SBIR-STTR Award

A low-cost, easy-to-use fit monitor of socket-suspension systems for lower limb amputeesFor lower limb amputees, the use of prosthetic legs is critical to remain active and live independently. Interfacebetween the residual limb and the prosthetic leg, usually a prosthetic socket with related suspension system (SSS),only works well if the SSS is fit appropriately. To maintain an appropriate SSS fit, repeated interventions fromboth amputees and clinicians are necessary; otherwise, the SSS fit deteriorates due to fluctuation of amputees'residual limb volume caused by long term factors, such as body weight changes, and short-term factors, such asimpact during locomotion. Currently, all interventions are guided by amputees' haptic sensation, which is not areliable information source for regulation of the SSS fit. Guided by this inaccurate information source,interventions are often not effectively or timely, and deterioration of the SSS fit is often ignored until side effectsbecome severe. These unfavorable side effects include unexpected stress concentrated on the residual limb,abnormal gait patterns, increased risk of secondary conditions such as back pain, and skin abrasions that arepainful and difficult to heal.Objective of the proposal is to develop a novel SSS fit monitor to track the SSS fit based on kinematic features ofpistoning, which describes the relative motion between the residual limb and the prosthetic socket. We willaccomplish our study objectives by pursuing three specific aims.Aim 1: Identify phase-dependent kinematic features of pistoning, which are sensitive to change of SSS fit, onmultiple locations on the residual limb; Aim 2: Design a sensor array to track pistoning motions in 3D space; andAim 3: demonstrate the capability to monitor SSS fit during walking on amputee subjects using the developedSSS fit monitor.All these efforts will help us to reach our long-term goal: help amputees and clinicians to improve their capabilityto manage the interface between the residual limb and their prosthetic legs.

Public Health Relevance Statement:
RELEVANCE TO PUBLIC HEALTH The proposed research is relevant to public health because the developed socket fit monitoring system will improve the capability of lower limb amputees to manage their residual limbs more effectively. This, in turn, enables amputees to adjust their socket-suspension system appropriately, reduce skin injury, and have better quality of life. The project is relevant to the part of the NIH's mission such that developing the capability to measure relative motion between residual limbs and prosthetic sockets will help to improve the effectiveness of residual limb management, which prevents skin injury on amputees' residual limb, encourage prosthesis usage, and improve the health of lower limb amputees.

Project Terms:
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