Article

The overall goal of this paper was to investigate approaches to
controlling active participation in stroke patients during robot-assisted gait
therapy. Although active physical participation during gait rehabilitation after
stroke was shown to improve therapy outcome, some patients can behave passively
during rehabilitation, not maximally benefiting from the gait training. Up to
now, there has not been an effective method for forcing patient activity to the
desired level that would most benefit stroke patients with a broad variety of
cognitive and biomechanical impairments. METHODS: Patient activity was quantified
in two ways: by heart rate (HR), a physiological parameter that reflected
physical effort during body weight supported treadmill training, and by a
weighted sum of the interaction torques (WIT) between robot and patient, recorded
from hip and knee joints of both legs. We recorded data in three experiments,
each with five stroke patients, and controlled HR and WIT to a desired temporal
profile. Depending on the patient's cognitive capabilities, two different
approaches were taken: either by allowing voluntary patient effort via visual
instructions or by forcing the patient to vary physical effort by adapting the
treadmill speed. RESULTS: We successfully controlled patient activity quantified
by WIT and by HR to a desired level. The setup was thereby individually adaptable
to the specific cognitive and biomechanical needs of each patient. CONCLUSION:
Based on the three successful approaches to controlling patient participation, we
propose a metric which enables clinicians to select the best strategy for each
patient, according to the patient's physical and cognitive capabilities. Our
framework will enable therapists to challenge the patient to more activity by
automatically controlling the patient effort to a desired level. We expect that
the increase in activity will lead to improved rehabilitation outcome.

Langue : ANGLAIS