Transient analysis to enhance Wii Fit sleepiness tester

We are developing a posturographic sleepiness tester that employs wavelet and fractal dimension analysis. It detects and characterizes transients in postural sway signals. We measured 6 subjects' postural steadiness (eyes open/closed) with a Nintendo Wii Fit ® balance board every hour during 10 h. During the next two weeks, we performed three additional measurements with different time awake (TA) for each subject. We analyzed the results with 5 literature-based continuous sway measures and with 8 transient-based sway measures. In the eyes open situation 95% of the estimated TA's were inside ±4.8 h and ±2.8 h, respectively. These results show that the transient analysis has potential to detect daytime changes in postural steadiness and that it can be used to enhance posturographic TA estimation during daytime and possibly during sustained wakefulness.