document

SPAD-based Light Detection and Ranging for 3D imaging: Receiver operation and in-pixel TDC design for automotive application

Son, Dongjin (author)

In this work, a SPAD-based LiDAR system is studied. In particular, the system employs a direct time-of-flight (dToF) method to reconstruct a target-reflected pulses using histogram, from which the distance to the target is estimated. More particularly, a time correlated single photon counting (TCSPC) method has been used to record the flight...

master thesis 2022

document

Evaluating different localization methods for robotic swarming

Dukker, Sven (author), Minten, Melle (author)

Localization is an important element for a moving swarm of robots. A swarm contains many individuals, and it is essential that the swarm members do not collide. Expensive and complex implementations to localize others is undesirable. Hence, a localization system designed using the available resources is desired. The available techniques that...

bachelor thesis 2022

document

Time of Flight in Perspective: Instrumental and Computational Aspects of Time Resolution in Positron Emission Tomography

Schaart, D.R. (author), Schramm, Georg (author), Nuyts, Johan (author), Surti, Suleman (author)

The first time-of-flight positron emission tomography (TOF-PET) scanners were developed as early as in the 1980s. However, the poor light output and low detection efficiency of TOF-capable detectors available at the time limited any gain in image quality achieved with these TOF-PET scanners over the traditional non-TOF PET scanners. The...

review 2021

document

Phenotypic characterization by mass cytometry of the microenvironment in ovarian cancer and impact of tumor dissociation methods

Anandan, Shamundeeswari (author), Thomsen, Liv Cecilie V. (author), Gullaksen, Stein Erik (author), Abdelaal, T.R.M. (author), Kleinmanns, Katrin (author), Skavland, Jørn (author), Bredholt, Geir (author), Gjertsen, Bjørn Tore (author), McCormack, Emmet (author), Bjørge, Line (author)

Improved molecular dissection of the tumor microenvironment (TME) holds promise for treating high-grade serous ovarian cancer (HGSOC), a gynecological malignancy with high mortality. Reliable disease-related biomarkers are scarce, but single-cell mapping of the TME could identify patient-specific prognostic differences. To avoid technical...

journal article 2021

document

Physics and technology of time-of-flight PET detectors

Schaart, D.R. (author)

The imaging performance of clinical positron emission tomography (PET) systems has evolved impressively during the last ∼15 years. A main driver of these improvements has been the introduction of time-of-flight (TOF) detectors with high spatial resolution and detection efficiency, initially based on photomultiplier tubes, later silicon...

review 2021

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Modeling and Analysis of a Direct Time-of-Flight Sensor Architecture for LiDAR Applications

Padmanabhan, P. (author), Zhang, C. (author), Charbon-Iwasaki-Charbon, E. (author)

Direct time-of-flight (DTOF) is a prominent depth sensing method in light detection and ranging (LiDAR) applications. Single-photon avalanche diode (SPAD) arrays integrated in DTOF sensors have demonstrated excellent ranging and 3D imaging capabilities, making them promising candidates for LiDARs. However, high background noise due to solar...

journal article 2019

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Proximity Sensing using Time-of-Flight and Single-Photon Avalanche Diodes: Measuring travel time of infrared photons in well-lit environments

Hill, Kevin (author)

Most current proximity sensing methods fail the stringent requirements of modern smartphones. A position-sensing device (PSD) requires a laser placed some distance away from the sensor, intensity-based solutions are sensitive to changes in reflectivity, and ultrasound-based sensors cannot measure small distances because of resonance. With modern...

master thesis 2019

document

CMOS SPAD Sensors for 3D Time-of-Flight Imaging, LiDAR and Ultra-High Speed Cameras

Zhang, C. (author)

In conventional applications, such as bio-imaging and microscopy, SPAD is typically used as a single-photon counter. However, this advantage has been challenged by other photon-counting technologies, especially from CMOS-based QIS. Comparatively, apart from single-photon counting capability, QIS is superior to SPAD in terms of intrinsic multi...

doctoral thesis 2019

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A CMOS SPAD Imager with Collision Detection and 128 Dynamically Reallocating TDCs for Single-Photon Counting and 3D Time-of-Flight Imaging

Zhang, C. (author), Lindner, S.A. (author), Antolović, I.M. (author), Wolf, Martin (author), Charbon-Iwasaki-Charbon, E. (author)

Per-pixel time-to-digital converter (TDC) architectures have been exploited by single-photon avalanche diode (SPAD) sensors to achieve high photon throughput, but at the expense of fill factor, pixel pitch and readout efficiency. In contrast, TDC sharing architecture usually features high fill factor at small pixel pitch and energy efficient...

journal article 2018

document

Development of Time of Flight Modulation of Intensity by Zero Effort for Larmor

Geerits, Niels (author)

A time of flight MIEZE spectrometer, which employs radio frequency spin flippers with square pole shoes and a magnetic yoke is presented. These flippers can achieve higher fields than conventional resonant RF flippers, which employ an air core. High fields are crucial for the construction of a high resolution and compact MIEZE spectrometer....

master thesis 2018

document

Sub-3 mm, near-200 ps TOF/DOI-PET imaging with monolithic scintillator detectors in a 70 cm diameter tomographic setup

Borghi, G. (author), Tabacchini, V. (author), Bakker, P.J. (author), Schaart, D.R. (author)

Recently, a monolithic scintillator detector for time-of-flight (TOF)/depth-of-interaction (DOI) positron emission tomography (PET) was developed. It has a detector spatial resolution of ∼1.7 mm full-width-at-half-maximum (FWHM), a coincidence resolving time (CRT) of ∼215 ps FWHM, and ∼4.7 mm FWHM DOI resolution. Here, we demonstrate, for the...

journal article 2018

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Towards a Full-Flexible and Fast-Prototyping TOF-PET Block Detector Based on TDC-on-FPGA

Venialgo Araujo, E. (author), Lusardi, Nicola (author), Garzetti, Fabio (author), Geraci, Angelo (author), Brunner, S. (author), Schaart, D.R. (author), Charbon-Iwasaki-Charbon, E. (author)

Typically, a time-of-flight (TOF) PET block detector is built using application-specific integrated circuits (ASICs), since they integrate a high number of channels at a reasonable power consumption and into a small area. However, ASICs’ flexibility is limited and prototyping times are long because a semiconductor fabrication process is required...

journal article 2018

document

Simulation of proton range monitoring in an anthropomorphic phantom using multi-slat collimators and time-of-flight detection of prompt-gamma quanta

Cambraia Lopes, Patricia (author), Crespo, Paulo (author), Simões, Hugo (author), Ferreira Marques, Rui (author), Parodi, Katia (author), Schaart, D.R. (author)

Prompt-gamma (PG) imaging has the potential for monitoring proton therapy in real time. Different approaches are investigated. We focus on developing multi-slat collimators to image PG quanta, aiming at optimizing collimator performance to detect deviations in treatment delivery. We investigated six different multi-slat configurations, which...

journal article 2018

document

BGO as a hybrid scintillator / Cherenkov radiator for cost-effective time-of-flight PET

Brunner, S. (author), Schaart, D.R. (author)

Due to detector developments in the last decade, the time-of-flight (TOF) method is now commonly used to improve the quality of positron emission tomography (PET) images. Clinical TOF-PET systems based on L(Y)SO:Ce crystals and silicon photomultipliers (SiPMs) with coincidence resolving times (CRT) between 325 ps and 400 ps FWHM have recently...

journal article 2017

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Improved image quality using monolithic scintillator detectors with dual-sided readout in a whole-body TOF-PET ring: A simulation study

Tabacchini, V. (author), Surti, Suleman (author), Borghi, G. (author), Karp, Joel S. (author), Schaart, D.R. (author)

We have recently built and characterized the performance of a monolithic scintillator detector based on a 32 mm × 32 mm × 22 mm LYSO:Ce crystal read out by digital silicon photomultiplier (dSiPM) arrays coupled to the crystal front and back surfaces in a dual-sided readout (DSR) configuration. The detector spatial resolution appeared to be...

journal article 2017

document

Modelling of ultrasonic beam propagation from an array through transversely isotropic fibre reinforced composites using Multi Gaussian beams

Anand, C. (author), Shroff, S. (author), Groves, R.M. (author), Benedictus, R. (author)

Ultrasonic arrays are used for non-destructive evaluation of structures for aerospace and other applications. With the increase in the usage of fibre-reinforced composites in aerospace structures, this evaluation becomes complex due to the effects of attenuation and reflection from the layer boundaries in composite laminates. Hence there is...

conference paper 2017

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A comprehensive characterization of the time resolution of the Philips Digital Photon Counter

Brunner, S. (author), Gruber, L. (author), Hirtl, A. (author), Suzuki, K. (author), Marton, J. (author), Schaart, D.R. (author)

Photodetectors with excellent time resolution are becoming increasingly important in many applications in medicine, high energy- and nuclear physics applications, biology, and material science. Silicon photomultipliers (SiPM) are a novel class of solid-state photodetectors with good timing properties. While the time resolution of analog SiPMs...

journal article 2016

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First in situ TOF-PET study using digital photon counters for proton range verification

Cambraia Lopes, P (author), Bauer, J. (author), Salomon, A. (author), Rinaldi, I (author), Tabacchini, V. (author), Tessonnier, T. (author), Crespo, P (author), Parodi, K (author), Schaart, D.R. (author)

Positron emission tomography (PET) is the imaging modality most extensively tested for treatment monitoring in particle therapy. Optimal use of PET in proton therapy requires in situ acquisition of the relatively strong ¹⁵O signal due to its relatively short half-life (∼2 min) and high oxygen content in biological tissues, enabling...

journal article 2016

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Time-of-Flight Mass Spectrometric Analysis of Ionic Liquid Electrospray Emission: Effects of Liquid Constituents and Ion Transport on Emission of Binary Ionic Liquid Mixtures

Heldens, J.C. (author)

Ionic liquid ions sources (ILIS) are under investigation for their application in micro-propulsion for small spacecraft as well as their potential bene?ts for mass spectrometry. Micro-fabricated ILIS based thrusters have been under investigation at the École Politechnique Fédérale de Lausanne (EPFL), the Massachusetts Institute of Technology,...

master thesis 2015

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Time-resolved imaging of prompt-gamma rays for proton range verification using a knife-edge slit camera based on digital photon counters

Cambraia Lopes, P. (author), Clementel, E. (author), Crespo, P. (author), Henrotin, S. (author), Huizenga, J. (author), Janssens, G. (author), Parodi, K. (author), Prieels, D. (author), Roellinghoff, F. (author), Smeets, J. (author), Stichelbaut, F. (author), Schaart, D.R. (author)

Proton range monitoring may facilitate online adaptive proton therapy and improve treatment outcomes. Imaging of proton-induced prompt gamma (PG) rays using a knife-edge slit collimator is currently under investigation as a potential tool for real-time proton range monitoring. A major challenge in collimated PG imaging is the suppression of...

journal article 2015