Posturographic sleepiness monitoring

Abstract

SUMMAR Y Although reduced sleep often underlies traffic and occupational accidents, convenient sleepiness testing is lacking. We show that posturographic balance testing addresses this issue, because balance testing predicts hours of wakefulness, which could facilitate sleepiness testing. Here, we equate balance scores from separate trials, blinded to the experimenter, with those recorded as a function of known and increasing time awake (i.e. during sustained wakefulness); we show, that the time awake in separate trials is posturographically measurable: positive predictive value 69%, sensitivity 56%, and specificity 96%. These results encourage further work developing posturographic sleepiness monitoring.

Modeling balance control during sustained waking allows posturographic sleepiness testing

“…Studies on balance during sustained waking are COP-based, not examining control mechanisms (Forsman et al, 2007;Liu et al, 2001;Morad et al, 2007;Nakano et al, 2001). Sustained waking increases the time interval for open-loop stance control (Dt c ) by 0.68% per hour (Forsman et al, 2007).…”

“…Sustained waking increases the time interval for open-loop stance control (Dt c ) by 0.68% per hour (Forsman et al, 2007). The TA estimation procedure equates the Dt c test score with those in the reference curve (the subject's Dt c scores recorded during increasing TA) (Forsman et al, 2007). The TA-dependent impairment accounts for only 60% of the diurnal balance variations because balance also exhibits circadian rhythm (Forsman et al, 2007;Nakano et al, 2001).…”

“…The TA estimation procedure equates the Dt c test score with those in the reference curve (the subject's Dt c scores recorded during increasing TA) (Forsman et al, 2007). The TA-dependent impairment accounts for only 60% of the diurnal balance variations because balance also exhibits circadian rhythm (Forsman et al, 2007;Nakano et al, 2001). We suggest that COM-based Dt c scores are more TA-dependent than COP-based Dt c scores and allow more accurate TA estimates.…”

“…Sleepiness causes 10% of all road accidents (Philip et al, 2001), but where an alcoholmeter tests alcohol intoxication there is no convenient sleepiness test (Guilleminault and Brooks, 2001). Clinical balance testing ) is a potential test because it estimates a subject's time awake (TA) with 69% positive predictive value (PPV) (Forsman et al, 2007). Assessing ''posturographic fitness'' of individuals is interesting because traditional parameters have been insensitive in individual cases.…”

“…Sustained waking increases the time interval for open-loop stance control (Dt c ) by 0.68% per hour (Forsman et al, 2007). The TA estimation procedure equates the Dt c test score with those in the reference curve (the subject's Dt c scores recorded during increasing TA) (Forsman et al, 2007).…”