Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8926311
Shan He, W. Pang, X. Duan, Yanyan Wang
Regulating the differentiation and regeneration of nerve cells has been proved effective for treating neurological disorders diseases. Although there have been several studies related to neuromodulation, these studies have suffered from invasiveness or low spatial resolution. Herein, a hypersound acoustic stimulation on nerve cells was explored and the results demonstrated this novel method had powerful effect on targeted nerve cell regulation. A bulk acoustic wave resonator fabricated with MEMS process was used to generate hypersound. The acoustic fluid (AF) effect was produced with mechanical pressure when hypersound transmitted with attention in the solution. Results indicated that exposing PC12 cells to AF stimulation, small protrusions would appear within 10 minutes. And differentiation ratio of the AF stimulated cells was 16% higher than that of cells cultured with nerve growth factor (NGF). This original and effective method is compatible with conventional cell culture and had potential in single nerve cells regulation.
{"title":"Regulating the differentiation of PC12 by acoustic fluid stimulation","authors":"Shan He, W. Pang, X. Duan, Yanyan Wang","doi":"10.1109/ULTSYM.2019.8926311","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8926311","url":null,"abstract":"Regulating the differentiation and regeneration of nerve cells has been proved effective for treating neurological disorders diseases. Although there have been several studies related to neuromodulation, these studies have suffered from invasiveness or low spatial resolution. Herein, a hypersound acoustic stimulation on nerve cells was explored and the results demonstrated this novel method had powerful effect on targeted nerve cell regulation. A bulk acoustic wave resonator fabricated with MEMS process was used to generate hypersound. The acoustic fluid (AF) effect was produced with mechanical pressure when hypersound transmitted with attention in the solution. Results indicated that exposing PC12 cells to AF stimulation, small protrusions would appear within 10 minutes. And differentiation ratio of the AF stimulated cells was 16% higher than that of cells cultured with nerve growth factor (NGF). This original and effective method is compatible with conventional cell culture and had potential in single nerve cells regulation.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"47 1","pages":"273-275"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79116539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8926231
R. Varadarajan, Gabriela Torres, M. Hossain, C. Gallippi
Low blood SNR makes detecting small vessels, measuring slow flow rates, and assessing blood perfusion without contrast administration challenging. A potential approach is to use Variance of Acceleration (VoA) imaging, which has been demonstrated previously in humans in vivo for monitoring subcutaneous bleeding and delineating intraplaque hemorrhage. We hypothesize that, without the addition of contrast agents, VoA can detect slow flow in small vessels for perfusion assessment. Experiments were performed on an ATS 700-D 527 calibrated flow phantom (vessel diameter of 1 mm, flow rates of 0-53 cm/s) and in the surgically exteriorized right kidneys of 3 pigs (2M/1F, mean body weight of 74.4 ± 9.3 kg) at baseline and after inducing ischemia. In the phantom, logVoA increased in the vessel with increasing flow rate, and it remained constant in the background. LogVoA values were higher in the background with versus without the ARF excitation. Similarly, logVoA values were higher in the vessel, particularly for flow rates < 12 cm/s, with versus without ARF excitation. Vessel CNR by logVoA was higher with versus without ARF excitation for flow rates < 12 cm/s, and CNR by logVoA was greater than CNR by power Doppler for all flow rates. Additionally, logVoA was statistically significantly greater at baseline than ischemia in all three in vivo pig kidneys. Finally, logVoA delineates a 1.25 mm-diameter vessel in a pig renal cortex in vivo, while power Doppler does not. These results suggest that logVoA could support contrast-free detection of slow blood flow in small vessels and in vivo perfusion assessment.
{"title":"Non-Contrast Perfusion Detection with ARFI Variance of Acceleration (VoA) Imaging: Phantom and In Vivo Results","authors":"R. Varadarajan, Gabriela Torres, M. Hossain, C. Gallippi","doi":"10.1109/ULTSYM.2019.8926231","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8926231","url":null,"abstract":"Low blood SNR makes detecting small vessels, measuring slow flow rates, and assessing blood perfusion without contrast administration challenging. A potential approach is to use Variance of Acceleration (VoA) imaging, which has been demonstrated previously in humans in vivo for monitoring subcutaneous bleeding and delineating intraplaque hemorrhage. We hypothesize that, without the addition of contrast agents, VoA can detect slow flow in small vessels for perfusion assessment. Experiments were performed on an ATS 700-D 527 calibrated flow phantom (vessel diameter of 1 mm, flow rates of 0-53 cm/s) and in the surgically exteriorized right kidneys of 3 pigs (2M/1F, mean body weight of 74.4 ± 9.3 kg) at baseline and after inducing ischemia. In the phantom, logVoA increased in the vessel with increasing flow rate, and it remained constant in the background. LogVoA values were higher in the background with versus without the ARF excitation. Similarly, logVoA values were higher in the vessel, particularly for flow rates < 12 cm/s, with versus without ARF excitation. Vessel CNR by logVoA was higher with versus without ARF excitation for flow rates < 12 cm/s, and CNR by logVoA was greater than CNR by power Doppler for all flow rates. Additionally, logVoA was statistically significantly greater at baseline than ischemia in all three in vivo pig kidneys. Finally, logVoA delineates a 1.25 mm-diameter vessel in a pig renal cortex in vivo, while power Doppler does not. These results suggest that logVoA could support contrast-free detection of slow blood flow in small vessels and in vivo perfusion assessment.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"7 1","pages":"2252-2255"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84250931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8925682
A. Demčenko, M. Mazilu, R. Wilson, J. Reboud, J. Cooper
We report a novel ultrasonic measurement technique based on non-classical nonlinear evanescent field interactions. We demonstrate significant enhancement in sensitivity of contactless measurements at interfaces, with the potential to detect material degradation, such as fatigue and ageing, which is currently not possible using linear ultrasonics.
{"title":"Non-Classical Second-Order Nonlinear Elastic Wave Interactions","authors":"A. Demčenko, M. Mazilu, R. Wilson, J. Reboud, J. Cooper","doi":"10.1109/ULTSYM.2019.8925682","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8925682","url":null,"abstract":"We report a novel ultrasonic measurement technique based on non-classical nonlinear evanescent field interactions. We demonstrate significant enhancement in sensitivity of contactless measurements at interfaces, with the potential to detect material degradation, such as fatigue and ageing, which is currently not possible using linear ultrasonics.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"43 1","pages":"158-161"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84278494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8926091
Moein Mozaffarzadeh, Claudio Minonzio, M. Verweij, S. Hemm, V. Daeichin
Deep brain stimulation (DBS) is used to modify the brain function. Localization of the electrode(s) used in DBS is an important mater since the success of the treatment highly depends on it. Transcranial ultrasound imaging (TUI) can be a proper candidate to monitor the electrode(s), but it is affected by the phase aberration caused by the skull bone. To address this issue, in this paper, we propose a novel beamforming method based on the sound velocity map of the imaging medium. For each combination of the imaging grid and element of the array, an averaged sound speed (ASD) is calculated. Then, the ASD is used inside a delay-and-sum beamforming method. The numerical results show that the proposed method compensates the phase aberration caused by the skull having a thickness of 5 mm with a sound speed twice of the imaging medium (i.e., water). The proposed method can be implemented in a real-time manner, which makes it a great candidate to be used in operation rooms for surgeries.
{"title":"Phase Aberration Correction in Transcranial Ultrasound Imaging using Averaged Sound Velocity Map in Delay-and-Sum Beamformer","authors":"Moein Mozaffarzadeh, Claudio Minonzio, M. Verweij, S. Hemm, V. Daeichin","doi":"10.1109/ULTSYM.2019.8926091","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8926091","url":null,"abstract":"Deep brain stimulation (DBS) is used to modify the brain function. Localization of the electrode(s) used in DBS is an important mater since the success of the treatment highly depends on it. Transcranial ultrasound imaging (TUI) can be a proper candidate to monitor the electrode(s), but it is affected by the phase aberration caused by the skull bone. To address this issue, in this paper, we propose a novel beamforming method based on the sound velocity map of the imaging medium. For each combination of the imaging grid and element of the array, an averaged sound speed (ASD) is calculated. Then, the ASD is used inside a delay-and-sum beamforming method. The numerical results show that the proposed method compensates the phase aberration caused by the skull having a thickness of 5 mm with a sound speed twice of the imaging medium (i.e., water). The proposed method can be implemented in a real-time manner, which makes it a great candidate to be used in operation rooms for surgeries.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"426 1","pages":"1894-1897"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84950630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8925999
K. Sugimoto, T. Sugimoto, H. Morioka, N. Utagawa, Chitose Kuroda, Takeyuki Ohdaira
Deterioration of concrete structures is a serious problem in social infrastructures such as tunnels and viaducts. In order to solve this problem, we have examined the method to inspect the internal defects of concrete structure in a noncontact and non-destructive manner. In our noncontact acoustic inspection method, the concrete surface is vibrated by strong airborne sound waves, 2-dimensional distribution of vibration velocity is measured by a scanning laser Doppler vibrometer (SLDV). And the internal defects (up to a depth of about 10 cm from the surface) is detected from a long distance (about 5-30m). It was made possible to detect internal defects of concrete with smooth surface in a released space such as a viaduct or a tunnel. However, in a closed space surrounded by concrete, such as an underground cavity, the S/N ratio was lowered due to reverberation from the surroundings. In shotcrete with uneven surface, the reflectance of laser light on the surface varies. And it is more difficult to detect internal defects. To detect internal defects of concrete, we have proposed the defect detection algorithm combining acoustic features (vibrational energy ratio and spectral entropy). At a measured point of internal defect, vibrational energy tends to be high and spectral entropy tends to be low. Since acoustic excitation is used, in a closed space, more intense resonance occurs in a head of SLDV due to reverberation from the surroundings. Since resonance frequency of a laser head and its frequency range can be detected by spatial spectral entropy (SSE) proposed previously, the resonance frequency peaks can be removed in data analysis. In addition, the influence of shotcrete surface was reduced by detecting resonance frequencies of internal defects on the measured surface by SSE, selecting frequency bands to analyze, and statistically evaluating healthy part by two acoustical features.
{"title":"Detection and acoustical visualization of internal defects in shotcrete structures by spatial spectral entropy for noncontact acoustic inspection method","authors":"K. Sugimoto, T. Sugimoto, H. Morioka, N. Utagawa, Chitose Kuroda, Takeyuki Ohdaira","doi":"10.1109/ULTSYM.2019.8925999","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8925999","url":null,"abstract":"Deterioration of concrete structures is a serious problem in social infrastructures such as tunnels and viaducts. In order to solve this problem, we have examined the method to inspect the internal defects of concrete structure in a noncontact and non-destructive manner. In our noncontact acoustic inspection method, the concrete surface is vibrated by strong airborne sound waves, 2-dimensional distribution of vibration velocity is measured by a scanning laser Doppler vibrometer (SLDV). And the internal defects (up to a depth of about 10 cm from the surface) is detected from a long distance (about 5-30m). It was made possible to detect internal defects of concrete with smooth surface in a released space such as a viaduct or a tunnel. However, in a closed space surrounded by concrete, such as an underground cavity, the S/N ratio was lowered due to reverberation from the surroundings. In shotcrete with uneven surface, the reflectance of laser light on the surface varies. And it is more difficult to detect internal defects. To detect internal defects of concrete, we have proposed the defect detection algorithm combining acoustic features (vibrational energy ratio and spectral entropy). At a measured point of internal defect, vibrational energy tends to be high and spectral entropy tends to be low. Since acoustic excitation is used, in a closed space, more intense resonance occurs in a head of SLDV due to reverberation from the surroundings. Since resonance frequency of a laser head and its frequency range can be detected by spatial spectral entropy (SSE) proposed previously, the resonance frequency peaks can be removed in data analysis. In addition, the influence of shotcrete surface was reduced by detecting resonance frequencies of internal defects on the measured surface by SSE, selecting frequency bands to analyze, and statistically evaluating healthy part by two acoustical features.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"61 1","pages":"2099-2102"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85054918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8926202
P. Kroh, Ralph Simon, S. Rupitsch
A neural network-based approach for detection of sonar targets in air is presented in this contribution. Our approach may facilitate autonomous mobile systems to reliably detect and classify objects in their surrounding by using sonar information. This task might be extremely important in changing as well as unorganized environments. We perform target iden-tification with long short-term memory networks as classifiers. Such are capable of dealing with variable numbers of echoes from multiple positions per input sequence, which facilitates more flexible operation. The impact of the number of recording positions per sequence and of noise is investigated. Furthermore, we demonstrate the improvement in classification performance in comparison to previously obtained results from multi-layer-perceptrons.
{"title":"Neural Network-Based Detection of Ultrasonic Targets with Respect to Noise and Number of Sampling Positions","authors":"P. Kroh, Ralph Simon, S. Rupitsch","doi":"10.1109/ULTSYM.2019.8926202","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8926202","url":null,"abstract":"A neural network-based approach for detection of sonar targets in air is presented in this contribution. Our approach may facilitate autonomous mobile systems to reliably detect and classify objects in their surrounding by using sonar information. This task might be extremely important in changing as well as unorganized environments. We perform target iden-tification with long short-term memory networks as classifiers. Such are capable of dealing with variable numbers of echoes from multiple positions per input sequence, which facilitates more flexible operation. The impact of the number of recording positions per sequence and of noise is investigated. Furthermore, we demonstrate the improvement in classification performance in comparison to previously obtained results from multi-layer-perceptrons.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"3 1","pages":"1870-1873"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81913757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8926131
P. Bradley, S. Lee, M.S. Kang, J. Kim
Relentless pressure to reduce the size of filters, duplexers and multiplexers in mobile phone RF front end modules requires close packing of the filters and any associated PCB or SMT inductors. In these multiplexers, however, every Tx filter has to reject every Rx frequency and vice versa, while TDD bands/filters must be rejected by and reject nearly every other band -60 dB typical with -55 dB guaranteed. These seemingly contradictory requirements can both be satisfied if we reduce the magnitude of the grounding inductors of the filters to a point that their mutual inductance is not significantly degrading isolation. The Band 25 duplexer described is 1.5 mm x 1.1 mm x 0.6 mm.
在手机射频前端模块中，不断减小滤波器、双工器和多工器尺寸的压力要求滤波器和任何相关的PCB或SMT电感紧密封装。然而，在这些多路复用器中，每个Tx滤波器必须拒绝每个Rx频率，反之亦然，而TDD频带/滤波器必须拒绝并拒绝几乎所有其他频带-典型60 dB，保证-55 dB。如果我们减小滤波器接地电感的幅度，使它们的互感不会显著降低隔离，那么这些看似矛盾的要求都可以得到满足。Band 25双工器尺寸为1.5 mm x 1.1 mm x 0.6 mm。
{"title":"FBAR Duplexers with Minimal Shunt Inductance for Better Isolation and Packing Density","authors":"P. Bradley, S. Lee, M.S. Kang, J. Kim","doi":"10.1109/ULTSYM.2019.8926131","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8926131","url":null,"abstract":"Relentless pressure to reduce the size of filters, duplexers and multiplexers in mobile phone RF front end modules requires close packing of the filters and any associated PCB or SMT inductors. In these multiplexers, however, every Tx filter has to reject every Rx frequency and vice versa, while TDD bands/filters must be rejected by and reject nearly every other band -60 dB typical with -55 dB guaranteed. These seemingly contradictory requirements can both be satisfied if we reduce the magnitude of the grounding inductors of the filters to a point that their mutual inductance is not significantly degrading isolation. The Band 25 duplexer described is 1.5 mm x 1.1 mm x 0.6 mm.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"1 1","pages":"1693-1695"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81918601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8925825
Y. Li, D. Hyun, J. Dahl
Vector flow imaging (VFI) is a novel velocity measurement technique that provides flow velocity information in both azimuth and axial dimensions. Compared to conventional color Doppler imaging, VFI provides velocity estimation that is independent of flow directions. Previous VFI techniques utilize either multiple transmit or receive beams or angles, or speckle tracking. This creates a trade-off between computational intensity and estimate quality or equipment cost. In this work, we present a vector flow velocity estimation technique based on deep neural networks using only beamsummed radio-frequency (RF) data. The deep neural network extracts features from the RF data, and performs flow velocity estimation on the features, and maps the estimates back to the spatial domain. The structure and training of the neural network model is presented. The performance of the technique is demonstrated and evaluated using simulations and flow phantom experiments.
{"title":"Vector Flow Velocity Estimation from Beamsummed Data Using Deep Neural Networks","authors":"Y. Li, D. Hyun, J. Dahl","doi":"10.1109/ULTSYM.2019.8925825","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8925825","url":null,"abstract":"Vector flow imaging (VFI) is a novel velocity measurement technique that provides flow velocity information in both azimuth and axial dimensions. Compared to conventional color Doppler imaging, VFI provides velocity estimation that is independent of flow directions. Previous VFI techniques utilize either multiple transmit or receive beams or angles, or speckle tracking. This creates a trade-off between computational intensity and estimate quality or equipment cost. In this work, we present a vector flow velocity estimation technique based on deep neural networks using only beamsummed radio-frequency (RF) data. The deep neural network extracts features from the RF data, and performs flow velocity estimation on the features, and maps the estimates back to the spatial domain. The structure and training of the neural network model is presented. The performance of the technique is demonstrated and evaluated using simulations and flow phantom experiments.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"57 1","pages":"860-863"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79448274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8925652
Nick Bottenus
Swept synthetic aperture imaging has been previously proposed as a method of extending the effective size of an ultrasound transducer to improve lateral resolution, especially at depth. This method requires precise knowledge of array position and orientation in space as it is moved across a field of view. Previous experimental realizations have used motorized translation stages or calibrated measurement arms to track the transducer. We demonstrate a 1 degree-of-freedom sweep device that constrains the transducer motion and enables a new channel-domain motion estimation method. This channel correlation method is compared against conventional speckle tracking motion estimation and the known applied motion from a motorized stage. Swept synthetic aperture was successfully performed in a phantom using both estimators without external position tracking to extend a 2 cm transducer over a 5 cm sweep and achieve a lateral resolution improvement of 70%.
{"title":"Estimation of transducer translation using channel-domain correlation","authors":"Nick Bottenus","doi":"10.1109/ULTSYM.2019.8925652","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8925652","url":null,"abstract":"Swept synthetic aperture imaging has been previously proposed as a method of extending the effective size of an ultrasound transducer to improve lateral resolution, especially at depth. This method requires precise knowledge of array position and orientation in space as it is moved across a field of view. Previous experimental realizations have used motorized translation stages or calibrated measurement arms to track the transducer. We demonstrate a 1 degree-of-freedom sweep device that constrains the transducer motion and enables a new channel-domain motion estimation method. This channel correlation method is compared against conventional speckle tracking motion estimation and the known applied motion from a motorized stage. Swept synthetic aperture was successfully performed in a phantom using both estimators without external position tracking to extend a 2 cm transducer over a 5 cm sweep and achieve a lateral resolution improvement of 70%.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"1 1","pages":"1009-1012"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79680640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.1109/ULTSYM.2019.8925997
Lucas M. Martinho, A. Kubrusly, N. Pérez, A. Braga, Jean Pierre von der Weid
Ultrasonic guided waves can be used to measure mechanical strain in plates due to the stress-induced velocity change. Strain monitoring is usually performed by measuring the time-of-flight shift. However, interpretation of results can be difficult due to wave mixing, mainly when several dispersive modes propagate, or in the presence of reflections. In these cases, the time-reversal focusing technique can be used to monitor the strain level, by observing the peak of the focused time-reversal signal, which changes proportionally to the strain level. However, not all components of the spectrum contribute with the same sensitivity to strain changes. In this paper, we developed a signal filtering procedure based on the phase of the Fourier spectrum that increases the time-reversal strain sensitivity. The time-reversal process is modified by using a new signal as reference which is synthesized relying on prior knowledge of the impulse response at some non-null strain level. The technique was evaluated with different pairs of transducers in an aluminium plate, effectively producing more strain-sensitive signals. However, high strain-sensitive signal presents poor energy concentration which, in turn, can be difficult to detect. The technique can be adapted to provide strain-robust signals.
{"title":"Strain sensitivity enhancement of ultrasonic waves in plates using phase filter","authors":"Lucas M. Martinho, A. Kubrusly, N. Pérez, A. Braga, Jean Pierre von der Weid","doi":"10.1109/ULTSYM.2019.8925997","DOIUrl":"https://doi.org/10.1109/ULTSYM.2019.8925997","url":null,"abstract":"Ultrasonic guided waves can be used to measure mechanical strain in plates due to the stress-induced velocity change. Strain monitoring is usually performed by measuring the time-of-flight shift. However, interpretation of results can be difficult due to wave mixing, mainly when several dispersive modes propagate, or in the presence of reflections. In these cases, the time-reversal focusing technique can be used to monitor the strain level, by observing the peak of the focused time-reversal signal, which changes proportionally to the strain level. However, not all components of the spectrum contribute with the same sensitivity to strain changes. In this paper, we developed a signal filtering procedure based on the phase of the Fourier spectrum that increases the time-reversal strain sensitivity. The time-reversal process is modified by using a new signal as reference which is synthesized relying on prior knowledge of the impulse response at some non-null strain level. The technique was evaluated with different pairs of transducers in an aluminium plate, effectively producing more strain-sensitive signals. However, high strain-sensitive signal presents poor energy concentration which, in turn, can be difficult to detect. The technique can be adapted to provide strain-robust signals.","PeriodicalId":6759,"journal":{"name":"2019 IEEE International Ultrasonics Symposium (IUS)","volume":"29 1","pages":"928-931"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79812737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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