A Cortisol-Based Energy Decoder for Investigation of Fatigue in Hypercortisolism

Dilranjan S. Wickramasuriya, Rose T. Faghih

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    Hormones play a fundamental role in homeostasis. We develop a state-space model relating the body's internal energy to cortisol hormone secretions. Cortisol is secreted in pulses and follows a 24 h circadian rhythm. Secretory event timings carry important information regarding internal feedback signaling taking place, as do the upper and lower serum cortisol levels. We relate an internal energy state variable to cortisol pulse timings and to the upper and lower serum cortisol envelopes. We derive Bayesian filter equations for state estimation and use the Expectation-Maximization algorithm for model parameter recovery. Results on multi-day simulated data show circadian energy variations in healthy subjects and non-circadian fluctuations throughout 24 h periods in patient models suffering from hypercortisolism. The results shed new light on why patients diagnosed with excess cortisol disorders frequently experience symptoms of daytime fatigue and sleep disturbances at night. The state-space model is also an important first step towards the design of closed-loop controllers for treating hormone-related disorders in a manner that closely emulates the body's own pulsatile feedback mechanisms.

    Original languageEnglish (US)
    Title of host publication2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019
    PublisherInstitute of Electrical and Electronics Engineers Inc.
    Pages11-14
    Number of pages4
    ISBN (Electronic)9781538613115
    DOIs
    StatePublished - Jul 2019
    Event41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019 - Berlin, Germany
    Duration: Jul 23 2019Jul 27 2019

    Publication series

    NameProceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS
    ISSN (Print)1557-170X

    Conference

    Conference41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019
    Country/TerritoryGermany
    CityBerlin
    Period7/23/197/27/19

    ASJC Scopus subject areas

    • Signal Processing
    • Biomedical Engineering
    • Computer Vision and Pattern Recognition
    • Health Informatics

    Fingerprint

    Dive into the research topics of 'A Cortisol-Based Energy Decoder for Investigation of Fatigue in Hypercortisolism'. Together they form a unique fingerprint.

    Cite this