A novel method exploiting the nociceptive withdrawal reflexes in rehabilitation of hemiplegic gait

摘要

A novel closed loop method for improving gait in hemiplegic patients by supporting the production of the swing phase using electrical stimulations to evoke the nociceptive withdrawal reflex was developed and evaluated in one chronic hemiplegic subject Electrical stimulations were delivered to 4 locations on the sole of the foot at 3 different times between heel-off and toe-off. The system exploits the modular organization of the nociceptive withdrawal reflex and its stimulation site- and gait phase-modulation in order to evoke optimal flexion of the hip, knee and ankle joints in the early swing phase. A Rule-based Model Reference Adaptive Controller (MRAC) was designed to select the optimal stimulation parameters. It was hypothesized that the MRAC-system would result in a better walking pattern compared with a preprogrammed fixed stimulation pattern controller. Based on the unperturbed gait and withdrawal strategies of the patient, an individual controller target for hip, knee and ankle flexion was set The patient walked 10 min with the MRAC-system, 10 min with the fixed pre-programmed stimulation pattern, and 10 min with no-stimulation. The results indicate that both stimulation paradigms resulted in a more functional gait compared with no-stimulation and that the control strategy in the MRAC system is superior suggesting that it will be able to adapt better to the varying needs during rehabilitation therapy.