Assessing Physical Performance of Elders Using Fuzzy Logic

This paper describes the application of fuzzy logic to the Short Physical Performance Battery (SPPB) test, a series of timed physical activities that have been created to evaluate, discriminate, and predict physical functional performance for both research and clinical purposes, primarily for physically impaired older adults. The original scoring system of SPPB test uses crisp time boundaries to assign the subject to discrete classes of performance. The crisp (and somewhat arbitrary) nature of the crisp thresholds can easily produce anomalies. Fuzzy Logic theory allows the natural description, in linguistic terms, of input/output relationships rather than relying on precise numerical threshold values. This advantage, dealing with the complicated systems in simple way, is the main reason why fuzzy logic theory is widely applied. In this paper, we offer a new approach for scoring the SPPB test. We demonstrate that in the proposed system, the Fuzzy Short Physical Performance Battery (FSPPB), we can improve the sensitivity and data distribution of the scoring system for the SPPB test. We present the procedures of constructing a fuzzy inference system using fuzzy logic to score the SPPB test and compare the original scoring system with our fuzzy scoring system. As part of a large project in technology for Eldercare, our goal is to accurately measure trends in physical performance of seniors over time.