Author/Editor		Bunc, M; Šuput, D; Rozman, J
Title		Improved stimulation of motor nerve using quasitrapezoidal stimulating pulses
Type		članek
Source		Period Biol
Vol. and No.		Letnik 105, št. 2
Publication year		2003
Volume		str. 141-6
Language		eng
Abstract		Background and Purpose: Functional Neuromuscular Stimulation (FNS) of motor nerves, using neural prostheses, could provide artificial control of muscle contraction. Conventional method of stimulation used in FNS of motor nerves unavoidably excites larger motor units before smaller ones resulting in poor force gradation and rapid muscle fatigue. To improve the ability of a stimulating system to control tension during FNS it is desirable to activate motor units in a more physiological manner. In our study we compared the control of recruitment of muscle fibres during selective electrical stimulation using quasitrapezoidal and conventional, rectangular stimulating pulses. Material and Methods: A 33-electrode spiral cuff (cuff) was fitted on the sciatic nerve of a dog to stimulate selectively a superficial region that innervates mainly the GM. Then Me calcanean tendon (CT) was surgically insulated and dissected in segments belonging to different muscles and mechanically attached to the force transducer (FFT). Peakforce (PF), time to peak force (TPF), half contraction time (1/2CT), and half relaxation time (1/2RT) of the muscle twitches were measured. Results: The results showed that an average value of TPF, 1/2CTs and 1/2RTs were lower in stimulation using rectangular pusles than in stimulation using quasitrapezoidal pulses. According to our results, FNS of peripheral nerves using quasitrapezoidal pulses is more physiological and less fatiguing.
Descriptors		MUSCLE CONTRACTION ELECTRIC STIMULATION NERVE FIBERS SCIATIC NERVE DOGS