Zobrazeno 1 - 10
of 26
pro vyhledávání: '"Pawan Chaturvedi"'
Publikováno v:
The Journal of the Acoustical Society of America. 110:3243-3251
Acoustic properties of two types of soft tissue-like media were measured as a function of compressive strain. Samples were subjected to uniaxial strains up to 40% along the axis of the transducer beam. Measurements were analyzed to test a common assu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::84fe41560a6098d81d2b34745894c685
https://doi.org/10.1121/1.1414703
https://doi.org/10.1121/1.1414703
Publikováno v:
The Journal of the Acoustical Society of America. 107:1421-1434
A maximum-likelihood (ML) strategy for strain estimation is presented as a framework for designing and evaluating bioelasticity imaging systems. Concepts from continuum mechanics, signal analysis, and acoustic scattering are combined to develop a mat
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::673a794e61021d80ffab5d95591324f4
https://doi.org/10.1121/1.428429
https://doi.org/10.1121/1.428429
Autor:
Pawan Chaturvedi, Michael F. Insana
Publikováno v:
Computer Methods in Biomechanics and Biomedical Engineering. 3:109-118
The finite-difference time-domain (FDTD) method provides a numerical technique for solving acoustic forward problems. The FDTD is particularly useful in geometries that encompass heterogeneities. Plane-wave modeling permits the simulation of many pra
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4237d26e3625c0dfa5055f21107d79ec
https://doi.org/10.1080/10255840008915258
https://doi.org/10.1080/10255840008915258
Publikováno v:
Ultrasonic Imaging. 21:127-146
Ultrasonic strain imaging has drawn much attention recently because of its ability to noninvasively provide information on spatial variation of the elastic properties of soft tissues. Traditionally, local strain is estimated by scaling and cross corr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4cdc7abbccd7956a053ac0d50b6a8e4c
https://doi.org/10.1177/016173469902100204
https://doi.org/10.1177/016173469902100204
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 45:1022-1031
Companding may be used as a technique for generating low-noise strain images. It involves warping radio-frequency echo fields in two dimensions and at several spatial scales to minimize decorrelation errors in correlation-based displacement estimates
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::dfac2555f392f6a5952cf2c2eb55e903
https://doi.org/10.1109/58.710585
https://doi.org/10.1109/58.710585
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 45:179-191
Companding is a signal preprocessing technique for improving the precision of correlation-based time delay measurements. In strain imaging, companding is applied to warp 2-D or 3-D ultrasonic echo fields to improve coherence between data acquired bef
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b51e95a4238d4912eb2d0657eaf87130
https://doi.org/10.1109/58.646923
https://doi.org/10.1109/58.646923
Publikováno v:
Ultrasonic Imaging. 19:209-220
The visibility of soft-tissue lesions in strain imaging is currently limited by strain noise from waveform decorrelation. Attempts to balance noise reduction with concerns for contrast and spatial resolution rely on accurate models of time delay cova
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e4e495ddd27d715ea766d358d35dbebb
https://doi.org/10.1177/016173469701900304
https://doi.org/10.1177/016173469701900304
Autor:
Pawan Chaturvedi, Michael F. Insana
Publikováno v:
Journal of Theoretical Biology. 185:357-365
A simple mathematical model is proposed that predicts the dynamics of chronic progressive renal disease. The model consists of coupled linear differential equations formed from three state variables, four control parameters, and three parameters rela
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::58e57338427448e3a5454b1d5365dd7f
https://doi.org/10.1006/jtbi.1996.0311
https://doi.org/10.1006/jtbi.1996.0311
Autor:
Michael F. Insana, Pawan Chaturvedi
Publikováno v:
The Journal of the Acoustical Society of America. 100:392-399
Precision errors that occur in estimating the average scatterer size from pulse-echo ultrasound waveforms are examined in detail. The method-independent lower bound on estimation error is found from the Cramér-Rao inequality for comparison with the
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::04522ae5e3cce40fd268ac69e63844cf
https://doi.org/10.1121/1.415958
https://doi.org/10.1121/1.415958
Autor:
Pawan Chaturvedi, Michael F. Insana
Publikováno v:
Ultrasonic Imaging. 18:10-24
An autoregressive (AR) spectral estimation method was considered for the purpose of estimating scatterer size images. The variance and bias of the resulting estimates were compared with those using classical FFT periodograms for a range of input sign
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6342b406ca182203baf74a18d641b11a
https://doi.org/10.1006/uimg.1996.0002
https://doi.org/10.1006/uimg.1996.0002