajectories, the influence of different types of damage on wave behavior is intuitively revealed. This work presents an accurate SAW-based tool for NDE with broad applicability to damage assessment of material surfaces.
{"title":"A multiscale peridynamic model for surface acoustic wave-defect interactions","authors":"Yong Li, Bin Lin, Zaiwei Liu, Haiyuan Jia, Wenxing Chen, Xiaokang Ma, Yangfan Wan","doi":"10.1016/j.ultras.2025.107934","DOIUrl":"10.1016/j.ultras.2025.107934","url":null,"abstract":"<div><div>Surface acoustic wave (SAW)-based ultrasonic inspection has emerged as a promising technique for non-destructive evaluation (NDE) of machined surfaces of hard and brittle materials. However, accurately simulating SAW propagation and its interaction with crack remains challenging. In this study, an efficient multiscale ultrasound peridynamic (PD) modeling framework is developed to address these limitations. A strategy for developing a low-scattering model with smooth SAW transmission is introduced by introducing a transition PD horizon and combining with a convergence analysis of the wavelength-to-particle-spacing ratio. Furthermore, a customizable local damage matrix mapping method is implemented, significantly enhancing modeling flexibility and computational efficiency. The proposed approach is applied to simulate SAW propagation in polysilicon, investigating the influence of transverse cracks, longitudinal cracks, and cracks with different growth stages. Numerical results clearly capture the SAW evolution under varying damage scenarios. Moreover, by extracting the Rayleigh ellipse characteristics from the surface receiving point trajectories, the influence of different types of damage on wave behavior is intuitively revealed. This work presents an accurate SAW-based tool for NDE with broad applicability to damage assessment of material surfaces.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107934"},"PeriodicalIF":4.1,"publicationDate":"2025-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885627","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}
Pub Date : 2025-12-27DOI: 10.1016/j.ultras.2025.107936
Hsien-Jung Chan , Chun-Hao Lu , Chiao-Yin Wang , Bao-Yu Hsieh , Chih-Kuang Yeh , Dar-In Tai , Po-Hsiang Tsui
Accurate assessment of liver fibrosis in the left liver lobe remains clinically challenging due to motion artifacts that compromise the reliability of shear wave elastography. This feasibility study introduces cardiovascular pulsing-based ultrasound strain imaging (CPUSI) integrated with deep learning, employing dual strain sequence strategies to assess its potential for detecting liver fibrosis in the left hepatic lobe by leveraging intrinsic cardiac motion. A total of 104 patients was enrolled for ultrasound image acquisition, which included B–mode imaging, acoustic radiation force impulse imaging (ARFI), and FibroScan measurements. The dataset was also used for CPUSI generation, extraction of proximal (cardiac-wall) and distal (intrahepatic) strain sequences, and calculation of strain metrics, including time-averaged strain (TAS) and the distal-to-proximal strain ratio (DPSR). Five deep learning models, namely recurrent neural network (RNN), long short-term memory (LSTM), gated recurrent unit (GRU), transformer, and temporal convolutional network (TCN), were trained using paired proximal and distal strain sequences to classify liver fibrosis stages, with histopathology serving as the reference standard. Diagnostic performance was evaluated using independent t-tests and area under the receiver operating characteristic curve (AUROC). CPUSI-derived TAS and DPSR significantly differentiated early-stage (F0–F1) from advanced-stage (F2–F4) fibrosis (p < 0.05). ARFI, FibroScan, CPUSI-derived strain metrics (TAS and DPSR), and the CPUSI-based deep learning framework using dual strain sequences achieved AUROC values of 0.83, 0.82, 0.72–0.73, and 0.95, respectively, with the highest performance observed for the LSTM model. The proposed CPUSI–deep learning framework offers a feasible noninvasive approach for left-lobe fibrosis assessment and may serve as a complementary tool to right-lobe-based elastography. Further studies with larger cohorts are warranted.
{"title":"Cardiovascular pulsing-based ultrasound strain imaging with deep learning using paired proximal and distal strain sequences for liver fibrosis detection: a feasibility study","authors":"Hsien-Jung Chan , Chun-Hao Lu , Chiao-Yin Wang , Bao-Yu Hsieh , Chih-Kuang Yeh , Dar-In Tai , Po-Hsiang Tsui","doi":"10.1016/j.ultras.2025.107936","DOIUrl":"10.1016/j.ultras.2025.107936","url":null,"abstract":"<div><div>Accurate assessment of liver fibrosis in the left liver lobe remains clinically challenging due to motion artifacts that compromise the reliability of shear wave elastography. This feasibility study introduces cardiovascular pulsing-based ultrasound strain imaging (CPUSI) integrated with deep learning, employing dual strain sequence strategies to assess its potential for detecting liver fibrosis in the left hepatic lobe by leveraging intrinsic cardiac motion. A total of 104 patients was enrolled for ultrasound image acquisition, which included B–mode imaging, acoustic radiation force impulse imaging (ARFI), and FibroScan measurements. The dataset was also used for CPUSI generation, extraction of proximal (cardiac-wall) and distal (intrahepatic) strain sequences, and calculation of strain metrics, including time-averaged strain (TAS) and the distal-to-proximal strain ratio (DPSR). Five deep learning models, namely recurrent neural network (RNN), long short-term memory (LSTM), gated recurrent unit (GRU), transformer, and temporal convolutional network (TCN), were trained using paired proximal and distal strain sequences to classify liver fibrosis stages, with histopathology serving as the reference standard. Diagnostic performance was evaluated using independent t-tests and area under the receiver operating characteristic curve (AUROC). CPUSI-derived TAS and DPSR significantly differentiated early-stage (F0–F1) from advanced-stage (F2–F4) fibrosis (<em>p</em> < 0.05). ARFI, FibroScan, CPUSI-derived strain metrics (TAS and DPSR), and the CPUSI-based deep learning framework using dual strain sequences achieved AUROC values of 0.83, 0.82, 0.72–0.73, and 0.95, respectively, with the highest performance observed for the LSTM model. The proposed CPUSI–deep learning framework offers a feasible noninvasive approach for left-lobe fibrosis assessment and may serve as a complementary tool to right-lobe-based elastography. Further studies with larger cohorts are warranted.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107936"},"PeriodicalIF":4.1,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885628","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}
Uncontrolled leakages of hydrocarbons from oil and gas wells can have vast environmental consequences and lead to huge costs for the companies responsible. Thus, preventing and detecting potential leakages in wells is of great importance. In this work, Doppler ultrasound was used for the detection of flow behind steel to help assess the integrity of oil and gas wells. The main goal was to enhance flow detection with Doppler ultrasound through steel by improving the beamforming of the ultrasonic pulse. A naive beamforming approach assuming the medium to be homogeneous was compared to a ray tracing based beamforming algorithm, both in a numerical study and in an experimental setup. Simulations showed a 5 dB increase of the peak amplitude when taking refraction in the steel into account by applying the ray tracing based beamforming. In addition, the targeted focus was hit with a narrower, more precisely controlled beam on the far side of the steel layer. These two beamforming techniques were then employed and compared for flow detection behind steel in an experimental setup. Two cases were investigated, low velocity and high velocity, using three different transmit voltages for each velocity. Pulsed wave Doppler spectra were displayed, and the ratio between the flow signal power averaged over a range of frequencies was calculated. An increase of 3-4 dB was observed using the ray tracing technique, showing enhanced flow detection compared to the naive technique.
{"title":"Enhanced Flow Detection through a Steel Barrier using Doppler Ultrasound: a Numerical and Experimental Study","authors":"Andreas Sørbrøden Talberg , Cristiana Golfetto , Tonni Franke Johansen , Jørgen Avdal , Ingvild Kinn Ekroll , Hefeng Dong , Svein-Erik Måsøy","doi":"10.1016/j.ultras.2025.107922","DOIUrl":"10.1016/j.ultras.2025.107922","url":null,"abstract":"<div><div>Uncontrolled leakages of hydrocarbons from oil and gas wells can have vast environmental consequences and lead to huge costs for the companies responsible. Thus, preventing and detecting potential leakages in wells is of great importance. In this work, Doppler ultrasound was used for the detection of flow behind steel to help assess the integrity of oil and gas wells. The main goal was to enhance flow detection with Doppler ultrasound through steel by improving the beamforming of the ultrasonic pulse. A naive beamforming approach assuming the medium to be homogeneous was compared to a ray tracing based beamforming algorithm, both in a numerical study and in an experimental setup. Simulations showed a 5 dB increase of the peak amplitude when taking refraction in the steel into account by applying the ray tracing based beamforming. In addition, the targeted focus was hit with a narrower, more precisely controlled beam on the far side of the steel layer. These two beamforming techniques were then employed and compared for flow detection behind steel in an experimental setup. Two cases were investigated, low velocity and high velocity, using three different transmit voltages for each velocity. Pulsed wave Doppler spectra were displayed, and the ratio between the flow signal power averaged over a range of frequencies was calculated. An increase of 3-4 dB was observed using the ray tracing technique, showing enhanced flow detection compared to the naive technique.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"162 ","pages":"Article 107922"},"PeriodicalIF":4.1,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145967050","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}
Pub Date : 2025-12-26DOI: 10.1016/j.ultras.2025.107935
Vincent Dorval , Nicolas Leymarie , Alexandre Imperiale , Edouard Demaldent , Pierre-Emile Lhuillier
Texture and grain elongation can occur in metallic microstructures due to various manufacturing processes, such as welding or rolling deformation. These microstructural characteristics generally lead to anisotropic macroscopic properties to which ultrasonic waves are particularly sensitive. It is therefore interesting to predict not only the speed but also the attenuation of these waves as a function of these microstructural properties. Finite Element Method has been applied to that aim in various works, mainly in the case of isotropic microstructures. Anisotropic microstructures raise specific challenges, including the random generation of samples, the handling of boundary effects, and the analysis of anisotropic modes. This communication details a method that addresses them. Results are presented for microstructures with elongation, texture, or both. Comparisons to analytical models are also provided.
{"title":"Numerical characterization of quasi-longitudinal and quasi-shear waves in anisotropic polycrystalline microstructures with elongation and texture","authors":"Vincent Dorval , Nicolas Leymarie , Alexandre Imperiale , Edouard Demaldent , Pierre-Emile Lhuillier","doi":"10.1016/j.ultras.2025.107935","DOIUrl":"10.1016/j.ultras.2025.107935","url":null,"abstract":"<div><div>Texture and grain elongation can occur in metallic microstructures due to various manufacturing processes, such as welding or rolling deformation. These microstructural characteristics generally lead to anisotropic macroscopic properties to which ultrasonic waves are particularly sensitive. It is therefore interesting to predict not only the speed but also the attenuation of these waves as a function of these microstructural properties. Finite Element Method has been applied to that aim in various works, mainly in the case of isotropic microstructures. Anisotropic microstructures raise specific challenges, including the random generation of samples, the handling of boundary effects, and the analysis of anisotropic modes. This communication details a method that addresses them. Results are presented for microstructures with elongation, texture, or both. Comparisons to analytical models are also provided.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107935"},"PeriodicalIF":4.1,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145912985","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}
Pub Date : 2025-12-25DOI: 10.1016/j.ultras.2025.107945
Andrea Orthodoxou, Margaret Lucas, Helen Mulvana
Low-intensity pulsed ultrasound (LIPUS) is approved to promote healing in non-union bone fractures in the UK (NICE) and USA (FDA). Despite extensive in vitro, pre-clinical, and clinical data indicating efficacy, patient outcomes remain inconsistent. A deeper understanding of the mechanisms by which ultrasound vibrations influence cellular behaviour is critical to optimising LIPUS for bone repair and to enable greater patient benefit. The literature offers a broad experimental base, but collective insights are hindered by two key issues: inadequate reporting of ultrasound exposure conditions, often overlooking reflections and standing waves, and reliance on spatial average temporal average intensity (ISATA) as the sole metric of ultrasound dose. While ISATA informs safety thresholds (TI, MI), it fails to describe the specific acoustic stimuli cells experience, masking variations in pressure, pulse repetition, and duty cycle.
To identify the ultrasound parameters that are most important for eliciting mechano-sensing responses in osteoblast-like cells, we systematically evaluated a 1 MHz pulsed field in a controlled cell culture environment. Immunofluorescence analysis of actin and vinculin were used to assess cytoskeletal changes in response to fully described LIPUS exposures. We identified a pulse repetition frequency (PRF) upper limit of 1 kHz, beyond which LIPUS lost efficacy in enhancing mechano-sensing. Optimal response occurred at 20 % duty cycle, 160 kPa, and 60 mW/cm2 ISATA, challenging the currently accepted standard and parameters used to operate existing clinical devices (1 MHz, 30 mW/cm2 ISATA). Our data demonstrate the necessity to report fully the parameters that describe the ultrasound dose experienced by cells to predict which conditions lead to an upregulation in mechano-sensing and that ISATA alone is not an adequate measure unless all other parameters are known and fixed. Finally, since PRF is determinant of achieving a cellular response, we reaffirm the already accepted understanding that pulsed exposures are critical to a cellular ability to detect and/or respond to ultrasound in a way that is useful for fracture repair.
{"title":"Pressure and not spatial average temporal average intensity governs mechanosensitive responses of osteoblast-like cells exposed to low intensity pulsed ultrasound","authors":"Andrea Orthodoxou, Margaret Lucas, Helen Mulvana","doi":"10.1016/j.ultras.2025.107945","DOIUrl":"10.1016/j.ultras.2025.107945","url":null,"abstract":"<div><div>Low-intensity pulsed ultrasound (LIPUS) is approved to promote healing in non-union bone fractures in the UK (NICE) and USA (FDA). Despite extensive <em>in vitro</em>, pre-clinical, and clinical data indicating efficacy, patient outcomes remain inconsistent. A deeper understanding of the mechanisms by which ultrasound vibrations influence cellular behaviour is critical to optimising LIPUS for bone repair and to enable greater patient benefit. The literature offers a broad experimental base, but collective insights are hindered by two key issues: inadequate reporting of ultrasound exposure conditions, often overlooking reflections and standing waves, and reliance on spatial average temporal average intensity (I<sub>SATA</sub>) as the sole metric of ultrasound dose. While I<sub>SATA</sub> informs safety thresholds (TI, MI), it fails to describe the specific acoustic stimuli cells experience, masking variations in pressure, pulse repetition, and duty cycle.</div><div>To identify the ultrasound parameters that are most important for eliciting mechano-sensing responses in osteoblast-like cells, we systematically evaluated a 1 MHz pulsed field in a controlled cell culture environment. Immunofluorescence analysis of actin and vinculin were used to assess cytoskeletal changes in response to fully described LIPUS exposures. We identified a pulse repetition frequency (PRF) upper limit of 1 kHz, beyond which LIPUS lost efficacy in enhancing mechano-sensing. Optimal response occurred at 20 % duty cycle, 160 kPa, and 60 mW/cm<sup>2</sup> I<sub>SATA</sub>, challenging the currently accepted standard and parameters used to operate existing clinical devices (1 MHz, 30 mW/cm<sup>2</sup> I<sub>SATA</sub>). Our data demonstrate the necessity to report fully the parameters that describe the ultrasound dose experienced by cells to predict which conditions lead to an upregulation in mechano-sensing and that I<sub>SATA</sub> alone is not an adequate measure unless all other parameters are known and fixed. Finally, since PRF is determinant of achieving a cellular response, we reaffirm the already accepted understanding that pulsed exposures are critical to a cellular ability to detect and/or respond to ultrasound in a way that is useful for fracture repair.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107945"},"PeriodicalIF":4.1,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885629","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}
As oil production enters its middle and later stages, high water content and severe emulsification in oil wells are becoming increasingly prominent, leading to excessive energy consumption and environmental pollution. Existing downhole oil–water (O/W) separation technologies, such as gravity-based separation and hydrocyclone separation, prove inadequate for separating micro-sized oil droplets in heavily emulsified production fluids. Acoustic O/W separation has shown promising capabilities for micron-sized droplet removal, yet current studies predominantly address emulsions with high oil content. Acoustic separation techniques targeting high-water-cut emulsions have only been validated in stationary, millimeter-scale channels and lack research in large-scale, high throughput, and rapid flow rates under realistic downhole conditions. To overcome this limitation, this study introduces a novel ring-shaped acoustic focusing piezoelectric transducer. The transducer employs the inverse piezoelectric effect to excite the radial contraction–expansion vibrations of the annular structure, generating a diametrically focused full-wave acoustic field within the emulsion, with the center of the pipe serving as the focal point. Under the combined effects of acoustic radiation and acoustic streaming drag forces, dispersed oil droplets migrate toward the pressure antinode, enabling O/W phase separation. Experimental results from both static and dynamic conditions indicate that the proposed transducer effectively enriches micron-sized oil droplets in high-water-cut oil-in-water emulsion and achieves separation. Nevertheless, under dynamic conditions, separation efficiency is sensitive to the flow velocity and declines as flow rate increases. In summary, the proposed acoustic transducer provides an efficient solution for downhole high-water-cut produced fluids, supporting further developments in acoustic-based downhole separation technologies.
{"title":"Design and application of a ring-shaped acoustic focusing piezoelectric transducer for emulsion separation","authors":"Wei Chen , Haoren Feng , Liang Wang, Yitao Wang, Xiaoqiang Wei","doi":"10.1016/j.ultras.2025.107944","DOIUrl":"10.1016/j.ultras.2025.107944","url":null,"abstract":"<div><div>As oil production enters its middle and later stages, high water content and severe emulsification in oil wells are becoming increasingly prominent, leading to excessive energy consumption and environmental pollution. Existing downhole oil–water (O/W) separation technologies, such as gravity-based separation and hydrocyclone separation, prove inadequate for separating micro-sized oil droplets in heavily emulsified production fluids. Acoustic O/W separation has shown promising capabilities for micron-sized droplet removal, yet current studies predominantly address emulsions with high oil content. Acoustic separation techniques targeting high-water-cut emulsions have only been validated in stationary, millimeter-scale channels and lack research in large-scale, high throughput, and rapid flow rates under realistic downhole conditions. To overcome this limitation, this study introduces a novel ring-shaped acoustic focusing piezoelectric transducer. The transducer employs the inverse piezoelectric effect to excite the radial contraction–expansion vibrations of the annular structure, generating a diametrically focused full-wave acoustic field within the emulsion, with the center of the pipe serving as the focal point. Under the combined effects of acoustic radiation and acoustic streaming drag forces, dispersed oil droplets migrate toward the pressure antinode, enabling O/W phase separation. Experimental results from both static and dynamic conditions indicate that the proposed transducer effectively enriches micron-sized oil droplets in high-water-cut oil-in-water emulsion and achieves separation. Nevertheless, under dynamic conditions, separation efficiency is sensitive to the flow velocity and declines as flow rate increases. In summary, the proposed acoustic transducer provides an efficient solution for downhole high-water-cut produced fluids, supporting further developments in acoustic-based downhole separation technologies.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107944"},"PeriodicalIF":4.1,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145858096","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}
This study investigates the reflection and refraction behaviour of shear-horizontal (SH) waves at the interface of and . The interface is modelled by an electrically induced classical spring and a piezoelectric membrane. An analytical framework is used to assess how interfacial mechanical and electrical stiffnesses, together with piezoelectric coupling, influence the amplitude and phase of reflected and transmitted SH waves. Results indicate that increased mechanical stiffness amplifies reflected SH-wave intensity while diminishing refraction and electro-acoustic conversion, whereas stronger electrical coupling facilitates enhanced refraction with reduced reflection. Notably, resonance phenomena near grazing incidence yield pronounced amplitude peaks and abrupt phase shifts, highlighting the sensitivity of wave behaviour to incident angle and interfacial properties. These findings provide useful guidance for the design of acoustic filters, waveguides, sensors and non-destructive evaluation components, and may be extended to multilayered or frequency-dependent systems in future work.
{"title":"Amplitude and phase modulation of SH waves by resonant scattering at PZT‐5A/BaTiO3 imperfect boundary","authors":"Koushik Maity , Kshitish Ch Mistri , Amrita Das , Abhishek Kumar Singh","doi":"10.1016/j.ultras.2025.107929","DOIUrl":"10.1016/j.ultras.2025.107929","url":null,"abstract":"<div><div>This study investigates the reflection and refraction behaviour of shear-horizontal (SH) waves at the interface of <span><math><mtext>PZT‐5A</mtext></math></span> and <span><math><msub><mtext>BaTiO</mtext><mn>3</mn></msub></math></span>. The interface is modelled by an electrically induced classical spring and a piezoelectric membrane. An analytical framework is used to assess how interfacial mechanical and electrical stiffnesses, together with piezoelectric coupling, influence the amplitude and phase of reflected and transmitted SH waves. Results indicate that increased mechanical stiffness amplifies reflected SH-wave intensity while diminishing refraction and electro-acoustic conversion, whereas stronger electrical coupling facilitates enhanced refraction with reduced reflection. Notably, resonance phenomena near grazing incidence yield pronounced amplitude peaks and abrupt phase shifts, highlighting the sensitivity of wave behaviour to incident angle and interfacial properties. These findings provide useful guidance for the design of acoustic filters, waveguides, sensors and non-destructive evaluation components, and may be extended to multilayered or frequency-dependent systems in future work.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"161 ","pages":"Article 107929"},"PeriodicalIF":4.1,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842366","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}
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