The electrodiagnostic consultant must become familiar with the limitations of the instrumentation and be able to interact with the recording equipment, from the level of entry at the recording electrode to its display on the EMG.
Therefore, the goal of objective-interactive EMG is to extract reliable and reproducible information from the waveforms.
This is accomplished by the electrodiagnostician training his or her eye to truly measure the size, complexity, and stability of the waveforms.
This also means not being a passive observer of the waveforms as they race across the screen, but reaching out and manipulating the EMG instrument's settings to extract more information from this same signal (ie, interacting with the instrument).
QA forms the foundation upon which routine subjective assessment of the MUAP waveforms is made.
Over the decades, clinicians have become immured with a closed-mindedness that reflexively links the diagnosis to the waveforms (eg, myopathic MUAP, neurogenic MUAP, BSAPs [brief, small, abundant potentials]).
QA is not necessarily needed in every study, but careful analysis of the MUAP signal is essential.
So why is an understanding of at least the principles of QA important?For information and instructions on how to renew your clinical laboratory personnel license or certificate, visit the LFS personnel renewal web page.On November 14, 2017, Laboratory Field Services (LFS) will be launching an update to PERL, the online application system for personnel licenses and certificates, which will allow licensees and certificate holders to submit renewal applications online.The authors refer to this approach as objective-interactive EMG, a practical compromise to traditional QA.This article primarily addresses the changes in MUAPs that may be observed in neuromuscular disorders.These are patterns of random or rogue sub-MUAP activity that may yield important clues in the interpretation of the EMG signal.