The goal of the proposed project is to design and develop a purely mechanical, ratcheting prosthetic finger ? the Women?s Digit ? which 1) can be sized for a 5th percentile female hand using advanced metal 3D printing technology, 2) has an industry leading strength to weight ratio, and 3) can be operated using unilaterally (one- handed) using a novel ratcheting mechanism. The largest population of upper limb amputees are those with partial hand amputations. This population outnumbers all other levels of upper limb amputees by a factor of 10. Therefore, a significant clinical impact can be made if a product serves this population effectively. However, current commercial products for partial hand amputees do not satisfy all of the needs of female patients; no commercially available prosthetic finger is appropriately sized for the full range of female hand sizes. Effectively, certain women veterans with partial hand amputation are untreatable. This proposal is in response to the VA RR&D Request for Proposals (RFP) to develop female veteran specific prosthetic components. The proposed research plan includes 1) the design and development of the Women?s Digit ? a ratcheting mechanical prosthetic finger, 2) the manufacturing of multiple prototypes at various lengths, 3) mechanical testing to confirm scalability, strength, reliability, and manufacturability, and 4) an in-laboratory testing session with a female partial hand amputee. The care of Veterans with upper limb amputation requires a highly individualized approach to medicine. Each Veteran brings unique needs to the clinic including various levels of amputation, lifestyles, personal experience, and other medical indicators. Prosthetists and occupational therapists work with each Veteran to provide a personalized medical solution using whatever component and technologies are available on the open market. Very often, the bottleneck in this system is the development of clinically sound prosthetic components that can be readily sourced by the prosthetists to provide an optimal prosthetic limb system. The mission of the VA Biomechatronics Development Laboratory is to innovate devices and algorithms in the field of upper limb prosthetic design. The Biomechatronics Development Laboratory develops products that provide prosthetists and Veterans with solutions to meet the unique needs of each Veteran in this dynamic and challenging healthcare setting. The Women?s Digit will provide an effective and durable solution for women veterans with partial hand amputation and ensure their ability to enjoy their work, family, and life to the fullest.

Public Health Relevance

The Women?s Digit is a purely mechanical, ratcheting prosthetic finger ? independent from electronics and batteries, thereby reducing cost, size, and complexity while increasing reliability and durability- that is sized to fit a 5th percentile to 95th percentile female hand. The amputation of full or partial fingers can cause physical, psychosocial, and economic damage to an individual. Replacement of a finger requires a mechanical design that can withstand the forces, torques, and environmental conditions of everyday life. The challenging requirements for an effective prosthetic finger have caused an absence of products for women veterans with typically smaller hand sizes. This proposal seeks to fill this void through the development, manufacturing, and testing of the Women?s Digit.

National Institute of Health (NIH)
Veterans Affairs (VA)
Non-HHS Research Projects (I01)
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Rehabilitation Engineering & Prosthetics/Orthotics (RRD5)
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VA Eastern Colorado Health Care System
United States
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