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The search for living worlds and the connection to our cosmic origins

Barstow, M. A. (author), Aigrain, S. (author), Barstow, J. K. (author), Barthelemy, M. (author), Evans, C. (author), Ferrari, M. (author), Garcia, M. (author), Rossi, L. (author), Stam, D.M. (author)

One of the most exciting scientific challenges is to detect Earth-like planets in the habitable zones of other stars in the galaxy and search for evidence of life. During the past 20 years the detection of exoplanets, orbiting stars beyond our own, has moved from science fiction to science fact. From the first handful of gas giants, found...

journal article 2021

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High Frame Rate Volumetric Imaging of Microbubbles Using a Sparse Array and Spatial Coherence Beamforming

Wei, Luxi (author), Wahyulaksana, G. (author), Meijlink, Bram (author), Ramalli, Alessandro (author), Noothout, E.C. (author), Verweij, M.D. (author), van der Steen, A.F.W. (author), de Jong, N. (author), Vos, H.J. (author)

Volumetric ultrasound imaging of blood flow with microbubbles enables a more complete visualization of the microvasculature. Sparse arrays are ideal candidates to perform volumetric imaging at reduced manufacturing complexity and cable count. However, due to the small number of transducer elements, sparse arrays often come with high clutter...

journal article 2021

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Full wavefield least squares reverse time migration

Davydenko, M.V. (author), Verschuur, D.J. (author)

Waveform inversion based on least-squares reverse time migration (LSRTM) usually involves Born modeling, which models the primary-only data. As a result the inversion process handles only primaries and corresponding multiple elimination pre-processing of the input data is required prior to imaging and inversion. Otherwise, multiples left in...

journal article 2021

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Acquisition geometry analysis with point-spread functions

Revelo Obando, B.A. (author), Blacquière, G. (author)

Seismic data are traditionally acquired based on spatial sampling requirements, noise properties and budgetary constraints. However, designing a survey without taking into account the complexity of the subsurface may result in an image without the expected quality. Also, the subsequent preprocessing and processing steps may exploit or misuse...

journal article 2021

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A Pitch-Matched Transceiver ASIC With Shared Hybrid Beamforming ADC for High-Frame-Rate 3-D Intracardiac Echocardiography

Hopf, Y.M. (author), Ossenkoppele, Boudewine W. (author), Soozande, Mehdi (author), Noothout, E.C. (author), Chang, Z.Y. (author), Chen, Chao (author), Vos, H.J. (author), Bosch, Johan G. (author), Verweij, M.D. (author), de Jong, N. (author), Pertijs, M.A.P. (author)

In this article, an application-specific integrated circuit (ASIC) for 3-D, high-frame-rate ultrasound imaging probes is presented. The design is the first to combine element-level, high-voltage (HV) transmitters and analog front-ends, subarray beamforming, and in-probe digitization in a scalable fashion for catheter-based probes. The...

journal article 2022

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A Pitch-Matched Low-Noise Analog Front-End With Accurate Continuous Time-Gain Compensation for High-Density Ultrasound Transducer Arrays

Guo, P. (author), Chang, Z.Y. (author), Noothout, E.C. (author), Vos, H.J. (author), Bosch, Johan G. (author), de Jong, N. (author), Verweij, M.D. (author), Pertijs, M.A.P. (author)

This article presents a compact analog front-end (AFE) circuit for ultrasound receivers with linear-in-dB continuous gain control for time-gain compensation (TGC). The AFE consists of two variable-gain stages, both of which employ a novel complementary current-steering network (CCSN) as the interpolator to realize continuously variable gain....

journal article 2022

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2D body-wave seismic interferometry as a tool for reconnaissance studies and optimization of passive reflection seismic surveys in hardrock environments

Chamarczuk, Michał (author), Malinowski, Michał (author), Draganov, D.S. (author)

Despite the unrivalled spatial resolution and depth penetration of active-source seismic methods used for mineral exploration in hardrock environment, economic and environmental restrictions (e.g., source permitting) may preclude its full-scale application. In such a case, 2D passive reflection seismics can be considered a cost-effective way...

journal article 2021

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Rapid Whole-Knee Quantification of Cartilage Using T ₁, T ₂ ^∗, and T _RAFF2 Mapping With Magnetic Resonance Fingerprinting

Tourais, Joao (author), Ploem, T.W. (author), Zadelhoff, Tijmen A.van (author), Steeg-Henzen, Christal van de (author), Oei, Edwin H.G. (author), Weingärtner, S.D. (author)

Objective: Quantitative Magnetic Resonance Imaging (MRI) holds great promise for the early detection of cartilage deterioration. Here, a Magnetic Resonance Fingerprinting (MRF) framework is proposed for comprehensive and rapid quantification of T ₁, T ₂ ^∗, and T _RAFF2 with whole-knee coverage....

journal article 2023

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Ultrasonic imaging through aberrating layers using covariance matching

van der Meulen, P.Q. (author), Coutino, Mario (author), Bosch, Johannes G. (author), Kruizinga, P. (author), Leus, G.J.T. (author)

We consider the scenario of finding the transfer function of an aberrating layer in front of a receiving ultrasound (US) array, assuming a separate non-aberrated transmit source. We propose a method for blindly estimating this transfer function without exact knowledge of the ultrasound sources or acoustic contrast image, and without directly...

journal article 2023

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Chessboard Focal Plane Array for a CMOS-Integrated Terahertz Camera

Hoogelander, M. (author), van Berkel, S.L. (author), Malotaux, E.S. (author), Alonso Del Pino, M. (author), Cavallo, D. (author), Spirito, M. (author), Llombart, Nuria (author)

This article presents the development of a focal plane array (FPA) for terahertz imaging applications with a near diffraction-limited resolution achieved through a very tight sampling of the focal plane. The antenna array is integrated with direct detectors in a 22-nm CMOS technology and operates from 200 to 600 GHz. The tight sampling of the...

journal article 2023

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Research Note: Near-surface layer replacement for sparse data: Is interpolation needed?

Sun, Yimin (author), Verschuur, D.J. (author), Luo, Yi (author)

Near-surface problem is a common challenge faced by land seismic data processing, where often, due to near-surface anomalies, events of interest are obscured. One method to handle this challenge is near-surface layer replacement, which is a wavefield reconstruction process based on downward wavefield extrapolation with the near-surface...

journal article 2017

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A Front-End ASIC With High-Voltage Transmit Switching and Receive Digitization for 3-D Forward-Looking Intravascular Ultrasound Imaging

Tan, M. (author), Chen, C. (author), Chen, Z. (author), Janjic, Jovana (author), Daeichin, V. (author), Chang, Z.Y. (author), Noothout, E.C. (author), van Soest, G. (author), Verweij, M.D. (author), de Jong, N. (author), Pertijs, M.A.P. (author)

This paper presents an area- and power-efficient application-specified integrated circuit (ASIC) for 3-D forward-looking intravascular ultrasound imaging. The ASIC is intended to be mounted at the tip of a catheter, and has a circular active area with a diameter of 1.5 mm on the top of which a 2-D array of piezoelectric transducer elements is...

journal article 2018

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Joint migration inversion: Features and challenges

Sun, Yimin (author), Kim, Young Seo (author), Qu, S. (author), Verschuur, D.J. (author)

Joint migration inversion is a recently proposed technology, accommodating velocity model building and seismic migration in one integrated process. Different from the widely accepted full waveform inversion technology, it uses imaging parameters, i.e. velocities and reflectivities of the subsurface, to parameterize its solution space. The...

journal article 2020

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Refraction-Corrected Transcranial Ultrasound Imaging through the Human Temporal Window using a Single Probe

Mozaffarzadeh, M. (author), Verschuur, D.J. (author), Verweij, M.D. (author), Daeichin, V. (author), de Jong, N. (author), Renaud, G.G.J. (author)

Transcranial ultrasound imaging (TUI) is a diagnostic modality with numerous applications, but unfortunately, it is hindered by phase aberration caused by the skull. In this article, we propose to reconstruct a transcranial B-mode image with a refraction-corrected synthetic aperture imaging (SAI) scheme. First, the compressional sound...

journal article 2022

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An automated workflow based on hip shape improves personalized risk prediction for hip osteoarthritis in the CHECK study

Gielis, W. P. (author), Weinans, Harrie (author), Welsing, P. M.J. (author), van Spil, W. E. (author), Agricola, R. (author), Cootes, T. F. (author), de Jong, P. A. (author), Lindner, C. (author)

Objective: To design an automated workflow for hip radiographs focused on joint shape and tests its prognostic value for future hip osteoarthritis. Design: We used baseline and 8-year follow-up data from 1,002 participants of the CHECK-study. The primary outcome was definite radiographic hip osteoarthritis (rHOA) (Kellgren–Lawrence grade ≥2...

journal article 2020

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Independent Component Analysis Filter for Small Vessel Contrast Imaging During Fast Tissue Motion

Wahyulaksana, G. (author), Wei, Luxi (author), Schoormans, Jasper (author), Voorneveld, J.D. (author), van der Steen, A.F.W. (author), de Jong, N. (author), Vos, H.J. (author)

Suppressing tissue clutter is an essential step in blood flow estimation and visualization, even when using ultrasound contrast agents. Blind source separation (BSS)-based clutter filter for high-framerate ultrasound imaging has been reported to perform better in tissue clutter suppression than the conventional frequency-based wall filter and...

journal article 2022

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Order-controlled closed-loop focal beams and resolution comparison of primary and multiple reflections for seismic acquisition geometries

Wei, Wei (author), Blacquière, G. (author)

Focal beam analysis has built a bridge between the acquisition parameters on the surface and the image quality of underground targets. However, as a practical matter, it is still difficult to answer how to choose a proper acquisition geometry according to the complexity of medium, especially considering the contradictory effects of multiple...

journal article 2021

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Determination of mechanical properties of biofilms by modelling the deformation measured using optical coherence tomography

Picioreanu, C. (author), Blauert, Florian (author), Horn, Harald (author), Wagner, Michael (author)

The advantage of using non-invasive imaging such as optical coherence tomography (OCT) to asses material properties from deformed biofilm geometries can be compromised by the assumptions made on fluid forces acting on the biofilm. This study developed a method for the determination of elastic properties of biofilms by modelling the biofilm...

journal article 2018

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Marchenko imaging by unidimensional deconvolution

M. A. Matias, Mayara (author), da C. Pestana, Reynam (author), van der Neut, J.R. (author)

Obtaining an accurate image of the subsurface still remains a great challenge for the seismic method. Migration algorithms aim mainly on positioning seismic events in complex geological contexts. Multiple reflections are typically not accounted for in this process, which can lead to the emergence of artefacts. In Marchenko imaging, we...

journal article 2018

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Angle-insensitive Human Motion and Posture Recognition Based on 4D imaging Radar and Deep Learning Classifiers

Zhao, Yubin (author), Yarovoy, Alexander (author), Fioranelli, F. (author)

The need for technologies for Human Activity Recognition (HAR) in home environments is becoming more and more urgent because of the aging population worldwide. Radar-based HAR is typically using micro-Doppler signatures as one of the main data representations, in conjunction with classification algorithms often inspired from deep learning...

journal article 2022