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EN109-1498751-47 IFU
A variation to the standard biphasic asymmetrical pulsed current is the alternating one, in which the
successive pulse phases alternate with respect to the baseline (figure 7). This waveform is also fully
balanced.
To prevent accommodation to stimulation or to improve patient tolerance, the pulse frequency can be
varied through frequency modulation. Several frequency modulation programs are available (figure
26-28).
Parameters:
•
Phase duration
, expressed in microseconds (µs), is the elapsed time from the beginning to the
end of the initial pulse phase.
•
Pulse frequency
, expressed in Hz or pps (pulses per second), defines the repetition rate of the
TENS pulses.
•
Frequency modulation,
expressed in Hz, defines a variable frequency range that is summed to
the Pulse frequency i.e. when the Pulse frequency is set to 80 Hz and the Frequency modulation is
set to 40 Hz, the final frequency will vary from 80
–
120 Hz.
•
Modulation program,
defines the time and sequence in which the frequency will sweep through
the Frequency modulation range.
Burst asymmetrical and burst alternating asymmetrical
The burst biphasic and burst biphasic alternating asymmetrical pulsed currents are variations to their
non-burst counterparts, in which the continuous train of pulses is interrupted by pulse pauses. A burst
frequency can be set for treating chronic pains, where the use of continuous stimulation with a low
pulse frequency would be too painful. Each burst last for 100ms and the burst rate can be adjusted
separately. With this milder TENS waveform, it is easier to exceed the motorial threshold stimulus.
Parameters:
•
Phase Duration
, expressed in microseconds (µs), is the elapsed time from the beginning to the
end of the initial pulse phase.
•
Pulse Frequency
, expressed in Hz or pps (pulses per second), defines the repetition rate of the
TENS pulses.
•
Burst Frequency
, expressed in Hz, defines the repetition rate of bursts of pulses. A burst consists
of a train of pulses. Each burst last for 100ms and the number of pulses in a burst depends on the
selected Pulse frequency i.e. at a Pulse Frequency of 100Hz, 10 pulses are available in each burst.
Symmetrical
TENS current pulses can also be used for muscle stimulation applications. Often the symmetrical
biphasic pulsed current waveform is used. The specified phase duration applies to both pulse phases,
which doubles the amount of available energy with respect to the asymmetrical pulsed current
waveform. This waveform is fully balanced (no residual DC components are present).
Parameters:
•
Phase Duration
, expressed in microseconds (µs), is the elapsed time from the beginning to the
end of a pulse phase. The phase duration applies to each pulse phase.
•
Pulse Frequency
, expressed in Hz or pps (pulses per second), defines the repetition rate of the
TENS pulses.
•
Frequency Modulation
, expressed in Hz, defines a variable frequency range that is summed to
the Beat frequency i.e. when the Beat frequency is set to 80 Hz and the Frequency modulation is
set to 40 Hz, the final frequency will vary from 80
–
120 Hz.
•
Modulation Program
defines the time and sequence in which the frequency will sweep through
the Frequency modulation range.
