Artifacts Flashcards
Describe electroretinagram artifact and how to monitor it
Seen during photic in the prefrontal leads (fp1/fp2) most often at high sensitivities needed for recording suspected electrocerebral inactivity. Artifact will match the frequency of photic
hold an opaque card over eye to block photic light flash from reaching retina
Describe tremor artifact and how to monitor it
Rhythmic theta activity with myogenic potentials superimpoced that occurs at 4-7 hz as the head or body tremors
-Put leads on extremities with tremors
Describe how to monitor eye movement artifact
Place additional electrodes infraorbitally or on that outer canthus of each eye
reference eye leads to ear
How are 60hz artifacts caused by electromagnetic effects? How do you eliminate them?
- Caused by electrical appliances or equipment
- eliminate by determining cause of 60hz and remove , put on battery power, or turn off
Describe EKG artifact and how to monitor it
No way to eliminate
You can use 2ekg leads (1 on upper right 1 upper left or on each wrist
What causes glossokinetic artifact and how do you monitor it?
Artifact from tongue movement tip of tongue is negative:root of tongue is positive
-Monitor by placing one electrode above from mouth and one below , ask patient to say ‘lilt/ “lala” to produce artifact
Describe pacemaker artifact and how to monitor it?
Seen as a fast spike which is the electrical stimulus delivered to the heart by an internal cardiac pacemaker
-Seen in channel monitoring ekg
What is corneoretinal potential?
The cornea is (+) relative to the retina which is (-)
Describe respiration artifact and how to monitor it?
Fairly rhythmic slow activity that is synchronous with movement related to respiration
try to eliminate by repositioning patients head
How are 60 hz artifact caused by electrostatic effects? How do you eliminate them?
Caused by capacitarice between 60 hz conductor
Eliminate by determing cause and removing
Describe an electrode malfunction artifact and how to eliminate it
Caused by an electrically unstable electrode of high impedance “electrode pop”
-Eliminate by repairing electrode
Describe pulse artifact and how to monitor it
Periodic slow wave that has a slight delay from but is time locked to the EKG waveform
-Monitor by recording ekg
Describe muscle artifact and how to eliminate it
A very short duration potentials that usually occurs in clusters or periodic runs
-To eliminate ask pt to relax jaw
Describe skin potentials artifact and how to eliminate and monitor it
Areas of skin with many sweat glands are electrically negative, sweat glands can generate electrical potentials when active. Sweating can cause slow waves, most likely slow rolling delta waves. Eleminate by wiping head with alcohol cool head, ETC
Place 2 leads on hand , one on palm, one on dorsum
Describe an intravenous (IV) drip artifact and how to monitor it
Resembles EKG artifact
Monitor by typing “X” on EEG
eliminate by asking nurse to turn off use or use battery power
