Fall-Risk Classification in Amputees Using Smartphone Sensor Based Features in Turns.

Identifying people at risk of falling can prevent life altering injury. Existing research has demonstrated fall-risk classifier effectiveness in older adults from accelerometer-based data. The amputee population should similarly benefit from these classification techniques; however, validation is still required. 83 individuals with varying levels of lower limb amputation performed a six-minute walk test while wearing an Android smartphone on their posterior belt, with TOHRC Walk Test app to capture accelerometer and gyroscope data. A random forest classifier was applied to feature subsets found using three feature selection techniques. The feature subset with the greatest accuracy (78.3%), sensitivity (62.1%), and Matthews Correlation Coefficient (0.51) was selected by Correlation-based Feature Selection. The peak distinction feature was chosen by all feature selectors. Classification outcomes with this lower extremity amputee group were similar to results from elderly faller classification research. The 62.1% sensitivity and 87.0% specificity would make this approach viable in practice, but further research is needed to improve faller classification results.