Precautions - EMS COMBINATION 850 Manual

Precautions

Interferential Therapy
Interferential therapy is a safe and effective modality. The therapist must,
however, be aware of the following precautions and potential hazards.
Simultaneous connection of a patient to high frequency surgical equipment may
result in burns at the site of the stimulator electrodes and possible damage to
the stimulator itself.
Operation in close proximity (less than 1 metre) to shortwave or microwave
therapy equipment may produce instability in the stimulator output.
Consideration must be given to the current densities for any electrode used with
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the Combination 850 Unit. Current densities greater than 2 mA rms/cm are not
recommended because of the risk of an interferential burn. The small size EMS
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conductive rubber electrodes (NC3052B 70 x 50 mm) have an area of 35 cm
and should, therefore, only be used with output currents up to 100 mA peak (
70 mA rms). All other standard EMS conductive rubber electrodes may be used
up to the maximum output of the unit without exceeding this figure. When
using other electrodes, the maximum safe output current should be assessed
before use. First estimate the effective contact area of the electrode in square
cm, and then apply the following formula:-
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Maximum peak output current (mA) = Area of electrode (cm ) x 2.8
The factor of 2.8 is the maximum recommended rms output current multiplied
by the ratio of the peak current to the rms current for a sinusoidal waveform.
The output display on the Combination 850 control panel shows the peak output
current in mA. For sinusoidal currents the rms current is approximately 70% of
the peak value.
Patients with implanted electronic devices (eg cardiac pacemaker) should not be
subjected to stimulation unless specialist medical opinion has first been
obtained.
COMBINATION 850 10 ISSUE 2