SECTION 4 – INSTRUMENT OPERATION IN HIGH
OUTPUT RANGE
4.A. HIGH OUTPUT PATTERNS
With the NSL-5 Patient Lead Cable connected, the unit
automatically sets to the HIGH output range, with no stimulation
pattern active (null mode). While in the null mode, the unit
emits no stimulation output current and no audible chirps. When
the user selects a mode, the unit stimulates the target nerve with
200 microsecond (0.2 milliseconds) wide pulses, in the selected
pattern.
Twitch: When the Twitch Mode is selected in the
HIGH output range, the default pattern is the 2 Hz
Twitch. The user can toggle the pattern frequency
between 1 Hz and 2 Hz by pressing the Twitch Mode
button. The unit emits an audible chirp with each
stimulus pulse.
2 Hz Twitch Pattern = 2 twitches per second
500 milliseconds
1 Hz Twitch Pattern = 1 twitch per second
1000 milliseconds
= 0.2 milliseconds
Figure 4.1: Twitch Patterns (HIGH Output Range)
50 Hz Tetanus: Press and hold this button to deliver
continuous 0.2 millisecond, 50 Hz stimulation pulses
up to a maximum duration of 30 seconds.
The unit emits a continuous tone while stimulating.
When the tetanus button is released, or if it is pressed
continuously for 30 seconds, the unit stops delivering the tetanus
stimulus and returns to the prior setting (TO4, Twitch, DBS or null
mode).
50 Hz ~ Twitch Pattern
= 20 milliseconds
= 0.2 milliseconds
Figure 4.2: 50 Hz ~ Tetanus Pattern
8
= 0.2 milliseconds
100 Hz Tetanus: Press and hold this button to deliver
continuous 0.2 millisecond, 100 Hz stimulation pulses
up to a maximum duration of 30 seconds.
The unit emits a continuous tone while stimulating.
When the tetanus button is released, or if it is pressed
continuously for 30 seconds, the unit stops delivering the tetanus
stimulus and returns to the prior setting (TO4, Twitch, DBS, or null
mode).
100 Hz ~ Twitch Pattern
= 10 milliseconds
= 0.2 milliseconds
Figure 4.3: 100 Hz ~ Tetanus Pattern
Double-Burst Stimulus (DBS): In the DBS mode, the
unit delivers a stimulation pattern that consists of two
groups (bursts) of three 0.2 millisecond pulses. Each of
the pulses within a group is separated by 20
milliseconds ± 5%. The delay from the first pulse of the
first group to the first pulse of the second group is 750 milliseconds
± 5%. While in the DBS mode, the pattern repeats every ten (10)
seconds.
Each burst is accompanied by an audible chirp. In addition, while
counting down the 10 second interval between auto-repeating
patterns, the unit emits a long beep as a reminder that the next
stimulus will be delivered in one (1) second.
Double-Burst Pattern
= 20 milliseconds
= 0.2 milliseconds
750 milliseconds
Figure 4.4: Double-Burst Pattern
Train-of-Four (TO4): In the TO4 mode, the unit
delivers a group of four 0.2 millisecond pulses, spaced
500 milliseconds ± 5% apart (2 Hz rate). While in the
TO4 mode, the pattern repeats every ten (10) seconds.
Each TO4 is accompanied by an audible chirp. In
addition, while counting down the 10 second interval between
auto-repeating patterns, the unit emits a long beep as a reminder
that the next stimulus will be delivered in one (1) second.
Train-of-Four (TO4) Pattern
500 milliseconds
= 0.2 milliseconds
Figure 4.5: Train-of-Four Pattern