What is an artifact in a signal?
In natural science and signal processing, an artifact or artefact is any error in the perception or representation of any information introduced by the involved equipment or technique(s).
What is an artifact in sleep study?
In a sleep study, an artifact is an extraneous signal that represents activity other than what is intended for a given channel on a PSG.
What is motion artifact in pulse oximetry?
Metadata. Abstract: Oxygen saturation estimates from pulse oximeters (SpO 2 ) have been shown to be unreliable in the presence of motion artifact. This may cause errors in the clinical environment if the device falsely detects normal or desaturated conditions.
What is an artifact in medical terms?
1. Anything (especially in a histologic specimen or a graphic record) that is caused by the technique used or is not a natural occurrence but is merely incidental. 2. A skin lesion produced or perpetuated by self-inflicted action, such as scratching in dermatitis artefacta.
What is artifact EEG?
Artifacts are signals recorded by EEG but not generated by brain. Some artifact may mimic true epileptiform abnormalities or seizures. Awareness of logical topographic field of distribution for true EEG abnormality is important in distinguishing artifact from brain waves.
What does artifact mean on CT scan?
In computed tomography (CT), the term artifact is applied to any systematic discrepancy between the CT numbers in the reconstructed image and the true attenuation coefficients of the object.
What does motion artifact mean?
When a patient moves, it can cause distortion on the image, which is referred to as a motion artifact. Motion artifacts may appear as a blurring of contrast or edges, replication of part or all of a structure, signal loss or undesired strong signals.
What does artifact mean on a CT scan?
What does artifact mean in MRI?
An MRI artifact is a visual artifact (an anomaly seen during visual representation) in magnetic resonance imaging (MRI). It is a feature appearing in an image that is not present in the original object.
What is the cause of artifact?
Electromagnetic interference (EMI) artifact usually results from electrical power lines, electrical equipment, and mobile telephones. In the United States this is sometimes referred to as 60 cycle interference (or 60 Hz pickup).
What causes artifact on ECG?
Causes of electrical artifacts on ECGs are manifold. External artifacts are usually caused by line current, which has a frequency of 50 Hz or 60 Hz. Internal electrical artifacts can be caused by tremors, muscle shivering, hiccups or, as in the present case, medical devices.
How to analyze the signal to detect an artifact?
The signal to analyze is read from the continuous file (options “Channel name” and “Time window”). Frequency band: The signal is filtered in a frequency band where the artifact is easy to detect. For EOG: 1.5-15Hz ; for ECG: 10-40Hz.
How do you detect artifact in ECG?
Frequency band: The signal is filtered in a frequency band where the artifact is easy to detect. For EOG: 1.5-15Hz ; for ECG: 10-40Hz. Threshold: An event of interest is detected if the absolute value of the filtered signal value goes over a given number of times the standard deviation.
What causes artifactual activity on EEG?
This artifactual activity can be caused by a range of sources such as electrical (ventilators, incubator heaters, mains power lines, pumps) or biological (movement, muscle activity, ECG/pulse, and respiration). While artifact detection is a critical component of any EEG interpretation, it is the most neglected in terms of automated EEG analysis.
Why is it important to detect and identify pacing artifacts?
It is important to be able to detect and identify pacing artifacts because they indicate the presence of the pacemaker—and help in evaluating its interaction with the heart.