TY  - JOUR
PY  - 2000//
TI  - Pupillography as an objective indicator of fatigue
JO  - Current eye research
A1  - Morad, Yair
A1  - Lemberg, H.
A1  - Yofe, N.
A1  - Dagan, Y.
SP  - 535
EP  - 542
VL  - 21
IS  - 1
N2  - PURPOSE: To determine whether parameters calculated from pupillary activity can identify subjects with sleep deprivation, and whether the objective values correlate with a subjective feeling of fatigue. METHODS: pupil size in the dark was recorded continuously for 10 minutes in 12 healthy volunteers using an infrared video camera. Two recordings were made for each subject: after a full night's sleep, and after 24 hours of sleep deprivation. Several parameters calculated from pupil size and activity were analyzed and compared with a subjective rating of the state of alertness provided by the participants in each test. RESULTS: All pupillary parameters differed significantly between alertness and fatigue (p = 0.0076-0. 0186). Changes in one of the parameters - average pupillary diameter - correlated with changes in the subjective level of sleepiness (r = -0.51, p = 0.028). Although the values of most parameters differed among subjects, an absolute value of more than 25 in one parameter, cumulative pupillary variability ratio, was always associated with sleep deprivation. CONCLUSION: On-line analysis of the pupillogram using the suggested parameters can be performed easily to produce a real-time assessment of an individual's state of alertness or fatigue that correlates with his/her subjective assessment of this state.<p />  <p>Language: en</p>
LA  - en
SN  - 0271-3683
UR  - http://dx.doi.org/
ID  - ref1
ER  -