Tech Tips: A Checklist for Troubleshooting Artifacts:  

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Artifacts in Neurodiagnostic testing are ubiquitous and found in every recording, and therefore, as the eyes and ears of the physician, it is every technologist’s responsibility to minimize the effect(s) of artifacts on the recording and improve the overall interpretability of the recording. There are many common artifacts that technologists troubleshoot daily, however, an astute technologist approaches artifact troubleshooting in a systematic and meticulous way to ensure an efficient and effective resolution. Furthermore, and most importantly, an astute technologist will document, document, document, not just the source(s) of artifact, but the steps taken to determine, isolate and reduce or eliminate the artifact.   

In an effort to provide technologists with a convenient source of documentation, below is a general checklist, which is by no means a comprehensive list, but it provides a general guide to walk through the systematic process of troubleshooting artifacts  

1 

Check input cables  

 

  Electrode connections into headbox amplifier  

 

  Headbox connection to the computer 

 

  Computer connection to the monitor 

 

 

2 

Check electrodes 

 

  Electrode placement into appropriate headbox designation (tap test) 

 

  Electrodes are securely attached to patient 

 

  Electrode wires securely bundled together (can help reduce 60 Hz) 

 

  Individual electrode integrity, change/replace for isolated activity 

 

 

3 

Check electrode placement  

 

 Distance between electrodes is consistent and equal 

 

 Ensure no salt bridge is present and any sweat from the patient is minimized 

 

 

4 

Check impedances 

 

  10 Ω 

 

  Balanced 

 

  Ground and system reference electrode integrity 

 

 

5 

Check montage (ANCS Guideline 3: https://www.acns.org/UserFiles/file/Guideline3-ProposalforStandardMontagestobeUsedinClinicalEEG_v1.pdf 

 

 Referential 

 

 Longitudinal Bipolar 

 

 Transverse Bipolar 

 

 Ensure the selected montage is appropriate for the test 

 

 Change/test montage setting which may help localize the artifact 

 

 

6 

Check chart speed/timescale (ACNS Guideline 1: 10–20 seconds/page, depending on display size [should correspond to chart speed of 30 mm/second) 

 

 

7 

Check filter settings (ACNS Guideline 1: https://www.acns.org/UserFiles/file/Guideline1-MinimumTechnicalRequirementsforPerofrmingClinicalEEG_v1.pdf 

 

 HFF (ACNS Guideline 1: 70 Hz [–3Db]) 

 

 LFF (ACNS Guideline 1:  1 Hz [23 dB], i.e., time constant of at least 0.16 second) 

 

 Notch (ACNS Guideline 1: Only used when other measures to reduce 60 Hz fail) 

 

 

8 

Check sensitivity (per Guideline 1, range of 5–10 µV/mm; commonly set to 7 µV/mm) 

 

 

9 

Check the patient for physiologic sources of artifact and patient surroundings for non-physiologic sources 

 

 ECG/EKG 

 

 Respiration 

 

 Glossokinetic, mouth movement 

 

 Review medical record for implantable devices: cochlear implant, pacemaker, DBS, etc. 

 

 Proximity of cell phone or other mobile device 

 

 Proximity of headbox or equipment cables to patient bed monitors and/or cable 

 

 Proximity of headbox or equipment cables to ancillary monitors in the patient room 

 

 

10 

Check software settings 

 

 Camera and/or audio settings 

 

 Common mode rejection ratio (CMRR) 

 

 Ensure filter and sensitivity settings are consistent for all channels 

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