Towards Natural Feedback Interfaces for Tactile Restitution

Prosthetic users typically depend on sensory feedback from various sources to compensate for the loss of natural sensory inputs. This feedback includes visual cues, proprioceptive signals from residual muscles, and auditory feedback from motor actuation. However, the role of natural vibration transmission through the prosthetic socket as a source of tactile information remains underexplored, especially in non-invasive feedback systems for upper-limb prosthetics. This thesis explores innovative methods to restore and amplify tactile feedback in upper-limb prosthetics, offering a comprehensive analysis of the natural transmission and perception of tactile cues through various prosthetic hands. Key factors, such as degrees of freedom, types of articulation, and material properties, are considered to assess their impact on tactile signals transmission. Building on these insights, the research presents a series of novel tactile feedback devices, each rigorously designed, characterized, and tested through detailed user trials. The study assesses tactile perception in advanced, soft prosthetic hands and rigid designs, analyzing user performance with and without artificial feedback. The findings show significant advancements in prosthetic efficiency, user embodiment, and intuitiveness. This research underscores the importance of leveraging natural feedback pathways to improve tactile devices for upper-limb prostheses.