CAREER: An Integrated Sense of Movement to Promote the Control and Embodiment of Prostheses for Children with Congenital Limb Deficiencies

University Of California-Davis, Davis CA

Investigators

Abstract

The sense of moving our body parts (kinesthesia) influences nearly every action we perform, contributing to how we learn tasks and shaping the perception of our body parts and actions as our own (embodiment). Despite this critical importance, even sophisticated upper extremity prostheses for children do not provide movement feedback; they remain numb, disconnected tools prone to rejection. This project will explore non-invasive strategies to provide pediatric prosthesis users with movement feedback, either as feelings of their missing hand moving or as vibrations on their skin. The research will investigate how best to apply these techniques for effective pediatric prosthesis control, and will afford a deeper understanding of the role kinesthesia plays in these children’s ability to learn tasks and embody their prosthetic limb. Project outcomes will contribute interdisciplinary knowledge (in engineering, neuroscience, and pediatric care) that has important implications for developing prosthetic devices that amplify children's physical capabilities, informing treatment strategies, and providing a quantitative understanding of children's sensorimotor abilities. The work will be tightly integrated with the education plan through various mechanisms, including engaging children with limb differences in exciting summer camp activities, broadening access to prostheses in under-served communities, providing research opportunities for historically under-represented students, and developing undergraduate and graduate students in cutting-edge interdisciplinary research. Two non-invasive strategies to provide pediatric prosthesis users with kinesthetic (movement) feedback will be the focus of the research. The first will use a vibration-based perceptual illusion that restores the sense of missing hand movements, while the second will employ haptic buzzing (skin vibration) to encode prosthesis movement information. The core hypothesis is that providing pediatric prosthesis users with kinesthetic feedback will improve prosthetic control, the learning of motor tasks, and device embodiment, and that these effects will be heightened when the feedback is experienced as illusory missing-hand movements. To validate this hypothesis, vibration parameters will first be modeled and refined so that they can be tuned to effectively communicate prosthetic movement characteristics. The effects of kinesthetic feedback (illusory and buzzing) on subjects’ learning of novel prosthetic control tasks will then be characterized using a human-prosthesis co-adaptive paradigm. Finally, the relationships between device control, movement sensation, and prosthesis embodiment will be examined. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.