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Access Presentation Matsangas

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Matsangas (2008) - Evaluation of mild motion sickness nauseogenic space and comparison with current standards: Should we go forward?

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Access Presentation Matsangas

  1. 1. Evaluation of mild motion sickness nauseogenic space and comparison with current standards: Should we go forward? ACCeSS Meeting 2008 The Atlantic Center for the Innovative Design and Control of Small Ships By LCDR P. Matsangas, M.Sc., Hellenic Navy [email_address]
  2. 2. Overview <ul><li>Motion sickness </li></ul><ul><li>HFR model </li></ul><ul><li>Existing standards </li></ul><ul><li>What we know </li></ul><ul><li>What we don’t know </li></ul><ul><li>Modeling approach </li></ul><ul><li>The way forward </li></ul>
  3. 3. Why?
  4. 4. Motion Sickness <ul><li>ISO standard 9996:2000 </li></ul><ul><ul><li>Motion sickness is a commonly experienced and sometimes severe but reversible disorder specifically associated with exposure to actual or perceived oscillatory motion in the frequency range 0,l Hz to 1 Hz . One or more of a constellation of symptoms (with or without frank vomiting) may afflict the sufferer. </li></ul></ul><ul><ul><li>In severe cases it is immediately and profoundly disruptive of motivation, concentration, activity and task performance in both individuals and groups, but in the less severe case with premonitory manifestations it remains an open question whether individual task performance is degraded until activities are interrupted or abandoned . </li></ul></ul><ul><ul><li>Group performance (for example the work of a ship’s department) may be delayed or impaired by attrition in the crew. The malady afflicts sufferers in a highly idiosyncratic manner. Most sufferers can benefit from diminishing effect of continued or repeated exposure to the provocative stimulus (habituation).” </li></ul></ul>
  5. 5. Sopite Syndrome <ul><li>ISO standard 9996:2000 </li></ul><ul><ul><li>“ A state of sleepiness, lassitude, or drowsy inattention induced by motion or vibration ”. </li></ul></ul><ul><ul><li>Furthermore, it notices: “ Profound lassitude and drowsiness have been specifically identified as the sopite syndrome, when associated with low-frequency (below 1 Hz) motion such as is commonly experienced aboard ships. The neurological basis of the sopite syndrome, and its relationship to classical sickness, remain open questions in physiological science.” </li></ul></ul>
  6. 6. HFR model (1974-1976) Model Characteristics Vertical Acceleration Only true motion MSI: % of people who vomit Two-hour nauseogenic period Nauseogenic frequency range 0.1 – 0.7 [Hz] Central nauseogenic frequency 0.167 [Hz]
  7. 7. Motion Sickness Adaptation example
  8. 8. Problems <ul><li>The standards </li></ul><ul><ul><li>Are based </li></ul></ul><ul><ul><ul><li>on the HFR regression model </li></ul></ul></ul><ul><ul><li>Refer to </li></ul></ul><ul><ul><ul><li>Vomiting only (not motion sickness in general) </li></ul></ul></ul><ul><ul><ul><li>0.1 Hz to 0.5 Hz </li></ul></ul></ul><ul><ul><ul><li>No visual input </li></ul></ul></ul><ul><ul><ul><li>No relation to task performance </li></ul></ul></ul><ul><ul><ul><li>Sopite syndrome? </li></ul></ul></ul>
  9. 9. Constraints <ul><li>The definition of motion sickness, </li></ul><ul><li>The corresponding nauseogenic frequency range, </li></ul><ul><li>The nauseogenic motion incorporated for the evaluation of motion sickness (z-axis), </li></ul><ul><li>The settings the standard refers to (no external visual), and </li></ul><ul><li>The motion category (real not apparent) </li></ul><ul><li>The motion attributes (simple sinusoidal) </li></ul>
  10. 10. Current status of knowledge related to MS <ul><li>What we know </li></ul><ul><ul><li>MS=f(acceleration(amplitude,frequency)) </li></ul></ul><ul><ul><li>More acceleration = more MS </li></ul></ul><ul><li>What we don’t know </li></ul><ul><ul><li>Frequency response vs </li></ul></ul><ul><ul><ul><li>Symptoms (not only vomiting) </li></ul></ul></ul><ul><ul><ul><li>Visual input </li></ul></ul></ul><ul><ul><li>Effect on task performance </li></ul></ul>
  11. 11. What we must do <ul><li>Develop appropriate models </li></ul><ul><li>Research on the effect of mild motion sickness on task performance </li></ul><ul><li>Simulate operational effectiveness </li></ul>
  12. 12. Current (2008) Model in Detail <ul><li>Proposed Model </li></ul><ul><li>Z-axis (Vertical Acceleration) </li></ul><ul><li>Linear </li></ul><ul><li>Time invariant </li></ul><ul><li>Stable </li></ul>
  13. 13. Predicted MSI Proposed Model Characteristics Vertical Acceleration MSI: % of people who vomit Two-hour nauseogenic period Nauseogenic frequency range 0.05 – 0.6 [Hz] Central nauseogenic frequency 0.17 [Hz]
  14. 14. Model Validation True Motion Settings Proposed model HFR model MSI Comparison between Proposed and HFR models 1 2 3
  15. 15. MSI Accumulation Characteristics Vertical Acceleration MSI: % of people who vomit Two-hour nauseogenic period Nauseogenic frequency range 0.05 – 0.6 [Hz] Central nauseogenic frequency 0.17 [Hz]
  16. 16. MSI Habituation
  17. 17. MSI Habituation and Retention
  18. 18. Model significance <ul><li>Parametric </li></ul><ul><li>Easily extended to various combinations of sensory cues </li></ul><ul><li>Partially Validated but not “tuned” </li></ul><ul><li>Precise </li></ul><ul><li>Etiologic </li></ul><ul><li>Linear and time invariant </li></ul>
  19. 19. Future Research <ul><li>Regarding the model </li></ul><ul><ul><li>Implementation in SIMULINK </li></ul></ul><ul><ul><li>Input of ships’ raw motion data </li></ul></ul><ul><ul><ul><li>evaluate the model’s performance </li></ul></ul></ul><ul><ul><li>Increase external validity </li></ul></ul><ul><ul><li>Use the model in order to analyze its’ possible predictive validity </li></ul></ul>
  20. 20. Future Research <ul><li>Regarding standards </li></ul><ul><li>Nauseogenic space of sopite syndrome </li></ul><ul><li>Quantification of sopite syndrome effects </li></ul><ul><ul><li>Vigilance tasks </li></ul></ul><ul><ul><li>Automation supervision </li></ul></ul><ul><ul><li>Combined effect with sleep deprivation </li></ul></ul><ul><ul><li>Other common tasks naval vessels </li></ul></ul><ul><li>Extend the existing standards </li></ul><ul><li>Increase habitability </li></ul>
  21. 21. Project Description Research Questions <ul><li>Are sopite syndrome symptoms evident in the same nauseogenic frequency range, as it is defined in existing standards? </li></ul><ul><li>Is sopite syndrome related to the known main nauseogenic environmental parameters (motion acceleration and frequency, time of nauseogenic exposure)? </li></ul><ul><li>Is there a relation between vigilance decrement and motion stimulus? </li></ul>
  22. 22. Project Description Goals <ul><li>Ship Predicted Motion Profile </li></ul>Predicted MS Profile Predicted MII Profile Design Phase
  23. 23. <ul><li>Questions? </li></ul>
  24. 24. Motion Sickness Incidence (MSI) <ul><li>A common index of motion sickness severity. </li></ul><ul><li>The percentage of people who vomit when exposed to a nauseogenic environment. </li></ul>
  25. 25. Normalization & Linear Combination of 2 Sources of Error = MSI
  26. 26. Current Model (2008) in Detail

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