Hybrid control:
Assist
to make walking easier.
Resist
for precision ankle therapy
Figure 2. SPARK Control System
The SPARK has two modes of operation (“hybrid control”):
●
Assistance:
Assistance mode provides ankle joint plantarflexion torque
during stance and dorsiflexion torque during swing.
●
Resistance:
Resistance mode provides ankle joint dorsiflexion torque
during stance.
Ranges for optimal peak stance phase plantarflexor assistance and resistance
levels (0.25-0.30 Nm/kg for assistance and 0.10-0.15 Nm/kg for resistance) were
established during clinical walking testing. The default settings are 0.30 Nm/kg
and 0.12 Nm/kg, for assistance and resistance, respectively. For example, peak
default assistance torque for a participant with a body mass of 75 lbs (34 kg)
would be 8.5Nm. These settings can be customized by the therapist at their
discretion after assessing the user’s gait pattern. Nominal, on-off dorsiflexor
torque can be provided during the swing phase between 0-5 Nm.
SYSTEM CALIBRATION
REC-184 Version 0
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