Electromagnetic Attachment of Assistive Devices

Reduced movement ability is linked to devastating health effects, including obesity, heart disease, and depression. There has recently been an exciting surge in technology aimed at restoring lost mobility; prostheses, orthoses, and exoskeletons are more reliable, precise, and biomimetic than ever. Unfortunately, the impact and clinical acceptance of these assistive devices is limited by an inability to attach them safely and comfortably to the body.

This is a particular challenge for the nearly two million Americans living with limb amputation. Current prosthetic attachment systems are uncomfortable, restrict motion, and require regular clinical adjustment. To address these limitations, this project will advance a new attachment system that improves the mechanical interface between arm prostheses and the body.

The project’s goal is to create prosthetic suspension systems that are safer and more comfortable, fit better, and require less frequent adjustment in the clinic. In addition to the direct impacts of this research, the project team will seek to increase disability awareness among undergraduate students and medical trainees, by incorporating principles from the proposed work into formal course curricula and inviting undergraduates and medical trainees to participate in research, clinic visits, and relevant surgical procedures.

The PI Team will also work closely with a student-led professional organization called the Society for Engineers Experiencing Disabilities, which was founded by one of lead graduate students on the project; this student plans to present their progress in the proposed research at seminars to undergraduate and K-12 students to emphasize the crucial role of people with disability in STEM.

The primary objective of this work is to establish an adaptive fixation strategy for assistive devices that effectively transmits forces to the human body, while preventing large soft-tissue strains and eliminating relative body-device motion. Toward this end, this project will advance a new system that uses electromagnetics to transmit loads from a prosthetic limb directly to the residual bone of persons with limb amputation.

The research goals are to i) measure and model attachment force requirements for above-elbow prostheses during activities of daily living, ii) determine the relationship between electromagnet design parameters and system performance, and iii) evaluate large-gap electromagnetic force control strategies. These experiments will elucidate the biomechanical and operational requirements for electromagnetic suspension of limb prostheses.

The proposed work is also expected to produce technical knowledge that applies to other assistive devices, as well as to non-rehabilitation applications involving large-gap electromagnetic control. This research has the potential to advance the field of assistive technology by improving the comfort, safety, and effectiveness of chronic load transfer from prosthetic devices.

Additionally, the proposed approach challenges the conventional design paradigm for assistive devices, emphasizing parallel engineering of body and machine.

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.