Regenerative Peripheral Nerve Interfaces to Enhance Function and Sensation in People with Transfemoral Amputation
Abstract
Individuals with an above-knee lower-limb amputation are known to walk more slowly, expend more energy, have a greater risk of falling, and have reduced quality of life compared to individuals without amputation and those with below-knee amputation. One of the driving factors behind these deficits is the lack of active function provided by above-knee prostheses with prosthetic knees and ankles. While many prosthetic devices have been developed for functional restoration after major lower-extremity amputation, there remains no stable interface to facilitate reliable, long-term volitional control of an advanced robotic limb capable moving multiple joints. Moreover, there is no existing interface that provides useful sensory feedback that, in turn, enhances the functional capabilities of the prosthesis. To achieve both greater signal specificity and long-term signal stability, we have developed a biologic interface known as the Regenerative Peripheral Nerve Interface (RPNI). An RPNI consists of a peripheral nerve that is implanted into a free muscle graft that would otherwise go unused in the residual limb. As the nerve grows, it reinnervates the free muscle graft, which undergoes a predictable sequence of revascularization and regeneration. The RPNI leverages these biological processes to provide three essential benefits to people with amputation: intuitive motor control, sensory feedback, and mitigation of post-amputation pain. This proposal will determine the extent to which the RPNIs enable generation of high-fidelity motor control signals for an advanced lower-limb prosthesis with active knee and ankle motion. We will evaluate the amplitude, movement specificity, and stability of signals derived from the lower-limb RPNIs over 1 year. We will use these signals to control a powered knee-ankle prosthesis while participants perform cyclic tasks (e.g., walking) and unpredictable tasks (e.g., sudden stops). We expect that this control approach will enable users to feel more confident and stable with decreased cognitive effort associated with their movements. Finally, we will determine whether stimulation of lower-extremity RPNIs provides meaningful sensory feedback that can enhance stability while the user is standing and walking with their prescribed prosthesis. We expect these findings will motivate future clinical trials using RPNIs for control and sensation simultaneously.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2024
- Source ID
- HT94252310678
Entities
People
- Deanna H. Gates
Organizations
- United States Army
- University of Michigan