Pub Date : 1995-11-07DOI: 10.1109/ULTSYM.1995.495816
Jian-yu Lu
Limited diffraction beams have a large depth of field. They could have applications in medical imaging, tissue characterization, Doppler velocity estimation, nondestructive evaluation (NDE) of materials, as well as other physics related areas such as electromagnetics and optics. In this paper, a method is developed that uses limited diffraction beams discovered previously, such as, Bessel beams and X waves, as basis functions to construct new limited diffraction beams that may have practical usefulness. The method is implemented with linear matrix operations. Results show that the method is powerful and can obtain limited diffraction beams that are not intuitive to get directly from solving the wave equation.
{"title":"Construction of limited diffraction beams with Bessel bases","authors":"Jian-yu Lu","doi":"10.1109/ULTSYM.1995.495816","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495816","url":null,"abstract":"Limited diffraction beams have a large depth of field. They could have applications in medical imaging, tissue characterization, Doppler velocity estimation, nondestructive evaluation (NDE) of materials, as well as other physics related areas such as electromagnetics and optics. In this paper, a method is developed that uses limited diffraction beams discovered previously, such as, Bessel beams and X waves, as basis functions to construct new limited diffraction beams that may have practical usefulness. The method is implemented with linear matrix operations. Results show that the method is powerful and can obtain limited diffraction beams that are not intuitive to get directly from solving the wave equation.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127967828","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495691
H. Dabirikhah, C. Turner
Radiation of acoustic waves into fluids from plate modes propagating in thin membranes has been shown to provide an efficient mechanism for air-coupled transducers. The real and imaginary parts of the propagation vector have been calculated with high accuracy for membranes of different materials radiating into air, as a function of frequency and membrane thickness. We have shown that mode coupling between the zeroth antisymmetrical plate mode (A/sub 0/) and the interface Scholte mode occurs over a range of fluid density and this coupling is the basis of anomalous behaviour of wave propagation in immersed membranes. Calculations of the acoustic power flow in the membrane and the fluid explain why the damping of the A/sub 0/ mode reaches a maximum value in the region where mode coupling occurs.
{"title":"Coupled mode behaviour in radiating membranes immersed in fluids","authors":"H. Dabirikhah, C. Turner","doi":"10.1109/ULTSYM.1995.495691","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495691","url":null,"abstract":"Radiation of acoustic waves into fluids from plate modes propagating in thin membranes has been shown to provide an efficient mechanism for air-coupled transducers. The real and imaginary parts of the propagation vector have been calculated with high accuracy for membranes of different materials radiating into air, as a function of frequency and membrane thickness. We have shown that mode coupling between the zeroth antisymmetrical plate mode (A/sub 0/) and the interface Scholte mode occurs over a range of fluid density and this coupling is the basis of anomalous behaviour of wave propagation in immersed membranes. Calculations of the acoustic power flow in the membrane and the fluid explain why the damping of the A/sub 0/ mode reaches a maximum value in the region where mode coupling occurs.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128461286","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495562
R. Weigel, C. Knorr, K. Wagner, L. Reindl, F. Seifert
We report on the design and performance of two SAM MSK Tapped Delay Lines (TDLs) using PN code sequences of length 128 chips, As a substrate, LiTaO/sub 3/ has been used due to the system requirements of a given CDMA/TDMA system. Center frequency, bandwidth of the major lobe, and integration time were 266.66 MHz, 65.7 MHz, and 3 /spl mu/s, respectively. TDL 1 employed two non-weighted transducers, whereas TDL 2 incorporated one cosine-apodized transducer. Split-fingers with a metalization height of 150 nm (aluminum) were used. The experimental data of both design approaches were very similar with an unmatched insertion loss of 37 dB which is improved by more than 18 dB by proper matching. Amplitude ripple was less than 1 and 2 db, respectively, and the close-in selectivity was 23 dB.
{"title":"MSK SAW tapped delay lines on LiTaO/sub 3/ with moderate processing gain for CDMA indoor and mobile radio applications","authors":"R. Weigel, C. Knorr, K. Wagner, L. Reindl, F. Seifert","doi":"10.1109/ULTSYM.1995.495562","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495562","url":null,"abstract":"We report on the design and performance of two SAM MSK Tapped Delay Lines (TDLs) using PN code sequences of length 128 chips, As a substrate, LiTaO/sub 3/ has been used due to the system requirements of a given CDMA/TDMA system. Center frequency, bandwidth of the major lobe, and integration time were 266.66 MHz, 65.7 MHz, and 3 /spl mu/s, respectively. TDL 1 employed two non-weighted transducers, whereas TDL 2 incorporated one cosine-apodized transducer. Split-fingers with a metalization height of 150 nm (aluminum) were used. The experimental data of both design approaches were very similar with an unmatched insertion loss of 37 dB which is improved by more than 18 dB by proper matching. Amplitude ripple was less than 1 and 2 db, respectively, and the close-in selectivity was 23 dB.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128714607","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495814
M. Krueger, H. Ermert, M. Li, H. Kaarmann
The design of ultrasonic B-mode imaging systems with linear arrays requires the optimization of numerous parameters. A hybrid simulation method using finite element analysis data, a Huygens-integral modified in order to consider inhomogeneities, and the first order Born approximation has been developed to optimize beam forming operating modes. B-mode images and spatially compounded images are calculated for a 3.5 MHz phased array. The influence of layered media on the extension of the point spread function can be corrected using backpropagation. Irregularly aberrating media influence the point spread function and the image quality significantly. Parameters for beam forming in B-mode imaging and spatial compounding are selected taking these inhomogeneities into account.
{"title":"Simulation of B-mode imaging and spatial compounding in inhomogeneous media","authors":"M. Krueger, H. Ermert, M. Li, H. Kaarmann","doi":"10.1109/ULTSYM.1995.495814","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495814","url":null,"abstract":"The design of ultrasonic B-mode imaging systems with linear arrays requires the optimization of numerous parameters. A hybrid simulation method using finite element analysis data, a Huygens-integral modified in order to consider inhomogeneities, and the first order Born approximation has been developed to optimize beam forming operating modes. B-mode images and spatially compounded images are calculated for a 3.5 MHz phased array. The influence of layered media on the extension of the point spread function can be corrected using backpropagation. Irregularly aberrating media influence the point spread function and the image quality significantly. Parameters for beam forming in B-mode imaging and spatial compounding are selected taking these inhomogeneities into account.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130840286","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495538
R. Dill, J. Machui, G. Muller
We have developed an improved SAW filter for IF-filtering in DECT systems. The filter is a two track reflector filter using EWC-SPUDTs as in- and output-IDTs and reflectors in the center of each track The propagation path of the SAW is folded in order to make better use of the total chip length. A similar configuration with identical reflectors in the tracks is known in literature, however, we used different reflectors in the tracks and this way we could improve the filter performance and especially the stop band attenuation considerably. The SPUDTs are withdrawal weighted, for the reflector design we used an electrode width weighting technique. The filter fits into a very small QCC10 package (9.1/spl times/7.1/spl times/1.8 mm/sup 3/) and has high performance so that it can be used in a DECT base-station, too. The substrate is LiTaO/sub 3/, X112.2Y, the center frequency is 110.59 MHz, the minimum IL is 8 dB typically, the 3-dB-bandwidth is 1.1 MHz and the stopband attenuation is better than 40 dB.
{"title":"A novel SAW filter for IF-filtering in DECT systems","authors":"R. Dill, J. Machui, G. Muller","doi":"10.1109/ULTSYM.1995.495538","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495538","url":null,"abstract":"We have developed an improved SAW filter for IF-filtering in DECT systems. The filter is a two track reflector filter using EWC-SPUDTs as in- and output-IDTs and reflectors in the center of each track The propagation path of the SAW is folded in order to make better use of the total chip length. A similar configuration with identical reflectors in the tracks is known in literature, however, we used different reflectors in the tracks and this way we could improve the filter performance and especially the stop band attenuation considerably. The SPUDTs are withdrawal weighted, for the reflector design we used an electrode width weighting technique. The filter fits into a very small QCC10 package (9.1/spl times/7.1/spl times/1.8 mm/sup 3/) and has high performance so that it can be used in a DECT base-station, too. The substrate is LiTaO/sub 3/, X112.2Y, the center frequency is 110.59 MHz, the minimum IL is 8 dB typically, the 3-dB-bandwidth is 1.1 MHz and the stopband attenuation is better than 40 dB.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130323372","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495621
M. von Schickfus, H. Becker, C. Rupp, S. Hunklinger
In this paper we present a new technique for chemical sensing with surface acoustic waves. This technique makes use of the fact that the acoustic impedance of a SAW changes when a sensor film on the device absorbs the analyte. If the sensor film is structured as a reflecting array, the amplitude of the reflected wave varies with the mechanical or electrical properties of the film. The advantage is, that the amplitude is much less sensitive to temperature fluctuations of the device. High stability and sensitivity of the sensor can therefore be reached. We have built a NO/sub 2/ sensor based on this principle using copper-phthalocyanine as sensitive film. Similar properties are obtained if a multistrip coupler is used instead of a reflector array.
{"title":"SAW gas sensing using reflectors and multistrip couplers","authors":"M. von Schickfus, H. Becker, C. Rupp, S. Hunklinger","doi":"10.1109/ULTSYM.1995.495621","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495621","url":null,"abstract":"In this paper we present a new technique for chemical sensing with surface acoustic waves. This technique makes use of the fact that the acoustic impedance of a SAW changes when a sensor film on the device absorbs the analyte. If the sensor film is structured as a reflecting array, the amplitude of the reflected wave varies with the mechanical or electrical properties of the film. The advantage is, that the amplitude is much less sensitive to temperature fluctuations of the device. High stability and sensitivity of the sensor can therefore be reached. We have built a NO/sub 2/ sensor based on this principle using copper-phthalocyanine as sensitive film. Similar properties are obtained if a multistrip coupler is used instead of a reflector array.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129724458","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495689
Y. Mao, Y. Shui, W. Jiang, J. Yin
Two identical interdigital transducers, deposited on both sides of the 127.86/spl deg/ Y-X LiNbO/sub 3/ plate symmetrically, were used to generate Lamb waves. For the case of electrically symmetrical connection of transducers, the S/sub 0/ mode was generated four or five times more strongly than that for the same transducer on one side, while the A/sub 0/ mode was reduced by about 10 dB. For antisymmetrical electric connection, the A/sub 0/ mode is strong and the S/sub 0/ mode is suppressed. Experiments on nonpiezoelectric medium glass with 121/spl deg/ Y-X LiNbO/sub 3/ on both sides showed a similar result. A delay line composed of such a structure has an insertion loss of only 3 dB.
{"title":"Switchable single mode Lamb wave transduction by means of both side excitation","authors":"Y. Mao, Y. Shui, W. Jiang, J. Yin","doi":"10.1109/ULTSYM.1995.495689","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495689","url":null,"abstract":"Two identical interdigital transducers, deposited on both sides of the 127.86/spl deg/ Y-X LiNbO/sub 3/ plate symmetrically, were used to generate Lamb waves. For the case of electrically symmetrical connection of transducers, the S/sub 0/ mode was generated four or five times more strongly than that for the same transducer on one side, while the A/sub 0/ mode was reduced by about 10 dB. For antisymmetrical electric connection, the A/sub 0/ mode is strong and the S/sub 0/ mode is suppressed. Experiments on nonpiezoelectric medium glass with 121/spl deg/ Y-X LiNbO/sub 3/ on both sides showed a similar result. A delay line composed of such a structure has an insertion loss of only 3 dB.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129313578","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495730
Ping Wu, R. Kazys, T. Stepinski
This paper aims at calculating transient fields radiated by linear arrays into immersed solids by using the angular spectrum approach (ASA), which is implemented based upon the temporal and the 2-D spatial discrete Fourier transform (DFT). The sinc-Fourier transform algorithm is extensively employed and allows arbitrary spatial sampling frequency to be used for sampling source plane without restriction of integer number of sampling intervals representing the elements and the gaps between the adjacent elements in various arrays. Calculation of transient fields in immersed solids from the array is presented in some detail. The wave mode conversion at the liquid-solid interface is taken into account. Specific fields in copper immersed in water are given according to the focusing laws used by the arrays in two different cases, i.e., nonfocusing and focusing longitudinal (or compressional) wave (LW). For each case, transient LW and shear wave (SW) fields are presented.
{"title":"Calculation of transient fields in immersed solids radiated by linear focusing arrays","authors":"Ping Wu, R. Kazys, T. Stepinski","doi":"10.1109/ULTSYM.1995.495730","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495730","url":null,"abstract":"This paper aims at calculating transient fields radiated by linear arrays into immersed solids by using the angular spectrum approach (ASA), which is implemented based upon the temporal and the 2-D spatial discrete Fourier transform (DFT). The sinc-Fourier transform algorithm is extensively employed and allows arbitrary spatial sampling frequency to be used for sampling source plane without restriction of integer number of sampling intervals representing the elements and the gaps between the adjacent elements in various arrays. Calculation of transient fields in immersed solids from the array is presented in some detail. The wave mode conversion at the liquid-solid interface is taken into account. Specific fields in copper immersed in water are given according to the focusing laws used by the arrays in two different cases, i.e., nonfocusing and focusing longitudinal (or compressional) wave (LW). For each case, transient LW and shear wave (SW) fields are presented.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129535418","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495589
B. Boyanov, K. Djordjev, V. Strashilov, I. Avramov
The dispersion characteristics of surface transverse waves (STWs) on 36/spl deg/ Y cut quartz substrate have been analysed numerically. A closed-form dispersion relation has been introduced in the equations of the coupling-of-modes (COM) theory to account for the variation of trapping with frequency. The transmission and reflection coefficients at the finger edges have been determined from the stopband characteristics. Introducing an electromechanical coupling which varies with the electrode mass loading, quantitative agreement with experimental results on 650 MHz two-port STW resonators has been achieved.
{"title":"COM-theory analysis of STW resonator structures","authors":"B. Boyanov, K. Djordjev, V. Strashilov, I. Avramov","doi":"10.1109/ULTSYM.1995.495589","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495589","url":null,"abstract":"The dispersion characteristics of surface transverse waves (STWs) on 36/spl deg/ Y cut quartz substrate have been analysed numerically. A closed-form dispersion relation has been introduced in the equations of the coupling-of-modes (COM) theory to account for the variation of trapping with frequency. The transmission and reflection coefficients at the finger edges have been determined from the stopband characteristics. Introducing an electromechanical coupling which varies with the electrode mass loading, quantitative agreement with experimental results on 650 MHz two-port STW resonators has been achieved.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129634976","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 : 1995-11-07DOI: 10.1109/ULTSYM.1995.495795
A. Saied, L. Iachino, M. Goudinet, P. Giat, P. Laugier, J. Legeais, G. Berger
High frequency ultrasound has been widely used in ophthalmology to measure ultrasonic properties and thickness of tissues of the anterior segment of the eye. However, specific applications such as biointegrable keratoprosthesis (artificial cornea) control have not yet been reported. Keratoprosthesis has been developed as an alternative treatment to human cornea transplantation. The keratoprosthetic device consists of an optical system supported by a biocolonizable microporous polymer which is implanted in the damaged cornea. The polymer (200 microns thick, 50 microns pore size) is integrated into the recipient cornea through the progressive penetration (colonization) of the corneal cells into the pores of the polymer. The purpose of this work is to assess the polymer colonization and integration into the corneal tissue using high frequency ultrasound imaging and characterization. Polymer implantation was performed in rabbit cornea and a backscatter ultrasound microscope operating at 50 MHz (30 microns axial resolution) was used to acquire in vitro signal backscattered by the polymer and the surrounding corneal tissue 3 days, 10 days, 2 months, 70 days and 6 months after implantation. The frequency variation of the apparent acoustic backscatter and the apparent integrated backscatter were measured. Measurements were correlated with histologic data which established the level of cellular ingrowth and cell density in each specimen.
{"title":"In vitro high frequency ultrasonic characterization of colonization of microporous polymer used to support artificial cornea","authors":"A. Saied, L. Iachino, M. Goudinet, P. Giat, P. Laugier, J. Legeais, G. Berger","doi":"10.1109/ULTSYM.1995.495795","DOIUrl":"https://doi.org/10.1109/ULTSYM.1995.495795","url":null,"abstract":"High frequency ultrasound has been widely used in ophthalmology to measure ultrasonic properties and thickness of tissues of the anterior segment of the eye. However, specific applications such as biointegrable keratoprosthesis (artificial cornea) control have not yet been reported. Keratoprosthesis has been developed as an alternative treatment to human cornea transplantation. The keratoprosthetic device consists of an optical system supported by a biocolonizable microporous polymer which is implanted in the damaged cornea. The polymer (200 microns thick, 50 microns pore size) is integrated into the recipient cornea through the progressive penetration (colonization) of the corneal cells into the pores of the polymer. The purpose of this work is to assess the polymer colonization and integration into the corneal tissue using high frequency ultrasound imaging and characterization. Polymer implantation was performed in rabbit cornea and a backscatter ultrasound microscope operating at 50 MHz (30 microns axial resolution) was used to acquire in vitro signal backscattered by the polymer and the surrounding corneal tissue 3 days, 10 days, 2 months, 70 days and 6 months after implantation. The frequency variation of the apparent acoustic backscatter and the apparent integrated backscatter were measured. Measurements were correlated with histologic data which established the level of cellular ingrowth and cell density in each specimen.","PeriodicalId":268177,"journal":{"name":"1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124326589","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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