Service manual

Revision 2/18/05 2 - 3
System Overview
Test Modality Descriptions
Introduction
This section provides an overview of the test categories
performed by VIASYS neurodiagnostic instruments.
Nerve Conduction Studies (NCS)
A nerve conduction study is the recording and analysis
of waveforms generated by the peripheral nervous
system in response to electric or physiologic
stimulation. The recorded waveforms are compound
muscle action potentials (CMAPs) and compound nerve
action potentials (CNAPs).
The types of nerve conduction studies include:
• Motor Nerve Conduction (MNC)
• Sensory Nerve Conduction (SNC)
• Additional Nerve Studies
• F-Waves
• H-Waves
• Repetitive Stimulation (Rep. Stim.)
• Blink Reflex
• Motor Unit Number Estimate
Compared to an evoked potential, CMAPs and CNAPs
waveforms are large in amplitude. The waveform
amplitude is measured in milli-volts (mV)
Electromyography (EMG)
Electromyography is the recording and analysis of the
insertional, spontaneous an involuntary electrical
activity generated by single or group muscle action. The
recorded waveforms are called motor unit action
potentials (MUAPs).
The types of EMG studies include:
• Spontaneous Activity (SPA)
• Maximum Voluntary Activity (MVA)
• Automatic Motor Unit Potential (AMUP)
• Interference Pattern Analysis (IPA)
• Quantitative EMG (QEMG)
• Single Fiber EMG (SFEMG)
The response amplitude is measured in uV.
Example of EMG Recording
Example of a Nerve Conduction Study