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Matsangas & McCauley (2006) - Prediction of Motion Sickness Incidence:Modeling Efforts based on Human Physiology
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Prediction of Motion Sickness Prediction of Motion Sickness Incidence:Incidence:Modeling Efforts based on Human PhysiologyModeling Efforts based on Human Physiology
ABCD Meeting 2006“Human Performance at Sea: Influence of ShipMotions on Biomechanics and Fatigue"
By
Lieutenant P. Matsagas, M.Sc., Hellenic [email protected], [email protected]
M.E. McCauley, Ph.D., Naval Postgraduate [email protected]
Motion SicknessMotion Sickness
A general term that describes the discomfort A general term that describes the discomfort and associated emesis (vomiting) induced and associated emesis (vomiting) induced by motion. by motion.
Effects are evident in numerous Effects are evident in numerous environments:environments:– ShipsShips– AircraftAircraft– AutomobilesAutomobiles– Air-cushioned vehicles. Air-cushioned vehicles.
Cause of motion Cause of motion sicknesssickness
Neural mismatch theoryNeural mismatch theory
Current sensory input
Neural store
Vestibular systemVision
ProprioceptionError signal
Motion Sickness Motion Sickness Incidence (MSI)Incidence (MSI) A common index of motion sickness A common index of motion sickness
severity.severity. The percentage of people who vomit The percentage of people who vomit
when exposed to a nauseogenic when exposed to a nauseogenic environment. environment.
HFR model (1974)HFR model (1974)
Model CharacteristicsVertical AccelerationOnly true motionMSI: % of people who vomitTwo-hour nauseogenic period
Nauseogenic frequency range0.05 – 0.7 [Hz]
Central nauseogenic frequency0.167 [Hz]
Proposed ModelProposed ModelCharacteristicsCharacteristics
Conceptually based on existing Conceptually based on existing theoriestheories
Observer theory conceptsObserver theory concepts MSI based on:MSI based on:
– Gravity estimation errorGravity estimation error– Residual optical flowResidual optical flow
Linear and Time InvariantLinear and Time Invariant Vertical sinusoidal motionsVertical sinusoidal motions
Proposed ModelProposed ModelAssumptionsAssumptions
Model input parametersModel input parameters– Motion characteristics detected by the Motion characteristics detected by the
vestibular system and somatosensationvestibular system and somatosensation– Motion characteristics detected by Motion characteristics detected by
peripheral visionperipheral vision
Current (2006) Model in Current (2006) Model in DetailDetail
Proposed Model
• Z-axis (Vertical Acceleration)
• Linear• Time invariant• Stable
Error Estimation SubsystemError Estimation Subsystem
Oman (1982)Glasauer & Merfeld (1997)Bles et al. (1998) Merfeld et al. (1993)
Visual SystemVisual System
Sandini et al. (2001)
Legend
Independent
variables
Intermediate
variables
Dependent
variables
Neural
Store
Current Model (2006)Current Model (2006)Adaptation MechanismAdaptation Mechanism in detailin detail
Predicted difference between sensory input and motion in the neural store
Sensory contents in Neural Store
1 2
3
Legend
Independent
variables
Intermediate
variables
Dependent
variables
Neural
Store
Normalization & Linear Normalization & Linear Combination of 2 Sources of Combination of 2 Sources of Error = MSIError = MSI
Current Model(2006)Current Model(2006)in Detailin Detail
Predicted MSIPredicted MSI
Proposed Model
CharacteristicsVertical AccelerationMSI: % of people who vomitTwo-hour nauseogenic period
Nauseogenic frequency range0.05 – 0.6 [Hz]
Central nauseogenic frequency0.17 [Hz]
0.05 0.16 0.27 0.38 0.49 0.6
0.050
0.082
0.135
0.222
0.365
0.600
Amplitude ARMS
[g]
Fre
quen
cy F
[Hz]
-25
-20 -20-15
-15 -15
-15 -15
-10 -10-10
-10-10 -10
-5
-5 -5-5
-5 -5 -5
0 00
0
0 00
0
5
Model ValidationModel ValidationTrue Motion SettingsTrue Motion Settings
Proposed model
HFR model
MSI Comparison between Proposed and HFR models
1
2
3
MSI AccumulationMSI Accumulation
CharacteristicsVertical AccelerationMSI: % of people who vomitTwo-hour nauseogenic period
Nauseogenic frequency range0.05 – 0.6 [Hz]
Central nauseogenic frequency0.17 [Hz]
101
102
0
50
100
MSI [%
]
Proposed modelHFR dataA
RMS=0.333 [Hz]
101
102
0
50
100
MSI [%
]
Proposed modelHFR dataA
RMS=0.222 [Hz]
10 20 30 40 50 607080 1001200
20
40
Time in [min]
MSI [%
]
Proposed modelHFR dataA
RMS=0.111 [Hz]
MSI HabituationMSI Habituation
1 2 3 4 520
40
60
80Pre
dict
ed M
SI [%
]
1 2 3 4 520
40
60
80
Exposure day
Obs
erve
d M
SI [%
]
Proposed model
HFR data
MSI Habituation and MSI Habituation and RetentionRetention
1 2 3 4 5 120
20
40
60
80
100
Retention →
Pre
dict
ed M
SI [%
]
1 2 3 4 5 120
20
40
60
80
100
Retention →
Exposure day
Obs
erve
d M
SI [%
]
Proposed model
HFR data
Model significance I.Model significance I.
ParametricParametric Easily extended to various Easily extended to various
combinations of sensory cuescombinations of sensory cues Validated but not “tuned”Validated but not “tuned” PrecisePrecise EtiologicEtiologic Linear and time invariantLinear and time invariant
Model significance II.Model significance II.
Modeled Motion sickness attributesModeled Motion sickness attributesThe known systems contributing to The known systems contributing to
motion sicknessmotion sicknessNeural Store modelNeural Store modelAdaptationAdaptation““Vection” settings for VRsVection” settings for VRs
Future ResearchFuture Research
Include motion in 6 degrees of Include motion in 6 degrees of freedomfreedom
Further development of known Further development of known physiological systems’ modelsphysiological systems’ models
Central Nervous System (CNS) non-Central Nervous System (CNS) non-linear characteristics linear characteristics
Increase ecological and external Increase ecological and external validityvalidity
Questions?Questions?