Electromyograph (EMG) - working, applications

1. Electromyograph(EMG)
Mr.A.Rameshbabu AP/ECE
Ramco Institute of Technology
Academic Year 2018 – 2019 (Even)

2.  It is used to record electrical activity of the
muscles.
 It is used to study neuromuscular function &
condition, nerve lesion, reflex responses etc.
 Surface & Needle type electrodes are used to
measure bioelectric potentials.
 One ground electrode used for common
reference.
 The measured signal will be amplified and
displayed on the screen
 It is also applied to an audio amplifier
connected to a loudspeaker.

3. Block Diagram

4. Electromyogram (EMG)

6. Artefacts in EMG
 Power line interference:
Artefacts transmitted by electrical devices
around the EMG equipment.
 ECG artefacts:
Electrical signals generated by heart
muscle and can also be picked up in EMG
signals

7.  Movement artefacts:
It occur whenever a patient moves and
electrodes are disturbed or the cables are pulled.
 DC offset:
Difference in the electrical impedance
between Skin and electrodes.
 Muscle crosstalk:
Electrical signals generated by muscles
other than the one under investigation.

8. Reference
Leslie Cromwell, “Biomedical
Instrumentation and Measurement”,
Prentice Hall of India, New Delhi,
2007.