Light sensors for determination of lights off time in home polysomnography

Schembri, R., Spong, J., Berlowitz, D., O'Donoghue, F., Greenwood, K., Barnes, M., Churchward, T., and Rochford, P. (2011) Light sensors for determination of lights off time in home polysomnography. Journal of Sleep Research, 20 (Supplement 1). Po91. p. 58.

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Introduction: Polysomnography (PSG) in the home has advantages over in-laboratory PSG, but one important disadvantage is the inability of current devices to record lights off (Loff) and on times and thus important indices such as sleep onset latency and sleep efficiency cannot be determined. This study evaluates the characteristics of a prototype light sensor (Compumedics) used with a portable PSG device (SomtePSG, Compumedics), and its utility in the home where light conditions are uncontrolled and it is impractical to calibrate the light sensor to the conditions in each individual home.

Methods: Three examples of the light sensor were exposed to incandescent light at a range of controlled light levels to determine their signal characteristics. Twenty-four home PSGs were analysed to explore the characteristics of the light sensor signal in the home.

Results: The table below shows the results for the sensor signal characteristics. The light sensor allowed a discernable Loff to be identified in 19 of 24 home PSGs, and in these 19, the mean difference between patient reported and light sensor Loff was 1.2 min (SD 16.6, range -23 to +50).

Discussion: The light sensor signals were found to have good sensitivity and linearity, low drift and record a range of lux appropriate for the home setting. When used in home PSG, these light sensors were able to establish Loff in the majority of PSGs. The wide range of differences between patient reported and sensor Loff demonstrates the importance of objective determination of Loff in home PSG, particularly for studies where accurate measurements of Loff dependant indices such as sleep onset latency are needed.

Item ID: 40610
Item Type: Article (Abstract)
ISSN: 1365-2869
Additional Information:

Sleep DownUnder 2011, sleep and the city, Australasian Sleep Association and Australasian Sleep Technologists Association, 23rd Annual Scientific Meeting, Sydney Convention Centre, 27-29 October 2011.

Date Deposited: 24 Sep 2015 03:03
FoR Codes: 17 PSYCHOLOGY AND COGNITIVE SCIENCES > 1701 Psychology > 170106 Health, Clinical and Counselling Psychology @ 100%
SEO Codes: 92 HEALTH > 9201 Clinical Health (Organs, Diseases and Abnormal Conditions) > 920111 Nervous System and Disorders @ 100%
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