thesisA wireless, wearable, real-time gait asymmetry detection system-the Lower Extremity Ambulatory Feedback System (LEAFS)-has been validated by comparison to clinical motion capture (force plate and three-dimensional cameras) measurements, and evaluated in training sessions with seven subjects. LEAFS is a low-cost in-shoe gait detection device that provides real-time auditory feedback based on stance time ratio and allows long-term gait asymmetry training to be performed outside of the clinical environment. Stance time ratio, which is also known as Symmetry Ratio (SR), is calculated by dividing the stance time on one limb (typically the more affected limb) by the other, and control subjects have been shown to have SR of 1.02 ± 0.02. The validation test results demonstrate that the SR measured by LEAFS as compared to clinical motion capture results has a mean error of 0.003 ± 0.05 for control subjects and 0.008 ± 0.04 for subjects with unilateral trans-tibial amputations. The LEAFS was used for gait asymmetry training in seven subjects with unilateral trans-tibial amputations; subjects received six 30-minute training sessions over a 3-week training period. The results demonstrate that LEAFS is accurate at measuring mean SR of a trial of steps, and it is reliable and practical to use LEAFS to train the gait of patients with unilateral trans-tibial amputations by bringing their SR towards a normal range
