Fillauer Myolab II, Prosthetist Manual

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9. To determine the actual EMG signal strength (/- 10%),
place the gain switch at the X1 setting and the gain dial in the 10
position. The meter will now display the actual EMG in Microvolts,
i.e., 100 (full scale deflection) = 100 microvolts. To measure EMG
signals in the 0 to 10 microvolt range, the operator may use the
X10 setting with the gain dial control on.
10. The actual microvolt signal strength is the meter reading divided
by 10, i.e., a full scale deflection of the needle to the 100 meter
reading = 10 microvolts.
To determine actual EMG skin microvolts at gain dial settings other
than the 10 position, use the chart in the table below.
Microvolts at Full Scale (Needle at 100)
Microvolts per Division
(50 Meter Divisions)
Gain Dial X1 Gain X10 Gain X1 Gain X10 Gain
12 83 8 1.6 .13
10 100 10 2.0 .20
8 125 13 2.6 .26
6 167 17 3.4 .34
4 250 25 5.0 .50
2 500 50 10 1.0
Set the audio volume at the desired level using the appropriate
sound dial. (Note: The pitch of the sound [not the volume] will
increase with an increase in EMG signal intensity. In addition, the
sound of each channel differentiates the two signals).
At the conclusion of the training session, remove the preamplifiers
from the patient and turn the power switch off. Be sure to store the
preamplifiers inside the static protection bag supplied.
Using the Myolab II for EMG Site Selection
1. Before probing for EMG electrode sites, examine the patient for
problem areas such as wounds, scar tissue and painful areas.
Determine the range of motion and areas of muscle inadequacy.
2. All of the remnant muscles which could be used for control sites
should be evaluated before fitting a myoelectric prosthesis. Note:
when the biceps or triceps are not present on an amputee, e.g.,
shoulder disarticulation amputee, other control sites such as the
pectoralis and infraspinatus muscles may be successfully used.
Begin EMG probing with the most distal of the remnant muscles.
While probing, have the subject contract the appropriate muscle
being tested.