Pointdexter: A Prosthetic Fingertip Terminal Device

Abstract The proposed dexterous terminal device technology would allow amputees more utility from their prosthetic hands and fingers, in tasks requiring fine grasping, such as in tying shoes or in work activities, such as manufacturing small components. Bilateral amputees would be able to achieve fine dexterity with two multi- articulating hands. All users would be able to have the best aspects of fine-motor control, gross function, and cosmetic appeal in a single terminal device.Project Narrative Modern dynamic upper limb prosthetic terminal devices tend to either be functional or cosmetic, with most common designs making compromises between both aspects. Prosthetic hooks and grippers are particularly good at grasping a variety of objects but are not cosmetic. Conventional electric hands are more cosmetic, but do not allow for conformal grasp or multiple grasp patterns and also have difficulty grasping small objects. Multi- articulating hands are also cosmetic, can conform to larger objects that are grasped, and offer multiple grasp patterns. However, multi-articulating hands still have difficulty grasping and manipulating smaller objects. As no single terminal device meets all of the criteria of an ideal terminal device, users often have to physically remove and don different terminal devices to achieve the variety of tasks that they need to perform in their activities of daily living (ADLs). The proposed solution aims to combine the advantages of the common terminal devices into one solution, by combining the practicality and dexterity of a split-hook or gripper with the aesthetics of multi- articulating hands. The primary objective of the proposed project is iterate, test, and commercialize novel dexterous terminal device technology. Design criteria related to size, grasping force, etc. will be refined as iterations of the device are created. The ability of the device to meet the design criteria will be verified through bench top testing. The device will then be tested with prosthesis end-users using clinically validated outcomes measures. These tests will evaluate the functionality, features, and product viability of the technology, demonstrate improvements in function, and drive further development. Feedback from both amputees and clinicians will also be solicited to guide design iteration. The proposed dexterous terminal device technology would allow amputees more utility from their prosthetic hands/fingers in tasks requiring fine grasping, such as in tying shoes or in work activities, such as manufacturing small components. Bilateral amputees would be able to achieve fine dexterity with two multi-articulating hands. All users would be able to have the best aspects of fine-motor control, gross function, cosmetic appeal, and anthropomorphic acceptance in a single terminal device.