Evaluation of mild motion sickness Evaluation of mild motion sickness nauseogenic space and comparison nauseogenic space and comparison with current standards:with current standards:Should we go forward?Should we go forward?

ACCeSS Meeting 2008The Atlantic Center for the Innovative Design and Control of Small Ships

By

LCDR P. Matsangas, M.Sc., Hellenic Navypmatsang@nps.edu

OverviewOverview

Motion sicknessMotion sickness HFR modelHFR model Existing standardsExisting standards What we knowWhat we know What we don’t knowWhat we don’t know Modeling approachModeling approach The way forwardThe way forward

Why?Why?

Ship’s motion

Motion Sickness Incidence (MSI)

Motion Induced Interruptions (MII)

Sleep amount and quality

Sopite Syndrome Human

Performance

Circadian Disynchrony

Motion-induced fatigue (MIF)

Ship’s motion

Human

Performance

Ship’s motion

Human

Performance

Models

Ship’s motion

Existing

HPMs

“Would like to have”

HPMs

Ship’s motion

Existing

HPMs

“Would like to have”

HPMs

Existing

models

“Would like to have”

models

Ship Design models

Human Performance models

Motion SicknessMotion Sickness

ISO standard 9996:2000ISO standard 9996:2000– Motion sickness is a commonly experienced and sometimes Motion sickness is a commonly experienced and sometimes

severe but reversible disorder specifically associated with severe but reversible disorder specifically associated with exposure to actual or perceived oscillatory motion in the exposure to actual or perceived oscillatory motion in the frequency range 0,l Hz to 1 Hzfrequency range 0,l Hz to 1 Hz. One or more of a . One or more of a constellation of symptoms (with or without frank vomiting) may constellation of symptoms (with or without frank vomiting) may afflict the sufferer. afflict the sufferer.

– In severe cases it is immediately and profoundly disruptive of In severe cases it is immediately and profoundly disruptive of motivation, concentration, activity and task performance in both motivation, concentration, activity and task performance in both individuals and groups, but in the individuals and groups, but in the less severe case with less severe case with premonitory manifestations it remains an open question premonitory manifestations it remains an open question whether individual task performance is degraded until whether individual task performance is degraded until activities are interrupted or abandonedactivities are interrupted or abandoned. .

– Group performanceGroup performance (for example the work of a ship’s (for example the work of a ship’s department) department) may be delayed or impaired by attritionmay be delayed or impaired by attrition in the in the crew. The malady afflicts sufferers in a highly idiosyncratic crew. The malady afflicts sufferers in a highly idiosyncratic manner. Most sufferers can benefit from diminishing effect of manner. Most sufferers can benefit from diminishing effect of continued or repeated exposure to the provocative stimulus continued or repeated exposure to the provocative stimulus (habituation).”(habituation).”

Sopite SyndromeSopite Syndrome

ISO standard 9996:2000ISO standard 9996:2000– ““A state of A state of sleepiness, lassitude, or drowsy sleepiness, lassitude, or drowsy

inattentioninattention induced by motion or vibration induced by motion or vibration”.”.– Furthermore, it notices: “Furthermore, it notices: “Profound lassitude and Profound lassitude and

drowsiness have been specifically identified as drowsiness have been specifically identified as the sopite syndrome, when associated with low-the sopite syndrome, when associated with low-frequency (below 1 Hz) motion such as is frequency (below 1 Hz) motion such as is commonly experienced aboard ships. The commonly experienced aboard ships. The neurological basis of the sopite syndrome, and neurological basis of the sopite syndrome, and its relationship to classical sickness, its relationship to classical sickness, remain remain open questionsopen questions in physiological science.” in physiological science.”

HFR model (1974-1976)HFR model (1974-1976)

Model CharacteristicsVertical AccelerationOnly true motionMSI: % of people who vomitTwo-hour nauseogenic period

Nauseogenic frequency range0.1 – 0.7 [Hz]

Central nauseogenic frequency0.167 [Hz]

Motion SicknessMotion SicknessAdaptation exampleAdaptation example

ProblemsProblems

The standardsThe standards– Are basedAre based

on the HFR regression modelon the HFR regression model

– Refer toRefer to Vomiting only (not motion sickness in Vomiting only (not motion sickness in

general)general) 0.1 Hz to 0.5 Hz0.1 Hz to 0.5 Hz No visual inputNo visual input No relation to task performanceNo relation to task performance Sopite syndrome?Sopite syndrome?

ConstraintsConstraints

The definition of motion sickness, The definition of motion sickness, The corresponding nauseogenic frequency The corresponding nauseogenic frequency

range, range, The nauseogenic motion incorporated for The nauseogenic motion incorporated for

the evaluation of motion sickness (z-axis), the evaluation of motion sickness (z-axis), The settings the standard refers to (no The settings the standard refers to (no

external visual), and external visual), and The motion category (real not apparent)The motion category (real not apparent) The motion attributes (simple sinusoidal)The motion attributes (simple sinusoidal)

Current status of Current status of knowledge related to MSknowledge related to MS What we knowWhat we know

– MS=f(acceleration(amplitude,frequency))MS=f(acceleration(amplitude,frequency))– More acceleration = more MSMore acceleration = more MS

What we don’t knowWhat we don’t know– Frequency response vsFrequency response vs

Symptoms (not only vomiting)Symptoms (not only vomiting) Visual inputVisual input

– Effect on task performanceEffect on task performance

What we must doWhat we must do

Develop appropriate Develop appropriate modelsmodels

Research on the Research on the effect of mild motion effect of mild motion sickness on task sickness on task performanceperformance

Simulate operational Simulate operational effectivenesseffectiveness

Current (2008) Model in Current (2008) Model in DetailDetail

Proposed Model

• Z-axis (Vertical Acceleration)

• Linear• Time invariant• Stable

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 significanceModel significance

ParametricParametric Easily extended to various Easily extended to various

combinations of sensory cuescombinations of sensory cues Partially Validated but not “tuned”Partially Validated but not “tuned” PrecisePrecise EtiologicEtiologic Linear and time invariantLinear and time invariant

Future ResearchFuture Research

Regarding the modelRegarding the model– Implementation in SIMULINKImplementation in SIMULINK– Input of ships’ raw motion dataInput of ships’ raw motion data

evaluate the model’s performanceevaluate the model’s performance

– Increase external validityIncrease external validity– Use the model in order to analyze its’ Use the model in order to analyze its’

possible predictive validitypossible predictive validity

Future ResearchFuture Research

Regarding standardsRegarding standards Nauseogenic space of Nauseogenic space of

sopite syndromesopite syndrome Quantification of Quantification of

sopite syndrome sopite syndrome effectseffects– Vigilance tasks Vigilance tasks – Automation Automation

supervisionsupervision– Combined effect with Combined effect with

sleep deprivationsleep deprivation– Other common tasks Other common tasks

naval vesselsnaval vessels

Extend the existing standards

Increase habitability

Project DescriptionProject DescriptionResearch QuestionsResearch Questions Are sopite syndrome symptoms Are sopite syndrome symptoms

evident in the same evident in the same nauseogenic frequency range, nauseogenic frequency range, as it is defined in existing as it is defined in existing standards?standards?

Is sopite syndrome related to Is sopite syndrome related to the known main nauseogenic the known main nauseogenic environmental parameters environmental parameters (motion acceleration and (motion acceleration and frequency, time of nauseogenic frequency, time of nauseogenic exposure)?exposure)?

Is there a relation between Is there a relation between vigilance decrement and motion vigilance decrement and motion stimulus?stimulus?

Project DescriptionProject DescriptionGoalsGoals

Ship Ship Predicted Predicted Motion Motion ProfileProfile

Predicted MS Profile

Predicted MII Profile

Design Phase

Questions?Questions?

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 The percentage of people who vomitvomit

when exposed to a nauseogenic when exposed to a nauseogenic environment. environment.

Normalization & Linear Normalization & Linear Combination of 2 Sources of Combination of 2 Sources of Error = MSIError = MSI

Current Model (2008)Current Model (2008)in Detailin Detail