Pub Date : 2024-09-12DOI: 10.1109/OJUFFC.2024.3459858
Thong Huynh;Trym Haakon Eggen;Lars Hoff
Tissue harmonic imaging requires good control of the nonlinearity in the ultrasound probe, as transmitted second harmonics from the probe may interfere with tissue harmonics and degrade image quality. We have studied the nonlinearity in four different medical ultrasound probes by measuring the capacitive part of their electrical impedances under varying electric fields, at frequencies well below and above the resonances. The probes were made with two different piezoelectric materials, piezoceramic PZT and single-crystal PMN-PT, with either soft backing operating at half-wavelength resonance or hard backing operating at quarter-wavelength resonance. When the applied electric field amplitude E was increased from $mathrm {0.05~V/mu m}$ to $mathrm {0.5~V/mu m}$ , we observed an increase in both the capacitance at high frequency, interpreted as clamped conditions, and at low frequency, interpreted as free conditions. This is a nonlinear phenomenon as these capacitances will not change in the linear regime. The increase in free capacitance was from 4 to 10 times larger than the increase in clamped capacitance for all the investigated probes. This indicates a stronger nonlinearity for the free capacitance. At the low-frequency excitation, we observed distortion in the current passing through the acoustic stack corresponding to a relative second harmonic level of −20 dB. We conclude that the nonlinear impedance of the acoustic stack in the investigated probes was primarily caused by nonlinearities in the mechanical coefficients, while contributions from dielectric nonlinearity were negligible.
{"title":"Investigation of Non-Linearities in Medical Ultrasound Imaging Probes by Characterizing Free and Clamped Capacitances","authors":"Thong Huynh;Trym Haakon Eggen;Lars Hoff","doi":"10.1109/OJUFFC.2024.3459858","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3459858","url":null,"abstract":"Tissue harmonic imaging requires good control of the nonlinearity in the ultrasound probe, as transmitted second harmonics from the probe may interfere with tissue harmonics and degrade image quality. We have studied the nonlinearity in four different medical ultrasound probes by measuring the capacitive part of their electrical impedances under varying electric fields, at frequencies well below and above the resonances. The probes were made with two different piezoelectric materials, piezoceramic PZT and single-crystal PMN-PT, with either soft backing operating at half-wavelength resonance or hard backing operating at quarter-wavelength resonance. When the applied electric field amplitude E was increased from \u0000<inline-formula> <tex-math>$mathrm {0.05~V/mu m}$ </tex-math></inline-formula>\u0000 to \u0000<inline-formula> <tex-math>$mathrm {0.5~V/mu m}$ </tex-math></inline-formula>\u0000, we observed an increase in both the capacitance at high frequency, interpreted as clamped conditions, and at low frequency, interpreted as free conditions. This is a nonlinear phenomenon as these capacitances will not change in the linear regime. The increase in free capacitance was from 4 to 10 times larger than the increase in clamped capacitance for all the investigated probes. This indicates a stronger nonlinearity for the free capacitance. At the low-frequency excitation, we observed distortion in the current passing through the acoustic stack corresponding to a relative second harmonic level of −20 dB. We conclude that the nonlinear impedance of the acoustic stack in the investigated probes was primarily caused by nonlinearities in the mechanical coefficients, while contributions from dielectric nonlinearity were negligible.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"116-125"},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10679659","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1109/OJUFFC.2024.3457503
Anabella Giacomozzi;Jose Benedito;Tomás E. Gómez Álvarez-Arenas;Jose V. García-Perez
In the context of the ongoing digital revolution, the food industry grapples with significant challenges concerning quality control, safety, production efficiency, and economic viability. Tackling these challenges requires analyzing a large volume of samples-preferably the whole production-to extract the maximum amount of information, facilitating food processing optimization, quality assurance, safety protocols, and minimizing the energetic impact. Developing monitoring systems for the non-invasive, accurate and real-time measurement of compositional properties, texture, and the detection of foreign bodies throughout the entire production remains a challenge in the agri-food sector. This challenge reflects that these properties affect both quality and food safety but also that current technologies are not capable of monitoring them at an industrial level. Over recent decades, ultrasound technology has garnered significant attention from stakeholders across the food supply chain owing to its potential to revolutionize food industry automation. Ultrasound inspection offers numerous advantages, including the rapid, precise, and cost-effective assessment of product properties, as well as the real-time monitoring of internal quality attributes across various stages of food processing. By interacting with matter, sound waves provide valuable insights into the composition, structure, and physical state of food constituents through changes in velocity, attenuation, and spectral response. This review summarizes recent findings in the use of air-coupled ultrasound inspection for ensuring food quality and safety control.
{"title":"Air-Coupled Ultrasonic Inspection of Foods: A Review","authors":"Anabella Giacomozzi;Jose Benedito;Tomás E. Gómez Álvarez-Arenas;Jose V. García-Perez","doi":"10.1109/OJUFFC.2024.3457503","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3457503","url":null,"abstract":"In the context of the ongoing digital revolution, the food industry grapples with significant challenges concerning quality control, safety, production efficiency, and economic viability. Tackling these challenges requires analyzing a large volume of samples-preferably the whole production-to extract the maximum amount of information, facilitating food processing optimization, quality assurance, safety protocols, and minimizing the energetic impact. Developing monitoring systems for the non-invasive, accurate and real-time measurement of compositional properties, texture, and the detection of foreign bodies throughout the entire production remains a challenge in the agri-food sector. This challenge reflects that these properties affect both quality and food safety but also that current technologies are not capable of monitoring them at an industrial level. Over recent decades, ultrasound technology has garnered significant attention from stakeholders across the food supply chain owing to its potential to revolutionize food industry automation. Ultrasound inspection offers numerous advantages, including the rapid, precise, and cost-effective assessment of product properties, as well as the real-time monitoring of internal quality attributes across various stages of food processing. By interacting with matter, sound waves provide valuable insights into the composition, structure, and physical state of food constituents through changes in velocity, attenuation, and spectral response. This review summarizes recent findings in the use of air-coupled ultrasound inspection for ensuring food quality and safety control.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"100-115"},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10679167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-19DOI: 10.1109/OJUFFC.2024.3445868
Håvard Kjellmo Arnestad;Ole Marius Hoel Rindal;Andreas Austeng;Sven Peter Näsholm
In ultrasound imaging, speckle originates from a large amount of sub-resolution scatterers within the medium. In idealized cases, the speckle envelope statistics follow a Rayleigh distribution, but in practical pulse-echo imaging, the distribution depends on both the imaging system and the underlying tissue structure. Estimating envelope statistics is part of quantitative ultrasound workflows and is also important for image quality assessment as it relates to lesion and tissue detectability. A concrete example is the generalized contrast-to-noise ratio (gCNR), which is a functional of two pixel-value probability density functions (PDFs) from different speckle regions. Such speckle PDFs have, by convention, been estimated from data using histograms, but the accuracy of these estimates can be affected by the nontrivial selection and tuning of the binning parameters. However, the statistics literature widely advocates kernel density estimation (KDE) as a better alternative to histogram-based approaches. In this article, we propose applying a KDE-based method to estimate speckle PDFs in medical ultrasound imaging. The method is practically tuning-free and leverages the Box-Cox transformation to achieve best-in-class performance across a wide range of test cases, and is also robust in cases where gCNR estimation may otherwise fail, such as for skewed distributions that may arise with adaptive beamformers. Furthermore, this work highlights theoretical aspects related to the estimation of PDFs and derived quantities, including the gCNR.
在超声成像中，斑点源于介质中大量的亚分辨率散射体。在理想情况下，斑点包络统计遵循瑞利分布，但在实际脉冲回波成像中，其分布取决于成像系统和底层组织结构。估算包络统计是定量超声工作流程的一部分，对于图像质量评估也很重要，因为这关系到病变和组织的可探测性。一个具体的例子是广义对比度-噪声比（gCNR），它是来自不同斑点区域的两个像素值概率密度函数（PDF）的函数。按照惯例，这种斑点概率密度函数是使用直方图从数据中估算出来的，但这些估算的准确性可能会受到分选参数的非线性选择和调整的影响。然而，统计文献普遍认为核密度估计（KDE）是基于直方图方法的更好替代方法。在本文中，我们建议在医学超声成像中应用基于 KDE 的方法来估计斑点 PDF。该方法实际上无需调整，并利用 Box-Cox 变换在广泛的测试案例中实现了同类最佳的性能，而且在 gCNR 估计可能失败的情况下也很稳健，例如自适应波束成形器可能出现的偏斜分布。此外，这项工作还强调了与估计 PDF 和派生量（包括 gCNR）相关的理论方面。
{"title":"Robust Non-Parametric Estimation of Speckle Probability Densities and gCNR","authors":"Håvard Kjellmo Arnestad;Ole Marius Hoel Rindal;Andreas Austeng;Sven Peter Näsholm","doi":"10.1109/OJUFFC.2024.3445868","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3445868","url":null,"abstract":"In ultrasound imaging, speckle originates from a large amount of sub-resolution scatterers within the medium. In idealized cases, the speckle envelope statistics follow a Rayleigh distribution, but in practical pulse-echo imaging, the distribution depends on both the imaging system and the underlying tissue structure. Estimating envelope statistics is part of quantitative ultrasound workflows and is also important for image quality assessment as it relates to lesion and tissue detectability. A concrete example is the generalized contrast-to-noise ratio (gCNR), which is a functional of two pixel-value probability density functions (PDFs) from different speckle regions. Such speckle PDFs have, by convention, been estimated from data using histograms, but the accuracy of these estimates can be affected by the nontrivial selection and tuning of the binning parameters. However, the statistics literature widely advocates kernel density estimation (KDE) as a better alternative to histogram-based approaches. In this article, we propose applying a KDE-based method to estimate speckle PDFs in medical ultrasound imaging. The method is practically tuning-free and leverages the Box-Cox transformation to achieve best-in-class performance across a wide range of test cases, and is also robust in cases where gCNR estimation may otherwise fail, such as for skewed distributions that may arise with adaptive beamformers. Furthermore, this work highlights theoretical aspects related to the estimation of PDFs and derived quantities, including the gCNR.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"89-99"},"PeriodicalIF":0.0,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10638550","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142090778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1109/OJUFFC.2024.3433316
Lola Fariñas;Domingo Sancho-Knapik;José J. Peguero-Pina;Eustaquio Gil-Pelegrín;Tomás E. Gómez Álvarez-Arenas
This paper reviews the origin, development and use of air-coupled ultrasonic techniques for the study of plant leaf tissues and their water relations. The two techniques proposed so far are included: Non-Contact Resonant Ultrasound Spectroscopy and Non-Resonant Time Domain Transmittance. While both are completely non-invasive, non-destructive and fast, the former has been used to determine water potential, turgor loss point and differential behavior of various leaf tissues, and has been extensively tested for different species, both in vivo and ex vivo in parallel with in-field experiments; while the latter has recently been proposed as a universal technique that can be applied to plant leaves regardless of the possibility of exciting thickness resonances.
{"title":"Origin, Development, and Applications of Air-Coupled Broadband Ultrasounds for the Study of Tissues and Water Relations in Plant Leaves: A Review","authors":"Lola Fariñas;Domingo Sancho-Knapik;José J. Peguero-Pina;Eustaquio Gil-Pelegrín;Tomás E. Gómez Álvarez-Arenas","doi":"10.1109/OJUFFC.2024.3433316","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3433316","url":null,"abstract":"This paper reviews the origin, development and use of air-coupled ultrasonic techniques for the study of plant leaf tissues and their water relations. The two techniques proposed so far are included: Non-Contact Resonant Ultrasound Spectroscopy and Non-Resonant Time Domain Transmittance. While both are completely non-invasive, non-destructive and fast, the former has been used to determine water potential, turgor loss point and differential behavior of various leaf tissues, and has been extensively tested for different species, both in vivo and ex vivo in parallel with in-field experiments; while the latter has recently been proposed as a universal technique that can be applied to plant leaves regardless of the possibility of exciting thickness resonances.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"77-88"},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10608179","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141965502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-14DOI: 10.1109/OJUFFC.2024.3413604
Victor Takahashi;Michaël Lematre;Jérôme Fortineau;Marc Lethiecq
Paintings are intricate structures made up of multiple layers of materials that possess different properties and thicknesses. Due to their fragility, they can be damaged by exposure to various environmental factors such very large amplitude vibrations, as well as temperature and humidity variations. Restorers use various techniques such as raking light, x-rays, infrared, and UV to gather information about the condition of the artwork. Unlike these methods, ultrasonic techniques use elastic waves and can thus provide information about the mechanical properties of the materials and their interfaces. The goal of this work is twofold. First, it consists in numerically analyzing the sensitivity of elastic parameters of painting layers through their influence on the acoustic transmission coefficient and dispersion curves. Then, an experimental device is set up to confirm some of these results by the determination of the values of the elastic parameters of the constituent layers of paintings. To this aim, we have developed an original association of numerical and experimental methods for characterization and determination of the layer elastic parameters of some materials used in paintings. A matrix stiffness model associated to a genetic algorithm are used for the numerical study and optimization process between the theoretical transmission coefficient and the experimental one. Then, focused Air-Coupled Transducers (ACTs) in conjunction with a rotary motor are used to perform measurements of transmitted signal amplitude on several components used in paintings under various angles of incidence. Our results concerning the determination of elastic parameters values on various materials including plexiglass (PMMA), acrylic paint, varnish, gesso and wood, taken as single plates, and bi-layered structures, are strongly supported by theoretical results obtained using the matrix stiffness model.
{"title":"Determination of Elastic Parameters of Thin Layers Used in Paintings by Air-Coupled Ultrasound Transmission Measurements Under Varying Incidence","authors":"Victor Takahashi;Michaël Lematre;Jérôme Fortineau;Marc Lethiecq","doi":"10.1109/OJUFFC.2024.3413604","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3413604","url":null,"abstract":"Paintings are intricate structures made up of multiple layers of materials that possess different properties and thicknesses. Due to their fragility, they can be damaged by exposure to various environmental factors such very large amplitude vibrations, as well as temperature and humidity variations. Restorers use various techniques such as raking light, x-rays, infrared, and UV to gather information about the condition of the artwork. Unlike these methods, ultrasonic techniques use elastic waves and can thus provide information about the mechanical properties of the materials and their interfaces. The goal of this work is twofold. First, it consists in numerically analyzing the sensitivity of elastic parameters of painting layers through their influence on the acoustic transmission coefficient and dispersion curves. Then, an experimental device is set up to confirm some of these results by the determination of the values of the elastic parameters of the constituent layers of paintings. To this aim, we have developed an original association of numerical and experimental methods for characterization and determination of the layer elastic parameters of some materials used in paintings. A matrix stiffness model associated to a genetic algorithm are used for the numerical study and optimization process between the theoretical transmission coefficient and the experimental one. Then, focused Air-Coupled Transducers (ACTs) in conjunction with a rotary motor are used to perform measurements of transmitted signal amplitude on several components used in paintings under various angles of incidence. Our results concerning the determination of elastic parameters values on various materials including plexiglass (PMMA), acrylic paint, varnish, gesso and wood, taken as single plates, and bi-layered structures, are strongly supported by theoretical results obtained using the matrix stiffness model.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"126-139"},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10558716","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-12DOI: 10.1109/OJUFFC.2024.3413603
Tony Merrien;Pierre Didier;Emmanuelle Algré
In this paper, a linear lumped-element equivalent circuit model (ECM) for ultrasonic laterally transduced electrostatic bulk-mode air-coupled resonant micro-electro-mechanical systems (MEMS) is described. A single-crystal silicon (SCS) square plate with T-shaped tethers is considered as the geometry of interest with a one-sided electrostatic actuation. This type of sensor can be used for sensitive mass sensing of airborne particles and possesses a large active surface with in-plane vibration modes in the ultrasonic frequency range. Firstly, the eigensolutions and eigenvectors of the problem are obtained using analytical equations and compared with finite-element modeling (FEM) solutions. Secondly, using modal analysis, the number of degrees of freedom is reduced and individual solutions are provided for each vibration mode, leading to various effective masses, stiffnesses and dampings. The first order Taylor expansion of both the electrical current equation and the electrostatic force applied on the resonator allows one to obtain expressions for the additional stiffness and the electro-mechanical transformation coefficient linked to the membrane actuation. Based on theses results, single-input single output (SISO) equivalent circuits are established using electro-mechanical and Butterworth-Van Dyke (BVD) approaches. Electrical admittance simulations resulting from different in-plane vibration modes are proven to be in excellent agreement with FEM simulations. Finally, a numerical mass sensing application is described to evaluate the relevance of both the model and the resonator design to act as a microbalance. The proposed model can be used to design, predict, analyze and optimize the behavior of highly sensitive air-coupled ultrasonic bulk-mode SCS MEMS for various physical applications.
本文描述了超声横向传导静电体模空气耦合谐振微机电系统（MEMS）的线性叠加元件等效电路模型（ECM）。单晶硅 (SCS) 方板与 T 形拴绳被视为具有单面静电驱动的相关几何形状。这种传感器可用于空气颗粒的灵敏质量传感，并具有较大的活动表面，在超声波频率范围内具有面内振动模式。首先，利用分析方程获得了问题的特征解和特征向量，并与有限元建模（FEM）解进行了比较。其次，通过模态分析，减少了自由度的数量，并为每种振动模式提供了单独的解决方案，从而得出各种有效质量、刚度和阻尼。通过对施加在谐振器上的电流方程和静电力进行一阶泰勒展开，可以获得与膜致动相关的附加刚度和电动机械转换系数的表达式。根据这些结果，利用电子机械和巴特沃斯-范戴克（BVD）方法建立了单输入单输出（SISO）等效电路。不同面内振动模式产生的电导纳模拟结果与有限元模拟结果非常吻合。最后，描述了一个数值质量传感应用，以评估模型和谐振器设计作为微天平的相关性。所提出的模型可用于设计、预测、分析和优化高灵敏度空气耦合超声波体模 SCS MEMS 的行为，适用于各种物理应用。
{"title":"Equivalent Circuit Modeling of Air-Coupled Laterally Actuated Electrostatic Bulk-Mode MEMS","authors":"Tony Merrien;Pierre Didier;Emmanuelle Algré","doi":"10.1109/OJUFFC.2024.3413603","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3413603","url":null,"abstract":"In this paper, a linear lumped-element equivalent circuit model (ECM) for ultrasonic laterally transduced electrostatic bulk-mode air-coupled resonant micro-electro-mechanical systems (MEMS) is described. A single-crystal silicon (SCS) square plate with T-shaped tethers is considered as the geometry of interest with a one-sided electrostatic actuation. This type of sensor can be used for sensitive mass sensing of airborne particles and possesses a large active surface with in-plane vibration modes in the ultrasonic frequency range. Firstly, the eigensolutions and eigenvectors of the problem are obtained using analytical equations and compared with finite-element modeling (FEM) solutions. Secondly, using modal analysis, the number of degrees of freedom is reduced and individual solutions are provided for each vibration mode, leading to various effective masses, stiffnesses and dampings. The first order Taylor expansion of both the electrical current equation and the electrostatic force applied on the resonator allows one to obtain expressions for the additional stiffness and the electro-mechanical transformation coefficient linked to the membrane actuation. Based on theses results, single-input single output (SISO) equivalent circuits are established using electro-mechanical and Butterworth-Van Dyke (BVD) approaches. Electrical admittance simulations resulting from different in-plane vibration modes are proven to be in excellent agreement with FEM simulations. Finally, a numerical mass sensing application is described to evaluate the relevance of both the model and the resonator design to act as a microbalance. The proposed model can be used to design, predict, analyze and optimize the behavior of highly sensitive air-coupled ultrasonic bulk-mode SCS MEMS for various physical applications.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"63-76"},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10555284","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141439401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-10DOI: 10.1109/OJUFFC.2024.3411578
Anders Emil Vrålstad;Ole Marius Hoel Rindal;Tore Grüner Bjåstad;Svein-Erik Måsøy
In beamforming, retrospective change in sound speed and recalculation of focusing delays is attractive both for improving image quality and for using it in an iterative image quality optimization process. Modifying the speed of sound retrospectively for focused transmits is challenging because the transmit focus position is a function of sound speed error. The virtual source model is a common way to calculate the transmit focusing delays where using the correct transmit focus position is imperative. In this paper, we provide the methods necessary to perform a retrospective sound-speed correction by compensating the receive grid and by calculating the effective transmit focus needed to perform proper synthetic transmit focusing. To evaluate the efficacy of our method, we simulate wave propagation and measure the resolution of in vitro images using both phased and curvilinear arrays. The results of the suggested virtual source estimation method match the simulated wave propagation for multiple F-numbers and both positive and negative sound speed errors. We compare beamformed images using correct/incorrect sound speeds and correct/incorrect virtual source positions. The results demonstrate that the Corrected Virtual Source (CVS) method generates artifact-free images with superior quality compared to images with incorrect sound speed. Furthermore, the image beamformed with the correct sound speed, but incorrect virtual source position, exhibits image artifacts and inferior focusing quality compared to the CVS image.
在波束成形中，追溯性地改变声速和重新计算聚焦延迟对提高图像质量和在迭代图像质量优化过程中使用都很有吸引力。由于发射聚焦位置是声速误差的函数，因此追溯性地修改聚焦发射的声速具有挑战性。虚拟声源模型是计算发射聚焦延迟的常用方法，在这种情况下，必须使用正确的发射聚焦位置。在本文中，我们提供了通过补偿接收网格和计算正确合成发射聚焦所需的有效发射聚焦来进行声速回溯校正的必要方法。为了评估我们方法的有效性，我们模拟了波的传播，并使用相位阵列和曲线阵列测量了体外图像的分辨率。所建议的虚拟声源估算方法的结果与模拟的多 F 数和正负声速误差的波传播相吻合。我们比较了使用正确/不正确声速和正确/不正确虚拟声源位置的波束形成图像。结果表明，与声速错误的图像相比，校正虚拟声源（CVS）方法生成的无伪影图像质量更高。此外，与 CVS 图像相比，采用正确声速但虚拟声源位置不正确的波束成形图像会出现图像伪影，聚焦质量较差。
{"title":"Sound Speed and Virtual Source Correction in Synthetic Transmit Focusing","authors":"Anders Emil Vrålstad;Ole Marius Hoel Rindal;Tore Grüner Bjåstad;Svein-Erik Måsøy","doi":"10.1109/OJUFFC.2024.3411578","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3411578","url":null,"abstract":"In beamforming, retrospective change in sound speed and recalculation of focusing delays is attractive both for improving image quality and for using it in an iterative image quality optimization process. Modifying the speed of sound retrospectively for focused transmits is challenging because the transmit focus position is a function of sound speed error. The virtual source model is a common way to calculate the transmit focusing delays where using the correct transmit focus position is imperative. In this paper, we provide the methods necessary to perform a retrospective sound-speed correction by compensating the receive grid and by calculating the effective transmit focus needed to perform proper synthetic transmit focusing. To evaluate the efficacy of our method, we simulate wave propagation and measure the resolution of in vitro images using both phased and curvilinear arrays. The results of the suggested virtual source estimation method match the simulated wave propagation for multiple F-numbers and both positive and negative sound speed errors. We compare beamformed images using correct/incorrect sound speeds and correct/incorrect virtual source positions. The results demonstrate that the Corrected Virtual Source (CVS) method generates artifact-free images with superior quality compared to images with incorrect sound speed. Furthermore, the image beamformed with the correct sound speed, but incorrect virtual source position, exhibits image artifacts and inferior focusing quality compared to the CVS image.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"52-62"},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10552357","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141435309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sandwich panels, composed of two steel faces and a rigid foam core, are an inexpensive and lightweight option for construction industry. However, voids can form in the foam core during the manufacturing process. This paper uses ultrasonic testing to detect such voids in the foam core of sandwich panels, buried a few millimeters below the surface. The testing setup employs both air-coupled and non-contact ultrasonic testing. Different frequencies are investigated for their influence on the detection capabilities. Two air-coupled experimental setups are constructed, one at 40kHz and the other one at 200kHz. Artificial defects are carved into the sandwich panel at different depths. The results are compared to a simulation. We found that detecting buried voids in these sandwich panels is feasible. The 40-kHz setup has a larger penetration depth of 14mm, while the 200-kHz setup has a smaller penetration depth of 2.5mm. The 200-kHz setup shows a better contrast, i.e. the amplitude at the defect increases by 27% compared to 6% with the 40-kHz setup. These methods enable air-coupled, non-contact ultrasonic testing of buried defects in sandwich panels. They have the potential to be integrated into production lines, contributing to improved material efficiency and quality control for these sandwich panels.
{"title":"Air-Coupled Lamb Wave Testing of Buried Air-Voids in Foam-Filled Sandwich Panels","authors":"Christoph Haugwitz;Andre Reinartz;Jan-Helge Dörsam;Sonja Wismath;Gianni Allevato;Jan Hinrichs;Paulina Gorol;Annalena Kühn;Thomas Hahn-Jose;Jörg Lange;Mario Kupnik","doi":"10.1109/OJUFFC.2024.3410169","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3410169","url":null,"abstract":"Sandwich panels, composed of two steel faces and a rigid foam core, are an inexpensive and lightweight option for construction industry. However, voids can form in the foam core during the manufacturing process. This paper uses ultrasonic testing to detect such voids in the foam core of sandwich panels, buried a few millimeters below the surface. The testing setup employs both air-coupled and non-contact ultrasonic testing. Different frequencies are investigated for their influence on the detection capabilities. Two air-coupled experimental setups are constructed, one at 40kHz and the other one at 200kHz. Artificial defects are carved into the sandwich panel at different depths. The results are compared to a simulation. We found that detecting buried voids in these sandwich panels is feasible. The 40-kHz setup has a larger penetration depth of 14mm, while the 200-kHz setup has a smaller penetration depth of 2.5mm. The 200-kHz setup shows a better contrast, i.e. the amplitude at the defect increases by 27% compared to 6% with the 40-kHz setup. These methods enable air-coupled, non-contact ultrasonic testing of buried defects in sandwich panels. They have the potential to be integrated into production lines, contributing to improved material efficiency and quality control for these sandwich panels.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"150-159"},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10549941","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper proposes a new 3D spatial sensing approach via compressed sensing (CS) by using a single-channel air-coupled piezoelectric micromachined ultrasonic transducer (PMUT) operated with multi-frequency. Our study focuses on a single-channel transducer with a PMUT array composed of several diaphragms with different radius sizes. It is known that small variations in the radius size can cause distinct transmission signals of all diaphragms that are excited by the same excitation signal. In this way, the acoustic field distribution of a region of interest (ROI) can be distorted especially in the direction perpendicular to the wave propagation, which could help to obtain more distinctive information about the scatterers at different locations in any 3D ROI. Therefore, a compressed 3D spatial sensing approach is proposed and used for acquiring measurements of the designed single-channel transducer. The information of any object in a 3D ROI can be mapped onto a collection of basis functions constructed via the nearly mutual orthogonal echo signals from all scatterers in the ROI. Furthermore, the proposed approach is verified with simulated acoustic measurements obtained from the established PMUT equivalent circuit model and the K-Wave acoustic propagation model via an obstacle-sensing application. Based on the sparsity nature of objects in the ROI, the reconstruction of 2D/3D images of objects can be accomplished via a CS-based algorithm. The obtained image reconstruction results show that the proposed approach allows not only for detecting localization but also for reconstructing descriptive features of an object.
本文提出了一种新的三维空间传感方法，即使用单通道空气耦合压电微机械超声换能器（PMUT）进行多频压缩传感（CS）。我们的研究侧重于单通道换能器，其 PMUT 阵列由多个半径不同的膜片组成。众所周知，半径大小的微小变化会导致被同一激励信号激发的所有膜片产生不同的传输信号。这样，感兴趣区域（ROI）的声场分布就会失真，特别是在垂直于波传播的方向上，这有助于获得有关任何三维 ROI 中不同位置散射体的更多独特信息。因此，我们提出了一种压缩三维空间传感方法，并将其用于获取所设计的单通道传感器的测量结果。三维 ROI 中任何物体的信息都可以映射到通过来自 ROI 中所有散射体的几乎相互正交的回波信号构建的基函数集合上。此外，通过障碍物感应应用，利用已建立的 PMUT 等效电路模型和 K 波声传播模型获得的模拟声学测量结果，对所提出的方法进行了验证。基于 ROI 中物体的稀疏性，可以通过基于 CS 的算法重建物体的 2D/3D 图像。获得的图像重建结果表明，所提出的方法不仅能检测定位，还能重建物体的描述性特征。
{"title":"Theoretical Validation of a Single-Channel Air-Coupled PMUT With Multi-Frequency Operation for Compressed 3D Spatial Sensing","authors":"Tingzhong Xu;Zhongjie Zhang;Rodrigo Tumolin Rocha;Liang Zeng;Chunlei Xu","doi":"10.1109/OJUFFC.2024.3408138","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3408138","url":null,"abstract":"This paper proposes a new 3D spatial sensing approach via compressed sensing (CS) by using a single-channel air-coupled piezoelectric micromachined ultrasonic transducer (PMUT) operated with multi-frequency. Our study focuses on a single-channel transducer with a PMUT array composed of several diaphragms with different radius sizes. It is known that small variations in the radius size can cause distinct transmission signals of all diaphragms that are excited by the same excitation signal. In this way, the acoustic field distribution of a region of interest (ROI) can be distorted especially in the direction perpendicular to the wave propagation, which could help to obtain more distinctive information about the scatterers at different locations in any 3D ROI. Therefore, a compressed 3D spatial sensing approach is proposed and used for acquiring measurements of the designed single-channel transducer. The information of any object in a 3D ROI can be mapped onto a collection of basis functions constructed via the nearly mutual orthogonal echo signals from all scatterers in the ROI. Furthermore, the proposed approach is verified with simulated acoustic measurements obtained from the established PMUT equivalent circuit model and the K-Wave acoustic propagation model via an obstacle-sensing application. Based on the sparsity nature of objects in the ROI, the reconstruction of 2D/3D images of objects can be accomplished via a CS-based algorithm. The obtained image reconstruction results show that the proposed approach allows not only for detecting localization but also for reconstructing descriptive features of an object.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"37-51"},"PeriodicalIF":0.0,"publicationDate":"2024-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10545345","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141333959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-08DOI: 10.1109/OJUFFC.2024.3397248
Delfino Reyes;Hyeonu Heo;Ángel M. Martínez-Argüello;Yasuhisa Fujita;Purnima B. Neogi;Arup Neogi
This work introduces a 2D PnC-based acoustic spectrometer capable of analyzing small solution volumes ($25~mu $ l) in aqueous environments with significative accuracy and reliability, thus addressing key limitations in current acoustic spectroscopic techniques. Optimally introducing rows of defects into the PnC structure enables guided acoustic modes to propagate at desired frequencies within the bandgap. We construct an acoustic interferometer to leverage the properties of acoustic cavities within these waveguides, which can configure and modulate wave propagation. Our approach involves harnessing the interference between acoustic waves in the two arms of a defects-based waveguide within a PnC, one arm containing an analyte cavity-holder. We demonstrate that the presence of an analyte (sucrose solutions at various concentrations) induces alterations in the acoustic properties of the cavity, leading to observable shifts in transmission characteristics of the propagating acoustic modes. We achieve exceptional spectral resolution through experimentation, facilitating highly sensitive acoustic sensing even with small analyte volumes ($lt 25~mu $ l). We utilize finite element method simulations to validate our findings and predict spectral shifts resulting from modified acoustic interference. Additionally, we provide a phenomenological description using tight-binding models. Notably, our approach surpasses conventional PnC sensors like Mach-Zehnder interferometers by overcoming challenges associated with analyte uniformity.
{"title":"Underwater Analyte Sensing Using a Phononic Crystal Waveguide-Based Interferometric Acoustic Spectrometer","authors":"Delfino Reyes;Hyeonu Heo;Ángel M. Martínez-Argüello;Yasuhisa Fujita;Purnima B. Neogi;Arup Neogi","doi":"10.1109/OJUFFC.2024.3397248","DOIUrl":"https://doi.org/10.1109/OJUFFC.2024.3397248","url":null,"abstract":"This work introduces a 2D PnC-based acoustic spectrometer capable of analyzing small solution volumes (<inline-formula> <tex-math>$25~mu $ </tex-math></inline-formula>l) in aqueous environments with significative accuracy and reliability, thus addressing key limitations in current acoustic spectroscopic techniques. Optimally introducing rows of defects into the PnC structure enables guided acoustic modes to propagate at desired frequencies within the bandgap. We construct an acoustic interferometer to leverage the properties of acoustic cavities within these waveguides, which can configure and modulate wave propagation. Our approach involves harnessing the interference between acoustic waves in the two arms of a defects-based waveguide within a PnC, one arm containing an analyte cavity-holder. We demonstrate that the presence of an analyte (sucrose solutions at various concentrations) induces alterations in the acoustic properties of the cavity, leading to observable shifts in transmission characteristics of the propagating acoustic modes. We achieve exceptional spectral resolution through experimentation, facilitating highly sensitive acoustic sensing even with small analyte volumes (<inline-formula> <tex-math>$lt 25~mu $ </tex-math></inline-formula>l). We utilize finite element method simulations to validate our findings and predict spectral shifts resulting from modified acoustic interference. Additionally, we provide a phenomenological description using tight-binding models. Notably, our approach surpasses conventional PnC sensors like Mach-Zehnder interferometers by overcoming challenges associated with analyte uniformity.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"216-226"},"PeriodicalIF":0.0,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10522781","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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