I-Corps: A Powered Prosthetic Hand with Continuous Multi-Grasp Control

Vanderbilt University, Nashville TN

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the development of a prosthetic hand that offers a truly “lifelike” appearance to enable an active lifestyle, confident return-to-work capabilities, athletic pursuits, and optimal self-image. Over half a million people in the US are affected by upper-limb loss and the majority choose either non-functional cosmetic prostheses or none. Though existing devices have evolved advanced technical capabilities, overall use has remained static due to problems with ease-of-use, weight, and size. This project proposes a novel prosthetic hand for decreased disability, increased productivity, and improved confidence. This I-Corps project is based on the development of technology in prosthetic hand control, production, and mechanical architecture. Currently, multi-fingered hands require the user to command coded patterns of muscle contractions whenever he/she wants to change posture. Users report this extra step and associated planning effort as onerous and disruptive to task performance. The proposed technology is a novel method of electromyographic interface (EMG) hand control that offers a more intuitive way of accessing a larger grasp space while retaining the simplicity and robustness of standard two-site EMG. Because prosthetic hands are attached to the body via soft tissue rather than directly to the bone, their weight is generally perceived as something that needs to be carried. The proposed device utilizes a production approach that capitalizes on newly available cellular structure synthesis software and additive manufacturing to significantly increase structural efficiency and reduce mass at competitive cost. Due to unnatural size, prosthetic hands typically draw unwanted attention even when covered with a glove. To reduce size, the proposed device utilizes a unique actuation topology facilitated by a bottom-up design approach that leverages practical finger individuation differences to reduce motor count and mechanical complexity. 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.