Robot-assisted gait training and assessment for neurological patients

Task-specific and intensive training of repetitive active movements results in
the largest functional improvements in the rehabilitation of stroke patients
and spinal cord injury patients. Providing this kind of therapy for gait
training puts a high physical burden on therapists. For instance, in gait
training on a treadmill with partial bodyweight usually 2 therapists are needed
to assist the patient in walking. In the past years, a new robot device, LOPES
II or III, has been developed which can provide neurological patients with the
necessary support in gait training. In LOPES II or III, the amount of support
during walking can be adjusted, varying from high (robot-in-charge mode) to
zero (patient-in-charge mode). The challenge is to apply as much support as the
patient needs to perform the selected exercise. The support should allow the
patient to walk and still encourage him/her to provide an active contribution.
Different algorithms have been proposed but they are not yet tested for their
feasibility in severely affected neurological patients.
Besides, different ankle modules have been developed for the LOPES III. One
ankle module can be used to assist plantarflexion and dorsiflexion actively,
however, other movements (inversion/eversion, endorotation/exorotation) might
be restricted. With another ankle module, it is not possible to actuate the
ankle, however, the subject can move more freely in different degrees of
freedom (inversion/eversion, endorotation/exorotation,
plantarflexion/dorsiflexion). LOPES II only has a non-actuated ankle module. In
the future, additional robotic modules might be developed for the LOPES II or
III. The effect of these different modules in healthy subjects and severly
affected patients is unknown.
Additionally, to be able to tailor the support to the patient*s needs, the
patient impairments need to be characterized. The response of patients to the
robotic forces applied during walking can be used to derive a measure of the
impairments that limit the walking ability

Primary objective:
Determine for different control algorithms and robotic modules whether the
algorithm and/or robotic module is effective in providing the patient with the
required support and measure bringing about the desired changes in the walking
pattern in healthy subjects and neurological patients.
Secondary objectives:
-Determine whether the different control algorithms and robotic modules result
in changes of the self- generated activity of the neurological patients and
healthy subjects.
-To determine whether different control algorithms and robotic modules result
in changes of metabolic parameters in neurological patients and healthy
subjects.
-Quantify the impairments that limit walking in neurological patients using
LOPES II or III.
-Compare different control algorithms and robotic modules and determine which
algorithms and modules might be most effective in providing the required
support.

This protocol describes a framework according to which a set of studies and
experiments can be designed. The different studies are designed as
observational studies.

Subjects will participate in at least one session and maximally in 5 sessions.
In the first session the subject will be asked to walk with LOPES II or III
maximally 4 trials of maximal 7 minutes. The trials differ in the used
algorithm to control LOPES II or III, the used robotic modules and/or the
magnitude of the provided support. Depending on the patient*s physical
condition and the physical effort in the first session, the amount of trials
will be slowly upgraded to maximal 10 trials of maximal 7 minutes in subsequent
sessions. Between the trials subjects will receive time to rest. The LOPES II
and III device was extensively tested for safety. During all test the
implemented safety measures will assure that the exerted torques and the
performed movements are within safe limits.