1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)最新文献_第7页

Proximity sensors utilizing an evanescent acoustic field formed by flexural plate waves 利用由弯曲板波形成的倏逝声场的接近传感器

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663066

S. Hongo, I. Naliamura, N. Hosokawa

引用次数: 2

Clinical assessment of the backscatter coefficient in osteoporosis 骨质疏松症后向散射系数的临床评价

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661772

P. Laugier, P. Giat, C. Chappard, C. Roux, G. Berger

{"title":"Clinical assessment of the backscatter coefficient in osteoporosis","authors":"P. Laugier, P. Giat, C. Chappard, C. Roux, G. Berger","doi":"10.1109/ULTSYM.1997.661772","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.661772","url":null,"abstract":"Current commercial ultrasound \"bone densitometers\" process only the through-transmitted signals while failing to extract additional information contained in the scattered signals. This work was conducted to investigate the clinical interest of a backscatter ultrasound technique for bone characterization in 24 healthy premenopausal (group N), 24 postmenopausal (group PM), and 13 osteoporotic patients with fractures (group O). Pulse-echo measurements of the backscatter power were performed at the calcaneus (heel bone) using an ultrasound bone imaging scanner. The pulse-echo waveforms backscattered by the internal trabecular micro-architecture were recorded to compute the integrated backscatter coefficient (BUB, dB) in the frequency range 200-600 kHz. BUB was compared to the slope of the frequency-dependent attenuation (BUA, dB/MHz) derived from signals transmitted through the bone and to bone mineral density. Measurements were averaged in an operator-independent automatic ROI. The short-term reproducibility was 1.4%, and 3.5% for BUA, and BUB respectively. Femoral bone mass density (BMD) was measured in all subjects and calcaneal BMD was measured in a subset of 30 patients. The correlation between ultrasound and calcaneal BMD was moderate for BUB (r=0.55, p<10/sup -3/) and strong for BUA (r=0.82, p<10/sup -4/). Significant differences were found in ultrasound parameters and BMD between fracture and non-fracture groups. There was a significant difference in BMD and ultrasound parameters between young normal controls and healthy post-menopausal women. In summary, reflection ultrasound appears to be promising in osteoporosis and larger studies are clearly warranted.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"33 1","pages":"1101-1104 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75096096","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}

引用次数: 35

Single element and linear array PZT ultrasound biomicroscopy transducers 单元件和线性阵列PZT超声生物显微镜换能器

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663340

M. Lukacs, M. Sayer, S. Foster

引用次数: 14

Application of a Sagnac interferometer for the characterization of scattered ultrasonic fields Sagnac干涉仪在散射超声场表征中的应用

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663095

P. Fomitchov, A. Kromine, S. Krishnaswamy, J. Achenbach

引用次数: 1

Influence of metallization on temperature stability of SAW devices 金属化对SAW器件温度稳定性的影响

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663014

E. Henry, S. Ballandras, E. Bigler, G. Marianneau, G. Martin, S. Camou

{"title":"Influence of metallization on temperature stability of SAW devices","authors":"E. Henry, S. Ballandras, E. Bigler, G. Marianneau, G. Martin, S. Camou","doi":"10.1109/ULTSYM.1997.663014","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.663014","url":null,"abstract":"Most Surface Acoustic Wave (SAW) devices exhibit a very small sensitivity to thermal effects. However, even on instrinsically compensated crystal cuts, the deposition of metal strips at the surface (transducers or reflectors) induces important changes in the thermoelastic properties of the device. A theoretical approach based on the Sinha-Tiersten perturbation method is proposed to model the influence of metallization on SAW properties on (ST,X) quartz, namely the temperature stability of the phase velocity of Rayleigh waves. Since this perturbation method only gives access to the first order Temperature Coefficient of Frequency (TCF), it is combined with a conventional calculation of the second order TCF to predict the evolution of the turnover temperature. The proposed calculation also requires temperature derivatives of the elastic constants of the metal which can be calculated for different materials. More classical approaches are also considered based on the calculation of surface permittivity using thermally varied elastic constants. Finally, theoretical results are compared to experimental data measured on SAW devices on (ST,X) quartz using Aluminium, Gold or Chromium gratings.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"286 1","pages":"221-225 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77149309","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}

引用次数: 4

Acoustic and electromechanical behavior of 1-3 piezocomposites for ultrasonic transducer applications 用于超声波换能器的1-3压电复合材料的声学和机电性能

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663083

Q.M. Zhang, X. Geng

引用次数: 1

Effects of abdominal wall morphology on ultrasonic pulse distortion 腹壁形态对超声脉冲畸变的影响

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661859

L. M. Hinkelman, T. Mast, M. J. Orr, R. Waag

{"title":"Effects of abdominal wall morphology on ultrasonic pulse distortion","authors":"L. M. Hinkelman, T. Mast, M. J. Orr, R. Waag","doi":"10.1109/ULTSYM.1997.661859","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.661859","url":null,"abstract":"Wavefront propagation through the abdominal wall was investigated by measurements employing full-thickness specimens and their individual fat and muscle layers. These measurements confirm that both fat and muscle produce significant wavefront distortion and focus degradation. However, the spatial characteristics of the distortion produced by fat and muscle differ, and the total distortion produced by the abdominal wall is not the arithmetic sum of that produced by the individual layers. The interface between the muscle and subcutaneous fat layers, which consists of a thin layer of connective tissue, was found to be smooth or slightly curved. Distortion produced by different tissues was further characterized by simulations using a finite-difference time-domain implementation of the linearized wave propagation equations for a lossless inhomogeneous fluid. Scanned images of six human abdominal wall cross sections provided the data for the propagation media in the simulation. The images were mapped into regions of fat, muscle, and connective tissue, each of which was assigned a uniform sound speed and density obtained from literature values. The computed wavefronts contained arrival time, energy level, and wave shape distortion similar to that in measurements. Visualization of wave propagation within the tissue cross sections suggests that most arrival time distortion is produced by acoustic path length differences while amplitude and waveform variations are the result of scattering from inhomogeneities. Many arrival time fluctuation and energy level fluctuation features could be traced to specific anatomical structures. These results indicate that wavefront distortion, apart from bulk attenuation effects, is primarily caused by tissue structures and inhomogeneities rather than refraction at layer interfaces.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"113 1","pages":"1493-1496 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79864138","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}

引用次数: 28

Multi-parametric imaging of atherosclerotic plaque by 50 MHz ultrasound and 3 Tesla magnetic resonance 动脉粥样硬化斑块的50 MHz超声和3特斯拉磁共振多参数成像

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.661765

S. Bridal, J. Toussaint, J. Raynaud, P. Fornés, A. Leroy-Willig, G. Berger

引用次数: 2

Modified Green's function approach to analysis of long SAW transducers 改进的格林函数法分析长SAW换能器

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.662992

S. Balashov, C. M. Cabreira, C. Finardi

{"title":"Modified Green's function approach to analysis of long SAW transducers","authors":"S. Balashov, C. M. Cabreira, C. Finardi","doi":"10.1109/ULTSYM.1997.662992","DOIUrl":"https://doi.org/10.1109/ULTSYM.1997.662992","url":null,"abstract":"Low loss filters based on Single Phase Unidirectional Transducers (SPUDT) could be characterized as a separate class of Surface Acoustic Wave (SAW) filters because they overcome the main SAW filters limitation-6 dB bidirectional insertion loss. For the substrate with the high value of electroacoustic coupling coefficient k/sup 2/ the main effect used to obtain unidirectionality is electrical regeneration which could be treated directly by the Green's Function Model (GFM). The GFM being applicable to an interdigital transducer (IDT) with arbitrary topology is difficult to be applied to the IDT with large number of periods because computation time increases in power law with growth of the IDT length reaching very quickly unacceptable values. In this paper we present the method for calculation of arbitrary SAW filter parameters based on the GFM. Symmetry consideration being used for presentation of the central region of the long IDT, computation time decreases dramatically. At the same time edge effects of the IDT are correctly taken into account. The method developed works both for high and low k/sup 2/ value substrates. Results of calculation of SPUDT characteristics with the help of method proposed are presented.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":"201 1","pages":"123-126 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80144256","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}

引用次数: 1

Automatic design procedure using circuit composition technique for SAW devices 使用电路组成技术的SAW器件自动设计程序

1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118) Pub Date : 1997-10-05 DOI: 10.1109/ULTSYM.1997.663002

T. Shiba, Y. Fujita, N. Kamogawa, N. Hosaka, S. Ogawa, K. Oda, M. Hikita

引用次数: 4