Pub Date : 1999-10-17DOI: 10.1109/ULTSYM.1999.849461
G. Mansfeld, S. Alekseev, Y. Gulyaev, Z. Kosakovskaya
The BAW spectroscopy method for the acoustic characterization of carbon nanotubes was applied. The material density and the elastic constants for carbon nanotube films were evaluated directly. The effect of the increase in the electric field near the electrodes with nanotube thin films may be conveniently used in electrostatic transducers for acoustic wave excitation in nonpiezoelectric solids and liquids.
{"title":"Microwave HBAR spectroscopy and transducer application of carbon nanotube films","authors":"G. Mansfeld, S. Alekseev, Y. Gulyaev, Z. Kosakovskaya","doi":"10.1109/ULTSYM.1999.849461","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849461","url":null,"abstract":"The BAW spectroscopy method for the acoustic characterization of carbon nanotubes was applied. The material density and the elastic constants for carbon nanotube films were evaluated directly. The effect of the increase in the electric field near the electrodes with nanotube thin films may be conveniently used in electrostatic transducers for acoustic wave excitation in nonpiezoelectric solids and liquids.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123191341","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849362
A. Baghai-Wadji
In this paper we consider the massloading problem in surface acoustic wave devices under fairly general conditions. We assume a finite number of non-equidistantly spaced electrodes with arbitrary cross-section geometries and material constitutions. Electrical loading effect is also addressed and a model is presented which is a generalization of this author's model published in 1989. To solve our problem we have considerably improved the capabilities of the Fast-MoM analysis technique. It turns out that it is possible to generate bivariate universal functions which are frequency, material, and geometry independent. The purpose of this paper is to provide an idea about how the universal functions are created. Having the universal functions we simply have to follow the following recipe to solve a practical problem: (1) discretize the boundaries of electrodes; (2) find the positions of a number of sampling points; (3) sample the universal functions; (4) construct a square matrix; (5) solve a system of equations. If the frequency, or the material, or the geometry of an electrode alters only the locations of the sampling points change. In this paper we present examples for the universal functions and discuss one application of the Fast-MoM.
{"title":"Material, geometry, and frequency independent bivariate universal functions for the analysis of mechanical and electrical loading effects in acoustic devices: A Fast-MoM approach","authors":"A. Baghai-Wadji","doi":"10.1109/ULTSYM.1999.849362","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849362","url":null,"abstract":"In this paper we consider the massloading problem in surface acoustic wave devices under fairly general conditions. We assume a finite number of non-equidistantly spaced electrodes with arbitrary cross-section geometries and material constitutions. Electrical loading effect is also addressed and a model is presented which is a generalization of this author's model published in 1989. To solve our problem we have considerably improved the capabilities of the Fast-MoM analysis technique. It turns out that it is possible to generate bivariate universal functions which are frequency, material, and geometry independent. The purpose of this paper is to provide an idea about how the universal functions are created. Having the universal functions we simply have to follow the following recipe to solve a practical problem: (1) discretize the boundaries of electrodes; (2) find the positions of a number of sampling points; (3) sample the universal functions; (4) construct a square matrix; (5) solve a system of equations. If the frequency, or the material, or the geometry of an electrode alters only the locations of the sampling points change. In this paper we present examples for the universal functions and discuss one application of the Fast-MoM.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124890507","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849209
J. Zhao, Carlos H. F. Alves, K. Snook, J. Cannata, W.H. Chen, R. Meyer, S. Ayyappan, T. Ritter, K. Shung
The performance of high frequency single element transducers depends greatly upon the mechanical and electrical properties of the piezoelectric materials used. This study compares the design and performance of transducers incorporating different materials. The materials selected include 1-3 PZT fiber composite, PbTiO/sub 3/ ceramic, PVDF film and LiNbO/sub 3/ single crystal. Transducers were tested for insertion loss and -6 dB bandwidth using the pulse/echo response from a flat quartz target. All transducers were constructed with a 3 mm aperture size and f number between 2 to 3. Backing and matching materials were varied to optimize each design. An additional design consideration is electrical impedance matching to 50 ohm especially for the fiber composite and PbTiO/sub 3/ transducers due to their relatively high dielectric constant. Sensitivity between transducers displayed a significant variation, with insertion losses from -21.3 dB to -46 dB. -6 dB bandwidths were in the range of 47 to 118%. In-vitro UBM images of the human eye were made to compare the different transducers.
{"title":"Performance of 50 MHz transducers incorporating fiber composite, PVDF, PbTiO/sub 3/ and LiNbO/sub 3/","authors":"J. Zhao, Carlos H. F. Alves, K. Snook, J. Cannata, W.H. Chen, R. Meyer, S. Ayyappan, T. Ritter, K. Shung","doi":"10.1109/ULTSYM.1999.849209","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849209","url":null,"abstract":"The performance of high frequency single element transducers depends greatly upon the mechanical and electrical properties of the piezoelectric materials used. This study compares the design and performance of transducers incorporating different materials. The materials selected include 1-3 PZT fiber composite, PbTiO/sub 3/ ceramic, PVDF film and LiNbO/sub 3/ single crystal. Transducers were tested for insertion loss and -6 dB bandwidth using the pulse/echo response from a flat quartz target. All transducers were constructed with a 3 mm aperture size and f number between 2 to 3. Backing and matching materials were varied to optimize each design. An additional design consideration is electrical impedance matching to 50 ohm especially for the fiber composite and PbTiO/sub 3/ transducers due to their relatively high dielectric constant. Sensitivity between transducers displayed a significant variation, with insertion losses from -21.3 dB to -46 dB. -6 dB bandwidths were in the range of 47 to 118%. In-vitro UBM images of the human eye were made to compare the different transducers.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122076863","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849402
N. Kuze, H. Goto, Y. Kanno, M. Tsunashima, Y. Yamagata, K. Yamanouchi
Highly efficient surface acoustic wave (SAW) convolvers are required for application in spread spectrum communication systems. We present here for the first time the growth of GaSb/InSb/AlGaAsSb heterostructures on LiNbO3 substrates by molecular beam epitaxy (MBE) and their application to a novel strip-coupled SAW convolver. As a result of investigating the semiconductor thin film structure and the output electrode structure, we have succeeded in obtaining very high efficiencies of more than -14 dBm (F-value). We have also studied the correlation properties of the strip-coupled SAW convolver using a square wave signal and a pseudonoise (PN) code signal.
{"title":"Very highly efficient surface acoustic wave convolver using GaSb/InSb/AlGaAsSb heterostructures grown on LiNbO/sub 3/ substrates","authors":"N. Kuze, H. Goto, Y. Kanno, M. Tsunashima, Y. Yamagata, K. Yamanouchi","doi":"10.1109/ULTSYM.1999.849402","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849402","url":null,"abstract":"Highly efficient surface acoustic wave (SAW) convolvers are required for application in spread spectrum communication systems. We present here for the first time the growth of GaSb/InSb/AlGaAsSb heterostructures on LiNbO3 substrates by molecular beam epitaxy (MBE) and their application to a novel strip-coupled SAW convolver. As a result of investigating the semiconductor thin film structure and the output electrode structure, we have succeeded in obtaining very high efficiencies of more than -14 dBm (F-value). We have also studied the correlation properties of the strip-coupled SAW convolver using a square wave signal and a pseudonoise (PN) code signal.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"258 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121055180","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849167
Wei Luo, A. Ding, Haosu Luo, Z. Yin
Electric properties of relaxor ferroelectric Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ (PMN-PT) single crystals near the rhombohedral-tetragonal transition under high-field phase boundary were studied. The single crystals in the <001> direction exhibited a remanent polarization of 30 /spl mu/C/cm/sup 2/, coercive field of 3.5 kV/cm and switchable polarization of 51 /spl mu/C/cm/sup 2/ at 9 kV/cm. The polarization-temperature dependence of the crystals indicated a reduction of 5% in the remanent polarization and 3.2% in switchable polarization at 80/spl deg/C. The remanent polarization decreased to 5 /spl mu/C/cm/sup 2/ at 146/spl deg/C (T/sub m/). However the switchable polarization fell to zero at that temperature. A loss of 12% in the polarization was observed in the switching cycles up to 2.5/spl times/10/sup 8/ reversals under bipolar pulse of 12 kV/cm. On the other hand, the crystals have a resistivity of 1.6/spl times/10/sup 9/ /spl Omega/-cm at 100/spl deg/C and with a electric field of 10 kV/cm. These results are favorable to applications for device design of the PMN-PT crystals.
{"title":"High-field properties of PMN-PT single crystals","authors":"Wei Luo, A. Ding, Haosu Luo, Z. Yin","doi":"10.1109/ULTSYM.1999.849167","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849167","url":null,"abstract":"Electric properties of relaxor ferroelectric Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ (PMN-PT) single crystals near the rhombohedral-tetragonal transition under high-field phase boundary were studied. The single crystals in the <001> direction exhibited a remanent polarization of 30 /spl mu/C/cm/sup 2/, coercive field of 3.5 kV/cm and switchable polarization of 51 /spl mu/C/cm/sup 2/ at 9 kV/cm. The polarization-temperature dependence of the crystals indicated a reduction of 5% in the remanent polarization and 3.2% in switchable polarization at 80/spl deg/C. The remanent polarization decreased to 5 /spl mu/C/cm/sup 2/ at 146/spl deg/C (T/sub m/). However the switchable polarization fell to zero at that temperature. A loss of 12% in the polarization was observed in the switching cycles up to 2.5/spl times/10/sup 8/ reversals under bipolar pulse of 12 kV/cm. On the other hand, the crystals have a resistivity of 1.6/spl times/10/sup 9/ /spl Omega/-cm at 100/spl deg/C and with a electric field of 10 kV/cm. These results are favorable to applications for device design of the PMN-PT crystals.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123861758","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849379
G. Behme, E. Chilla, H.-J. Frohlich
We present first measurements on acoustic waves with quasi longitudinal polarization on quartz and lithium tantalate substrates as well as layered systems carried out by a scanning acoustic force microscope (SAFM). Acoustic phase velocities were measured for microscopic areas showing a good agreement with numerical calculations. The influence of the penetration depth of the high velocity pseudo SAWs (HVPSAW) on the SAFM signal formation is discussed.
{"title":"Investigation of longitudinal leaky surface acoustic waves by scanning acoustic force microscopy","authors":"G. Behme, E. Chilla, H.-J. Frohlich","doi":"10.1109/ULTSYM.1999.849379","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849379","url":null,"abstract":"We present first measurements on acoustic waves with quasi longitudinal polarization on quartz and lithium tantalate substrates as well as layered systems carried out by a scanning acoustic force microscope (SAFM). Acoustic phase velocities were measured for microscopic areas showing a good agreement with numerical calculations. The influence of the penetration depth of the high velocity pseudo SAWs (HVPSAW) on the SAFM signal formation is discussed.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"254 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124180925","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849467
Jian-jun Chen, Y. Mao, Yan Zhang, Wen‐hua Jiang, D. Zhang
The generation of reflected freely-propagating second harmonic SV wave at solid-solid interface is an interface nonlinear effect. It is anticipated that the bonding state of the interface will affect the effect. In this paper, the influence of the vibrating interface on the effect is studied. It is observed that the nonlinear reflective SV wave becomes amplitude modulation due to the vibration of the refractive media (PZT), whereas no modulation takes place for the linear reflective SV wave.
{"title":"A nonlinear amplitude modulation phenomenon","authors":"Jian-jun Chen, Y. Mao, Yan Zhang, Wen‐hua Jiang, D. Zhang","doi":"10.1109/ULTSYM.1999.849467","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849467","url":null,"abstract":"The generation of reflected freely-propagating second harmonic SV wave at solid-solid interface is an interface nonlinear effect. It is anticipated that the bonding state of the interface will affect the effect. In this paper, the influence of the vibrating interface on the effect is studied. It is observed that the nonlinear reflective SV wave becomes amplitude modulation due to the vibration of the refractive media (PZT), whereas no modulation takes place for the linear reflective SV wave.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125915894","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849230
M. Karaman, M. Kozak
A promising approach to reduce the complexity of the front-end hardware of an ultrasound imaging system is to utilize oversampling Delta-Sigma (/spl Delta//spl Sigma/) beamforming. Realization of dynamic receive focusing involves signal resampling of uniformly sampled radio frequency (RF) signals using beamforming timing. The resampling (deleting or repeating samples), however, causes a significant increase in the noise floor of the beamformer output. To overcome this problem, the authors have explored a new digital beamformer employing non-uniform oversampling. To avoid resampling during dynamic focusing, they have used a different sampling clock at each channel to sample RF echo signals non-uniformly at the time instants associated with receive focal points. The performance and validity of the new system are assessed by means of emulations using experimental 3.5 MHz RF data.
{"title":"Digital beamforming using non-uniform oversampling delta-sigma conversion","authors":"M. Karaman, M. Kozak","doi":"10.1109/ULTSYM.1999.849230","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849230","url":null,"abstract":"A promising approach to reduce the complexity of the front-end hardware of an ultrasound imaging system is to utilize oversampling Delta-Sigma (/spl Delta//spl Sigma/) beamforming. Realization of dynamic receive focusing involves signal resampling of uniformly sampled radio frequency (RF) signals using beamforming timing. The resampling (deleting or repeating samples), however, causes a significant increase in the noise floor of the beamformer output. To overcome this problem, the authors have explored a new digital beamformer employing non-uniform oversampling. To avoid resampling during dynamic focusing, they have used a different sampling clock at each channel to sample RF echo signals non-uniformly at the time instants associated with receive focal points. The performance and validity of the new system are assessed by means of emulations using experimental 3.5 MHz RF data.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129259724","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849411
D. Zhang, X. Tong, H. Qin
This paper presents some propagation properties of QLLSAW propagating on Y-rotated cut quartz substrates, such as the substrates at Euler angles [0°, 124°, 50°], [0°, 126°, 50°], [0°, 132°, 50°] etc. The advantages of properties of quasi-longitudinal leaky surface acoustic waves (QLLSAW) along these directions are small propagation attenuation (less than 10-4 dB/λ), small power flow deviation and high phase velocity (can be up from 6,200 m/s to 7,000 m/s). Frequency responses of experimental devices are smooth enough to be applied in practice and the leaky surface shear wave signal cannot be observed in the frequency response. The temperature coefficients on these substrates are also investigated.
{"title":"Study of propagation properties of quasi-longitudinal leaky surface acoustic wave propagating on Y-rotated cut quartz substrates","authors":"D. Zhang, X. Tong, H. Qin","doi":"10.1109/ULTSYM.1999.849411","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849411","url":null,"abstract":"This paper presents some propagation properties of QLLSAW propagating on Y-rotated cut quartz substrates, such as the substrates at Euler angles [0°, 124°, 50°], [0°, 126°, 50°], [0°, 132°, 50°] etc. The advantages of properties of quasi-longitudinal leaky surface acoustic waves (QLLSAW) along these directions are small propagation attenuation (less than 10-4 dB/λ), small power flow deviation and high phase velocity (can be up from 6,200 m/s to 7,000 m/s). Frequency responses of experimental devices are smooth enough to be applied in practice and the leaky surface shear wave signal cannot be observed in the frequency response. The temperature coefficients on these substrates are also investigated.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129354769","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 : 1999-10-17DOI: 10.1109/ULTSYM.1999.849257
T. Karjalainen, J.S. Thierman, K. Hynynen
Vibro-acoustography, a relatively new imaging modality, is applied to imaging ex vivo liver tissue from calves and New Zealand white rabbits. In the first series of experiments, calf liver tissue was heated while the USAE response and temperature were recorded. This demonstrated a strong temperature dependence of the USAE signal. In the second series of experiments lesions were created with focused ultrasound and then raster scanned in the focal plane by the two intersecting focused ultrasound fields. The FWHM of these USAE-amplitude scans correlates well with the lesion sizes measured in histological studies. This method successfully rendered high-resolution images of the necrosed lesions in the liver tissue. In addition, a correlation between the time after sonication and amplitude of the USAE response was observed.
{"title":"Ultrasound acoustic stimulated emission for controlling thermal surgery","authors":"T. Karjalainen, J.S. Thierman, K. Hynynen","doi":"10.1109/ULTSYM.1999.849257","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849257","url":null,"abstract":"Vibro-acoustography, a relatively new imaging modality, is applied to imaging ex vivo liver tissue from calves and New Zealand white rabbits. In the first series of experiments, calf liver tissue was heated while the USAE response and temperature were recorded. This demonstrated a strong temperature dependence of the USAE signal. In the second series of experiments lesions were created with focused ultrasound and then raster scanned in the focal plane by the two intersecting focused ultrasound fields. The FWHM of these USAE-amplitude scans correlates well with the lesion sizes measured in histological studies. This method successfully rendered high-resolution images of the necrosed lesions in the liver tissue. In addition, a correlation between the time after sonication and amplitude of the USAE response was observed.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128583159","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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