Searched for: subject%3A%22speckle%22
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van As, K. (author)
Cardiovascular diseases are one of the leading causes of death worldwide, for example by causing strokes. Timely diagnosis of such diseases is pivotal for a patient’s chance of survival. Furthermore, in the present world in which medical expenses are going through the roof, we can save greatly on costs if certain diseases are detected in an...
doctoral thesis 2024
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Zeng, Y. (author)
doctoral thesis 2023
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Tao, N. (author)
THICK composite materials, e.g., thickness of more than 50 mm, are increasingly being used across diverse industry sectors owing to their significant advantages of weightsavings, superiormaterial properties and load-carrying capability. These materials tend to be adopted in safety-critical applications such as large primary or secondary load...
doctoral thesis 2023
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Jin, J. (author)
Laser Doppler vibrometer (LDV) is a vibration-detecting instrument for noncontact and non-destructive measurement. It is superior to classic contact transducers in terms of the wide frequency range and high measurement resolution. LDV on moving platforms (LDVom) is one of the LDV measurement technology to one-way scan the vibrating surface, so...
doctoral thesis 2023
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Fang, Yitian (author), van Ooijen, Lisanne (author), Ambagtsheer, Gisela (author), Nikolaev, Anton V. (author), Clahsen-van Groningen, Marian C. (author), Dankelman, J. (author), de Bruin, Ron W.F. (author), Minnee, Robert C. (author)
Objectives: Normothermic machine perfusion (NMP) provides a platform for pre-transplant kidney quality assessment that is essential for the use of marginal donor kidneys. Laser speckle contrast imaging (LSCI) presents distinct advantages as a real-time and noncontact imaging technique for measuring microcirculation. In this study, we aimed to...
journal article 2023
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van Ooijen, Lisanne (author)
In the Netherlands, over 12% of the population has chronic kidney damage resulting in about 2000 patients with renal failure each year. Replacement of the kidney function by transplantation is desired, but due to a shortage of donor kidneys, the waiting list for a transplant is...
master thesis 2022
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Teeuwen, Tom (author)
<b>OBJECTIVE </b>This study aims to compare non-invasive real-time optical imaging and measuring methods for the quantification of microcirculation of organs during normothermic machine perfusion (NMP). This could help to determine which method is most promising for further development towards a clinical objective transplantability assessment...
master thesis 2022
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Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)
Speckle noise is a major problem for structural vibration measurements with Laser Doppler vibrometer on moving platform (LDVom) due to its highly random, frequent, and broadband nature, especially at high speeds. This paper develops a new post-processing framework to reduce speckle noise based on a case study of LDVom measurements on railway...
journal article 2022
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Jin, J. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)
Laser Doppler Vibrometer (LDV) is extensively applied in remote and precise vibration measurements for structural monitoring. Speckle noise is a severe signal issue restricting LDV applications, mainly when an LDV scans from moving platforms. Realistic simulations and thorough characterizations of speckle noise can support the despeckle...
journal article 2022
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Jin, J. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)
With increasing requirements for structural stability and durability, effective monitoring strategies for existing and potential damage are necessary. A laser Doppler vibrometer on moving platforms (LDVom) can remotely capture large-scale structural vibrations, but speckle noise, a significant signal issue mainly when one-way continuously...
journal article 2022
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van As, K. (author), Simons, Bram A. (author), Kleijn, C.R. (author), Kenjeres, S. (author), Bhattacharya, N. (author)
We study how the speckle contrast depends on scatterer velocity, with the goal of further developing laser speckle imaging as a quantitative measurement technique. To that end, we perform interferometric computer simulations on a dilute plug flow. The results of our numerical experiment, that we compare with known analytical expressions to...
journal article 2022
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Jin, J. (author), Li, Z. (author)
This paper presents a novel approach for eliminating speckle noises in Laser Doppler Vibrometer signals based on empirical wavelet transform (EWT). The moving root-mean-square thresholds are utilized to cut off signal drop-outs and produce noise discontinuity that EWT can identify. The extremum ratio behaves as the criterion to reject or accept...
conference paper 2021
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Waasdorp, R. (author), Mugge, W. (author), Vos, H.J. (author), De Groot, Jurriaan H. (author), Verweij, M.D. (author), de Jong, N. (author), Schouten, A.C. (author), Daeichin, V. (author)
Skeletal muscles generate force, enabling movement through a series of fast electro-mechanical activations coordinated by the central nervous system. Understanding the underlying mechanism of such fast muscle dynamics is essential in neuromuscular diagnostics, rehabilitation medicine and sports biomechanics. The unique combination of...
journal article 2021
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Pakdaman Zangabad, Reza (author), Iskander-Rizk, Sophinese (author), van der Meulen, P.Q. (author), Meijlink, Bram (author), Kooiman, Klazina (author), Wang, Tianshi (author), van der Steen, A.F.W. (author), van Soest, Gijs (author)
Photoacoustic (PA) imaging can be used to monitor flowing blood inside the microvascular and capillary bed. Ultrasound speckle decorrelation based velocimetry imaging was previously shown to accurately estimate blood flow velocity in mouse brain (micro-)vasculature. Translating this method to photoacoustic imaging will allow simultaneous...
journal article 2021
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Kumar, Karishma (author)
Detailed imaging of blood flow may improve the understanding of brain functions. The state-of-the-art non-invasive flow imaging of the brain is limited to a one-dimensional Doppler setting. We propose a method to estimate the two-dimensional flow vector in the fine vascular network of the brain by using a speckle tracking technique. The...
master thesis 2020
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Waasdorp, Rick (author)
Muscles generate force and enable movement. After excitation of a muscle the muscle fibers contract. Methods to assess muscle contraction in vivo are scarce. Electromechanical delay (EMD), defined as the time lag between muscle excitation and contraction onset, has been proposed as a measure for contraction efficiency, but provides limited...
master thesis 2019
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de Graaf, Jurjan (author)
Fascicle shear is theoretically a mechanism by which skeletal muscles lengthen. Existing ultrasound based techniques allow measurement of muscle architecture parameters, but not the quantification of shear strain. In this study, an algorithm that tracks the shear strain from ultrasound images using a continuum representation of the muscle was...
master thesis 2019
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Gomarasca, Silvia (author)
master thesis 2018
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Van Hauwermeiren, Amber (author)
Clear ice formation on aircraft is a large economic and safety problem. The phenomenon, also known as ‘freezing rain’, usually occurs when subcooled rain droplets impact the aircraft while it descends from high altitude to prepare for landing. It can quickly increase the aerodynamic drag by up to 80% and reduce the lift force by 50%. Inefficient...
master thesis 2018
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van der Walle, P (author), Kramer, E. (author), van der Donck, J.C.J. (author), Mulckhuyse, W (author), Nijsten, L. (author), Bernal Arango, F.A. (author), de Jong, A. (author), van Zeijl, E. (author), Spruit, H. E.T. (author), van den Berg, J.H. (author), Nanda, G. (author), van Langen-Suurling, A.K. (author), Alkemade, P.F.A. (author), Pereira, S.F. (author), Maas, D.J. (author)
Particle defects are important contributors to yield loss in semi-conductor manufacturing. Particles need to be detected and characterized in order to determine and eliminate their root cause. We have conceived a process flow for advanced defect classification (ADC) that distinguishes three consecutive steps; detection, review and...
conference paper 2017
Searched for: subject%3A%22speckle%22
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