RESUMO
Use of multichannel electrical stimulators (MES) for the rehabilitation of patients with plegic or paretic extremity muscles in one of the most promising trends in rehabilitation. Two clinically oriented therapeutic stimulators are described. The aim and the realization of walking rate dependent functioning, gradually modulated stimulation sequences, mini-computer and hardware closed-loop control of stimulation amplitude are described. The difficulties arising from the poor interface between the technical and biological part of the system prevent the described stimulators from being used as orthotic devices. Experiments with three types of electrodes are given, and the problem of an excessive mounting time for most clinical environments is also stressed.
Assuntos
Terapia por Estimulação Elétrica/instrumentação , Hemiplegia/reabilitação , Eletrodos , Marcha , Hemiplegia/terapia , Humanos , Fatores de TempoRESUMO
The degree of pain reported by ten volunteers upon electrical stimulation of their peroneal nerves was measured while stimulus parameters were varied. The responses were compared for stimulations, all of which produced the same amount of ankle torque. The stimulation parameters examined were pulse duration, 0.3 and 1.0 msec; repetition frequence, 20, 50 and 100 hertz; pulse shape, square wave and exponential wave; impedance of stimulator output, constant voltage and constant current; direct current bias, positive or negative to the stimulus; and wave phase, uniphasic and biphasic. Pulse duration of 0.3 msec and constant voltage output were the only two parameters significantly associated with minimum pain response. Analysis of voltage and current wave forms for the different stimulus parameters indicated that the sensation of pain was dependent upon the total amount of electrical charge delivered to the tissue with the pulse.
