NeuroTherm NT1100 Operator's Manual page 85

It is a natural reaction to think of pulsed radiofrequency as being analogous to the neural modulation
effects achieved using spinal cord stimulators or TENS units. However, these two modalities are very
different. In neural modulation the therapeutic effect is achieved by applying low frequency (< 1000 Hz)
rectangular pulses.
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Figure 10.6 shows the frequency spectrum of a two Hz rectangular pulse. As can be seen from
the figure, the major frequency component is at two Hz and falls off as the frequency increases.
At frequencies above 1000 Hz, the amplitude of the frequency component is getting very small.
There is a very different situation with pulsed radiofrequency. In this case, the rectangular pulses
have radiofrequency inside of them. This changes the frequency spectrum entirely. As can be
seen from figure 10.7, the major frequency component is now 500 kHz and decreases at higher
and lower frequencies. At frequencies below 1000 Hz, the contribution can be shown to be
negligible .
In conclusion, the frequency spectrums of pulsed radiofrequency are entirely different than the
frequency spectrums of low frequency stimulators.
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Document 109.00
NEUROTHERM RADIO FREQUENCY LESION GENERATOR
OPERATORS MANUAL
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Figure 10.6
500 kHz
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MODEL NT1100
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frequency Hz
Frequency Hz
10September2012 Issue 06
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