A combination of inertial sensors and vibrotactile feedback for balance improvements in therapeutic applications

Biofeedback systems are being widely used on patients with balance disorders due to vestibular loss, stroke or aging. Undergoing continuous balance training regimens with the aid of biofeedback systems have proven to be able to effectively augment postural stability. A variety of feedback modalities are available ranging from audio signaling, visual indications, tactile cueing, etc, and their suitability relates to the nature of the application. This paper presents the development of a real time vibrotactile biofeedback system for medial-lateral trunk tilt. The prototype employs a wireless inertial sensor for trunk tilt angle measurements, a comprehensive software interface for data acquisition, data processing and display, video recording, feedback signal generation and data analysis, and wearable vibrotactile actuators to provide biofeedback based on trunk tilt measurements. Feedback is provided based on a threshold angle range entered via the interface. To test the applicability of the system, a commonly used balance training protocol was identified, standing in tandem Romberg Position with eyes open and eyes closed. Two young, healthy subjects participated in the experiment with and without the biofeedback system, and the effectiveness of biofeedback was analyzed. The results proved the developed system´s capability in providing real time biofeedback for balance improvements.