Functional electrical stimulation (FES) systems for restoration of motor function of paralyzed muscles--versatile systems and a portable system.

Multichannel functional electrical stimulation (FES) systems were developed to restore the motor functions of the paralyzed muscles, i.e. two kinds of versatile systems for laboratory use and a practical portable system were developed. The first microcomputer-based FES system was composed of an 8 bit microcomputer (PC-8801mkII) with a voice recognition board and 30 stimulation outputs, in which the voice commands were used for selecting a motion pattern, and for executing (start), (hold), (restart) and (stop) commands. In combination with the voice commands, a proportional control command detected from a head angle sensor was used for volitional control of motion. The second microcomputer-based FES system was composed of a 16 bit microcomputer (PC-9801 UV or compatible) with flexible control capabilities (e.g. respiratory sensors) for volitional control and with 64 stimulation outputs. An originally designed practical portable FES system was 89 x 145 x 31 mm in dimension and 380 g in weight. This paper describes the system configurations, the control methods of these FES systems and three examples of the clinical applications of the FES systems.