Pile-up Artifacts
Pile-up Artifacts - Related Videos
08:57
Introduction to the Power Pole Board
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2023
Source: Ali Bazzi, Department of Electrical Engineering, University of Connecticut, Storrs, CT. DC/DC converters are power electronic converters that convert DC voltages and currents from a certain level to another level. Typically, voltage conversion is the main purpose of DC/DC converters and three main types of conversion exist in a single converter: stepping up, stepping down, and stepping up or down. Among the most common step-up converters are boost converters (Refer to this collections...
01:24
Pole and System Stability
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2024
The transfer function is a fundamental concept representing the ratio of two polynomials. The numerator and denominator encapsulate the system's dynamics. The zeros and poles of this transfer function are critical in determining the system's behavior and stability. Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's response.
14:21
Dissection of Organizer and Animal Pole Explants from Xenopus laevis Embryos and Assembly of a Cell Adhesion Assay
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Cited by 2 •
2007
This video demonstrates the technique used for preparation of organizer and animal pole explants from Xenopus laevis embryos, including the use of the eyebrow knife - a specialized dissection tool made of one's eyebrow. The protocol for assembling an adhesion assay is also given, which probes for the presence of key adhesion molecules present on the surface organizer or animal pole cells that are critical for proper development.
06:42
A Multi-hole Cryovial Eliminates Freezing Artifacts when Muscle Tissues are Directly Immersed in Liquid Nitrogen
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Cited by 9 •
2017
This protocol describes a procedure to freeze muscle tissues by plunging them directly into liquid nitrogen. This protocol also highlights a new cryovial that can avoid the "blanket effect" of nitrogen gas when liquid nitrogen contacts the tissue surface of a specimen.
10:23
Equipment Setup and Artifact Removal for Simultaneous Electroencephalogram and Functional Magnetic Resonance Imaging for Clinical Review in Epilepsy
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Cited by 1 •
2023
This article details simultaneous electroencephalogram and functional magnetic resonance imaging (EEG-fMRI) recording procedures that can be used in both clinical and research settings. EEG processing procedures to remove imaging artifacts for clinical review are also included. This study focuses on the example of epilepsy during the interictal period.
FAQs
The detector’s resolving time determines how closely spaced signals can be before the system treats them as one measurement. If several events arrive within that interval, the recorded result may combine their pulse information instead of preserving each event separately. This makes resolving time a central engineering parameter for limiting amplitude, energy, timing, and counting errors.
Overlapping pulses can produce a single recorded event whose amplitude or energy does not represent any individual signal. Timing information may also become inaccurate, while some events disappear from the count entirely. In a spectrum, these effects can distort the expected distribution and create false features, making interpretation less reliable at elevated event rates.
High event rates increase the chance that signals arrive during the detector’s resolving or processing interval. The problem is therefore especially important when radiation detection, spectroscopy, particle counting, or imaging systems operate under conditions with many closely spaced events. Electronics that process pulses slowly can further limit the system’s ability to separate those signals.
Common mitigation strategies include using faster electronics, applying pulse-shape analysis, correcting for dead time, and controlling the count rate. Faster processing helps separate closely spaced pulses, while pulse-shape analysis supports discrimination between overlapping signal forms. Dead-time correction and controlled operating conditions help compensate for or limit losses in recorded events.
Engineers should assess them whenever a system measures discrete signals at potentially high event rates. Radiation detectors, spectrometers, particle counters, and imaging systems are particularly relevant because overlapping events can affect counts, spectra, amplitudes, energies, and timing. Evaluating the issue during design and operation supports more accurate measurements and improves overall system reliability.
Testing under controlled count-rate conditions can show how measurement quality changes as events become more frequent. Engineers can examine whether counts are missed, spectra become distorted, or recorded amplitudes, energies, and timing values deviate from expected results. These observations help determine whether faster electronics, pulse-shape analysis, dead-time correction, or reduced event rates are needed.