Optimal schedules of light exposure for multiple individuals for Quick Circadian Alignment

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The invention of quick transportation modes that allow trans-meridian travel has caused circadian misalignment to be a common problem amongst people today. This leads to lower cognitive alertness in the short term and increases the risks of other maladies in the long term. Light, when applied at correct levels and times, can shift and re-entrain the circadian clock to the local time zone, and minimize the negative impact of any circadian misalignment. In this paper, we developed a new method (algorithm) to calculate common optimal light schedules of light exposure and avoidance, to quickly re-entrain the circadian systems of a group of individuals who have different internal circadian parameters. We used an experimentally validated mathematical model to define a target circadian phase, from which, our optimization algorithm iteratively adjusts the switching times of a bang-bang light input (restricted to two light levels) to minimize the difference between the current phase of all individuals and the target phase, within a set time period. The proposed algorithm generated light schedules that successfully minimizes the re-entrainment time of all the individuals with phase shifts up to 12 hours of delay or advancement.

Original languageEnglish
Title of host publication21st IFAC World Congress, Proceedings
EditorsRolf Findeisen, Sandra Hirche, Klaus Janschek, Martin Monningmann
Place of PublicationNetherlands
Number of pages6
Publication statusPublished - 2020
EventInternational Federation of Automatic Control World Congress 2020 - Berlin, Germany
Duration: 12 Jul 202017 Jul 2020
Conference number: 21st
https://www.sciencedirect.com/journal/ifac-papersonline/vol/53/issue/2 (IFAC PapersOnline — ISSN 2405-8963 Volume 53, Issue 2 )

Publication series

PublisherElsevier - International Federation of Automatic Control (IFAC)
ISSN (Print)2405-8963


ConferenceInternational Federation of Automatic Control World Congress 2020
Abbreviated titleIFAC 2020
Internet address


  • Bang-bang control
  • Circadian Re-entrainment
  • Human Circadian System
  • Optimal Control

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