MyoTrac Infiniti
™
User Guide
39
that, it is a period of time where the client rests following a period of activation of the muscle being
monitored. During the rest period it is not possible to stimulate, and the threshold trigger is
ignored. The illustration below shows a Script of 20 second work and rest steps, with a threshold
set to 40uV and a delay of 5 seconds on a positive crossing trigger. It shows two work segments:
one where the stimulation is not triggered, the other when it is.
What is an Alternating EMG-Stim session?
An Alternating EMG-Stim session is a repeated sequence of Stim and EMG. It is not the same
thing as an EMG triggered Stim session. In this mode the Stim occurs during the rest period and it
is used in order to make the patient understand what the muscle contraction should feel like.
During the work period, the patient will need to reproduce the contraction achieved during the
previous stim session. This combination of stimulation and reiterative behavior can strengthen the
muscles and help the patient relearn the natural reflexes.
Features of an Alternating EMG-Stim session
Threshold Mode:
For Alternating EMG-Stim sessions, automatic threshold mode is used to determine the value of
the threshold. This works in the same was as for script SEMG sessions. Auto-threshold mode
allows for the system, as opposed to the clinician, to determine the threshold value. This means
that during the first 3 activities of a session (i.e. work or fast-flick), the threshold that the patient is
able to reach is automatically calculated and displayed. The patient must then continue to reach
that target throughout the remainder of the session.
Script Structure
Alternating EMG-Stim sessions are conducted in a Script format. A Script takes the form of a
number of work and rest steps. During a work step, the MyoTrac Infiniti will deliver an electrical
impulse to the muscle being monitored. This stimulation will cause the muscle to contract. During
the rest step, the patient will volitionally contract their muscle in a manner similar to what was felt
when the electrical impulse was delivered during the previous work step. In this case the threshold
acts solely as a target that the patient must reach. The illustration below shows a Script of 20
second work and rest steps, with a threshold set to 40uV. It shows three rest segments and two
work segments: during each of the work segments, muscle contractions similar to the stim-induced
ones occur.