# Presentation: 545617

## Development of an Index of Habitability Using Converging Indicators

**Patricia Cowings, Ph.D.** 	 	NASA ARC
- Coinvestigators:
- William Toscano, Ph.D. 		NASA ARC
- Charles DeRoshia, M.S.		NASA ARC
- Bruce Taylor, Ph.D. 		University of Akron
- Seleimeh Hines, Ph.D. 		NRC Post Doctoral Fellow

**Development of an Index of Habitability**** Using Converging Indicators**

##        Enable a permanent human presence in space

- Develop protocols to:
- Accurately assess spaceflight effects on crew health, safety, and operational performance.
- Evaluate and test countermeasures that will remedy these environmental effects.

** **Primary Mission Goal of Space Human Factors

## Technical Background

- Extended spaceflight affects physiology with associated adverse effects on crew performance and health.
- Other factors like workload, isolation, fatigue, etc. are known to effect operational efficiency.
- There is a wide range in the ability of individuals to adapt to space and re-adapt to Earth.
- Future crew complements:men and women, multi-cultural, different professional backgrounds and physical condition.

## Statement of Problem

- Methods are needed:
- to examine individual differences in the environmental effects of extended spaceflight on crew.
- to evaluate the efficacy of countermeasures for individuals.

## Psychophysiological Research Laboratory

- Research program includes:
- Motion sickness in space and on Earth
- Post-flight orthostatic intolerance
- Performance during chronic and acute stress
- Neurobehavioral/psychosocial function

##    Psychophysiological Research Laboratory

-     Method of Assessment:  Converging Indicators
- Physiological measures
- Performance metrics
- Standardized self-report scales
- Method of Correction:  Preflight Training
- Autogenic-Feedback Training Exercise (AFTE)
- 	6-hour physiological conditioning program

-    Psychophysiological Research Laboratory

## Converging Indicators

- Physiology
- (ANS, CNS)

- Subjective States
- (mood, symptoms)

- Performance
- (cognitive, perceptual, neuro-motor)

## Autogenic Feedback System-2

- Physiological Measures

** **skin temperature
-  finger blood volume pulse
-  skin conductance
-  heart rate
-  respiration rate

- Autogenic-Feeback System-2  (AFS-2)

- Reported Symptoms

- warmth
- dizziness
- headache
- drowsiness
- salivation
- pallor
- sweating
- nausea
- vomiting

##  Mood Scale and Delta Performance Battery

- motivation to perform
- arousal state
- fatigue level
- ease of concentration
- physiological tension
- elation
- physical discomfort
- contentedness

- Reported Mood States  		Performance Subtests

** **code substitution
-  spatial transformation
-  non-preferred hand tapping
-  preferred hand tapping
-  pattern comparison
-  three-choice reaction time
-  grammatical reasoning

** **Mood Scale and Delta Performance Battery

## Approach

- Database analyses and archival.
- Develop signal analysis and processing software.
- Test converging indicators methods in operational environments.

## Habitability in Rotating Centrifuge

- 22 hour exposures at G-levels up to 1.5 G

## Individual Differences in Adaptational Capacity

- Each subject lived aboard the centrifuge for 22 hours at 1.0g (i.e., no rotation), and 1.25 g.
- One subject also participated in a 1.5g test

## Individual Differences in Adaptational Capacity

- Ambulatory physiological data were collected continuously.** **

## Individual Differences in Adaptational Capacity

- Subjects occupied a small compartment, equipped with bed, video entertainment, laptop computer, toilet facilities and food and beverages.

## Individual Differences in Adaptational Capacity

- Subjects were in video and voice contact with investigators and medical monitors at all times.

## Individual Differences in Adaptational Capacity

- G-tolerance tests were administered before and after each 22 hour habitat test.
- G-load was increased until subjects experienced reduced peripheral vision and/or pre-syncope.

## Individual Differences in Adaptational Capacity

- Subjects were required to perform a ‘stand test’ at 4-hour intervals to evaluate their orthostatic tolerance.

## Individual Differences in Adaptational Capacity

- Performance tests and a mood state scale were performed on a laptop computer following each stand test, and symptom reports were obtained verbally.** **

## Stand Tests at 1.0g Heart Rate and Blood Pressure

**Subject Q20**

**Subject Q22**

**Subject Q21**

**Subject Q23**

**Time of Day**

**Time of Day**

## Stand Tests at 1.25g Heart Rate and Blood Pressure

**Subject**** ****Q20**

**Subject Q21**

**Subject Q22**

**Subject Q23**

## Blood Pressure and Heart Rate of Subject Q20 During Hyper-g

-  As g-load increased, this subject showed both increases in heart rate and diastolic blood pressure which enabled cardiac output to stabilize.
-  Although his autonomic profile protected him from syncope, he was more susceptible to motion sickness than others.

## Cardiac Responses to G-Tolerance Tests

## Cardiac Responses During Stand Tests at 1.25g

## Converging Indicators for Subject Q20 at Different G-loads

## Converging Indicators for Subject Q23 at Different G-loads

## Conclusions

- Converging indicators can be used to identify individual differences in adaptational capacity (e.g., susceptibility to orthostatic intolerance and motion sickness).
- Psychomotor performance was significantly degraded during hypergravity. Symptoms generally increased with g-load.  Reductions of mood, perceptual or cognitive responses were highly idiosyncratic.
- Physiological profiles may be used to predict how well individuals adapt and suggest that training control of autonomic responses (i.e., Autogenic-Feedback Training Exercise-AFTE) may help to reduce or eliminate symptoms.