This is an application for a Small Projects in Rehabilitation Research (SPiRE) award to Dr. David Ewart, MD, a staff rheumatologist at the Minneapolis VA Medical Center and Assistant Professor at the University of Minnesota. Dr. Ewart has a history of research and publications in biomechanics, immunology, and animal models of arthritis and is transitioning to a focus on the treatment and rehabilitation of joint damage. Dr. Ewart is an early career investigator with protected time to establish an independent line of investigation. This SPiRE award will provide Dr. Ewart with the support to: 1) develop a unique interinstitutional collaboration to build an orthosis with an integrated microphone to measure acoustic emissions from the knee at the point of care 2) use acoustic emissions to identify patients with pre-radiographic osteoarthritis of the knee 3) establish a mentored role in a busy research group and generate the preliminary data with which to apply for a career development award (CDA-2). To achieve these goals, Dr. Ewart has established a mentorship team consisting of Dr. Andrew Hansen, head of the Minneapolis Adaptive Design and Engineering (MADE) program at the Minneapolis VA, and Dr. Omer Inan, PhD, Associate Professor of Electrical and Computer Engineering at Georgia Tech. Dr. Ewart will work with the MADE program to perform the technical construction of the knee orthosis, integrate the microphone into it, and collaborate remotely with Dr. Inan to analyze the data from and refine the microphone system for function in the wearable device. Osteoarthritis (OA) is a prevalent and disabling disease. Pharmacologic and surgical treatments for symptoms of OA are insufficient for many patients and there are no therapies which halt or even delay the structural progression of disease. One difficulty in the study of such therapies is identification of patients at an early enough stage of disease that the damage to the joint is potentially reversible. In patients at risk of OA but with no signs of it on x-rays, MRI has been shown to be able to identify changes in the knee that are predictive of subsequent development of OA. However, these findings are not specific in all circumstances and MRI is expensive, time-consuming, and can’t be used at the point of care. Measurement of acoustic emissions from the knee with a modern, miniature microphone can differentiate health in the knee from disease and would offer novel method of screening for early OA. In Aim 1, Dr. Ewart will work with the MADE program and Dr. Inan’s group to prototype and iteratively design a portable orthosis with an integrated microphone system for measuring acoustic emissions from the knee at the point of care. In Aim 2, Dr. Ewart will identify patients at risk for development of osteoarthritis of the knee but without radiographic signs of advanced disease and compare acoustic emissions from their knees to healthy controls. If acoustic emissions are abnormal in the at- risk group, ...