Error Signal is excluded from SatScreen's data analysis. 

This article reviews the purpose of the error signal message, common causes of error during data collection, and tips for minimizing the amount of error noted in your reports.

Error Signal Messages:

The yellow Error Signal message in a SatScreen report serves to notify the clinician to review the raw data to determine if there is a sufficient amount of valid data to form conclusions from the results. Valid Recording Time, the % Error noted and the underlying cause of error should be considered when determining if a repeat study is required. If repeat testing produces the same results, the clinician may wish to consider whether an alternate testing method may be appropriate (such as a polysomnogram)

Common Causes of Error:

  • Excessive movement not associated with a respiratory event. 
  • Diminished signal. For example, excessive pressure or poor circulation caused by laying on the probe, improper application of the probe, acrylic nails/dark nail polish, or poor peripheral perfusion. 
    • This will typically show up in the raw data as repeated periods where the signal drops to zero, or a significant change in the signal’s baseline just after a movement.
  • No signal. I.e., if the probe falls off, the patient takes it off, the patient starts the study early or the patient forgets to turn the oximeter off when he/she gets out of bed in the morning.

Tips for Minimizing Error (Minolta Pulsox-300i):

  • Wear the oximeter probe on ring or pinky finger of non-dominant hand.
  • Secure the probe.
    1. Place the probe on the finger (cable facing the back of the hand), then use a cloth probe cover over top of the probe to hold it in place. 
2.  You can also secure the oximeter by using a small strip of medical tape to tape the probe cord loosely to the back of the hand as shown above. *The probe should not be taped to the finger as this may restrict bloodflow.
  • Do not turn oximeter ON until ready to sleep.
  • If the patient gets up during the night, request he/she to turn the oximeter off when getting out of bed, and be sure to turn it back ON when returning.
  • Turn OFF the oximeter at the end of each night.
  • The first night may have more error as the patient adjusts to sleeping with the oximeter, therefore some practices record 2-3 nights, then generate the report for the last night or all nights.