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23 results on '"Department of Information Engineering [Firenze]"'

1. Spectral Doppler Measurements With 2-D Sparse Arrays

Author: Emmanuel Roux, Paolo Mattesini, Piero Tortoli, Alessandro Ramalli, Lorena Petrusca, Herve Liebgott, Olivier Basser, Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), RMN et optique : De la mesure au biomarqueur, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Imagerie Ultrasonore, and Université de Florence
Subjects: Acoustics and Ultrasonics, Acoustics, Spectral doppler, Doppler measurements, chemistry.chemical_element, 030204 cardiovascular system & hematology, 01 natural sciences, Spectral line, 03 medical and health sciences, symbols.namesake, [SPI]Engineering Sciences [physics], 0302 clinical medicine, Sparse array, 0103 physical sciences, Electrical and Electronic Engineering, 010301 acoustics, Instrumentation, ComputingMilieux_MISCELLANEOUS, Physics, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Bandwidth (signal processing), Grid, Hafnium, chemistry, symbols, Doppler effect, 2-D arrays, 3-D imaging, sparse arrays, spectral Doppler measurements
Abstract: The 2-D sparse arrays, in which a few hundreds of elements are distributed on the probe surface according to an optimization procedure, represent an alternative to full 2-D arrays, including thousands of elements usually organized in a grid. Sparse arrays have already been used in B-mode imaging tests, but their application to Doppler investigations has not been reported yet. Since the sparsity of the elements influences the acoustic field, a corresponding influence on the mean frequency (Fm), bandwidth (BW), and signal-to-noise ratio (SNR) of the Doppler spectra is expected. This article aims to assess, by simulations and experiments, to what extent the use of a sparse rather than a full gridded 2-D array has an impact on spectral Doppler measurements. Parabolic flows were investigated by a 3 MHz, 1024-element gridded array and by a sparse array; the latter was obtained by properly selecting a subgroup of 256 elements from the full array. Simulations show that the mean Doppler frequency does not change between the sparse and the full array while there are significant differences on the BW (average reduction of 17.2% for the sparse array, due to different apertures of the two probes) and on the signal power (Ps) (22 dB, due to the different number of active elements). These results are confirmed by flow phantom experiments, which also highlight that the most critical difference between sparse and full gridded array in Doppler measurements is in terms of SNR (-16.8 dB). ispartof: IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL vol:67 issue:2 pages:278-285 ispartof: location:United States status: published
Published: 2020
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2. Spectrophotometry and Photoacoustic Imaging: A Comparative Study

Author: E. Roméo, Francois Varray, Didier Vray, Thomas Dehoux, Aneline Dolet, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Institut Lumière Matière [Villeurbanne] (ILM), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Multispectral image, Biomedical Engineering, Biophysics, Photoacoustic imaging in biomedicine, 02 engineering and technology, Functional image, 01 natural sciences, Multispectral photoacoustic imaging, 010309 optics, Absorbance, Optics, Spectrophotometry, 0103 physical sciences, medicine, Tissue specific, Supervised classification method, Absorption (electromagnetic radiation), [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], medicine.diagnostic_test, Chemistry, business.industry, Multispectral photoacoustic imaging, spectrophotometry, supervised classification method, 021001 nanoscience & nanotechnology, 0210 nano-technology, business
Abstract: International audience; Photoacoustic imaging is a hybrid modality that is used to image biological tissues. Using multispectral optical excitation, a functional image is obtained due to the tissue specific optical absorption that depends on the wavelengths. To classify multispectral photoacoustic images, supervised methods are classically used. However, definition of the reference spectra is often difficult, and this choice can have a large impact on the classification results. A possible approach to build relevant reference spectra is to use spectrophotometry. This study aims at comparing absorbance measured by a spectrophotometer and multispectral photoacoustic signals of various coloured phantoms. We compare qualitatively the shape of the spectra obtained, using these two modalities for each sample. Our data suggest that spectrophotometry is a promising way to define reference spectra for classification of multispectral photoacoustic datasets.
Published: 2017
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3. High Frame Rate Vector Flow Imaging with a Convex Array in a simulated vessel phantom

Author: Nina Ghigo, Stefano Ricci, Didier Vray, Vincent Perrot, Brahim Harbaoui, Anne Long, Piero Tortoli, Herve Liebgott, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), and Université de Florence
Subjects: Physics, Convex geometry, Vector flow, Oscillation, Mathematical analysis, Phase (waves), 01 natural sciences, Standard deviation, Imaging phantom, [SPI]Engineering Sciences [physics], 03 medical and health sciences, Transverse plane, 0302 clinical medicine, Flow (mathematics), 0103 physical sciences, 030212 general & internal medicine, 010301 acoustics, ComputingMilieux_MISCELLANEOUS
Abstract: In this paper, a flow estimation method based on transverse oscillation is applied, in high frame rate conditions, to the data collected using a convex array. All simulations were based on the transmission of the "natural" diverging wave due to the convex geometry of the probe when all elements are simultaneously excited. Transverse oscillation was introduced in the tangential direction in post-acquisition in the Fourier domain. Finally, 2D velocity vectors were extracted thanks to a phase-based estimator. Velocities were estimated with a bias of 8% of the peak velocity and a standard deviation lower than 7 %. The method is now ready for experimental tests on flow phantoms and in vivo studies.
Published: 2019
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4. Wideband 2-D Array Design Optimization With Fabrication Constraints for 3-D US Imaging

Author: Marc Robini, Alessandro Ramalli, Christian Cachard, Emmanuel Roux, Piero Tortoli, Herve Liebgott, Department of Information Engineering [Firenze], Università degli Studi di Firenze [Firenze], Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), 3 - Imagerie Ultrasonore, Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE ), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie Ultrasonore, Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE)
Subjects: Optimization, Engineering, Scanner, 2-D transducers, Acoustics and Ultrasonics, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, 02 engineering and technology, 01 natural sciences, Imaging, Sparse array, simulated annealing (SA), 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, Electrical and Electronic Engineering, Wideband, 010301 acoustics, Instrumentation, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], business.industry, 3-D ultrasound (US), 020208 electrical & electronic engineering, Finite element analysis, Volume (computing), Two dimensional displays, Acoustics, Function (mathematics), Finite element method, Simulated annealing, Three-dimensional displays, Probes, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, sparse array, Energy (signal processing)
Abstract: Ultrasound (US) 2-D arrays are of increasing interest due to their electronic steering capability to investigate 3-D regions without requiring any probe movement. These arrays are typically populated by thousands of elements that, ideally, should be individually driven by the companion scanner. Since this is not convenient, the so-called microbeamforming methods, yielding a prebeamforming stage performed in the probe handle by suitable custom integrated circuits, have so far been implemented in a few commercial high-end scanners. A possible approach to implement relatively cheap and efficient 3-D US imaging systems is using 2-D sparse arrays in which a limited number of elements can be coupled to an equal number of independent transmit/receive channels. In order to obtain US beams with adequate characteristics all over the investigated volume, the layout of such arrays must be carefully designed. This paper provides guidelines to design, by using simulated annealing optimization, 2-D sparse arrays capable of fitting specific applications or fabrication/implementation constraints. In particular, an original energy function based on multidepth 3-D analysis of the beam pattern is also exploited. A tutorial example is given, addressed to find the $N_{\mathrm{ e}}$ elements that should be activated in a 2-D fully populated array to yield efficient acoustic radiating performance over the entire volume. The proposed method is applied to a $32 \times 32$ array centered at 3 MHz to select the 128, 192, and 256 elements that provide the best acoustic performance. It is shown that the 256-element optimized array yields sidelobe levels even lower (by 5.7 dB) than that of the reference 716-element circular and (by 10.3 dB) than that of the reference 1024-element array.
Published: 2017
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5. Spectral Doppler analysis with sparse and full 2-D arrays

Author: Piero Tortoli, Alessandro Ramalli, Gianluca Goti, Paolo Mattesini, Lorena Petrusca, Olivier Basset, Herve Liebgott, Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), RMN et optique : De la mesure au biomarqueur, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Imagerie Ultrasonore, and Université de Florence
Subjects: Physics, business.industry, Bandwidth (signal processing), Spectral doppler, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Spectral line, [SPI]Engineering Sciences [physics], symbols.namesake, Sparse array, Optics, 2D arrays, 3D imaging, sparse arrays, spectral Doppler measurements, 0103 physical sciences, Doppler frequency, symbols, Perpendicular, 0210 nano-technology, business, 010301 acoustics, Doppler effect, Frequency modulation, ComputingMilieux_MISCELLANEOUS
Abstract: Sparse arrays represent an alternative to full-gridded arrays in 2-D probes realization. Sparse arrays have been used in B-mode imaging tests, but not in spectral Doppler measurements yet. In this paper, we have investigated, by mean of simulations and experiments, how the use of a sparse array instead of a full-gridded 2-D array impacts on spectral Doppler measurements. A 3 MHz, 1024-element gridded array and a sparse array obtained by properly selecting 256 elements from the full array, have been used to interrogate a parabolic flow. Simulations and experiments highlight that the mean Doppler frequency does not change by using the sparse array instead of the full one. Significant differences appear for the bandwidth (17.2% average bandwidth reduction for the sparse array), and for the signal power (22 dB). Possible explanations of this behavior are discussed. Furthermore, it is shown that the empty lines in the 2-D array impact on the Doppler spectra, leading to sidelobes when steering in the direction perpendicular to such lines.
Published: 2019
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6. Spatial and spectral regularization to discriminate tissues using multispectral photoacoustic imaging

Author: Zhen Yuan, Francois Varray, Didier Vray, Aneline Dolet, Piero Tortoli, Thomas Grenier, Simon Mure, Yubin Liu, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Images et Modèles, Bioimaging Core, Faculty of Health Sciences, and University of Macau (UMac)
Subjects: Materials science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Multispectral image, Transmitted light, lcsh:TK7800-8360, Photoacoustic imaging in biomedicine, 02 engineering and technology, 01 natural sciences, Imaging phantom, lcsh:Telecommunication, 010309 optics, Multispectral imaging, lcsh:TK5101-6720, 0103 physical sciences, Segmentation, Cluster analysis, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Pixel, Spatial and spectral filtering, business.industry, lcsh:Electronics, Pattern recognition, 021001 nanoscience & nanotechnology, Wavelength, Artificial intelligence, sense organs, Photoacoustic imaging, 0210 nano-technology, business
Abstract: International audience; Photoacoustics is a hybrid modality used to image biological tissues. As optical absorption of tissues depends on the wavelength of the transmitted light, multispectral photoacoustic datasets can be obtained by changing this wavelength. This study presents a regularization method to segment multispectral photoacoustic images based on both the spatial and spectral features of the dataset pixels. The proposed processing is adapted from the spatiotemporal mean-shift approach and cluster patterns with similar spectral profiles, i.e., the variation of the received amplitude among the wavelengths, independent of their initial position. The segmentation performance of this method has been experimentally tested on multispectral photoacoustic tomographic data. We initially used a phantom that contained fresh and stale liver samples, and then a second phantom that contained two blood dilutions or a colored absorber. Experimentally, a clustering performance greater than 98% is achieved. This method makes it possible to discriminate between different media, between the same medium as fresh or stale, and between the same medium with different dilutions.
Published: 2018
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7. Optimal virtual sources distribution in 3-D diverging wave Ultrasound Imaging: an experimental study

Author: Olivier Bassett, Piero Tortoli, Lorena Petrusca, Emmanuel Roux, Herve Liebgott, Paolo Mattesini, Goulven Le Moign, Emilia Badescu, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Electronics and Telecommunications [Florence] (DET), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, RMN et optique : De la mesure au biomarqueur, Department of Information Engineering [Firenze], and Università degli Studi di Firenze = University of Florence [Firenze]
Subjects: Computer science, Acoustics, Labex CELYA, Virtual sources, 01 natural sciences, 030218 nuclear medicine & medical imaging, Labex PRIMES, Diverging waves, 03 medical and health sciences, 0302 clinical medicine, Sparse array, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, 0103 physical sciences, Medical imaging, 010301 acoustics, Spiral, ComputingMilieux_MISCELLANEOUS, 2-D Sparse array, 3-D Ultrasound imaging, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Ultrasonic imaging, Imagerie Ultrasonore, Distribution (mathematics), Transmission (telecommunications), Ultrasound imaging, reseau international, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; The use of 2-D array probes to perform 3-D ul-trasound imaging is still investigated in many domains. The extension from 2-D to 3-D imaging causes problems because of the need to control a very large number of elements on the probe. It might be overcome by using 2-D sparse array. This problem has been recently shown that sparse 2-D arrays can be used for 3-D fast ultrasound imaging based on the transmission of Diverging Waves (DW). The aim of this work is to experimentally analyze how the distribution of a given number (25) of Virtual Sources (VS) over a predefined area affects the images obtained with one fully populated probe and two sparse array probes, respectively. In order to do that, gridded and spiral distributions of virtual sources have been implemented. The results show that with the spiral distribution there is a general improvement of the contrast despite of a degradation on both lateral and axial resolutions.
Published: 2018
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8. Quantification of Multispectral Photoacoustic Images: Unsupervised Unmixing Methods Comparison

Author: Didier Vray, Francois Varray, Aneline Dolet, Thomas Grenier, Rita Ammanouil, Cédric Richard, Piero Tortoli, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS - UM 4 (UMR 8258 / U1022)), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Department of Electronics and Telecommunications [Florence] (DET), Università degli Studi di Firenze [Firenze], and Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Descartes - Paris 5 (UPD5)-Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)
Subjects: [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Computer science, business.industry, Labex CELYA, Physics::Medical Physics, Multispectral image, Photoacoustic imaging in biomedicine, Pattern recognition, Laser, Group lasso, Vertex component analysis, Imaging phantom, law.invention, reseau_international, Imagerie Ultrasonore, Wavelength, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Method comparison, law, categₛt2i, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Artificial intelligence, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS
Abstract: Multispectral photoacoustic imaging is a functional modality based on the detection of ultrasound waves coming from tissues illuminated by laser pulses at different wavelengths. The specific photoacoustic behavior of different media for each illuminating wavelength allows their quantification which is of great interest for various medical applications. The quantification algorithm performances are related to the correct estimation of reference spectra for each medium to quantify. This study aims at comparing three different unsupervised methods to extract these reference spectra (Group Lasso with Unit sum and Positivity constraints, Vertex Component Analysis and Spatio-Spectral Mean-Shift). After the reference extraction, a supervised unmixing method called Fully Constrained Least-Square is used to estimate the medium concentrations. Using Vevo LAZR as acquisition system, the quantification performances are evaluated on a colored 4% agar phantom containing two pure media and a mix of both. The results highlight the suitability of the Spatio-Spectral Mean-Shift to extract reference spectra that allow the assessment of photoacoustic for dataset medium concentration.
Published: 2018
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9. Spontaneous Expression Detection from 3D Dynamic Sequences by Analyzing Trajectories on Grassmann Manifolds

Author: Boulbaba Ben Amor, Stefano Berretti, Taleb Alashkar, Mohamed Daoudi, Modeling and Analysis of Static and Dynamic Shapes (3D-SAM), Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Université de Lille-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), ANR-11-EQPX-0023,IRDIVE,Plateforme Recherche et Innovation dans les Environnements Visuels Numériques et Interactifs(2011), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Università degli Studi di Firenze = University of Florence (UniFI)
Subjects: Computer science, 02 engineering and technology, Grassmannian, 0202 electrical engineering, electronic engineering, information engineering, Computer vision, Point (geometry), Event (probability theory), Grassmann manifold, spontaneous expression, business.industry, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], 020207 software engineering, Pattern recognition, linear subspaces, 16. Peace & justice, Depth sequences, Linear subspace, Expression (mathematics), Manifold, Human-Computer Interaction, Support vector machine, pain detection, Face (geometry), 020201 artificial intelligence & image processing, Artificial intelligence, business, Software
Abstract: International audience; In this paper, we propose a unified framework for the purpose of online spontaneous emotion detection, such as happiness or physical pain, from depth videos. Our approach consists on mapping the video streams onto a Grassmann manifold (i.e., space of k-dimensional linear subspaces) to form time-parameterized trajectories. To this end, depth videos are decomposed into short-time subsequences, each approximated by a k-dimensional linear subspace, which is in turn a point on the Grassmann manifold. Then, the temporal evolution of subspaces gives rise to a precise mathematical representation of trajectories on the underlying manifold. In the final step, extracted spatio-temporal features based on computing the velocity vectors along the trajectories, termed Geometric Motion History (or GMH), are fed to an early event detector based on Structured Output SVM, which enables online emotion detection from partially-observed data. Experimental results obtained on the publicly available Cam3D Kinect and BP4D-spontaneous databases validate the proposed solution. The first database has served to exemplify the proposed framework using depth sequences of the upper part of the body collected using depth-consumer cameras, while the second database allowed the application of the same framework to physical pain detection from high-resolution and long 3D-face sequences.
Published: 2018
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10. An open real-time photoacoustic imaging scanner

Author: Alessandro Dallai, Enrico Boni, Alessandro Ramalli, Didier Vray, Francois Varray, Piero Tortoli, Aneline Dolet, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Information Engineering (DINFO), and Department of Electronics and Telecommunications [Florence] (DET)
Subjects: Scanner, business.industry, Computer science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Ultrasound, Labex CELYA, Photoacoustic imaging in biomedicine, Acoustic wave, Laser, Imaging phantom, law.invention, real-time imaging, photoacoustic imaging, passive mode, Wavelength, Imagerie Ultrasonore, reseau_international, Optics, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, law, Region of interest, categₛt2i, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, ComputingMilieux_MISCELLANEOUS
Abstract: © 2018 IEEE. Photo acoustic imaging is a functional technique based on the detection of acoustic waves originated from tissues excited by an optical source (laser pulses). When different laser wavelengths are used., this modality allows the discrimination of different media., which is promising for various medical applications. The acquisition system must show two main capabilities: 1)the real-time imaging of the region of interest and 2)the access to raw data to test reconstruction and processing methods under development. However., today's systems provide only one of these two requirements. Therefore., this study presents the development of a 2D hybrid ultrasound/photoacoustic real-time mode., based on the ultrasound open scanner ULA-OP256., which allows the access to raw data. The system validation was done on a 4% agar phantom containing two graphite mines illuminated by a pulsed laser at 1064 nm. The test highlights the correct synchronization of the optical illumination with the photo acoustic acquisition., as well as the accurate display of photoacoustic and ultrasound images. Print on Demand (PoD) ISBN: 978-1-5386-3426-4 ispartof: IEEE International Ultrasonics Symposium, IUS vol:2018-October ispartof: 2018 IEEE International Ultrasonics Symposium (IUS) location:Kobe, Japan date:22 Oct - 25 Oct 2018 status: Published online
Published: 2018

11. Accelerating Plane Wave Imaging through Deep Learning-Based Reconstruction: An Experimental Study

Author: Maxime Gasse, Fabien Millioz, Emmanuel Roux, Hervé Liebgott, Denis Friboulet, Images et Modèles, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Imagerie Ultrasonore, ANR-11-LABX-0063,PRIMES,Physique, Radiobiologie, Imagerie Médicale et Simulation(2011), 2 - Images et Modèles, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ), Università degli Studi di Firenze [Firenze], 3 - Imagerie Ultrasonore, and ANR-11-IDEX-0007-02/11-LABX-0063,PRIMES,Physique, Radiobiologie, Imagerie Médicale et Simulation ( 2011 )
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging
Abstract: International audience; Background, Motivation and ObjectiveObtaining ultrafast images using steered plane wave (PW) imaging remains a challenge due to the trade-off between image quality and frame rate. PW imaging indeed relies on compounding in order to preserve a good image quality, usually using multiple successive emissions, which in turn yields a decrease of the frame rate. As opposed to this classicalapproach, we propose a new strategy to reduce the number of emitted PWs. This is done using a deep learning technique, i.e. by training a convolutional neural network (CNN) to reconstruct high quality images using a small number of PW emissions (typically two).Statement of Contribution/MethodsThe training data was generated as follows. A standard linear array probe (ATL L7-4 38 mm, 128 elements, bandwidth 4-7 MHz, transmitted frequency 5.208 MHz) was interfaced with a Verasonics system. 31 PWs were emitted (angle spanning ±15° in one degree steps). For each PW emission, the received raw-data was then processed using the f-k migration method [Garcia et al. IEEE UFFC13] to produce the reconstructed RF image. These 31 images were then averaged to get the final compounded image used as a reference in the training process, while only two images corresponding to angles -10° and +10° were given as input to the CNN.A total of 2000 reference images were acquired, 1000 images from in-vivo tissues (carotid and thyroid), 500 images from a Gammex phantom (410 SCG), and 500 images from a water-based polyamide mixture with air bubbles. 1800 images were used for training, 100 for validation, and 100 for testing. The CNN employed in this study is a fully-convolutionalneural network, with 4 hidden layers and maxout activation units. Training is done via stochastic gradient descent and the minimized loss function is the mean absolute error (MAE) between the CNN-reconstructed and the reference RF image, plus a L2 regularization term.Results/DiscussionOur approach was evaluated by comparing the CNN-based reconstruction of the test images with the conventional compounding method (see Fig. 1). Preliminary results indicate that CNN-based reconstruction is a very promising approach, as the reconstructed images are visually very close to those obtained by standard compounding with 31 PWs, while implying the emission of only 2 PWs.
Published: 2017

12. Validation of Optimal 2D Sparse Arrays in Focused Mode: Phantom Experiments

Author: Lorena Petrusca, Christian Cachard, Alessandro Ramalli, Francois Varray, Emilia Badescu, Marc Robini, Herve Liebgott, Piero Tortoli, Emmanuel Roux, Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence (UniFI), Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), RMN et optique : De la mesure au biomarqueur, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Rayet, Béatrice, Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Firenze [Firenze], 3 - Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), 5 - RMN et optique : De la mesure aux biomarqueurs, and 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE )
Subjects: 0301 basic medicine, Computer science, Main lobe, Acoustics, Lateral resolution, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, 01 natural sciences, Grayscale, Imaging phantom, 03 medical and health sciences, wideband optimization, Optics, 0302 clinical medicine, Contrast-to-noise ratio, Side lobe, experimental validation, 0103 physical sciences, 2D sparse arrays, medicine, 3D ultrasound, multi-depths, 010301 acoustics, Image resolution, 030304 developmental biology, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], 0303 health sciences, [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], medicine.diagnostic_test, business.industry, [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], 030104 developmental biology, Simulated annealing, business, focused mode, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, 030217 neurology & neurosurgery
Abstract: International audience; Background, Motivation and ObjectiveIn parallel with the increasing interest for 3D ultrasound imaging, different design techniques have been investigated to find the best configurations of 2D sparse arrays to scan an entire volume of interest [Trucco, IEEE UFFC99], [Diarra, IEEE TBME13]. In particular, we recently addressed the issue of driving a full 2D array of 1024 elements with a reduced number of channels (128, 192 or 256): the optimal arrays (opti128, opti192 and opti256) were obtained using simulated annealing to sculpt the radiated wideband pressure field at multiple depths [Roux, IEEE UFFC17]. The aim of the present work is to experimentally validate these optimal configurations by performing 3D focused imaging on phantoms.Statement of Contribution/MethodsThe 1024 elements of a 3 MHz array made by Vermon were individually driven by four synchronized Verasonics Vantage 256 systems. The systems were programmed to transmit 3-cycle sine bursts at 3 MHz focused at 25 mm and to scan a 3D sector with span ±30° in 31×29 steered beams in azimuth and elevation, respectively. Six arrays were compared: the optimal arrays (opti128, opti192 and opti256), an array whose active elements where randomly selected (rand256) and two references (REF716 and REF1024). The circular dense array REF716 corresponds to the full array REF1024 array without the corner elements. The comparison criteria were the lateral resolution (full width at half maximum - FWHM) and the contrast to noise ratio (CNR), measured on the images obtained by scanning a Gammex (Sono410 SCG) and CIRS (054GS) phantoms respectively.Results/DiscussionThe results are reported in Table 1. The opti256 performs the best among all the compared sparse arrays because it presents the same resolution performance as the REF1024 and an acceptable loss of CNR while using only 25% of the active elements of REF1024. The REF716 array is very competitive with only 70% of the active elements of REF1024.
Published: 2017

13. 3D Diverging Waves with 2D Sparse Arrays: A Feasibility Study

Author: Emmanuel , Roux, Varray , Francois, Petrusca , Lorena, Cachard , Christian, Tortoli , Piero, Liebgott , Hervé, Department of Information Engineering [Firenze], Università degli Studi di Firenze [Firenze], 3 - Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), 5 - RMN et optique : De la mesure aux biomarqueurs, Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and RMN et optique : De la mesure au biomarqueur
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging
Abstract: International audience; Background, Motivation and ObjectiveVery high frame rates can be reached both in 2D and 3D ultrasound imaging thanks to diverging waves (DWs) transmission. Up to now 3D ultrafast imaging has been performed controlling full 2D arrays with thousands of active elements which cannot be directly controlled by scanners with limited number of channels. The motivation here is to perform 3D ultrafast imaging with 128, 192 or 256 active elements. We recently addressed a similar issue in focused mode [Roux et al. IEEE UFFC17]: three optimal arrays (opti128, opti192 and opti256) were obtained by reducing the amount of energy out of the main lobe at multiple depths. In this work we experimentally investigate the feasibility of acquiring 3D volumes at high frame rate by transmitting DWs with the opti128, opti192 and opti256 sparse arrays under the hypothesis that these optimal arrays for focused imaging are also the most adequate sparse configurations to produce well resolved and artifactless virtual sources based on time reversal principle.Statement of Contribution/MethodsThe 1024 (32x32) elements of a 3 MHz array made by Vermon were individually driven by four synchronized Verasonics Vantage 256 systems. The systems were programmed to transmit 2.5-cycle sine bursts at 3 MHz. The evaluated image was made by compounding 25 images produced by 5x5 virtual sources located at 25 mm behind the array with span ±15° in both azimuth and elevation. Six arrays were compared: opti128, opti192, opti256, an array whose active elements where randomly selected (rand256) and two references (REF716 and REF1024). The circular dense array REF716 corresponds to the full 32x32 REF1024 array without the corner elements. The comparison criteria were the full width athalf maximum (FWHM) and the contrast to noise ratio (CNR).Results/DiscussionThe results are reported in Table 1. The performance of rand256 in resolution is very close to REF1024 and even better than REF716 whereas the optimized arrays (opti128, opti192 and opti256) yield a resolution about 30 % coarser. However opti256 yields +1dB CNR improvement compared to rand256. The REF716 array is very competitive with REF1024 (+0.3 mm, -0.9 dB) using only 70% of the active elements. As a conclusion, is has been shown that 3D ultrafast imaging can be performed using 2D sparse arrays but potential improvements may be achieved with dedicated optimization e.g. cost function to homogenize DW wavefront.
Published: 2017

14. Unmixing of multispectral photoacoustic images

Author: Dolet, Aneline, Ammanouil, Rita, Varray, Francois, Liu, Yubin, Tortoli, Piero, Ferrari, André, Richard, Cédric, Vray, Didier, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Bioimaging Core, Faculty of Health Sciences, and University of Macau (UMac)
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; Photoacoustic imaging is an hybrid modality to image biological tissues. Using multispectral optical excitation, photoacoustic imaging allows to obtain functional images due to the fact that a tissue has a specific optical absorption depending on the used wavelengths. Quantification of multispectral photoacoustic images can be of great interest to different applications by quantifying oxygenated (HbO2) and deoxygenated (Hb) blood in tissue. Quantification can be done by examining the abundance maps resulting from unmixing methods. Two hyperspectral unmixing methods, namely Group Lasso with Unit sum and Positivity constraints (GLUP) and Fully Constrained Least-Square (FCLS), are used to quantify multispectral photoacoustic images. Experiments using two synthetic and one experimental dataset show that unmixing methods provide good quantification performances, which is of great interest for various medical applications.; L’imagerie photoacoustique est une modalité hybride qui permet d’imager les tissus biologiques. L’illumination d’une zone d’intérêt par des impulsions laser à différentes longueurs d’onde permet d’obtenir une technique d’imagerie fonctionnelle car l’absorption optique des tissus est spécifique à la longueur d’onde utilisée. Pour différentes applications médicales, l’analyse d’images photoacoustiques multispectrales par la quantification du sang oxygéné (HbO2) et désoxygéné (Hb) dans les tissus est intéressante. Celle-ci peut être réalisée en utilisant les cartes d’abondance issues de méthodes de démélange. Ici, des méthodes de démélange, Group Lasso with Unit sum and Positivity constraints (GLUP) et Fully Constrained Least-Square (FCLS), utilisées dans le domaine hyperspectrale, sont mises en oeuvre pour quantifier des images photoacoustiques multispectrales. Les résultats de cette étude sont présentés sur deux jeux de données synthétiques et un jeu de données expérimentales. Ceux-ci montrent que ces méthodes permettent de quantifier des images photoacoustiques multispectrales avec de bonnes performances.
Published: 2017

15. 2-D Ultrasound Sparse Arrays Multidepth Radiation Optimization Using Simulated Annealing and Spiral-Array Inspired Energy Functions

Author: Christian Cachard, Emmanuel Roux, Alessandro Ramalli, Piero Tortoli, Marc Robini, Herve Liebgott, Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie Ultrasonore, Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Università degli Studi di Firenze [Firenze], Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), 3 - Imagerie Ultrasonore, Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), and 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE )
Subjects: Engineering, Acoustics and Ultrasonics, Main lobe, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Acoustics, Transducers, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, Spirals, 01 natural sciences, Simulated annealing, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, Optics, Sparse array, Imaging, Three-Dimensional, Side lobe, Position (vector), 0103 physical sciences, Electrical and Electronic Engineering, 010301 acoustics, Instrumentation, Spiral, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, Ultrasonography, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], business.industry, [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], Finite element analysis, Two dimensional displays, Models, Theoretical, Finite element method, Probes, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Energy (signal processing), Algorithms
Abstract: International audience; Full matrix arrays are excellent tools for 3-D ultrasound imaging, but the required number of active elements is too high to be individually controlled by an equal number of scanner channels. The number of active elements is significantly reduced by the sparse array techniques, but the position of the remaining elements must be carefully optimized. This issue is faced here by introducing novel energy functions in the simulated annealing (SA) algorithm. At each iteration step of the optimization process, one element is freely translated and the associated radiated pattern is simulated. To control the pressure field behavior at multiple depths, three energy functions inspired by the pressure field radiated by a Blackman-tapered spiral array are introduced. Such energy functions aim at limiting the main lobe width while lowering the side lobe and grating lobe levels at multiple depths. Numerical optimization results illustrate the influence of the number of iterations, pressure measurement points, and depths, as well as the influence of the energy function definition on the optimized layout. It is also shown that performance close to or even better than the one provided by a spiral array, here assumed as reference, may be obtained. The finite-time convergence properties of SA allow the duration of the optimization process to be set in advance.
Published: 2016
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16. Spatial and spectral regularization for multispectral photoacoustic image clustering

Author: Yubin Liu, Thomas Grenier, Francois Varray, Piero Tortoli, Aneline Dolet, Zhen Yuan, Didier Vray, Simon Mure, Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Images et Modèles, Bioimaging Core, Faculty of Health Sciences, University of Macau (UMac), Department of Information Engineering [Firenze], and Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI)
Subjects: Media, Clustering algorithms, Computer science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Physics::Medical Physics, Multispectral image, Photoacoustic imaging in biomedicine, 02 engineering and technology, 01 natural sciences, Regularization (mathematics), Phantoms, Optical imaging, Image (mathematics), Multispectral pattern recognition, 010309 optics, Multispectral photoacoustic, spatio-temporal mean-shift, clustering, 0103 physical sciences, Computer vision, Cluster analysis, Absorption (electromagnetic radiation), [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Image segmentation, business.industry, Pattern recognition, Acoustics, 021001 nanoscience & nanotechnology, Blood, Computer Science::Computer Vision and Pattern Recognition, Photoacoustic tomography, Artificial intelligence, 0210 nano-technology, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; Photoacoustic imaging is a hybrid modality used to image biological tissues. Multispectral optical excitation permits to obtain functional images thanks to the tissue specific optical absorption that depends on the light wavelength. The aim of this study is to propose a clustering method for photoacoustic multispectral images based on both spatial neighbourhood and spectral behaviour. The proposed methodology is adapted from spatio-temporal mean-shift approach: it clusters distant or neighbouring patterns having similar spectral profiles. The clustering performance of our modified mean-shift algorithm is experimentally tested on multispectral photoacoustic tomography data. Results obtained from phantoms including two blood dilutions and colored absorbers are presented. It is thus shown that our strategy allows the experimental discrimination of media, achieving a clustering performance of more than 99%. Moreover, depending on the applied pre-processing the discrimination of different concentrations of a same medium is possible.
Published: 2016
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17. Comparison of different optimized irregular sparse 2D ultrasound arrays

Author: Marc Robini, Piero Tortoli, Bakary Diarra, Christian Cachard, Herve Liebgott, S. S. Ravi, Emmanuel Roux, Electrical, Electronics, Computer & Telecommunication Engineering Department, Botswana International University of Science & Technology, Department of Information Engineering [Firenze], Università degli Studi di Firenze [Firenze], Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ), 3 - Imagerie Ultrasonore, Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE ), Botswana International University of Science & Technology (BIUST), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie Ultrasonore, Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE)
Subjects: Computer science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Acoustics, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, 01 natural sciences, Directivity, 030218 nuclear medicine & medical imaging, biomedical ultrasonics, Reduction (complexity), 03 medical and health sciences, 0302 clinical medicine, Optics, Sparse array, Dimension (vector space), ultrasonic arrays, 0103 physical sciences, 010301 acoustics, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], business.industry, [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], Simulated annealing, simulated annealing, business, Driven element, Realization (systems), [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Beam (structure)
Abstract: International audience; The role of 2D matrix arrays in the realization of real time 3D ultrasound imaging is crucial as the latter permit to acquire a complete volume. The lack of control systems for these arrays containing thousands of elements and the dimension of connection cables for such a number of elements are the main obstacles to the use of these technologies. The sparse array techniques present a solid candidate to solve these technological limitations but give rise to beam pattern deteriorations in terms of energy loss and unwanted lobes apparition. The irregular positioning of the array elements permits to drastically decrease the unwanted lobes while the energy loss may be compensated by increasing the element size. However, as elements get larger, the directivity decreases. To solve this directivity reduction, we propose to combine elements of different sizes in such a manner that a broad directivity is maintained using small elements whereas the energy loss may be compensated by wide ones. Additionally, an innovative simulated annealing based algorithm is used to refine the array beam profile when the active element number is set to 256. The results compared to those obtained by the basic non-grid array show significant improvement in the beam pattern.
Published: 2016
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18. The genetic history of Ice Age Europe

Author: Alexander Peltzer, Dorothée G. Drucker, Annamaria Ronchitelli, Stephan Schiffels, Maria Teschler-Nicola, Swapan Mallick, Svante Pääbo, Michael P. Richards, Daniel Fernandes, Martin Petr, Manuel R. González Morales, Marco Peresani, Jiří Svoboda, V. S. Slavinsky, Janet Kelso, David Reich, Isabelle Crevecoeur, Pontus Skoglund, E. Vacca, Francesco Mallegni, Donato Coppola, Oana Teodora Moldovan, Cosimo Posth, Nadin Rohland, Kurt Wehrberger, Anatoly P. Derevianko, Birgit Nickel, A. A. Tsybankov, Viviane Slon, Nicholas J. Conard, Stefano Ricci, Christine Neugebauer-Maresch, Corinne Thevenet, Qiaomei Fu, Lawrence Guy Straus, Vyacheslav Moiseyev, Frédérique Valentin, Johannes Krause, Iain Mathieson, Silviu Constantin, Mateja Hajdinjak, Sahra Talamo, Bernard Gély, Renata Grifoni Cremonesi, Dan Grigorescu, David Caramelli, Mark Lipson, Matthias Meyer, Damien Flas, Stefano Benazzi, Alissa Mittnik, Nick Patterson, Iosif Lazaridis, Martina Lari, Hervé Bocherens, Wolfgang Haak, Katerina Harvati, Patrick Semal, Christophe Cupillard, Hélène Rougier, Ron Pinhasi, Marcello A. Mannino, Anja Furtwängler, Nikolai I. Drozdov, Department of Genetics [Boston], Harvard Medical School [Boston] (HMS), Max Planck Institute for the Science of Human History (MPI-SHH), Max-Planck-Gesellschaft, Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology [Leipzig], Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Harvard School of Public Health, School of Archaeology [Dublin], University College Dublin [Dublin] (UCD), Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Université libre de Bruxelles (ULB), Department of Evolutianory Genetics, Max-Planck-Institut, Sackler Faculty of Medicine, Tel Aviv University (TAU), Department of Human Evolution [Leipzig], Nuffield Department of Medicine, Service régional de l'Archéologie Rhône-Alpes, Ministère de la Culture et de la Communication (MCC), Laboratory of Excellence for Financial Regulation (LABEX ReFi), Université Paris-Sud - Paris 11 (UP11), Institutul de Speologie ‘Emil Racoviţă', Str. Frumoasă 31, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Università degli Studi di Ferrara = University of Ferrara (UniFE), Università degli Studi di Firenze = University of Florence (UniFI), Department of Information Engineering [Firenze], U.R. Ecologia Preistorica, Dipartimento di Scienze Ambientali ', Archéologies et Sciences de l'Antiquité (ArScAn), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Institut national de recherches archéologiques préventives (Inrap)-Centre National de la Recherche Scientifique (CNRS), Museum Ulm, De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Service Anthropologie et Préhistoire [Bruxelles], Institut Royal des Sciences Naturelles de Belgique (IRSNB), Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Institut für Ur- und Frühgeschichte und Archäologie des Mittelalters, University of Tübingen, Faculty of Science [Brno] (SCI / MUNI), Masaryk University [Brno] (MUNI), Department of Physics, University of Sussex, Department of Animal Biology and Genetics, School of Archaeology, Broad Institute of MIT and Harvard (BROAD INSTITUTE), Harvard Medical School [Boston] (HMS)-Massachusetts Institute of Technology (MIT)-Massachusetts General Hospital [Boston], Centre International de Recherche Archéologique sur la Polynésie (CIRAP), Université de la Polynésie Française (UPF), Tel Aviv University [Tel Aviv], Università degli Studi di Ferrara (UniFE), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Max Planck Institute for Evolutionary Anthropology, Eberhard Karls Universität Tübingen, Max-Planck-Institut für evolutionäre Anthropologie (MPI-EVA), University College of London [London] (UCL), Laboratoire Chrono-environnement - CNRS - UFC (UMR 6249) (LCE), Department of Archaeogenetics [Jena] (DAG), Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), University of Bologna, Dipartimento di Scienze Fisiche, della Terra e dell'Ambiente., Università degli Studi di Siena = University of Siena (UNISI), Laboratoire d'Anthropologie et de Préhistoire, Institut royal des Sciences naturelles de Belgique (IRSNB), Travaux et recherches archéologiques sur les cultures, les espaces et les sociétés (TRACES), Ministère de la Culture et de la Communication (MCC)-École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J)-Centre National de la Recherche Scientifique (CNRS), Institut Royal des Sciences naturelles de Belgique, Univ Tubingen, Senckenberg Ctr Human Evolut & Palaeoecol, Palaeoanthropol, Tubingen, Germany, Laboratorio di Antropologia, Università degli Studi di Firenze = University of Florence [Firenze], Qiaomei, Fu, Posth, Cosimo, Hajdinjak, Mateja, Petr, Martin, Mallick, Swapan, Fernandes, Daniel, Furtwängler, Anja, Haak, Wolfgang, Meyer, Matthia, Mittnik, Alissa, Nickel, Birgit, Peltzer, Alexander, Rohland, Nadin, Slon, Viviane, Talamo, Sahra, Lazaridis, Iosif, Lipson, Mark, Mathieson, Iain, Schiffels, Stephan, Skoglund, Pontu, Derevianko, Anatoly P., Drozdov, Nikolai, Slavinsky, Vyacheslav, Tsybankov, Alexander, Cremonesi, Renata Grifoni, Mallegni, Francesco, Gély, Bernard, Vacca, Eligio, Morales, Manuel R. González, Straus, Lawrence G., Neugebauer Maresch, Christine, Teschler Nicola, Maria, Constantin, Silviu, Moldovan, Oana Teodora, Benazzi, Stefano, Peresani, Marco, Coppola, Donato, Lari, Martina, Ricci, Stefano, Ronchitelli, Annamaria, Valentin, Frédérique, Thevenet, Corinne, Wehrberger, Kurt, Grigorescu, Dan, Rougier, Hélène, Crevecoeur, Isabelle, Flas, Damien, Semal, Patrick, Mannino, Marcello A., Cupillard, Christophe, Bocherens, Hervé, Conard, Nicholas J., Harvati, Katerina, Moiseyev, Vyacheslav, Drucker, Dorothée G., Svoboda, Jiří, Richards, Michael P., Caramelli, David, Pinhasi, Ron, Kelso, Janet, Patterson, Nick, Krause, Johanne, Pääbo, Svante, and Reich, David
Subjects: 0301 basic medicine, Male, Neanderthal, Time Factors, [SDV]Life Sciences [q-bio], Population Dynamics, [SHS.ANTHRO-BIO]Humanities and Social Sciences/Biological anthropology, Neanderthal genome project, migration, Ancient Modern Humans, [SHS]Humanities and Social Sciences, 0302 clinical medicine, Ice Cover, History, Ancient, Phylogeny, ComputingMilieux_MISCELLANEOUS, Modern Humans, Neanderthals, Genetics, education.field_of_study, Multidisciplinary, Ancient DNA, Human migration, Biological Evolution, Founder Effect, Pleistocene, Europe, Ethnology, Female, Ancient DNA, Ancient Modern Humans, Neanderthals, Human, Animals, DNA, European Continental Ancestry Group, Genetics, Population, Human Migration, Humans, Middle East, Selection, Genetic, Sequence Analysis, DNA, Medicine (all), Archaeogenetics, Time Factor, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, Modern Humans, Genetics, Pleistocene, Europe, migration, culture, Europe glaciaire, Population, Socio-culturale, Biology, Article, White People, Prehistory, 03 medical and health sciences, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], biology.animal, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, education, Population Dynamic, Homo sapiens, Animal, business.industry, culture, 030104 developmental biology, [ SHS.ARCHEO ] Humanities and Social Sciences/Archaeology and Prehistory, business, génome humain, 030217 neurology & neurosurgery, Founder effect
Abstract: Modern humans arrived in Europe ∼45,000 years ago, but little is known about their genetic composition before the start of farming ∼8,500 years ago. Here we analyse genome-wide data from 51 Eurasians from ∼45,000-7,000 years ago. Over this time, the proportion of Neanderthal DNA decreased from 3-6% to around 2%, consistent with natural selection against Neanderthal variants in modern humans. Whereas there is no evidence of the earliest modern humans in Europe contributing to the genetic composition of present-day Europeans, all individuals between ∼37,000 and ∼14,000 years ago descended from a single founder population which forms part of the ancestry of present-day Europeans. An ∼35,000-year-old individual from northwest Europe represents an early branch of this founder population which was then displaced across a broad region, before reappearing in southwest Europe at the height of the last Ice Age ∼19,000 years ago. During the major warming period after ∼14,000 years ago, a genetic component related to present-day Near Easterners became widespread in Europe. These results document how population turnover and migration have been recurring themes of European prehistory.
Published: 2016
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19. Spiral array inspired multi-depth cost function for 2D sparse array optimization

Author: Herve Liebgott, Alessandro Ramalli, Emmanuel Roux, Christian Cachard, Marc Robini, Piero Tortoli, Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Imagerie Ultrasonore, Università degli Studi di Firenze [Firenze], Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ), 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), and 3 - Imagerie Ultrasonore
Subjects: Physics, Aperture, Main lobe, business.industry, 0206 medical engineering, 02 engineering and technology, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, 020601 biomedical engineering, 01 natural sciences, Sparse array, Optics, Side lobe, 0103 physical sciences, Simulated annealing, business, 010301 acoustics, Image resolution, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Beam (structure), Spiral
Abstract: International audience; Matrix sparse array optimization for 3D ultrasound imaging often uses simulated annealing (SA) algorithms to reduce the number of elements and to find their best position, intensity and size. The aim of optimization is to obtain the best possible radiated beam pattern in terms of main lobe width and side lobe level. This has a direct impact on the image resolution and contrast. However, to limit the convergence time, the calculation of the cost function that drives the optimization was usually based on analytically computed radiated beam patterns. In this work, realistic acoustic simulations are based on the FIELD II software, and a novel multi-depth cost function is introduced. Such a cost function allows taking into account the radiated pressure field at several depths, and not only at the focal depth. The multi-depth cost function was inspired by the recently introduced Blackman-tapered 256-element spiral array. The positions of 256 elements of two 7 MHz sparse arrays were obtained by optimizing the beam patterns at: the focal depth only (opti1d); three different depths (15, 25 and 35 mm) (opti3d). Both the arrays had a 6 mm aperture radius, λ-size square elements and are focused at 25 mm depth. The results show that using the multi-depth cost function significantly improves the sensitivity (+1.2dB) and the SLL (-9.7 dB and -10.7 dB at 15mm and 35mm depths, respectively). The optimization results were compared to the beam patterns produced by a 256-element spiral array and by a 2D dense array (2292 elements), respectively.
Published: 2015
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20. Plane-Wave Transverse Oscillation for High-Frame-Rate 2-D Vector Flow Imaging

Author: Alessandro Ramalli, Matteo Lenge, Christian Cachard, Piero Tortoli, Herve Liebgott, Department of Information Engineering [Firenze], Università degli Studi di Firenze [Firenze], Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), 3 - Imagerie Ultrasonore, Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie Ultrasonore, and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL)
Subjects: Acoustics and Ultrasonics, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Phase (waves), Plane wave, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, Sensitivity and Specificity, Displacement (vector), Optics, Oscillometry, Image Interpretation, Computer-Assisted, Humans, Computer Simulation, Electrical and Electronic Engineering, Instrumentation, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, Physics, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Vector flow, Oscillation, business.industry, Phantoms, Imaging, [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], Models, Cardiovascular, Reproducibility of Results, Ultrasonography, Doppler, Image Enhancement, Wavelength, Transverse plane, Blood Vessels, Radio frequency, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Algorithms, Blood Flow Velocity
Abstract: International audience; Transverse oscillation (TO) methods introduce oscillations in the pulse–echo field (PEF) along the direction transverse to the ultrasound propagation direction. This may be exploited to extend flow investigations toward multidimensional estimates. In this paper, the TOs are coupled with the transmission of plane waves (PWs) to reconstruct high-framerate RF images with bidirectional oscillations in the pulse–echo field. Such RF images are then processed by a 2-D phase-based displacement estimator to produce 2-D vector flow maps at thousands of frames per second. First, the capability of generating TOs after PW transmissions was thoroughly investigated by varying the lateral wavelength, the burst length, and thetransmission frequency. Over the entire region of interest, the generated lateral wavelengths, compared with the designed ones, presented bias and standard deviation of −3.3 ± 5.7% and 10.6 ± 7.4% in simulations and experiments, respectively. The performance of the ultrafast vector flow mapping method was also assessed by evaluating the differences between the estimated velocities and the expected ones. Both simulationsand experiments show overall biases lower than 20% when varying the beam-to-flow angle, the peak velocity, and the depth of interest. In vivo applications of the method on the common carotid and the brachial arteries are also presented.
Published: 2015
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21. Comparison of Carotid Artery Blood Velocity Measurements by Vector and Standard Doppler Approaches

Author: Gabriele Ciuti, D. Righi, Matteo Lenge, Herve Liebgott, Stefano Ricci, Piero Tortoli, Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Heart and Vessels Department, Azienda Ospedaliero-Universitaria Careggi (AOUC), Università degli Studi di Firenze [Firenze], 3 - Imagerie Ultrasonore, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), and Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: medicine.medical_specialty, Blood velocity, Acoustics and Ultrasonics, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Carotid arteries, Biophysics, Spectral doppler, Sensitivity and Specificity, symbols.namesake, Image Interpretation, Computer-Assisted, medicine, Humans, Radiology, Nuclear Medicine and imaging, Carotid Stenosis, Internal carotid artery stenosis, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, Observer Variation, Radiological and Ultrasound Technology, business.industry, Limits of agreement, Reproducibility of Results, Ultrasonography, Doppler, Repeatability, medicine.disease, Stenosis, Carotid Arteries, symbols, Radiology, Nuclear medicine, business, Doppler effect, Blood Flow Velocity
Abstract: International audience; Although severely affected by the angle dependency, carotid artery peak systolic velocity measurements are widely used for assessment of stenosis. In this study, blood peak systolic velocities in the common and internal carotid arteries of both healthy volunteers and patients with internal carotid artery stenosis were measured by two vector Doppler (VD) methods and compared with measurements obtained with the conventional spectral Doppler approach. Although the two VD techniques were completely different (using the transmission of focused beams and plane waves, respectively), the measurement results indicate that these techniques are nearly equivalent. The peak systolic velocities measured in 22 healthy common carotid arteries by the two VD techniques were very close (according to Bland–Altman analysis, the average difference was 3.2%, with limits of agreement of ±8.6%). Application of Bland–Altman analysis to comparison of either VD technique with the spectral Doppler method provided a 21%–25% average difference with ±13%–15% limits of agreement. Analysis of the results obtained from 15 internal carotid arteries led to similar conclusions, indicating significant overestimation of peak systolic velocity with the spectral Doppler method. Inter- and intra-operator repeatability measurements performed in a group of 8 healthy volunteers provided equivalent results for all of the methods (coefficients of variability in the range 2.7%–6.9%), even though the sonographers were not familiar with the VD methods. The results of this study suggest that the introduction of vector Doppler methods in commercial machines may finally be considered mature and capable of overcoming the angle-dependent overestimation typical of the standard spectral Doppler approach.
Published: 2015
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22. Transient Analysis of Networks of Stochastic Timed Automata using Stochastic State Classes

Author: Nathalie Bertrand, Paolo Ballarini, Marco Paolieri, András Horváth, Enrico Vicario, Mathématiques Appliquées aux Systèmes - EA 4037 (MAS), Ecole Centrale Paris, SUpervision of large MOdular and distributed systems (SUMO), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-LANGAGE ET GÉNIE LOGICIEL (IRISA-D4), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Dipartmento de Informatica, Università degli studi di Torino (UNITO), Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Télécom Bretagne-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), and Università degli Studi di Firenze = University of Florence (UniFI)
Subjects: Continuous-time stochastic process, Computer science, Stochastic process, Markov process, 020207 software engineering, 02 engineering and technology, Space (mathematics), Automaton, symbols.namesake, [INFO.INFO-PF]Computer Science [cs]/Performance [cs.PF], 0202 electrical engineering, electronic engineering, information engineering, symbols, 020201 artificial intelligence & image processing, Transient (computer programming), State (computer science), Algorithm, ComputingMilieux_MISCELLANEOUS, Event (probability theory)
Abstract: Stochastic Timed Automata (STA) associate logical locations with continuous, generally distributed sojourn times. In this paper, we introduce Networks of Stochastic Timed Automata (NSTA), where the components interact with each other by message broadcasts. This results in an underlying stochastic process whose state is made of the vector of logical locations, the remaining sojourn times, and the value of clocks. We characterize this general state space Markov process through transient stochastic state classes that sample the state and the absolute age after each event. This provides an algorithmic approach to transient analysis of NSTA models, with fairly general termination conditions which we characterize with respect to structural properties of individual components that can be checked through straightforward algorithms.
Published: 2013
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23. Modélisation et simulation acoustique pour l’optimisation de sondes échographiques 2D par recuit simulé

Author: Emmanuel Roux, Robini, Marc C., Alessandro Ramalli, Piero Tortoli, Christian Cachard, Hervé Liebgott, Department of Information Engineering [Firenze], Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Imagerie Ultrasonore, Università degli Studi di Firenze [Firenze], Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ), 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), and 3 - Imagerie Ultrasonore
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; The electronic steering capability of 2D ultrasound probes makes them excellent candidates for real-time 3D imaging. However, considering that current ultrasound scanners rarely control more than 256 channels, it is necessary to optimize these probes to operate with a reduced number of active elements. By integrating acoustic simulations into a simulated annealing algorithm, we optimize the radiated profile of a 256 elements 2D ultrasound probe; Les sondes 2D à balayage électronique sont d’excellentes candidates pour l’échographie 3D temps-réel. En revanche, ces sondes doivent être optimisées pour fonctionner avec les échographes existants qui contrôlent rarement plus de 256 canaux indépendants. Grâce à l’intégration de la simulation acoustique au sein de l’optimisation par recuit simulé, il a été possible d’optimiser le profil de rayonnement d’une sonde de 256 éléments

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23 results on '"Department of Information Engineering [Firenze]"'

1. Spectral Doppler Measurements With 2-D Sparse Arrays

2. Spectrophotometry and Photoacoustic Imaging: A Comparative Study

3. High Frame Rate Vector Flow Imaging with a Convex Array in a simulated vessel phantom

4. Wideband 2-D Array Design Optimization With Fabrication Constraints for 3-D US Imaging

5. Spectral Doppler analysis with sparse and full 2-D arrays

6. Spatial and spectral regularization to discriminate tissues using multispectral photoacoustic imaging

7. Optimal virtual sources distribution in 3-D diverging wave Ultrasound Imaging: an experimental study

8. Quantification of Multispectral Photoacoustic Images: Unsupervised Unmixing Methods Comparison

9. Spontaneous Expression Detection from 3D Dynamic Sequences by Analyzing Trajectories on Grassmann Manifolds

10. An open real-time photoacoustic imaging scanner

11. Accelerating Plane Wave Imaging through Deep Learning-Based Reconstruction: An Experimental Study

12. Validation of Optimal 2D Sparse Arrays in Focused Mode: Phantom Experiments

13. 3D Diverging Waves with 2D Sparse Arrays: A Feasibility Study

14. Unmixing of multispectral photoacoustic images

15. 2-D Ultrasound Sparse Arrays Multidepth Radiation Optimization Using Simulated Annealing and Spiral-Array Inspired Energy Functions

16. Spatial and spectral regularization for multispectral photoacoustic image clustering

17. Comparison of different optimized irregular sparse 2D ultrasound arrays

18. The genetic history of Ice Age Europe

19. Spiral array inspired multi-depth cost function for 2D sparse array optimization

20. Plane-Wave Transverse Oscillation for High-Frame-Rate 2-D Vector Flow Imaging

21. Comparison of Carotid Artery Blood Velocity Measurements by Vector and Standard Doppler Approaches

22. Transient Analysis of Networks of Stochastic Timed Automata using Stochastic State Classes

23. Modélisation et simulation acoustique pour l’optimisation de sondes échographiques 2D par recuit simulé

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23 results on '"Department of Information Engineering [Firenze]"'

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