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During the Ready phase, the threshold tracks the patient’s progress. For ex-
ample, the threshold will automatically drop if the patient’s generated signal
strength drops as shown below.
Ready
The Stimulation phase occurs when the patient has accomplished his goal. I.e.,
he has triggered the unit. He has produced a movement signal greater than or
equal to the threshold and has thus initiated one stimulation cycle. At this
point the unit will deliver a stimulation signal of programmed shape to the
electrodes for a programmed period of time.
Stim 15 mA
When the unit is triggered twice, the threshold is raised. Note that during
automatic adjustment of the threshold, it can only be raised if the patient
triggers the unit. During the Stimulation phase the threshold becomes dotted
indicating that EMG monitoring has been disabled. Thus EMG levels are not
displayed during this phase as shown above.
This phase represents a form of Pavlovian conditioning. I.e., assuming that the
externally derived muscle contraction is the “reward”, the patient will hopefully
become conditioned to receiving the reward. He will become conditioned to
making movements so that he can obtain a contraction. The goal is that, over
time, the patient will become more and more proficient at creating his own
movements rather than requiring the externally produced contraction.
The Rest phase occurs after the cessation of the externally produced, muscle
contracting, stimulation signal. During this phase, the patient is urged to do
the opposite of what he was trying to do during the Ready phase.
