Abstract
In the design and evaluation of upper limb prosthetic terminal device, the number of grasping forms of the robot hand has been diverted. This has misguided on designing and evaluating the terminal device which should suppress compensatory movements of the residual limb and body. The objective of this research was to extract features from the relation between grasp and posture control of terminal device to improve the design and selection of the prosthetic components. In this research, daily hand activities were recorded with body mounted video camera on three subjects. Grasping Direction indicating the positional relationship between trunk, forearms and hand, and the contribution ratio to grasps applied in daily life were derived. A combination of hook-shaped terminal device with radial/ulnar flexion wrist unit corresponded to 95.9% of the Grasping Direction utilized in desk work. In addition, commercially available prosthetic wrist components were modeled, and the executable desk work were evaluated. The combination of 2-Grasping Direction terminal device and the pronation/supination unit corresponded to 80.1% of the Grasping Directions. These results indicate that the proposed method is effective for the design and evaluation of the upper limb prosthesis.
