Paul M. Khoury
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Haptics Project
Modern upper-limb prosthetic hands allow users to grasp objects, but most provide little or no sense of touch. Without sensory feedback, users must rely entirely on sight or sound to judge grip force, often making interaction with everyday objects difficult and cognitively demanding. This project explores how wearable haptic technology can restore a sense of contact and improve confidence when using a prosthetic limb.
The system consists of a lightweight armband with four vibratory coin motors embedded within. It is to be worn on the upper part of the arm with the congenital limb difference. The aim is to communicate touch information from the prosthetic hand via haptic stimulation (specially designed vibrations and patterns of vibrations). When the prosthetic fingers make contact with an object, the device delivers brief, spatially mapped vibration cues corresponding to different regions of the hand. Rather than adding complex sensors, contact is inferred from changes in the motors’ electrical current, enabling feedback without increasing hardware complexity or weight.
The feedback follows an event-driven control paradigm: vibrations occur only when contact begins, mimicking how natural touch perception draws attention to changes rather than constant pressure. The arrangement of vibration motors preserves spatial awareness, aiding users in intuitively associatingsensations on the arm with what is occurring at the prosthetic hand.
User testing evaluated how accurately participants could localize signals and interpret hand mappings, informing design decisions aimed at reducing long-term prosthesis rejection rates — an important challenge in pediatric prosthetics.
A poster based on this work was presented at the undergraduate the 2025 BMES Annual Meeting in San Diego, CA. Another poster derived from this work was presented at the 2026 Florida Undergraduate Research Conference (FURC) at the Univeristy of North Florida.
Download paper: "Design of a Haptic System for Sensory Feedback in Pediatric Prostheses" ↓