Stroke is one of the most common major neurological
disorders comprising half of all patients admitted
to hospital for a neurological disease. A characteristic
neurological impairment of stroke patients is
the spastic hemiparesis of the limbs. Rehabilitation
of paretic patients involves, among others, very
intensive physiotherapy treatments. Antispastic
physiotherapy is mediated exclusively by physiotherapists
all over the world because sensation of and instant
reaction to the patient's kinesthetic and mental
status is required. The physical capabilities
as well as the availability of the physiotherapist
limit the realisation of effective physiotherapy
in daily routine.
Robot mediated physiotherapy is a promising approach
to support stroke rehabilitation. A robotic therapy
system not only unburdens the physiotherapist
from the routine rehabilitation load but also
minimizes the time spent in performing repetitive
physiotherapy exercises.
REHAROB is a robotic rehabilitation system for
upper limb motion therapy for the disabled. In
cooperation with partner institutions from several
countries in a 5th Framework Project of the European
Comission, the REHAROB project has been led by
the Department of Manufacturing Engineering of
the Budapest University of Technology and Economics
(BUTE) and the Hungarian National Institute for
Medical Rehabilitation. REHAROB provides personalized,
three-dimensional motion therapy for patients
with neuro-motor impairments. The system uses
two robotic arms for controlled moving of the
upper and lower arm respectively.
Our company has provided
a special version of the UniForce 6-axis Force-Torque
(FT) sensor system to support the project. Robot
control is partially based on FT feedback from sensors
mounted in the wrist of the robotic arms. A novel
indirect force control method has been developed
by the engineering team of BUTE for the programming
of the robots. During the teaching phase the position
controlled industrial robots behave as haptic devices:
the physiotherapist freely exercises the patient
while the robots follow and learn the trajectories.
Based on a special algorithm, the UniForce directly
provides the relative incremental motion coordinates
to the robot controller in real-time. During playing
back the robots behave as conventional position
controlled devices and the 6-axis FT sensors monitor
the exercising forces for safety purposes.
