LP - modulé en longues périodes
The LP waveform provides an MF signal for 5 seconds. Then over the next
2.5 seconds the other phase of the 50Hz rectified signal is smoothly
increased in amplitude to give a DF signal for a further 5 seconds. Finally the
signal returns to MF by smoothly reducing one phase of the rectified signal
over the next 2.5 seconds. The complete sequence takes 15 seconds. Part
of the LP waveform showing how the alternate phase increases in amplitude
is shown above.
RS – rythme syncopé
The RS waveform is 1 second of MF followed by 1 second of zero output,
this sequence being repeated continually.
Polarity
The above waveforms exhibit Pos (+) polarity as they all travel above the
ground (zero volts) level (equivalent to the flat part of the waveforms). The
polarity button enables the user to reverse this Neg (-) so that the above
waveforms would be rendered ‘upside-down’. This feature is particularly
useful in combination mode, when the ultrasound head becomes one
electrode, and we can select the polarity of the waveform relative to the head.
A third option is Auto-reverse, in which the polarity automatically reverses
half way through the selected treatment time.
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