Collaborative research: RUI: noninvasive, natural and intuitive electrocutaneous stimuli for bionic limbs

This Project Grant award from the National Science Foundation's (NSF) Engineering program (CFDA 47.041) provides $212,026 to Elizabethtown College to develop non-invasive, natural and intuitive electrocutaneous stimuli for bionic limbs. The goal is to create artificial touch sensations that feel natural and are easy to use for people with prosthetic arms, addressing a key challenge that causes many amputees to stop using their devices. The project aims to overcome limitations of current non-invasive neurostimulation technologies by developing novel biomimetic electrocutaneous stimulation algorithms that enhance the naturalness of sensations, improve functional performance, and reduce cognitive load during tasks requiring sensorimotor integration. This collaborative research between Elizabethtown College, a primarily undergraduate institution, and a major research university, also provides opportunities for undergraduate students to engage in high-impact research, enhancing their education and career prospects.

Abstract

Many people with amputated arms stop using their prosthetic devices because they lack a sense of touch, making everyday tasks difficult and less fulfilling. This project aims to develop artificial touch that feels natural and is easy to use for people with bionic arms. This natural feeling will be created through pulsed electrical stimulation that mimics the natural nerve signals in the skin. By using low-cost electrodes on the skin surface, this technology can be more easily commercialized and integrated with prosthetic arms, unlike technologies that require surgical implantation. Additionally, this project supports a collaboration between a primarily undergraduate institution and a major research university, allowing undergraduate students to engage in high-impact research to enhance their education and career opportunities while at the same time exposing graduate students to potential careers at primarily undergraduate institutions. Noninvasive neurostimulation to restore touch often feels electrical, unnatural and unpleasant. This proposal develops novel biomimetic electrocutaneous (EC) stimulation algorithms to enhance the naturalness of sensations and improve functional performance and reduce cognitive load during closed-loop sensorimotor tasks (e.g., fragile object manipulation). To create natural feeling sensory percepts, several obstacles unique to noninvasive EC stimuli need to be overcome. Because pulse frequencies above 50 HZ feel more natural but higher pulse frequencies are less able to convey a change in stimulus strength, frequency modulation alone reduces the range of perceived intensities. However, variations in electrical conductivity and build-up of electric charge at the electrode-skin interface can create unpleasant and painful sensations. Therefore, this research explores novel multi-modal biomimetic stimulation paradigms designed to avoid activation of pain or itch nerve fibers while also providing a useful range of stimulation intensity. Individuals with transradial amputation will be recruited at both a primarily undergraduate institution and an R1 research university to test the biomimetic EC stimulation algorithms while controlling bionic arms with electromyographic signals. 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.- subawards are not planned for this award.