Tactile Feedback in Upper Limb Prosthetics: A Pilot Study on Trans-Radial Amputees Comparing Different Haptic Modalities

• Published in: IEEE transactions on haptics Vol. 16; no. 4; pp. 760 - 769
• Main Authors: Barontini, Federica, Obermeier, Alina, Catalano, Manuel Giuseppe, Fani, Simone, Grioli, Giorgio, Bianchi, Matteo, Bicchi, Antonio, Jakubowitz, Eike
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.10.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amputation; Amputees; Artificial Limbs; DC motors; Feedback; Feedback, Sensory - physiology; Force; Grasping; Grasping force; Haptic Technology; Humans; Pilot Projects; Prostheses; Prosthetic hand; Rejection rate; Sensory feedback; Skin; tactile feedback; Tactile sensors; Task analysis; Touch Perception - physiology; Upper Extremity; user-centered approach; Vibrations; Visualization; Wearable computers; wearable haptics
• ISSN: 1939-1412; 2329-4051; 2329-4051
• DOI: 10.1109/TOH.2023.3322559

Despite technological advancements, upper limb prostheses still face high abandonment/rejection rates due to limitations in control interfaces and the absence of force/tactile feedback. Improving these aspects is crucial for enhancing user acceptance and optimizing functional performance. This pilot study, therefore, aims to understand which sensory feedback in combination with a soft robotic prosthetic hand could provide advantages for amputees, including performing everyday tasks. Tactile cues provided are contact information, grasping force, degree of hand opening, and combinations of this information. To transfer such feedback, different wearable systems are used, based on either vibrotactile or force stimulation in a non-invasive modality matching approach. Five volunteers with a trans-radial amputation controlling the new prosthetic hand SoftHand Pro performed a study protocol including everyday tasks. The results indicate the preference of amputees for a single, i.e. non-combined, feedback modality. The choice of appropriate haptic feedback seems to be subject and task-specific. Furthermore, in alignment with the participants' feedback, force feedback, with adequate granularity and clarity, could potentially be the most valuable feedback among those presented. Finally, the study suggests that prosthetic solutions should be preferred where amputees are able to choose their feedback system.