Upper limb amputation is a major cause of disability and is most effectively treated with a prosthesis. Powered prostheses - controlled by electromyographic (EMG) signals from residual muscles - are a popular and growing treatment option. Significant challenges with providing comfortable prosthesis suspension and robust EMG signal recordings challenge their wider acceptance and usage. There is a great need to develop a clinically viable, user-friendly method to comfortably suspend the prosthesis and acquire high quality EMG signals. Potential exists to embed EMG electrodes into a commercially available elastomeric liner that offers comfortable prosthesis suspension. The long-term goal is to bring to market a mass-producible elastomeric liner with an embedded grid of electrodes. The elastomeric liner will have EMG electrodes and leads, arranged in a grid array that can be donned and doffed as easily as currently available liners. The objective of this application is to determine if compliant EMG electrodes embedded into an existing elastomeric liner product will yield EMG data that is on par with data acquired using commercially available prosthesis electrodes. The feasibility of this objective is supported by the applicant's preliminar data. The rationale for the proposed work is that a grid of compliant EMG electrodes and leads would eliminate the challenge of customized electrode placement and would significantly reduce the burden on the patient by eliminating the need for the amputee to manipulate or manage any external wires and/or connectors. The electrode grid would also help bring advanced multi-DOF prosthesis for upper limb amputees closer to reality. The objective will be achieved by completing the following two specific aims: (1) Integrate a stretchable, flexible electrode grid array into an existing elastomeric liner product, (2) Develop and embed a connector in the elastomeric liner to route EMG signals from the embedded leads to a general electronics interface outside of the liner. Under the first aim, the feasibility of using fabric electrodes witin an elastomeric liner will be tested by comparing EMG signal properties recorded using fabric electrodes with properties of signals recorded using commercially available prosthesis electrodes. Under the second aim, the developed connector will be tested by recording EMG signals acquired with fabric electrodes and routed through the connector with signals acquired using commercially available prosthesis electrodes. The proposed liner is an innovative means of (1) greatly reducing the clinical challenge and time associated with customized electrode placement, (2) capturing high-quality EMG signals while eliminating the need for wire manipulation, and (3) providing a comfortable socket interface for myoelectric prostheses. The proposed work is significant because this versatile product is a self-contained, non-intrusive means of acquiring EMG signals for myoelectric devices in an efficient, and cost-effective manner, taking advantage of the added benefits of current liner technology. Ultimately, this work will allow upper limb amputees better use of myoelectric prostheses, thus improving their function and quality of life.
The proposed project offers a solution to a long-standing problem facing myoelectric prosthesis users: there is no clinically viable, user-friendly means of providing comfortable prosthesis suspension and collecting high- quality muscle activation pattern data from the patient's limb for prosthesis control. To solve this challenge, we propose a method to combine an existing, commercially available technology which has proven to provide comfortable prosthesis suspension - elastomeric liners - with novel type of electrodes. We will embed the electrodes directly into the elastomeric liners producing a self-contained liner system that will be capable of recording muscle activation signals and will be as easy to don/doff and use as standard, commercially availa- ble liners. The proposed liner would be mass-producible, relatively low cost, would reduce time a patient has to spend in the clinic and consequently, would increase the usage of myoelectric prostheses.