Pub Date : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192575
O. Al-Bataineh, R. Meyer, R.E. Newnharn, N. Smith
Miniature, high-frequency piezoelectric ceramic hollow spheres were evaluated for potential use as hydrophones for exposimetry of high intensity ultrasound fields and as minimally invasive ablation devices. As a hydrophone, the hollow sphere has unique characteristics regarding its geometry, dimensions and sensitivity, which make it ideal for use in exposimetry of high pressure fields. Spheres with diameters ranging from 0.7 to 1.0 mm and with resonance frequencies from 1.8 to 2.7 MHz were used as hydrophones. A relative (reciprocal) calibration method was performed to determine the end-of-cable sensitivity as well as the directivity of the hollow sphere hydrophones. An almost constant sensitivity was reported for the spherical hydrophones and an omni-directional receive pattern was also demonstrated. The hollow sphere hydrophone was shown to have twice the sensitivity of a needle type hydrophone but with no pre-amplification stages and could withstand four times the pressure. As a minimally invasive interstitial ablation device, several in vitro experiments were conducted using two different size spheres. The results demonstrated an increased necrosed tissue volume for increasing exposure time. With a 1.0 mm diameter sphere (f = 1.87 MHz), the necrosed tissue diameter as a function of exposure times was 2.35 /spl plusmn/ 0.34, 3.00 /spl plusmn/ 0.37 and 4.61 /spl plusmn/ 1.13 mm for 5, 10 and 15 second sonications, respectively. Using a 0.7 mm diameter sphere (f = 2.70 MHz), the size of the ablated tissue was 1.50 /spl plusmn/ 0.01 and 1.63 /spl plusmn/ 0.31 mm for 5 and 10 seconds sonications, respectively. As a tissue ablation device, the hollow sphere was able to produce controllable lesion diameters with sharp boundaries between the normal and necrosed tissue.
{"title":"Utilization of the high-frequency piezoelectric ceramic hollow spheres for exposimetry and tissue ablation","authors":"O. Al-Bataineh, R. Meyer, R.E. Newnharn, N. Smith","doi":"10.1109/ULTSYM.2002.1192575","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192575","url":null,"abstract":"Miniature, high-frequency piezoelectric ceramic hollow spheres were evaluated for potential use as hydrophones for exposimetry of high intensity ultrasound fields and as minimally invasive ablation devices. As a hydrophone, the hollow sphere has unique characteristics regarding its geometry, dimensions and sensitivity, which make it ideal for use in exposimetry of high pressure fields. Spheres with diameters ranging from 0.7 to 1.0 mm and with resonance frequencies from 1.8 to 2.7 MHz were used as hydrophones. A relative (reciprocal) calibration method was performed to determine the end-of-cable sensitivity as well as the directivity of the hollow sphere hydrophones. An almost constant sensitivity was reported for the spherical hydrophones and an omni-directional receive pattern was also demonstrated. The hollow sphere hydrophone was shown to have twice the sensitivity of a needle type hydrophone but with no pre-amplification stages and could withstand four times the pressure. As a minimally invasive interstitial ablation device, several in vitro experiments were conducted using two different size spheres. The results demonstrated an increased necrosed tissue volume for increasing exposure time. With a 1.0 mm diameter sphere (f = 1.87 MHz), the necrosed tissue diameter as a function of exposure times was 2.35 /spl plusmn/ 0.34, 3.00 /spl plusmn/ 0.37 and 4.61 /spl plusmn/ 1.13 mm for 5, 10 and 15 second sonications, respectively. Using a 0.7 mm diameter sphere (f = 2.70 MHz), the size of the ablated tissue was 1.50 /spl plusmn/ 0.01 and 1.63 /spl plusmn/ 0.31 mm for 5 and 10 seconds sonications, respectively. As a tissue ablation device, the hollow sphere was able to produce controllable lesion diameters with sharp boundaries between the normal and necrosed tissue.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131778523","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193359
A. Miyamoto, S. Wakana, A. Ito
We developed a new optical technique for observing the shear horizontal component of surface acoustic waves. The technique detects the change in polarization of the probe light caused by the photoelastic effect. We measured the distribution in and around a resonator on rotated Y-cut LiTaO/sub 3/, and occurrence and propagation of leakage was observed.
{"title":"Novel optical observation technique for shear horizontal wave in SAW resonators on 42/spl deg/YX-cut lithium tantalate","authors":"A. Miyamoto, S. Wakana, A. Ito","doi":"10.1109/ULTSYM.2002.1193359","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193359","url":null,"abstract":"We developed a new optical technique for observing the shear horizontal component of surface acoustic waves. The technique detects the change in polarization of the probe light caused by the photoelastic effect. We measured the distribution in and around a resonator on rotated Y-cut LiTaO/sub 3/, and occurrence and propagation of leakage was observed.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132187346","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193362
S. Kanna, K. Iizawa, T. Yamazaki, M. Takagi
We present surface acoustic wave resonators on the in-plane rotated 33/spl deg/Y-cut quartz with improved temperature stability. We calculate the frequency temperature characteristics of Rayleigh waves using finite element method under the condition of Euler angle (0, 123, 39-44). We confirmed the accuracy of calculated temperature coefficients by experiments. We also measured the resonance characteristics of prototype SAW resonators.
{"title":"Temperature stability of surface acoustic wave resonators on the in-plane rotated 33/spl deg/Y-cut quartz","authors":"S. Kanna, K. Iizawa, T. Yamazaki, M. Takagi","doi":"10.1109/ULTSYM.2002.1193362","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193362","url":null,"abstract":"We present surface acoustic wave resonators on the in-plane rotated 33/spl deg/Y-cut quartz with improved temperature stability. We calculate the frequency temperature characteristics of Rayleigh waves using finite element method under the condition of Euler angle (0, 123, 39-44). We confirmed the accuracy of calculated temperature coefficients by experiments. We also measured the resonance characteristics of prototype SAW resonators.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132295403","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193399
S. Malocha, B. Abbott
In this paper a fast and accurate method to calculate COM parameters (transduction and reflectivity) of a transducer cell with any arbitrary geometry and polarity sequence is presented. This method was applied to optimization of SPUDT cells on different materials. SPUDT structures with three and four electrodes per wavelength have been optimized for several different substrates. Very good agreement between predicted and experimental results is shown for SPUDT transducers on quartz, langasite and lithium tantalate.
{"title":"Calculation of COM parameters for an arbitrary IDT cell","authors":"S. Malocha, B. Abbott","doi":"10.1109/ULTSYM.2002.1193399","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193399","url":null,"abstract":"In this paper a fast and accurate method to calculate COM parameters (transduction and reflectivity) of a transducer cell with any arbitrary geometry and polarity sequence is presented. This method was applied to optimization of SPUDT cells on different materials. SPUDT structures with three and four electrodes per wavelength have been optimized for several different substrates. Very good agreement between predicted and experimental results is shown for SPUDT transducers on quartz, langasite and lithium tantalate.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134181029","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192599
D. Vray, A. Discher, J. Lefloc'h, W. Mai, P. Clarysse, Q. Pham, J. Montagnat, M. Janier
High frequency ultrasound imaging has become an effective tool for anatomical mice studies. This work is focused on 3D quantification of mouse embryo development to extract pertinent information of its evolution. A series of B-Scan ultrasound images was acquired at different spatial positions along the embryo. A 3D deformable model was used to segment the images. A pregnant female mouse at embryonic day 14.5 was imaged with an ATL HDI 5000, 7-15MHz linear array. The probe was moved by a step by step motor along the abdomen of the mouse. 3D segmentation results are presented including volume quantification of the embryo.
{"title":"3D quantification of ultrasound images: Application to mouse embryo imaging in vivo","authors":"D. Vray, A. Discher, J. Lefloc'h, W. Mai, P. Clarysse, Q. Pham, J. Montagnat, M. Janier","doi":"10.1109/ULTSYM.2002.1192599","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192599","url":null,"abstract":"High frequency ultrasound imaging has become an effective tool for anatomical mice studies. This work is focused on 3D quantification of mouse embryo development to extract pertinent information of its evolution. A series of B-Scan ultrasound images was acquired at different spatial positions along the embryo. A 3D deformable model was used to segment the images. A pregnant female mouse at embryonic day 14.5 was imaged with an ATL HDI 5000, 7-15MHz linear array. The probe was moved by a step by step motor along the abdomen of the mouse. 3D segmentation results are presented including volume quantification of the embryo.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115079083","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1193552
P. Krempl, C. Reiter, W. Wallnofer, J. Neubig
Results of investigations of temperature sensors using singly rotated Gallium Orthophosphate (GaPO/sub 4/) Y-cut resonators are presented in this paper. Depending on rotating angle the most important parameters - sensitivity, resolution and linearity differ in a wide range. Theoretical calculations leads to cuts owning nearly a linear response with sensitivity between 44.5 ppm//spl deg/C and 46.5 ppm//spl deg/C within a temperature range from room temperature to 600/spl deg/C with a high resolution of about 10/sup -6//spl deg/C. First measurements confirm the theoretically predicted sensitivity. The broad thermal stability range of GaPO/sub 4/ can also be used for temperature sensors based on surface acoustic wave devices. By theoretical calculations, suitable orientations with high temperature coefficients are identified.
{"title":"Temperature sensors based on GaPO/sub 4/","authors":"P. Krempl, C. Reiter, W. Wallnofer, J. Neubig","doi":"10.1109/ULTSYM.2002.1193552","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193552","url":null,"abstract":"Results of investigations of temperature sensors using singly rotated Gallium Orthophosphate (GaPO/sub 4/) Y-cut resonators are presented in this paper. Depending on rotating angle the most important parameters - sensitivity, resolution and linearity differ in a wide range. Theoretical calculations leads to cuts owning nearly a linear response with sensitivity between 44.5 ppm//spl deg/C and 46.5 ppm//spl deg/C within a temperature range from room temperature to 600/spl deg/C with a high resolution of about 10/sup -6//spl deg/C. First measurements confirm the theoretically predicted sensitivity. The broad thermal stability range of GaPO/sub 4/ can also be used for temperature sensors based on surface acoustic wave devices. By theoretical calculations, suitable orientations with high temperature coefficients are identified.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115548848","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192509
Shiwei Zhou, J. Hossack
High bandwidth transducers are of interest in all applications of ultrasound imaging. A stacked, phased multi-layer transducer was previously described that extended the bandwidth to multiple octaves. However, the frequency response of this transducer design is characterized by multiple peaks and troughs that will result in a 'ringy' waveform. However, Digital Signal Processing (DSP) and related devices are ubiquitous. Modern ultrasound systems digitize received signals and incorporate digital filters. In this paper the utility of digital filtering for improving transducer frequency response was tested in MATLAB. A Finite Element Analysis (FEA) model was developed in PZFlex to simulate a transducer array element. Our FEA and Matlab simulation results indicate that a matched filter in transducer receive path can remove the 'bumps' in the spectrum and reduce the -20dB pulse length by approximately 14%. An inverse filter employed in the transmitting path can also improve the characteristics of the transmitted signal - reducing the pulse length by 35%. A Pseudo-inverse procedure was used to design these FIR filters with a desired length. Furthermore, a design parameter iteration simulation demonstrates that this digital filtering technique can work effectively even when there is variation in the material properties and transducer element dimensions. Major parameters considered included: electro-mechanical coupling coefficient (+/-10%), dielectric permittivity (+/-10%) and transducer element thickness (+/-5%). The results demonstrate that digital filtering can play an important role in compensating for transducer spectral response imperfections. Thus, we can obtain reduced pulse length and improved imaging resolution with high bandwidth multi-layer transducers. The approach also has value for compensating for spectral imperfections in conventional single layer transducers.
{"title":"Investigation of digital filtering for stacked, phased ultrasound transducers","authors":"Shiwei Zhou, J. Hossack","doi":"10.1109/ULTSYM.2002.1192509","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192509","url":null,"abstract":"High bandwidth transducers are of interest in all applications of ultrasound imaging. A stacked, phased multi-layer transducer was previously described that extended the bandwidth to multiple octaves. However, the frequency response of this transducer design is characterized by multiple peaks and troughs that will result in a 'ringy' waveform. However, Digital Signal Processing (DSP) and related devices are ubiquitous. Modern ultrasound systems digitize received signals and incorporate digital filters. In this paper the utility of digital filtering for improving transducer frequency response was tested in MATLAB. A Finite Element Analysis (FEA) model was developed in PZFlex to simulate a transducer array element. Our FEA and Matlab simulation results indicate that a matched filter in transducer receive path can remove the 'bumps' in the spectrum and reduce the -20dB pulse length by approximately 14%. An inverse filter employed in the transmitting path can also improve the characteristics of the transmitted signal - reducing the pulse length by 35%. A Pseudo-inverse procedure was used to design these FIR filters with a desired length. Furthermore, a design parameter iteration simulation demonstrates that this digital filtering technique can work effectively even when there is variation in the material properties and transducer element dimensions. Major parameters considered included: electro-mechanical coupling coefficient (+/-10%), dielectric permittivity (+/-10%) and transducer element thickness (+/-5%). The results demonstrate that digital filtering can play an important role in compensating for transducer spectral response imperfections. Thus, we can obtain reduced pulse length and improved imaging resolution with high bandwidth multi-layer transducers. The approach also has value for compensating for spectral imperfections in conventional single layer transducers.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115693945","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192631
J. Krucker, C. Orifici, J. Fowlkes, P. Carson
A mismatch between the sound speed assumed for beam forming and scan conversion and the true sound speed in the field of view can lead to significant defocusing and some geometric distortions in ultrasound images. A method is presented for estimating the average sound speed based on detection of these distortions using automatic registration of overlapping, electronically steered images. An acrylamide gel phantom containing vaporized dodecafluoropentane (DDFP) droplets as point targets was constructed to evaluate the technique. Good agreement (errors <1 %) was found between the sound speeds measured in the phantom using a reference pulse-echo technique and the image-based sound speed estimates. A small improvement in accuracy was achieved by including the simulated sound field of the probe rather than assuming straight acoustic beams and refraction according to Snell's law.
{"title":"Registration-based sound speed estimation in phantoms with acoustically vaporized droplets","authors":"J. Krucker, C. Orifici, J. Fowlkes, P. Carson","doi":"10.1109/ULTSYM.2002.1192631","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192631","url":null,"abstract":"A mismatch between the sound speed assumed for beam forming and scan conversion and the true sound speed in the field of view can lead to significant defocusing and some geometric distortions in ultrasound images. A method is presented for estimating the average sound speed based on detection of these distortions using automatic registration of overlapping, electronically steered images. An acrylamide gel phantom containing vaporized dodecafluoropentane (DDFP) droplets as point targets was constructed to evaluate the technique. Good agreement (errors <1 %) was found between the sound speeds measured in the phantom using a reference pulse-echo technique and the image-based sound speed estimates. A small improvement in accuracy was achieved by including the simulated sound field of the probe rather than assuming straight acoustic beams and refraction according to Snell's law.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114662207","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192576
D. Melodelima, C. Lafon, F. Prat, A. Birer, Y. Theillère, D. Cathignol
In this study, the feasibility of a cylindrical phased array (10-mm O.D.) has been evaluated for intraductal thermal ablation. The principle of this applicator is to generate electronically rotating plane waves. A plane propagation is generated by exciting eight successive elements with appropriate excitation delay times. The shot direction was changed by exciting a different set of eight elements. In the future, the final applicator will be composed of 64 elements arranged all over the periphery of the cylinder. This study present a cylindrical prototype (10.6-mm O.D.) which is composed of 16 transducers working at 4.55 MHz and arranged on a quarter of the cylinder. The dimension of each transducer is 15 /spl times/ 0.45 mm/sup 2/ and the distance between two consecutive elements is 70-/spl mu/m. The mechanical strength of the device was reinforced by mounting a rigid damper structure on the rear face of the active part. Heat dissipation is favoured by the thermal properties of the backing. The active part is covered by a latex balloon and cooled internally and externally by a continuous flow of degassed water. This study showed that the ultrasound beam generated by eight elements excited with appropriated delay times is plane. Ex vivo experiments were carried out on pig liver and permit to generated three reproducible well-defined lesions up to 14-mm, separated from each other by a 23/spl deg/ angle.
{"title":"The feasibility of developing a 64-elements cylindrical phased array for intraductal thermal ablation","authors":"D. Melodelima, C. Lafon, F. Prat, A. Birer, Y. Theillère, D. Cathignol","doi":"10.1109/ULTSYM.2002.1192576","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192576","url":null,"abstract":"In this study, the feasibility of a cylindrical phased array (10-mm O.D.) has been evaluated for intraductal thermal ablation. The principle of this applicator is to generate electronically rotating plane waves. A plane propagation is generated by exciting eight successive elements with appropriate excitation delay times. The shot direction was changed by exciting a different set of eight elements. In the future, the final applicator will be composed of 64 elements arranged all over the periphery of the cylinder. This study present a cylindrical prototype (10.6-mm O.D.) which is composed of 16 transducers working at 4.55 MHz and arranged on a quarter of the cylinder. The dimension of each transducer is 15 /spl times/ 0.45 mm/sup 2/ and the distance between two consecutive elements is 70-/spl mu/m. The mechanical strength of the device was reinforced by mounting a rigid damper structure on the rear face of the active part. Heat dissipation is favoured by the thermal properties of the backing. The active part is covered by a latex balloon and cooled internally and externally by a continuous flow of degassed water. This study showed that the ultrasound beam generated by eight elements excited with appropriated delay times is plane. Ex vivo experiments were carried out on pig liver and permit to generated three reproducible well-defined lesions up to 14-mm, separated from each other by a 23/spl deg/ angle.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114601313","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 : 2002-10-08DOI: 10.1109/ULTSYM.2002.1192493
M. Sato, M. Tahara, I. Sakagami
The way for shooting a short ultrasonic pulse by a magnetostrictive bar type transducer is investigated. The method is as follows, 1. Make magnetization of the transducer to be saturated by a bias coil. 2. Induce a short pulse voltage or current to a driving coil. The half breadth of the signal is much shorter than the fundamental resonant period of the transducer. In a result, the short pulse ultrasonic waves are generated and launched. The reason of the phenomena is, we think, that the both ends of the bar transducer are not saturated, because the demagnetization exists on the sides.
{"title":"Short pulse ultrasonic generation with a bar type magnetostrictive transducer with saturated magnetization","authors":"M. Sato, M. Tahara, I. Sakagami","doi":"10.1109/ULTSYM.2002.1192493","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192493","url":null,"abstract":"The way for shooting a short ultrasonic pulse by a magnetostrictive bar type transducer is investigated. The method is as follows, 1. Make magnetization of the transducer to be saturated by a bias coil. 2. Induce a short pulse voltage or current to a driving coil. The half breadth of the signal is much shorter than the fundamental resonant period of the transducer. In a result, the short pulse ultrasonic waves are generated and launched. The reason of the phenomena is, we think, that the both ends of the bar transducer are not saturated, because the demagnetization exists on the sides.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116742974","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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