ARTIFICIAL HAND FOR PROSTHESES WITH BIO-ELECTRICAL CONTROL

1,201,182. Artificial hands. TSENTRALNY NAUCHNO - ISSLEDOVATELSKY INSTITUT PROTEZIROVANIYA PROTEZOSTROENIYA. 11 Aug., 1967, No. 34592/67. Heading A5R. An artificial hand for control by bioelectric signals from cut muscles of a natural arm stump comprises two individual and independent lines of control for actuating the fingers 2 and the thumb 5, respectively, each line of control incorporating a flexible link 20, 21 and an independent reversible motor 13 for control by the bioelectric signals and operatively connected with lever hinge systems simulating the phalanges of the four fingers and the thumb, respectively. In operation one motor 13 imparts rotation, in a direction corresponding to the signals received, through gearing 14 to a lead screw 16 to displace a slide 19. The slide operates rockers 27, 28 which are connected by rods 29, including ball and socket joints 10, to each of the hinges 2. The fingers are hinged to the hand at joints 22 and are opened or closed according to the direction of the motor 13 and resultant direction of displacement of the slide 19. Similary, the second motor 13 rotates a lead screw 17 to displace a slide 18 the slide 18 being connected with a rotatable crank rod 26 which flexes or extends the thumb about a hinge 11 according to the direction of the motor. The lead screws 16, 17 and slides 19, 18 are so constructed that they cannot be displaced by external forces on the fingers or thumb. A mechanism 6 including a spring lock permits passive abduction of the thumb by rotation about a pivot 25 and the ungual phalange of the thumb may be flexed at a joint 9. Rotation of the hand relative to the arm is permitted by a ball bearing connection 7. Elastic links 8 are connected between the rockers 27, 28 and the frame of the hand.