Pub Date : 1999-10-17DOI: 10.1109/ULTSYM.1999.849323
A. Bouakaz, K. Shung
Recent studies have shown that ultrasound contrast agent may be used to deliver drugs. These drugs are directly released to the target tissue when the microspheres are exposed to high amplitude acoustic waves. The goal of this study was to investigate the destruction of microspheres by ultrasound waves to better understand the rates of transport and release that could provide the optimal spatial and temporal pattern for a drug delivery system. Experimental investigations have demonstrated that depending on the transmitted frequency, certain microsphere sizes within the same distribution are easier to rupture than others, and therefore can be selectively destroyed. These results were confirmed by measurements performed on filtered distributions. The study illustrates the potentials of ultrasound contrast agent for pharmacological applications. Different therapeutic compounds can be loaded within microspheres of different sizes and the release can be selectively activated from different regions in the size distribution.
{"title":"Selective destruction of contrast agent microspheres [drug delivery application]","authors":"A. Bouakaz, K. Shung","doi":"10.1109/ULTSYM.1999.849323","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849323","url":null,"abstract":"Recent studies have shown that ultrasound contrast agent may be used to deliver drugs. These drugs are directly released to the target tissue when the microspheres are exposed to high amplitude acoustic waves. The goal of this study was to investigate the destruction of microspheres by ultrasound waves to better understand the rates of transport and release that could provide the optimal spatial and temporal pattern for a drug delivery system. Experimental investigations have demonstrated that depending on the transmitted frequency, certain microsphere sizes within the same distribution are easier to rupture than others, and therefore can be selectively destroyed. These results were confirmed by measurements performed on filtered distributions. The study illustrates the potentials of ultrasound contrast agent for pharmacological applications. Different therapeutic compounds can be loaded within microspheres of different sizes and the release can be selectively activated from different regions in the size distribution.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"12 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":"124978363","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.1999.849177
S. Hansen, B. Mossawir, A. Sanli Ergun, F. Levent Degertekin, B. Khuri-Yakub
Nondestructive evaluation techniques which use conventional piezoelectric transducers typically require liquid coupling fluids to improve the impedance mismatch between piezoelectric materials and air. Air-coupled ultrasonic systems can eliminate this requirement if the dynamic range of the system is large enough such that the losses at the air-solid interfaces are tolerable. Capacitive micromachined ultrasonic transducers (cMUTs) have been shown to have more than 100 dB dynamic range when used in bistatic transmission mode. This dynamic range, along with the ability to transmit ultrasound efficiently into air, makes cMUTs ideally suited for air-coupled nondestructive evaluation applications. These transducers can be used either in through transmission experiments at normal incidence to the sample or to excite and detect guided waves in aluminum and composite plates. In this paper, we present results of a pitch-catch transmission system using cMUTs that achieves a dynamic range in excess of 100 dB. The pair of transducers is modeled with an equivalent electrical circuit which predicts the transmission system's insertion loss and dynamic range. We also demonstrate the feasibility of Lamb wave defect detection for one-sided nondestructive evaluation applications. A pair of cMUTs excites and detects the so mode in a 1.2 mm-thick aluminum plate with a received signal-to-noise ratio of 28 dB without signal averaging.
{"title":"Air-coupled nondestructive evaluation using micromachined ultrasonic transducers","authors":"S. Hansen, B. Mossawir, A. Sanli Ergun, F. Levent Degertekin, B. Khuri-Yakub","doi":"10.1109/ULTSYM.1999.849177","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849177","url":null,"abstract":"Nondestructive evaluation techniques which use conventional piezoelectric transducers typically require liquid coupling fluids to improve the impedance mismatch between piezoelectric materials and air. Air-coupled ultrasonic systems can eliminate this requirement if the dynamic range of the system is large enough such that the losses at the air-solid interfaces are tolerable. Capacitive micromachined ultrasonic transducers (cMUTs) have been shown to have more than 100 dB dynamic range when used in bistatic transmission mode. This dynamic range, along with the ability to transmit ultrasound efficiently into air, makes cMUTs ideally suited for air-coupled nondestructive evaluation applications. These transducers can be used either in through transmission experiments at normal incidence to the sample or to excite and detect guided waves in aluminum and composite plates. In this paper, we present results of a pitch-catch transmission system using cMUTs that achieves a dynamic range in excess of 100 dB. The pair of transducers is modeled with an equivalent electrical circuit which predicts the transmission system's insertion loss and dynamic range. We also demonstrate the feasibility of Lamb wave defect detection for one-sided nondestructive evaluation applications. A pair of cMUTs excites and detects the so mode in a 1.2 mm-thick aluminum plate with a received signal-to-noise ratio of 28 dB without signal averaging.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"2 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":"128824457","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.1999.849152
N. Lamberti, A. Iula, R. Carotenuto, P. Di Rosa, M. Pappalardo
The most important property of a piezoelectric material for practical applications is its ability to convert electrical energy into mechanical energy and vice versa. As it is well known, the electromechanical coupling factor /spl kappa/ fully characterize this energy conversion. In a previous work we demonstrated that, like in static conditions, it is possible to define the /spl kappa/ factor also in dynamic situations as a ratio of energies. We also showed that the value of the /spl kappa/ factor computed in this way (/spl kappa//sub /spl omega//) coincides with the one obtained by using the empirical relation of the effective coupling factor /spl kappa//sub eff/. In this work we show that the proposed definition of the /spl kappa/ factor as ratio of energies can be extended to lossy elements, but, in this case, the k/sub eff/ does not give accurate estimation of the coupling factor. For composite Langevin-type structures, both /spl kappa/, and /spl kappa//sub eff/-fails.
{"title":"The evaluation of the /spl kappa/ factor for lossy and composite (Langevin-type) piezoelectric elements","authors":"N. Lamberti, A. Iula, R. Carotenuto, P. Di Rosa, M. Pappalardo","doi":"10.1109/ULTSYM.1999.849152","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849152","url":null,"abstract":"The most important property of a piezoelectric material for practical applications is its ability to convert electrical energy into mechanical energy and vice versa. As it is well known, the electromechanical coupling factor /spl kappa/ fully characterize this energy conversion. In a previous work we demonstrated that, like in static conditions, it is possible to define the /spl kappa/ factor also in dynamic situations as a ratio of energies. We also showed that the value of the /spl kappa/ factor computed in this way (/spl kappa//sub /spl omega//) coincides with the one obtained by using the empirical relation of the effective coupling factor /spl kappa//sub eff/. In this work we show that the proposed definition of the /spl kappa/ factor as ratio of energies can be extended to lossy elements, but, in this case, the k/sub eff/ does not give accurate estimation of the coupling factor. For composite Langevin-type structures, both /spl kappa/, and /spl kappa//sub eff/-fails.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"19 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":"126966243","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.1999.849155
R. Tasker, M. Lukacs, M. Sayer, S. Sherrit
Techniques to determine the dielectric, mechanical and piezoelectric losses for radial poled spherical, hemispherical, and thickness poled ring resonators were presented. The impedance equations of these resonators were derived from the theory of thin shells as discussed by Berlincourt, Curran and Jaffe. These have been generalized to include loss by making the material constants complex. Equations relating the complex frequency constants and complex material constants were also presented. The effect of measurement noise on results was examined by adding white noise on generated spectra. Analyzed material constants were found to be within 1 percent of the material constants used to generate the spectra. Applying a nonlinear regression technique was found to further reduce error in the determined constants. The radial poled cylinder was also discussed and methods to determine the complex material constants of this resonator were presented. The use of complex material constants with samples of these geometries was further demonstrated in the analysis of several ceramic PZT resonators.
{"title":"Techniques to determine the complex material constants of spherical and cylindrical ring resonators","authors":"R. Tasker, M. Lukacs, M. Sayer, S. Sherrit","doi":"10.1109/ULTSYM.1999.849155","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849155","url":null,"abstract":"Techniques to determine the dielectric, mechanical and piezoelectric losses for radial poled spherical, hemispherical, and thickness poled ring resonators were presented. The impedance equations of these resonators were derived from the theory of thin shells as discussed by Berlincourt, Curran and Jaffe. These have been generalized to include loss by making the material constants complex. Equations relating the complex frequency constants and complex material constants were also presented. The effect of measurement noise on results was examined by adding white noise on generated spectra. Analyzed material constants were found to be within 1 percent of the material constants used to generate the spectra. Applying a nonlinear regression technique was found to further reduce error in the determined constants. The radial poled cylinder was also discussed and methods to determine the complex material constants of this resonator were presented. The use of complex material constants with samples of these geometries was further demonstrated in the analysis of several ceramic PZT resonators.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"50 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120987730","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.1999.849498
K. Sakai, O. Kanda, K. Yamamoto, K. Takagi
The acoustic diffusion wave in a turbid medium including randomly dispersed wave scatterers was observed. Ultrasonic wave at 15 MHz was modulated in amplitude and emitted into water suspension of polystyrene beads with 0.2 mm in diameter. Ray trace of the wave takes a random walk in the multiple scattering, and the acoustic energy flows in a diffusional manner. The spatial distribution of the oscillating acoustic energy was observed with an optical probe based on the Raman-Nath diffraction. The wavenumber and the spatial damping of the diffusion waves were determined at the modulation frequency of 4-20 kHz range. The results were well described by a modified diffusion theory including the effect of ultrasonic absorption. The diffusion constant and the lifetime of the acoustic energy were determined, which led to the transport mean free path and the ultrasonic absorption. The experiment was made at different volume fractions of the suspension, and l* and the lifetime were found to decrease with the number density of the scatterer.
{"title":"Acoustic diffusion wave in turbid media","authors":"K. Sakai, O. Kanda, K. Yamamoto, K. Takagi","doi":"10.1109/ULTSYM.1999.849498","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849498","url":null,"abstract":"The acoustic diffusion wave in a turbid medium including randomly dispersed wave scatterers was observed. Ultrasonic wave at 15 MHz was modulated in amplitude and emitted into water suspension of polystyrene beads with 0.2 mm in diameter. Ray trace of the wave takes a random walk in the multiple scattering, and the acoustic energy flows in a diffusional manner. The spatial distribution of the oscillating acoustic energy was observed with an optical probe based on the Raman-Nath diffraction. The wavenumber and the spatial damping of the diffusion waves were determined at the modulation frequency of 4-20 kHz range. The results were well described by a modified diffusion theory including the effect of ultrasonic absorption. The diffusion constant and the lifetime of the acoustic energy were determined, which led to the transport mean free path and the ultrasonic absorption. The experiment was made at different volume fractions of the suspension, and l* and the lifetime were found to decrease with the number density of the scatterer.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"34 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":"121212328","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.1999.849286
G. Wojcik, T. Szabo, J. Mould, L. Carcione, F. Clougherty
Nonlinear propagation is recognized as an important aspect of ultrasonic medical imaging. In particular, rigorous estimates of tissue bioeffects must include it. Regulatory standards rely on measurements in water to estimate effects in lossy tissue, but nonlinearity confuses the relationship. To help clarify the connection the authors complement laboratory hydrophone data with computer simulations of acoustic pulses in water and a tofu tissue mimic. A 2.25 MHz focused disk transducer is used instead of a rectangular medical array to facilitate modeling with a 2D pseudospectral solver that includes causal attenuation, inhomogeneity, multiple reflections, nonlinearity, and shock smoothing. Pressure scans near the transducer characterize the source and drive the wave solver. Measured and calculated nonlinear acoustic fields are compared over a 6 cm range in water and behind tofu cylinders. In the absence of high drive data the authors rely on nonlinear simulations to contrast water and tofu results, in anticipation of derating studies.
{"title":"Nonlinear pulse calculations and data in water and a tissue mimic","authors":"G. Wojcik, T. Szabo, J. Mould, L. Carcione, F. Clougherty","doi":"10.1109/ULTSYM.1999.849286","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849286","url":null,"abstract":"Nonlinear propagation is recognized as an important aspect of ultrasonic medical imaging. In particular, rigorous estimates of tissue bioeffects must include it. Regulatory standards rely on measurements in water to estimate effects in lossy tissue, but nonlinearity confuses the relationship. To help clarify the connection the authors complement laboratory hydrophone data with computer simulations of acoustic pulses in water and a tofu tissue mimic. A 2.25 MHz focused disk transducer is used instead of a rectangular medical array to facilitate modeling with a 2D pseudospectral solver that includes causal attenuation, inhomogeneity, multiple reflections, nonlinearity, and shock smoothing. Pressure scans near the transducer characterize the source and drive the wave solver. Measured and calculated nonlinear acoustic fields are compared over a 6 cm range in water and behind tofu cylinders. In the absence of high drive data the authors rely on nonlinear simulations to contrast water and tofu results, in anticipation of derating studies.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"16 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":"127209764","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.1999.849442
J. Kondoh, Toshihisa Yamazaki, Y. Matsui, S. Shiokawa
The surface acoustic wave (SAW) on 36YX LiTaO3, the shear-horizontal mode (SH-SAW), can detect liquid properties. This paper describes the new method to identify and estimate components and concentration of ions in aqueous solutions by using a liquid-flow sensing system with the SH-SAW sensor without any selective organic films. The principle of the identification is based on the difference in transient responses. The proposed method includes a new technique for constituting the database of mixing ion solution from that of the single ion solutions.
{"title":"Identification of ion species in electrolytic solutions using surface acoustic wave liquid flow sensing system based on new pattern recognition method","authors":"J. Kondoh, Toshihisa Yamazaki, Y. Matsui, S. Shiokawa","doi":"10.1109/ULTSYM.1999.849442","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849442","url":null,"abstract":"The surface acoustic wave (SAW) on 36YX LiTaO3, the shear-horizontal mode (SH-SAW), can detect liquid properties. This paper describes the new method to identify and estimate components and concentration of ions in aqueous solutions by using a liquid-flow sensing system with the SH-SAW sensor without any selective organic films. The principle of the identification is based on the difference in transient responses. The proposed method includes a new technique for constituting the database of mixing ion solution from that of the single ion solutions.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"17 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":"125660761","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.1999.849186
E. Ledet, C. Zanelli
Effective aperture is a commonly used measure of the amount of acoustic or electrical crosstalk between elements in ultrasonic arrays. It is also important to assess element-to-element uniformity and quality of the separation between the elements. This parameter is obtained from the beam profile obtained by pulsing each individual element with a known excitation function. The traditional method, using hydrophones, presents many challenges that are overcome by the proposed method. Using a quantitative schlieren system, we imaged the acoustic burst from an array element. Automated processing allows determination of the average intensity over the burst at all angles (angular beam profile) and its width is used to determine the effective aperture for that element. Examples are presented for floating and purposefully coupled neighboring elements, and the results are in good agreement with those obtained with a hydrophone. The algorithm used for image analysis is also described.
{"title":"A novel, rapid method to measure the effective aperture of array elements","authors":"E. Ledet, C. Zanelli","doi":"10.1109/ULTSYM.1999.849186","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849186","url":null,"abstract":"Effective aperture is a commonly used measure of the amount of acoustic or electrical crosstalk between elements in ultrasonic arrays. It is also important to assess element-to-element uniformity and quality of the separation between the elements. This parameter is obtained from the beam profile obtained by pulsing each individual element with a known excitation function. The traditional method, using hydrophones, presents many challenges that are overcome by the proposed method. Using a quantitative schlieren system, we imaged the acoustic burst from an array element. Automated processing allows determination of the average intensity over the burst at all angles (angular beam profile) and its width is used to determine the effective aperture for that element. Examples are presented for floating and purposefully coupled neighboring elements, and the results are in good agreement with those obtained with a hydrophone. The algorithm used for image analysis is also described.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"16 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":"124071305","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.1999.849184
E. Kuhnicke
Because the refracted sound field of a finite beam extremely depends on the size and on the frequency of the generating element, Snell's law is not applicable to calculate the refraction angle of a finite beam. Approaches using plane reflection and transmission coefficient in connection with a discretization of the source into elementary point sources are more exact. This paper demonstrates that the application of plane reflection and transmission coefficients requires a point to point distance smaller than a half wavelength, in order to obtain an accurate sound field of the refracted beam.
{"title":"The limitations of Snell's law in the design of ultrasound transducers","authors":"E. Kuhnicke","doi":"10.1109/ULTSYM.1999.849184","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849184","url":null,"abstract":"Because the refracted sound field of a finite beam extremely depends on the size and on the frequency of the generating element, Snell's law is not applicable to calculate the refraction angle of a finite beam. Approaches using plane reflection and transmission coefficient in connection with a discretization of the source into elementary point sources are more exact. This paper demonstrates that the application of plane reflection and transmission coefficients requires a point to point distance smaller than a half wavelength, in order to obtain an accurate sound field of the refracted beam.","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":"126116695","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.1999.849247
E. Camus, M. Talmant, G. Berger, P. Laugier
Ultrasonic wave propagation in human cortical bone has been investigated in vitro using an axial transmission technique. Two quasi-point source elements, one transmitter and one receiver, were used to generate a wide ultrasonic beam including the longitudinal critical angle and to receive the signals radiated from the sample surface. Validation of the measuring technique was performed on test materials, followed by experiments on human cortical bones. Velocity measurements of the first arriving signal based on time-of-flight determinations were in agreement with reported values of longitudinal velocities for both test materials and bone specimens, and so did the experimental arrival times of the first arriving signal and ray arrival times of the lateral wave. The velocity in cortical bone ranged from 3600 to 4050 m.s/sup -1/. Our results strongly suggest that the first arriving signal corresponds to the lateral wave predicted by theory.
{"title":"In vitro measurements of the lateral wave in human cortical bone","authors":"E. Camus, M. Talmant, G. Berger, P. Laugier","doi":"10.1109/ULTSYM.1999.849247","DOIUrl":"https://doi.org/10.1109/ULTSYM.1999.849247","url":null,"abstract":"Ultrasonic wave propagation in human cortical bone has been investigated in vitro using an axial transmission technique. Two quasi-point source elements, one transmitter and one receiver, were used to generate a wide ultrasonic beam including the longitudinal critical angle and to receive the signals radiated from the sample surface. Validation of the measuring technique was performed on test materials, followed by experiments on human cortical bones. Velocity measurements of the first arriving signal based on time-of-flight determinations were in agreement with reported values of longitudinal velocities for both test materials and bone specimens, and so did the experimental arrival times of the first arriving signal and ray arrival times of the lateral wave. The velocity in cortical bone ranged from 3600 to 4050 m.s/sup -1/. Our results strongly suggest that the first arriving signal corresponds to the lateral wave predicted by theory.","PeriodicalId":339424,"journal":{"name":"1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027)","volume":"30 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":"127770974","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：