Pub Date : 2026-02-26DOI: 10.1109/OJUFFC.2026.3665475
Michael Huang;Donovan Le;Andrew Householder;James Camparo
Lamplight fluctuations in the rubidium (Rb) atomic frequency standard (RAFS) are a significant contributor to the clock’s long-term frequency instability. Briefly, random lamplight-intensity variations induce fluctuations in the Rb atoms’ 0-0 hyperfine frequency via the light-shift effect. These lamplight-induced frequency variations follow a compound Poisson process, and for GPS Block-IIR drive the Rb clock’s random-walk frequency noise, a dominant contributor to the GPS- signal-in-space user-range-error. Here, we show that lamplight stabilization via rf-power control can mitigate a RAFS’s lamplight variations without any undue harm to the clock’s short-term frequency stability. Rf-power control is achieved by a simple modification to the lamp’s oscillator circuit. For global navigation satellite systems, the present results could yield improved onboard clock frequency stability. For small satellites employing RAFS the results could yield longer holdover periods between satellite updates.
{"title":"Lamplight Stabilization in a Rb Atomic Clock for Improved Frequency Stability","authors":"Michael Huang;Donovan Le;Andrew Householder;James Camparo","doi":"10.1109/OJUFFC.2026.3665475","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3665475","url":null,"abstract":"Lamplight fluctuations in the rubidium (Rb) atomic frequency standard (RAFS) are a significant contributor to the clock’s long-term frequency instability. Briefly, random lamplight-intensity variations induce fluctuations in the Rb atoms’ 0-0 hyperfine frequency via the light-shift effect. These lamplight-induced frequency variations follow a compound Poisson process, and for GPS Block-IIR drive the Rb clock’s random-walk frequency noise, a dominant contributor to the GPS- signal-in-space user-range-error. Here, we show that lamplight stabilization via rf-power control can mitigate a RAFS’s lamplight variations without any undue harm to the clock’s short-term frequency stability. Rf-power control is achieved by a simple modification to the lamp’s oscillator circuit. For global navigation satellite systems, the present results could yield improved onboard clock frequency stability. For small satellites employing RAFS the results could yield longer holdover periods between satellite updates.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"6 ","pages":"38-43"},"PeriodicalIF":2.9,"publicationDate":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11414251","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147440543","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 : 2026-02-24DOI: 10.1109/OJUFFC.2026.3667021
{"title":"2025 Index IEEE Open Journal of Ultrasonics, Ferroelectrics, and Frequency Control","authors":"","doi":"10.1109/OJUFFC.2026.3667021","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3667021","url":null,"abstract":"","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"301-312"},"PeriodicalIF":2.9,"publicationDate":"2026-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11410108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147299611","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 : 2026-02-18DOI: 10.1109/OJUFFC.2026.3664135
{"title":"IEEE OPEN JOURNAL OF ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL","authors":"","doi":"10.1109/OJUFFC.2026.3664135","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3664135","url":null,"abstract":"","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"6 ","pages":"C2-C2"},"PeriodicalIF":2.9,"publicationDate":"2026-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11399566","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146223851","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 : 2026-02-13DOI: 10.1109/OJUFFC.2026.3664792
Luc Archambault;Mathieu Guéridon;Cédric Majek;Luca Lorini;Arnaud Landragin;Bruno Desruelle;Bruno Pelle
MuClock is a commercial transportable microwave clock developed at Exail Quantum Systems, using rubidium atoms cooled by isotropic laser light. MuClock is comparable with typical hydrogen masers in terms of volume and long-term frequency stability, as it nominally reaches a fractional frequency stability of $1times 10^{-15}$ in less than two days and maintains this level of performance over more than one month of integration time. The evaluation of several systematic frequency shifts is on-going. This article presents the impact of the frequency bias induced by microwave phase transients on the clock frequency stability and accuracy. Using an in-house designed test bench, the phase of the 6.8 GHz microwave clock signal is measured with a phase resolution close to 1 $mu $ rad and a temporal resolution below 100 ns. It enables a thorough optimization of the sequence and a better control of each phase transient event, making their contributions to the overall frequency shift negligible. Phase peaks induced by electronic components operating in parallel are shifted in time so that their contributions become negligible compared with other frequency uncertainties. The accuracy of the associated systematic effect is evaluated at $3times 10^{-15}$ .
{"title":"Development of a Phase Transient Test Bench to Optimize a Cold-Atom Microwave Clock","authors":"Luc Archambault;Mathieu Guéridon;Cédric Majek;Luca Lorini;Arnaud Landragin;Bruno Desruelle;Bruno Pelle","doi":"10.1109/OJUFFC.2026.3664792","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3664792","url":null,"abstract":"MuClock is a commercial transportable microwave clock developed at Exail Quantum Systems, using rubidium atoms cooled by isotropic laser light. MuClock is comparable with typical hydrogen masers in terms of volume and long-term frequency stability, as it nominally reaches a fractional frequency stability of <inline-formula> <tex-math>$1times 10^{-15}$ </tex-math></inline-formula> in less than two days and maintains this level of performance over more than one month of integration time. The evaluation of several systematic frequency shifts is on-going. This article presents the impact of the frequency bias induced by microwave phase transients on the clock frequency stability and accuracy. Using an in-house designed test bench, the phase of the 6.8 GHz microwave clock signal is measured with a phase resolution close to 1 <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>rad and a temporal resolution below 100 ns. It enables a thorough optimization of the sequence and a better control of each phase transient event, making their contributions to the overall frequency shift negligible. Phase peaks induced by electronic components operating in parallel are shifted in time so that their contributions become negligible compared with other frequency uncertainties. The accuracy of the associated systematic effect is evaluated at <inline-formula> <tex-math>$3times 10^{-15}$ </tex-math></inline-formula>.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"6 ","pages":"17-25"},"PeriodicalIF":2.9,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11396005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147299546","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 : 2026-02-12DOI: 10.1109/OJUFFC.2026.3664322
Geraldi Wahyulaksana;Colin K. L. Phoon;Glenn I. Fishman;Jeffrey A. Ketterling
Vector Doppler Imaging (VDI) addresses the limitations of traditional Doppler imaging by measuring blood flow in axial and lateral directions but will produce incorrect results if aliasing is present. Aliasing becomes more likely when using high transmit frequencies such as in small animal cardiac applications. The use of multiple transmit angles decreases the Nyquist limit, which further increases the likelihood of aliasing. A new transmission scheme, termed StaBle, is proposed to increase the Nyquist limit of conventional sequential angle VDI by multiple fold. StaBle combines the velocity limit extension of staggered multiple pulse repetition frequency (PRF) with a double transmission scheme. With three transmit angles and two PRFs, StaBle was able to achieve a 6-12 times higher velocity limit compared to sequential angle VDI. Simulation and phantom spinning disk experiments were conducted to evaluate StaBle’s performance. The simulation results showed a normalized root-mean-squared error of less than 5% compared to an ideal vector field in both axial and lateral directions. Phantom results showed a 9-fold improvement in detecting peak axial velocity over sequential three angle VDI. The ability of StaBle to obtain an unaliased vector field in vivo was demonstrated by imaging a mouse left ventricle where the Doppler signal was corrupted by aliasing artifacts using just a double transmit scheme. The resolved estimated vector velocity showed consistent beat-to-beat variation in velocity, confirming StaBle’s robustness under realistic conditions and its potential for use in investigative studies.
{"title":"StaBle: Staggered PRF With DouBle Transmission for Increasing the Velocity Limit of High-Frame-Rate Vector Doppler Imaging","authors":"Geraldi Wahyulaksana;Colin K. L. Phoon;Glenn I. Fishman;Jeffrey A. Ketterling","doi":"10.1109/OJUFFC.2026.3664322","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3664322","url":null,"abstract":"Vector Doppler Imaging (VDI) addresses the limitations of traditional Doppler imaging by measuring blood flow in axial and lateral directions but will produce incorrect results if aliasing is present. Aliasing becomes more likely when using high transmit frequencies such as in small animal cardiac applications. The use of multiple transmit angles decreases the Nyquist limit, which further increases the likelihood of aliasing. A new transmission scheme, termed StaBle, is proposed to increase the Nyquist limit of conventional sequential angle VDI by multiple fold. StaBle combines the velocity limit extension of staggered multiple pulse repetition frequency (PRF) with a double transmission scheme. With three transmit angles and two PRFs, StaBle was able to achieve a 6-12 times higher velocity limit compared to sequential angle VDI. Simulation and phantom spinning disk experiments were conducted to evaluate StaBle’s performance. The simulation results showed a normalized root-mean-squared error of less than 5% compared to an ideal vector field in both axial and lateral directions. Phantom results showed a 9-fold improvement in detecting peak axial velocity over sequential three angle VDI. The ability of StaBle to obtain an unaliased vector field in vivo was demonstrated by imaging a mouse left ventricle where the Doppler signal was corrupted by aliasing artifacts using just a double transmit scheme. The resolved estimated vector velocity showed consistent beat-to-beat variation in velocity, confirming StaBle’s robustness under realistic conditions and its potential for use in investigative studies.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"6 ","pages":"26-37"},"PeriodicalIF":2.9,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11395288","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147299751","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 : 2026-01-28DOI: 10.1109/OJUFFC.2026.3659047
Mate Gaal;Pascal Wernicke
Air-coupled ultrasonic testing avoids contamination and reduces maintenance costs, but suffers from poor signal-to-noise ratio (SNR) due to impedance mismatch. Rather than developing new transducers, this study improves SNR through signal processing by adapting pulse compression from radar. We propose a method using unipolar square pulses to make pulse compression compatible with non-linear transducers such as ferroelectrets and thermoacoustic emitters. Instead of relying on analytical models, a reference transmission measurement served as the matched filter, simplifying implementation and ensuring adaptability across transducer types. We evaluated unipolar coded excitation and pulse compression on ultrasonic transmission through a 25 mm polyvinyl chloride plate, varying code length and pulse delay. Significant SNR gains were observed across transducers, particularly with longer delays. These results confirm that pulse compression enhances peak localization and supports testing under low-SNR conditions. Further experiments showed that pulse compression remains effective despite side lobe overlap and noise, provided the pulse delay is chosen appropriately. Although SNR prediction is limited by electrical and acoustic interference, the method consistently improves detection. Overall, the results demonstrate the feasibility of unipolar excitation coding for pulse compression in air-coupled ultrasonic testing, with practical value for thick or attenuating materials.
{"title":"Improved Air-Coupled Ultrasonic Transmission Using Pulse Compression","authors":"Mate Gaal;Pascal Wernicke","doi":"10.1109/OJUFFC.2026.3659047","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3659047","url":null,"abstract":"Air-coupled ultrasonic testing avoids contamination and reduces maintenance costs, but suffers from poor signal-to-noise ratio (SNR) due to impedance mismatch. Rather than developing new transducers, this study improves SNR through signal processing by adapting pulse compression from radar. We propose a method using unipolar square pulses to make pulse compression compatible with non-linear transducers such as ferroelectrets and thermoacoustic emitters. Instead of relying on analytical models, a reference transmission measurement served as the matched filter, simplifying implementation and ensuring adaptability across transducer types. We evaluated unipolar coded excitation and pulse compression on ultrasonic transmission through a 25 mm polyvinyl chloride plate, varying code length and pulse delay. Significant SNR gains were observed across transducers, particularly with longer delays. These results confirm that pulse compression enhances peak localization and supports testing under low-SNR conditions. Further experiments showed that pulse compression remains effective despite side lobe overlap and noise, provided the pulse delay is chosen appropriately. Although SNR prediction is limited by electrical and acoustic interference, the method consistently improves detection. Overall, the results demonstrate the feasibility of unipolar excitation coding for pulse compression in air-coupled ultrasonic testing, with practical value for thick or attenuating materials.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"6 ","pages":"9-16"},"PeriodicalIF":2.9,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11366931","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146162234","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 : 2026-01-21DOI: 10.1109/OJUFFC.2026.3656857
Mate Gaal;Tomás Gómez Álvarez-Arenas
Air-coupled Ultrasound is a challenging field dominated by the drastic impedance mismatch between air and all condensed matter, the low ultrasound velocity in the air, and the rapidly increasing attenuation with frequency. These factors severely limit the applicability of air-coupled ultrasound; however, the potential is enormous. Ongoing research in this field continues to advance in the understanding of novel transduction systems and in the optimization of existing ones, by incorporating novel materials and designs. The emergence of improved transduction systems with better sensitivity, lower noise levels, wider bandwidth, higher frequency, lower cost, smaller size, and lower power consumption together with innovative signal processing and analysis methods, enables improvements of existing applications of air-coupled ultrasound in many different fields and, what is more interesting, the proposal of fully innovative use cases.
{"title":"Guest Editorial: Special Section on Air-Coupled Ultrasound","authors":"Mate Gaal;Tomás Gómez Álvarez-Arenas","doi":"10.1109/OJUFFC.2026.3656857","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3656857","url":null,"abstract":"Air-coupled Ultrasound is a challenging field dominated by the drastic impedance mismatch between air and all condensed matter, the low ultrasound velocity in the air, and the rapidly increasing attenuation with frequency. These factors severely limit the applicability of air-coupled ultrasound; however, the potential is enormous. Ongoing research in this field continues to advance in the understanding of novel transduction systems and in the optimization of existing ones, by incorporating novel materials and designs. The emergence of improved transduction systems with better sensitivity, lower noise levels, wider bandwidth, higher frequency, lower cost, smaller size, and lower power consumption together with innovative signal processing and analysis methods, enables improvements of existing applications of air-coupled ultrasound in many different fields and, what is more interesting, the proposal of fully innovative use cases.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"6 ","pages":"1-2"},"PeriodicalIF":2.9,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11359715","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146162230","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}
Osteoporosis fractures are a significant social problem. Despite having sufficient bone mineral density (BMD), postmenopausal women frequently experience bone fractures. This study investigated the effect of estrogen reduction on bone elasticity by comparing young female C57BL/6J mice that underwent either Sham or ovariectomized (OVX) surgery. Bone properties in two-year-old mice (post-senescence period: spontaneous menopause (SM)) were also examined. OVX mice were consistently heavier than Sham mice and showed increased visceral fat. Longitudinal wave velocities in tibia bones of these groups were evaluated using a micro-Brillouin scattering technique ($mu $ -BS). OVX mice bones exhibited a significant decrease in velocity (2.0–2.3% lower) at 24 weeks after surgery. The velocities in the tibia bones decreased more significantly in SM mice than in OVX mice. These findings highlight the effects of estrogen deficiency on bone elasticity in young mice during growth and identify additional age-related changes.
{"title":"Decreased Ultrasonic Wave Velocity in Bones of Ovariectomized and Spontaneous-Menopause Mice","authors":"Taiga Wada;Shouta Kitajima;Yoshifumi Tsuchiya;Mami Matsukawa","doi":"10.1109/OJUFFC.2026.3656109","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3656109","url":null,"abstract":"Osteoporosis fractures are a significant social problem. Despite having sufficient bone mineral density (BMD), postmenopausal women frequently experience bone fractures. This study investigated the effect of estrogen reduction on bone elasticity by comparing young female C57BL/6J mice that underwent either Sham or ovariectomized (OVX) surgery. Bone properties in two-year-old mice (post-senescence period: spontaneous menopause (SM)) were also examined. OVX mice were consistently heavier than Sham mice and showed increased visceral fat. Longitudinal wave velocities in tibia bones of these groups were evaluated using a micro-Brillouin scattering technique (<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>-BS). OVX mice bones exhibited a significant decrease in velocity (2.0–2.3% lower) at 24 weeks after surgery. The velocities in the tibia bones decreased more significantly in SM mice than in OVX mice. These findings highlight the effects of estrogen deficiency on bone elasticity in young mice during growth and identify additional age-related changes.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"6 ","pages":"3-8"},"PeriodicalIF":2.9,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11359200","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146162211","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 : 2026-01-12DOI: 10.1109/OJUFFC.2026.3652600
Felix CORDES;Julia Scholtyssek;Karl-Ludwig Krieger
Carbon fibre reinforced composites are being used in more and more areas of application, for example in hydrogen storage tanks. In addition to structural-mechanical advantages, these materials also have disadvantages, such as susceptibility to mechanical damage. This makes structural monitoring advisable in safety-critical applications. In addition to the detection of damage, the localization of the source of the acoustic signal, respectively the damage, is a central component. Signal localization on fibre composites is a major challenge, due to the high direction dependency of the speed of acoustic signals. Measurement inaccuracies and low signal strengths, especially in noisy environments, lead to high localization errors when locating the source based on the difference in signal arrival times in a sensor network. When using triangulation-based methods, it is even possible that several plausible signal sources are identified. This article therefore analyses the extent to which localization accuracy is affected by a reduction in the signal-to-noise ratio. Two different localization methods are used for the investigations and their accuracy is evaluated when the signal-to-noise ratio is reduced. These are, on the one hand, classic triangulation, adapted to an anisotropic material. On the other hand, localization via a convolutional neural network is investigated. For the investigations, acoustic signals with different signal-to-noise ratios are applied to a carbon fibre prepreg plate in three series of measurements and localized using a sensor grid. In addition to the effect of the signal-to-noise ratio, the effect of the source position relative to the sensor grid is investigated.
{"title":"Comparison of Triangulation and CNN-Based Acoustic Source Localization on Carbon Fibre Reinforced Composites Considering the Signal-to-Noise Ratio","authors":"Felix CORDES;Julia Scholtyssek;Karl-Ludwig Krieger","doi":"10.1109/OJUFFC.2026.3652600","DOIUrl":"https://doi.org/10.1109/OJUFFC.2026.3652600","url":null,"abstract":"Carbon fibre reinforced composites are being used in more and more areas of application, for example in hydrogen storage tanks. In addition to structural-mechanical advantages, these materials also have disadvantages, such as susceptibility to mechanical damage. This makes structural monitoring advisable in safety-critical applications. In addition to the detection of damage, the localization of the source of the acoustic signal, respectively the damage, is a central component. Signal localization on fibre composites is a major challenge, due to the high direction dependency of the speed of acoustic signals. Measurement inaccuracies and low signal strengths, especially in noisy environments, lead to high localization errors when locating the source based on the difference in signal arrival times in a sensor network. When using triangulation-based methods, it is even possible that several plausible signal sources are identified. This article therefore analyses the extent to which localization accuracy is affected by a reduction in the signal-to-noise ratio. Two different localization methods are used for the investigations and their accuracy is evaluated when the signal-to-noise ratio is reduced. These are, on the one hand, classic triangulation, adapted to an anisotropic material. On the other hand, localization via a convolutional neural network is investigated. For the investigations, acoustic signals with different signal-to-noise ratios are applied to a carbon fibre prepreg plate in three series of measurements and localized using a sensor grid. In addition to the effect of the signal-to-noise ratio, the effect of the source position relative to the sensor grid is investigated.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"292-300"},"PeriodicalIF":2.9,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11345239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082284","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 : 2025-12-05DOI: 10.1109/OJUFFC.2025.3641005
Andrea Pulido;Nitin Burman;Sandro Queirós;Jan D’Hooge
Cardiac ultrasound deformation imaging is a non-invasive and widely used modality for assessing left ventricular function. However, due to the variable image quality observed in clinical routine, deformation estimation remains challenging. Recently, deep learning (DL) approaches have been proposed to estimate motion from ultrasound images. In this study, we investigated whether combining in vivo data with a synthetic dataset during training improves motion estimation accuracy while also benchmarking the DL-based estimates against a state-of-the-art traditional optical flow method. Results demonstrate that the deep learning-based method excels in tracking the dense motion fields on a frame-by-frame basis. However, when performing contour tracking, it results in lower end-systolic peak strain values compared to the traditional optical flow method.
{"title":"Impact of Training Data Composition on Deep Learning-Based Cardiac Motion Estimation","authors":"Andrea Pulido;Nitin Burman;Sandro Queirós;Jan D’Hooge","doi":"10.1109/OJUFFC.2025.3641005","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3641005","url":null,"abstract":"Cardiac ultrasound deformation imaging is a non-invasive and widely used modality for assessing left ventricular function. However, due to the variable image quality observed in clinical routine, deformation estimation remains challenging. Recently, deep learning (DL) approaches have been proposed to estimate motion from ultrasound images. In this study, we investigated whether combining in vivo data with a synthetic dataset during training improves motion estimation accuracy while also benchmarking the DL-based estimates against a state-of-the-art traditional optical flow method. Results demonstrate that the deep learning-based method excels in tracking the dense motion fields on a frame-by-frame basis. However, when performing contour tracking, it results in lower end-systolic peak strain values compared to the traditional optical flow method.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"286-291"},"PeriodicalIF":2.9,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11278840","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145778363","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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