Signal Processing Algorithm and Health Care Application for Wearable Sense of Balance Monitoring Headphones

A wearable sense of balance monitoring headphones system utilizing a 3-axis low-noise accelerometer has been investigated to determine suitable parameters to describe physical conditions of the user. We performed a light physical stress test, in which the user goes up stairs for a short time, to cause gradual as well as monotonous changes in the sense of balance. From the results with an electromagnetic positioning system, a motion evaluation parameter calculated with 2-dimensional time-differential acceleration trace plots showed a well-defined monotonously decreasing curves as compared with velocity and coordinate trace plots. A population test using the headphones device with healthy subjects showed that the 2-axis acceleration signals should be measured for more than 10 seconds to describe the user's conditions. Moreover, daily changes in the motion evaluation parameter for more than 60 days suggested that the developed system can be used for daily health care monitoring.