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A novel closed-loop system for improving gait in hemiparetic patients by supporting the production of the swing phase using electrical stimulations evoking the nociceptive withdrawal reflex was designed. The system exploits the modular organization of the nociceptive withdrawal reflex and its stimulation site- and gait-phase modulation in order to evoke movements of the hip, knee, and ankle joints during the swing phase. A modified model-reference adaptive controller (MRAC) was designed to select the best stimulation parameters from a set of 12 combinations of four electrode locations on the sole of the foot and three different stimulation onset times between heel-off and toe-off. It was hypothesized that the MRAC system would result in a better walking pattern compared with an open-loop preprogrammed fixed pattern of stimulation (FPS) controller. Thirteen chronic or subacute hemiparetic subjects participated in a study to compare the performance of the two control schemes. Both control schemes resulted in a more functional gait compared to no stimulation (P < 0.05) with a weighted joint angle peak change of 4.0 ± 1.6 (mean ± Standard deviation) degrees and 3.1 ± 1.4 degrees for the MRAC and FPS schemes, respectively. This indicates that the MRAC scheme performed better than the FPS scheme (P < 0.001) in terms of reaching the control target. [ABSTRACT FROM PUBLISHER]

A haptic device with two active degrees-of-freedom and a tendon-driven transmission system was designed, later on constructed, and submitted to testing. It was embodied as a light-weight mechanism with a small workspace that wraps the finger workspace and can generate forces up to 10 N suitable for finger exercise. The control loop and the user application were implemented on a personal computer in the Microsoft Windows environment. Along with the device, application covering several different experiment types was developed. The system was evaluated in a group of stroke patients during a one-month period of therapy. Results for two types of experiments are presented. The progress of the patient affected hand side was found to be greater than for the one nonaffected, however, the mean values of the relevant parameters on the nonaffected side of patients are higher than those for the affected side. Results were compared to the motor component of functional independence measure (M-FIM) measured clinical scale. [ABSTRACT FROM AUTHOR]