Pub Date : 2000-10-22DOI: 10.1109/ULTSYM.2000.922661
Z. Thome, W. Pereira, J. C. Machado, J. Seixas, W. S. Filho, J.L. Chapot
Ultrasonic pulses (center frequency at 25 MHz) are incident on the rods of fuel assemblies. The echoes from the tube front wall as well as from the multireflections at the interface between the tube inner wall/gap were collected from a fuel assembly prototype containing intact rods and failed ones (water in the gap between the tube inner wall and the fuel). Detection of failed rods is based on signal analysis of the echo envelopes, employing three methods: exponential envelope estimation, Fisher linear discriminant and neural networks. Around 5,000 US signals were processed and up to 93% of failed rods were correctly identified, for a false alarm detection smaller than 2%.
{"title":"Ultrasonic system for fuel assembly inspection in pressurized water reactors","authors":"Z. Thome, W. Pereira, J. C. Machado, J. Seixas, W. S. Filho, J.L. Chapot","doi":"10.1109/ULTSYM.2000.922661","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.922661","url":null,"abstract":"Ultrasonic pulses (center frequency at 25 MHz) are incident on the rods of fuel assemblies. The echoes from the tube front wall as well as from the multireflections at the interface between the tube inner wall/gap were collected from a fuel assembly prototype containing intact rods and failed ones (water in the gap between the tube inner wall and the fuel). Detection of failed rods is based on signal analysis of the echo envelopes, employing three methods: exponential envelope estimation, Fisher linear discriminant and neural networks. Around 5,000 US signals were processed and up to 93% of failed rods were correctly identified, for a false alarm detection smaller than 2%.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126448140","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.921585
K. Mahoney, H. Martin, K. Hynynen
The main ear vessels, both artery and vein, of 22 New Zealand white rabbits were sonicated. Pulsed ultrasound with RF power levels from 50 to 900 W and burst durations of 10 s were used. Pulse repetition frequency was varied from 5 to 20 Hz and total sonication duration from 10 to 180 s. Transducer operating frequencies of 0.68 and 2.02 MHz were used. Sonications were performed with normal flow through the vessel except for experiments to study the effect of ultrasound contrast agent, which were performed on clamped vessels. In all experiments the animals were followed 1-3 h after sonications before sacrificing and harvesting the tissue samples. Most sonications caused constriction of the artery even at the lowest power. At 0.68 MHz vessel rupture was also seen. At 2.02 MHz the main damage mechanism in the vessels and surrounding tissues is thermal coagulation. Both the arteries and veins are constricted or occluded often without rupture of the vessel wall. The injection of the contrast agent caused the veins to constrict at a lower power level than without it.
{"title":"Focused ultrasound effects on blood vessels in vivo-limits for vascular interventions","authors":"K. Mahoney, H. Martin, K. Hynynen","doi":"10.1109/ULTSYM.2000.921585","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.921585","url":null,"abstract":"The main ear vessels, both artery and vein, of 22 New Zealand white rabbits were sonicated. Pulsed ultrasound with RF power levels from 50 to 900 W and burst durations of 10 s were used. Pulse repetition frequency was varied from 5 to 20 Hz and total sonication duration from 10 to 180 s. Transducer operating frequencies of 0.68 and 2.02 MHz were used. Sonications were performed with normal flow through the vessel except for experiments to study the effect of ultrasound contrast agent, which were performed on clamped vessels. In all experiments the animals were followed 1-3 h after sonications before sacrificing and harvesting the tissue samples. Most sonications caused constriction of the artery even at the lowest power. At 0.68 MHz vessel rupture was also seen. At 2.02 MHz the main damage mechanism in the vessels and surrounding tissues is thermal coagulation. Both the arteries and veins are constricted or occluded often without rupture of the vessel wall. The injection of the contrast agent caused the veins to constrict at a lower power level than without it.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"201 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123032522","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}
{"title":"Analysis of quartz and langasite STW device acceleration sensitivity","authors":"J. Kosiński, R. A. Pastore","doi":"10.1109/ULTSYM.2000.922545","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.922545","url":null,"abstract":"The acceleration sensitivity of STW on rotated Y-cut langasite is analyzed and compared to that of STW on rotated Y-cut quartz.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"562 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123063985","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.922638
K. Asai, M. Kurosawa, T. Higuchi
This paper describes influences of a pre-load and vibration amplitude on driving performance of a surface acoustic wave (SAW) linear motor, and proposes a simulation model for the SAW linear motor. In experimental results, maximum output force and maximum output power of the SAW linear motor depended on it's pre-load. Optimum pre-loads for the maximum output force and for the maximum output power were both linear functions of the SAW linear motor's vibration amplitude. No-load velocity of the SAW linear motor, however, decreased linearly with increasing pre-load. A new simulation model to explain these phenomena is proposed. There is a good agreement between the experimental and simulation results.
{"title":"Evaluation of the driving performance of a surface acoustic wave linear motor","authors":"K. Asai, M. Kurosawa, T. Higuchi","doi":"10.1109/ULTSYM.2000.922638","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.922638","url":null,"abstract":"This paper describes influences of a pre-load and vibration amplitude on driving performance of a surface acoustic wave (SAW) linear motor, and proposes a simulation model for the SAW linear motor. In experimental results, maximum output force and maximum output power of the SAW linear motor depended on it's pre-load. Optimum pre-loads for the maximum output force and for the maximum output power were both linear functions of the SAW linear motor's vibration amplitude. No-load velocity of the SAW linear motor, however, decreased linearly with increasing pre-load. A new simulation model to explain these phenomena is proposed. There is a good agreement between the experimental and simulation results.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126569651","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.922577
V. Proklov, V. N. Kurski, Y. Sindler, S. P. Baronin, O. Byshevski-Konopko, V. I. Grigorievski, V. V. Shtykov
The new method for comparison of the most significant properties of SAW based and digital correlation processors for applications in the code division multiple access (CDMA) systems is developed. On this basis with proper approximations there were at first time calculated and established for two alternative technologies the relevant relationships between the linear dynamic range, signal to noise ratio and the digital accuracy (the number of quantization levels in a binary representation) with the most important information parameters of the signal processors-the capacity and the bit-to-error rate.
{"title":"Comparative characteristics of SAW-based and digital correlation processors for mobile telecommunication system","authors":"V. Proklov, V. N. Kurski, Y. Sindler, S. P. Baronin, O. Byshevski-Konopko, V. I. Grigorievski, V. V. Shtykov","doi":"10.1109/ULTSYM.2000.922577","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.922577","url":null,"abstract":"The new method for comparison of the most significant properties of SAW based and digital correlation processors for applications in the code division multiple access (CDMA) systems is developed. On this basis with proper approximations there were at first time calculated and established for two alternative technologies the relevant relationships between the linear dynamic range, signal to noise ratio and the digital accuracy (the number of quantization levels in a binary representation) with the most important information parameters of the signal processors-the capacity and the bit-to-error rate.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126660584","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.921691
J. Allen, D. Druse, D. May, K. Ferrara
A variety of materials have been used in the construction of ultrasound contrast agent shells. These include protein, lipid, polymer and fluid. The shell material and thickness influence the magnitude and type of resonance response produced by the agent. Previously, we reported on a novel dipole response using modal scattering solutions for thick shell agents (>25 nm) whose shell material properties approximate albumin. These resonance responses are thought to in part originate from Lamb wave propagation within the shell. In this work, we extend our solutions to investigate the role of the interior gas on the dipole resonance responses. Novel oil-shelled agents do not support Lamb waves, but these shells undergo violent shape oscillations. As an initial step to understanding this phenomenon, we characterize their nonlinear, radial oscillations as a function of the shell thickness and viscosity. Finally, corresponding issues of contrast agent design and optimization are addressed.
{"title":"Surface wave phenomena on ultrasound contrast agents","authors":"J. Allen, D. Druse, D. May, K. Ferrara","doi":"10.1109/ULTSYM.2000.921691","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.921691","url":null,"abstract":"A variety of materials have been used in the construction of ultrasound contrast agent shells. These include protein, lipid, polymer and fluid. The shell material and thickness influence the magnitude and type of resonance response produced by the agent. Previously, we reported on a novel dipole response using modal scattering solutions for thick shell agents (>25 nm) whose shell material properties approximate albumin. These resonance responses are thought to in part originate from Lamb wave propagation within the shell. In this work, we extend our solutions to investigate the role of the interior gas on the dipole resonance responses. Novel oil-shelled agents do not support Lamb waves, but these shells undergo violent shape oscillations. As an initial step to understanding this phenomenon, we characterize their nonlinear, radial oscillations as a function of the shell thickness and viscosity. Finally, corresponding issues of contrast agent design and optimization are addressed.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"64 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116653599","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.922686
Y.T. Hu, J.S. Yang, Q. Jiang
Constitutive relations for nonlinear, isotropic, electroelastic solids quadratic in the finite strain tensor and the reference electric field are derived from the fully nonlinear theory of electroelasticity by tensor invariants, which can describe the behavior of electrostrictive materials. The equations are linearized for small, dynamic fields superposed on finite, static biasing fields. These linear equations are used to study plane waves propagating in an electroelastic body under various mechanical and/or electric biasing fields. It is shown that the speeds of the acoustic waves exhibit a strong dependence upon those material parameters in the nonlinear constitutive relations. Experimental determination of these material parameters using this dependence is discussed.
{"title":"Wave propagation in electrostrictive materials under biasing fields","authors":"Y.T. Hu, J.S. Yang, Q. Jiang","doi":"10.1109/ULTSYM.2000.922686","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.922686","url":null,"abstract":"Constitutive relations for nonlinear, isotropic, electroelastic solids quadratic in the finite strain tensor and the reference electric field are derived from the fully nonlinear theory of electroelasticity by tensor invariants, which can describe the behavior of electrostrictive materials. The equations are linearized for small, dynamic fields superposed on finite, static biasing fields. These linear equations are used to study plane waves propagating in an electroelastic body under various mechanical and/or electric biasing fields. It is shown that the speeds of the acoustic waves exhibit a strong dependence upon those material parameters in the nonlinear constitutive relations. Experimental determination of these material parameters using this dependence is discussed.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121714580","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.922626
H. Engan
The status of acousto-optic coupling in optical fibers as used for manipulation of the optical power is reviewed. Some resulting effects of this process are frequency shifting, filtering, switching and dynamic equalization. The paper will start with basic considerations on the propagation of various acoustic modes in cylindrical structures. This includes torsional, longitudinal as well as flexural modes. Also the propagation characteristics and other properties of optical modes in optical fibers are reviewed. Next the coupling between optical modes due to acoustic modes propagating along the same fiber is considered. Coupling equations and mode considerations are basic elements in this presentation. Special fiber properties related to the coupling will be considered. To achieve efficient coupling requires high acoustic intensities. For this purpose acoustic horns are widely used. Typically the acoustic energy is generated by a transducer at the thick end of the horn which is a multi-mode region while the other end being connected to the fiber is a single-mode region. General properties of such horns are analyzed and a few designs are discussed. Finally, several practical device and system applications will be reported.
{"title":"Acousto-optic coupling in optical fibers","authors":"H. Engan","doi":"10.1109/ULTSYM.2000.922626","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.922626","url":null,"abstract":"The status of acousto-optic coupling in optical fibers as used for manipulation of the optical power is reviewed. Some resulting effects of this process are frequency shifting, filtering, switching and dynamic equalization. The paper will start with basic considerations on the propagation of various acoustic modes in cylindrical structures. This includes torsional, longitudinal as well as flexural modes. Also the propagation characteristics and other properties of optical modes in optical fibers are reviewed. Next the coupling between optical modes due to acoustic modes propagating along the same fiber is considered. Coupling equations and mode considerations are basic elements in this presentation. Special fiber properties related to the coupling will be considered. To achieve efficient coupling requires high acoustic intensities. For this purpose acoustic horns are widely used. Typically the acoustic energy is generated by a transducer at the thick end of the horn which is a multi-mode region while the other end being connected to the fiber is a single-mode region. General properties of such horns are analyzed and a few designs are discussed. Finally, several practical device and system applications will be reported.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123864504","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.921644
R. Y. Chiao, L. Thomas
The frame rate in medical ultrasound imaging may be increased significantly by reducing the number of transmits per image frame. Cooley et al. (1994) and Lockwood et al. (1995) have described synthetic transmit aperture (STA) systems where each frame is imaged using data obtained from a small number of point sources fired in succession. These systems have potential for very high frame rates, but they also suffer from low SNR. In this paper we present a computationally efficient method to increase the SNR of STA systems by using spatio-temporal encoding which increases SNR by 101og(ML) dB, where M is the number of active phase centers or transmits and L is the temporal code length. By using an orthogonal Golay set for the spatio-temporal encoding, the received data can be sorted by each transmit phase center and pulse-compressed for subsequent synthetic aperture beamforming. Computer simulations are used to demonstrate the method.
通过减少每帧图像的传输次数，可以显著提高医学超声成像的帧速率。Cooley et al.(1994)和Lockwood et al.(1995)描述了合成透射孔径(STA)系统，其中每帧图像使用从少量连续发射的点源获得的数据进行成像。这些系统具有非常高的帧率的潜力，但它们也受到低信噪比的影响。本文提出了一种利用时空编码提高STA系统信噪比的计算效率高的方法，其中M为有源相位中心数或传输数，L为时间码长，使信噪比提高1010log (ML) dB。采用正交Golay集进行时空编码，将接收到的数据按每个发射相位中心进行排序，并进行脉冲压缩，用于后续的合成孔径波束形成。通过计算机仿真对该方法进行了验证。
{"title":"Synthetic transmit aperture imaging using orthogonal Golay coded excitation","authors":"R. Y. Chiao, L. Thomas","doi":"10.1109/ULTSYM.2000.921644","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.921644","url":null,"abstract":"The frame rate in medical ultrasound imaging may be increased significantly by reducing the number of transmits per image frame. Cooley et al. (1994) and Lockwood et al. (1995) have described synthetic transmit aperture (STA) systems where each frame is imaged using data obtained from a small number of point sources fired in succession. These systems have potential for very high frame rates, but they also suffer from low SNR. In this paper we present a computationally efficient method to increase the SNR of STA systems by using spatio-temporal encoding which increases SNR by 101og(ML) dB, where M is the number of active phase centers or transmits and L is the temporal code length. By using an orthogonal Golay set for the spatio-temporal encoding, the received data can be sorted by each transmit phase center and pulse-compressed for subsequent synthetic aperture beamforming. Computer simulations are used to demonstrate the method.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125152531","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 : 2000-10-22DOI: 10.1109/ULTSYM.2000.921491
T. Omori, T. Suzuki, Kunihiko Hashimoto, M. Yamaguchi
This paper describes a modified sol-gel method to prepare PZT discs of nearly 1 /spl mu/m thickness without repeating any spin-coating and prebaking processes. In the method, PZT precursor-gel discs having a small area are formed out of precursor-sol prior to sintering. This is carried out by pouring the precursor-sol into a ZnO mold. Ultrasonic transducers were fabricated using the PZT discs and their piezoelectricity in GHz ranges were discussed.
{"title":"Selective area preparation of PZT discs and their ultrasonic applications","authors":"T. Omori, T. Suzuki, Kunihiko Hashimoto, M. Yamaguchi","doi":"10.1109/ULTSYM.2000.921491","DOIUrl":"https://doi.org/10.1109/ULTSYM.2000.921491","url":null,"abstract":"This paper describes a modified sol-gel method to prepare PZT discs of nearly 1 /spl mu/m thickness without repeating any spin-coating and prebaking processes. In the method, PZT precursor-gel discs having a small area are formed out of precursor-sol prior to sintering. This is carried out by pouring the precursor-sol into a ZnO mold. Ultrasonic transducers were fabricated using the PZT discs and their piezoelectricity in GHz ranges were discussed.","PeriodicalId":350384,"journal":{"name":"2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125160223","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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