Visual Feedback in Balance Rehabilitation using Inexpensive Gaming Peripherals

Balance retraining is a critical part of rehabilitation for many individuals following neurotrauma such as stroke. This work focuses on implementation of visual feedback in balance therapy with the ultimate goal of improving the efficacy of clinical balance rehabilitation. Using the custom-built WeHab balance rehabilitation software tool, this work examines strategies for implementing visual feedback, as well as interpretation of balance information based on mediolateral weight shifting. By focusing on the Nintendo? Wii Balance Board gaming peripheral, which is inexpensive and widely available, this work has the potential to enable visual feedback for balance therapy in both clinical and home settings. One-hundred twenty-two young, healthy subjects between the ages of 17 and 22 participated in two studies of visual feedback design strategy. The first study examined the effects of feedback arrangement (direct center of pressure vs. mediolateral weight distribution), numeric feedback, and dimensionality, while the second study investigated implementation of feedback based on smoothed and filtered center of pressure information. Together, these studies demonstrated that feedback design has a significant impact on subject performance in both quiet standing and mediolateral weight-shifting balance tasks.Using mediolateral weight-shifting data from the young, healthy subjects in the first study, balance control parameters were obtained by matching experimental balance performance to simulated results using an inverted pendulum model. The close matching obtained across all subjects indicated the usefulness of this novel application of the simple model in examining mediolateral weight shifting. Additionally, this modeling study incorporated a novel non-minimum phase behavior metric in classifying subject weight-shifting performance.In addition to its use in a research setting, the WeHab system has been deployed to five local balance therapy facilities. Preliminary examination of the data from clinical sessions indicates that instrumentation of clinical balance therapy could provide a method for quicker balance assessment and quantitative insight into patient balance performance. Additionally, comparison of clinical data with data from the young, healthy subjects and 13 age-matched subjects demonstrates differences between the subject populations that should be explored further in future work.