Fillauer Myolab II, Prosthetist Manual

Page: 6 / 16

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Figure 3
Note that very dry skin or areas with a great deal of hair will
significantly increase skin resistance and can diminish the EMG
signal sensed by the preamplifier. Slightly moisten dry skin before
applying the electrodes. Occasionally the operator may wish to
use a small amount of a conductive salt free gel or lotion before
applying the electrodes to extremely hairy areas. Normally, no
such preparation is necessary.
3. If you are using only one preamplifier (i.e., monitoring only one
muscle group) be sure to protect the remaining preamplifier by
securing it in contact with the patient’s skin or placing it in the
static protection bag. Note: some electrical interference to the
EMG signal can occur if both preamplifiers are not in contact with
the patient (common ground) during monitoring.
4. Set the gain dials (Gain A and Gain B) to 0.
5. Rotate the sound dials (A and B) to the left until they stop. Sound
monitoring is now off.
6. Place the gain switch in the X1 setting.
7. Place the power switch in the ON position.
8. Slowly turn up the gain dial for the channel (A or B) that you
are using until you reach the appropriate meter reading for your
application. For example, have the patient attempt to contract
the appropriate muscle so that under best effort the needle will
read between 50 and 70 (above the mid-line) on the meter dial.
If the Myolab II is being used to monitor very low amplitude EMG
signals, the sensitivity of the system can be increased by placing
the gain switch in the X10 setting. This will increase the sensitivity
of the system by a factor of 10.