1983 Volume 49 Issue 11 Pages 1534-1539
The device is presented to improve the activity of the lower limb amputee, by constructing a new closed loop control system between amputee and artificial leg. Using the fluidics technology, the circuit is simple, compact and less than 150 g in weight, and is installed in the prosthesis. Each pressure of heel, large and small ball is detected with small rubber pouch installed in the artificial foot, and is modulated linearly to the stimulation frequency of pressure vibration from 10 to 80 Hz through the single feedback oscillator of bistable pure fluidics amplifier, sensitive to the output pressure. Each stimuli is displayed cutaneously on the stump of the amputee as pressure vibration with rubber pouch in the inner surface of the socket. The working fluid is dry air cleaned by 0.5 μm filter. From the psychophysical measurement of information transmission characteristics of the device, it is shown that the channel capacity is approximately 3. 8 bits, as large as conventional vibrotactile stimuli device.
