Gravity provides the eNS a fundamental reference for estimating spatial orientation and coordinaring movements in the terrestrial

environment.

Source of Acqu isition NASA Johnson Space Center

~

I https://ntrs.nasa.gov/search.jsp?R=20110011052 2018-05-19T09:11:21+00:00Z

2

Peripheral Vestibular System

Vestibular Recllp tors

Otolith Or2"ans: Sensitive to linear motion (and gravity)

Semi-circular canals: Sensitive to rotational motion

Hair Cell Anatomy

3

Otolith Physiology rc<?''':f,:'' rno .. l'<:mc~~ ~ . ~IOC~",\jClt Id f:2'r ----

~~~:~I i

--- " zona

Sl?ns~ry

cw:thahlJr-

,- --- y

F'~:" ,~",~.-"Y.L- < " .. :J"' ''~,,;!'..:v'll ----

Fi~ . ~9. ,\; l'n:sUJllcd Juechanic.al UnJ,a;.: hel\-..ee n Iht macul:..t: l'Jli l helia! cell..: UJld o"crlyin::! S!ruL1Un.'!o . 13: Eleir.!:nwry' m-:ch<1111C-.1 1 l~n;'l l og:-·. r. :'.:n~ii~ .I c>.:~;t::'l~ i Lm of ht:l.ld re l:-ttivt to

$pa~e; ,\. iH:c:~Je'.:Jliml or t)lll:.A};l1'1 rcilJt in: to <:;p:tcc; (. !'.;lauv t= dl,>piaccmenl 0; :.Hoccnia l.1r;d

lTI~tcub: ;'1' p~l!'ltion of t:nu (lr!!~n ar commenCCflh!iI' Dr 2cc('I:':;'~ li,m ' I. P~) .:; ili{m afl!!r lime ! . Benson, 1982

\

~ ... I ... ~-~· ,_ .... - -- ...... -1 _tooI ........... ;.1

"-.~ .... .:""." "' ........... ~ -,- t!: . t;

. ..~

, c::._t"< "' ............ .

,,.., . ' !J~~ .. ij / .... ,~

1 1 ;;-.:4,/ ~ - .... ~ "C'" -.e.. .... ~.;.:\..,....,~ .... - .. _..tr.;"~~<-I-!- . =-j(_ i':!.\ J

:;::' "'t~ ~i~ .... ..,,-:w. ;1'\ ,_:. ~-- .. ~ • ..,,,,,,~ A41-"M'j.

i ~, .t· ..... ..:.:.., .......

-!-/~~::-- «~~. , Q.~~ "'_11 ...w. ..... ~"W'....;:

<- 1',.-/ , "~'''''' ~-­I" ~t';:: . M-'7· ....... ·-->~ .-:-r:~ ~

,- ""C~ .. · I~_ .. '---""..,~ ..... -,,,

::.~;.~ .• ~aw.

4

\I:S.tlbulao efeb~U t ... CI.()th ..... -ay: 'rl,.!'! · ""0- (I ' i ~ IUS(raI101\.

C e'90allovestJtlUl .lH P:t!n,,·,,~ t ie l : ~.6c DI OII",'strlloll'f"j

I " > I ." ..,,,"' .... .' '>-..:

' '---''' '~!l~,...;; • ..,r-._/ II "' I.'r.:::i'=

Spatial Orientation and

Balance Control

Require

Central Integration of

Sensory Information

"'<:."~I !;t:I: ~:l' ne:r.-,:

Correia & Guedry, 1978

---. -~-

5

__ J

ANGULAR ACCELERATl ON fSf!:mlC'rT;ul. r Ce ~lI l s}

LINEAR ACCELERATION 6 GRAVITY {Otolilhs}

DOME: ROD/FRAMf L-___ ---.-__ -"

CENTRAL ESTI ...... TOR OF S'TA"tIC ANO DYNAMIC SPATIAL ORIENTATION

A/'IO BALANCE

CONTROL FUH:::TtON

POSTURE ("'b lnwl" b."~~

&. uDrtght pOstu~)

~;;;;;~ EYElHEAO MOV£"'~ Cs.- e~.""" ... _ m_)

SPATIAL OR1EHlATION l$.rnse posll~ .rod

'-'eloctty 01 boCIl'l

SENSORY CONFLICT SIGNA.LS

("' OTION SICKNESS)

DOME SPACE SICKNE SS

HOP/DROP PLAT FORM RAIL!;,

DO ME CHAIR

SLED ORIENTATION

SPACE SICKNESS

Ftg. 1. Scope o! the hm/~"l:!di::n Sp3celab 1 experim=nts , by ::.xp<:rimen! short name. rclativc: to l!. $ch!:mat.:i.:. repres!:Dtation of th~ rol~ of the vestibular Bod other senses io control of posture , eye movements and perception o f orientation . Expe rimenl short names are keyed to Table 1

Young et aI., Exp Brain Res, 1986

,1..,­o

r -/v

""':--:::="'::'::' ,~=--==.=-=-===::~, .. "' ... ...,.r">t'f~._~

(\,\!2_o..Y~ \A

~

<7~~ ?e~j)

,s s.~ f\~

~~ ~~ \)~'S1Q~~-

7

r--- -

During Space Flight Postural Muscles can be Activated with Foot Pressure

1400 ---.------ .-- ---.-.-----

·:;uo 300 600

Courtesy of J_ Bloomberg

-I

8

Base d­S91')€i15

Postural Stability

\ ,

HU111an Sensoly-Motor Balance Control

<n ~ := ~

S S c Q

:... C --0 :: -

cerebral cortex

motor control

--.------ ~ ~ ---- ------ - .

c. .... ---» ;..... c rn := <:) rn

9

I I

lBO ~

150 r ;

1 ;' I

v i

~ .:.;.., ..... J '--~#- _ ...

Postural Stability

a

C r ~wrac.",

s . •

b

~ 120 i .

c 9 0 r

j II L i ~~\\"'" i It>..·. ! .. \,

\ \ .1- f S D~ LL IJ .

"- 50 -.

30 ;...

! . .'\~""" . #.'i;:----!.}- .. I .... ", .... '.. ".,../." t---- , ~., • ,- ----_ .• --'!:.;..." .• -------i 1 . ----:,-

o ~----- .----Avcra oe 016 I RT 0 R ~ 1 A+2 ;:h"~ R-£

pre f hgnt

1;t~;: Pu ... !ut't: I.."t:'Hf'O! \\!It. C\:!I; :..l\.~ed. i)I(1\'.'m1! m:u'kcd ~k~rc:m""1" tllllltcdlal<:i) :,fl~· lllg.hl icr ~!:..tndJn~\~n ~ ~.--:-CO\ r:,ij O:-rt"rhlnJill~ hl.m t!~. t:."t.p":h:d 1Ot'·U~ 1111 ell) {'><I':Hrt' rl.l!rorzr. 16;. 1:; UI/. m" .. li~:=d SiU:rr-':IH.'tl ~"fIIl~('·lif le:;/ nH::t<:ur-cd i~H.d lime: !!'(;utdin; all r.~if rut tn~· hest t:lTe:: Cl 1)\"( \-mHlolc w.\h. In I!":. lilil..'r'CC L\IC· ;;cli\'il) h'r\:lilr;!:-~ ur:n.;; fruUl th.,: lihiHlt:-- ltnlt:nnr m:!:-cl~ of 0ac subJect dCIlIIi: III:.. Itf:-I He,-clf'Sc..! Y hX'-UI' ~ih ~h,\\\·,. lor}< - G. wc.r::::1~::;.i 1:1:'¥III\U\I~ :.t.nd ~lu~Ii~'~l (:r Ih:. !:tIC: 11:Srons:;:. . The drop in 1l::'!f!nlluJ.: hel!)\:" th~ rrefhpht v;dut IA'" S:''¢:i lo~ R - ii btl' !hlt lor the U:i:cl ~r~;,: .. ~It"!::::::l:::' .

Youn g et al ., Science, 1984

'1 l w\ (\" ~.'1 .&'\

~ -i \ 1\S.

10

r--- - - ~~- . ~~- ... . --- ---- ~~- - I

Ip Respo-nse to Suppori Surface Transiallons

i J O~ -- l- ~ J.. K:l_ ~ - ____ ~ _~~o::

~ ~ . II i ' .. : .if1

"0: ~ ·2(>f

1 ; 1 , i

.JOr ~J .50 1 L... __ -'-____ _

I

~

I

j

I i 0

' 2~O:----7-----:'.,.0----0

A-P Position (em)

Hip Response to Suppori Surface Translations

A-P PositIon (em)

11

·Adap tive Neural Control of Upright Stance

Des ired i\ Jo tor O utp u t -----~ + '" V~stibu l 3r Ori e n t~ t io n -

g} • '-' Visu!\1 '-' 1\

0 = ~. '-'

~j '-' ~ 0 1\ ~ W "'- 7~ '"' , G- Co rrelati on "'- ~ !~ Stor3ge

(in,erna l models) \.

.1 ~- ( Propriocep {i vt

'-' ~ u

;'

~ -'" " ~

Sensory Feed ba ck

based on Hein and Held (1962)

Adaptive Posture Control Model

-~ I I desired I I I I I I I I I I I I I I I I I I I I

ex te rn ... 1 diSl u rh ltnCCS

t'.~li m lt l n r :lujU) l m cn(

1 _ _ ___ -+ ___ b,-,o:.:d"-~--='.::t a:.:' =-t .::"'"",,n.::":.:"c=-_________ -->

affrrcncc errur

after Ku o (1995)

!

l~~iJ\'\J~

12

Eauilest ... Conditions Sensory Analysis

1. htHmal ~ "'IUOr. D @S ~: i= flll:c

~ .~ ~upoOI'l

2.

D ,IIbs!:nl

jt, VISion

\;:' @?) FncO r Supper: ~

fJ 3. '~} r: Swwy-Rclen:no:e::l ~ \lISlitfl

!'-;/" ; @?) \~:.I,'

VI: ,;: Fued

~ Sucoor:

4.

~ Nonnal ~ ~.;, .!" \1' 510"

!J) (2) ~j'r ,

i Swai'·hel.'ent~

~ Suooor.

5.

~ AI!lenl VI"U"

~)i) ~ i"' / ;;,: Swa ... ·heterl!need

~ !.. Suooon

Swlt ... · Rclf:r .. neeo ~ VI"un

~ sw;, ... · Rclcfenc.ed

~ Suppol'l

Patient Balance Test Performances

100

80

40

:w

(redra"wn from Black et a l. 1988)

Sensory-Neural Vestibular Loss (n=28)

• n orm~1 s ubjects e p~ t iellts

sar SOT sar SOT SOT SOT 5

{,

100

60

20

Head Trauma-BPPN (n=lI)

• norm:&1 subjects o p~ ti cnts

1 rn

SOT SOT SOT sar SOT SOT 6

13

Typical Astronaut Pelior111al1ce

-::: 0 '" ::::.. '" ~

rr)

-::: c:.> U

~

~ 0) ~

c::::: :.... , 0 >' ::::.. '" :>- -" = rr)rr)

Eyes Open

post

~ pre

SOT 1

=~ u , V>

5 sec

~ ~

SOT4

Eyes Closed

~ ~

SOT 2

~ ~

SOT5

Sway-Referenced Vision

SOT6

Paloski , et aI., 1997

Raw Sway Data From SOT 6 ~---------------------+(~~.-~~~S&~gGtS~)~---------------------1

12

OJ Q)

"0

>. CIl

5: en .. c.. 6. 4 . .

: ~

0 ·120

preflight postfl ight

... . ... .

. .

..

. : -.. ..... :..~ .. -! !": .•• :.::.".. .: , . ~': :.,.,..'"

'. I .; • . .; ...... ~~ .. ' ""! ...... -;;l' \. . . g' :: : ~ , : ...

·90 ·60 ·JO

time before launch (d)

o

• ':.' :0<" •• ....... ~. :i.: •. ~". : .. -f'_-.; ... ... -,. ' . ..... ,

.~ . ,

t ime after wheels stop (d)

10

14

Post.flight Sway Data [ roin SOT 6 ----- --- -

rookies (n=20) veterans (n=25)

.I ,j " :. 12.00

I OJ Cll

"0 .-8.00 "" "" >, · ". ": 0

0

'" . t Of: 00

~ '. 0

If) · .-" . .' . . . .. ~ . ... 0.. · : . ; ,-. ....

S. -:" .:;: ... ~ . ; .: 6.. 4.00

. '. .' .'- : .... ':'" : ' .. 1 '.' I.". . . , : :.,. : ., . ..l> •• ::r : .... -: .. ~. : - • .& ·'l ;. "\ or . :. , ,:' Of . " '" ~ , :! ,

I "-f -; 0.00

0_ 1 1.0 10.0 0.1 1.0 10.0

time after wheels stop (d) time after wheels st op (d)

Lal1ding Day Performance

8

I * 1 __ ,00k;.(0-16) J ----- veteran (n=1 8)

*

} T

/I ..L ..L

6

~ ~ ~ /

2

a pre post pre post pre poSt pre post pre post pre post

sot 1 sot 2 sot 3 so t 4 sot 5 sot 6

15

Risk of Ataxia Following Space Flight

s ot 6 (rookies) sot 6 (veterans) 0.70

CO 0.60

>< CO ..... CO

0 .50

-.-0 0.40

>-.... 0.30

..0 CO 0.20

..0 0 I.-

0.10 Q..

time after wheels stop (d) t ime after wheels stop (d)

16

1-

Bioastronautics Risk Mitigation Effectiveness

Q)

u C rn >= t: o 't: Q)

D.. '-o =a c rn

.5 rn Q)

.c

.....

.c

..... o

1 DO - -- - - - - - - - - - -

", -. lo~ risk .operating zoo"e

'-.

high risk operating zone

o

Ind iv idu a l crew prefl ight hea lth , fitness, a nd/o r proficiency

C lini ca lly degraded test resu lts High ri sk of de layed health conseq uences Signifi cantly reduced profi ciency

C lini ca ll y ab normal test results Una cceptably hi gh r isk of delayed hea lth co nseq uences Fa ilure to meet mi ni mum proficiency req uirem ents

Subject Distribution 20,-________________________________________________________ -.

15 / short-duration « 20 days) : n=5 1

C 10

long-duration (> 60 days): n=23

5

31 61 91 121 151 181 211 241 271 301 331 361 'j6j:J

Mission Duration (d)

17

o

Data .. 4nalysis Statist ica l Mod e l fo r EO Scores: The nomlalized l<Hem EQ scores (scale 0[0 [0 I) for each SOT are mode led as Beta disrribut ions: y- B(p, q) , The density ofy is:

f( ) = r ep + q) p-J (J - )q-J

Y r(p)r(q) Y Y

Fa ll M od el: The conditio nal probabil ity of a fall g iven latent EQ score is modeled as:

P(fall iy)=G(y)=(i-yr or p(fall )=r(p+q)r(r + q ) r(q)r(r + p + q)

where p, q and r depend on independent variables (miss ion duratio n and time after landing):

15 t5 iog(dllr) iog r =Cj +C6 -+C- _~----C

I + I I + I

log q = C4 (fixed fo r all cond itions)

I 0 - C ' C 0 ' C ~ C is Jog(dur) 0" P - 0 ~ I ~ 2 1+ t + 3 1 + I

where 0 = 0 prefl ight; I postflight, dur= miss ion d uration (days), I = time after landing (days) for postflight only, and CO"' " C7 are coeffic ie nts estimated from the data

Pelfo rmance Distributions Following 10-day M issions

8

,_ Prefiight l

_R~ I _R+1

_ R+2

' _ R+4

,_R+8 , 1 __ _ '

20

Latent EO Score (SOT 6)

18

I .. _-- -

o

Peliormance Distributions Following J80-day Missions

_ Preihght

_ R+12 Hours

_ R+1

_ R+2

:_ R+4

,_ R+8

0.5

/ -'

"

20 40 60 80

Latent EQ Score (SOT 6)

According to the NIH:

100

• There are more than 30,000,000 people over age 65 in the U_S_ (Bureau of Census, 1992)

• Vestibular disorders account for 20-25% of falls in the elderly that lead to hospitalization (Brockelhurstet at, 1991)

• Of the elderly people hospitalized because of fall s (over 200,000 per year with hip fracture alone), 40% die within one year (Rubenstein, 1983)

l

19

Risk of Falling in Nor/native Population

ctl

>< ctl

+oJ

ctl .... o

.:.:: (/)

(SOT 6 data from Peterka and Black. 1990)

1.0 ,----------------;-m-ITnT~____,

0 .8

0 .6

0.4

0 .2

III 0.0 0~---::-':20:----4c"=0,--~6=0------::8'"="0--'

age

SOT 6 Pelforlnance: EQ • Male (n:'89) r:lI Female (n=101 ) 1

.-~ , I,.} 1 ----~I ._-.-; IJ!!H\'\

0.8 +-------'-j--C------------+I --+I----il-~.

0.6 t=tj;=-::!:==~::~;;~I::jl==, I\li~~j-.l I . ,

i 1- i 0.4 ' ! , c~~~ •. : .. ::::--:~~ • • --=,.,-------:---1;.-' °_--:.-1 __ _

I ' '. .'- i; ! -~- ----..~--__j_---i---

0.2 ! ,; •• !,i:~ , .' ..... , I I L ; ',- "I..~

0.0 c=-;-----;-----"7": -' ----,';-\ --+-----i .,

o :20 40 60 80 ]00 Age

20

0.5

0.4

03

0_2

- 0.1

ro ~ 0_0 CL

0.4

0.3

0.2

0_1

0.0

SOT 6 Pelforntance: Falls

L --Session A

- -

r-§~islo_n -~l -

r- . - -

f--- -

0 10 20

- 1---- - ---- - - - vr------ - +-- .,/ -

~r~- - I---=-= ii Male (n=89) iii Female (n=101) ,

30

, , J.L0

l +b~~-I . 1 -- ---~------_-+I--~ ,

1 -i -----;;~

---- - '----- ! ----: ~ ----; - ---I- I

40 50

Age

60 70 80 90 ]00

re?

21

. - ' - - - -_ ... _- ------- --1

Option 1: Linear AG Constant acceleration during the first half of a trip to Mars

[ Constant decel~:tio::9 the last half of a trip to Mars

I d2R , :, F·= m ';.,..·· ~ma '­

dt 2 "

• Fuel requirements

• New propulsion systems '----

• Surface activities and operations

Option 2: Rotational AG

Approximate 9

1 I 1 I 1

Achieved by:

1) rotating entire vehicle during transit

or 2) providing human centrifuge within

vehicle

Radius (m) Angula, Velocity (rpm)

300 0.55

15 2.46

0.75 11 .02

22

Precedent fron1 the Past: 2001

Kubrick, 1968

Physics and Physiology

F •

---- ----- ----

ROTATIONAl AXIS

ROTATIONAl AXIS

F 9

LEGEND: ro Rotation Fg Gravitational Foree Fe Coriolis Force V Subjecfs Velocity

from Stone, 1970

Physics and Physiology

E

Objectives 1. Discuss the role of gravity in spatial

orientation and balance control.

2. Review the anatomy and physiology of thP nPl1ro- \ leC't1h1ular Q"\TC'tpn'l L..J....l. '-" .J......L ....... \...A.....l. Ul,....1V I-J.) 0\... '-" ..1..1..1...

3. Exan1ine the disruption and recovery of sensorY-lnotor function following space flight.

24

294

ANGULAR ACCELERATIO t.l ISemtClrcu lllr Cenllls)

LINEAR ACCELERATION 6 GRAVITY

IO tolilhs)

DOME ROO/FR!.IME

'----------,----"

CENTRAL ESTI MATOR OF STATIC AN D OYN AM IC SPATI AL ORI ENTAnON

AND BALANCE

~-J=:' ~.

-::- -;(

CONTRO\. FUNCTION

POSTUR E (' .... In .. ln ~wne­"u~hlpo3llure)

EYElHEAO MO"{EM EHTS rSe-r elelny " _ "'O¥t')

SPAT'A.l ORIENTATION (Sens. poellion .0<1

veloe.l'Y 01 body)

SENSORY CONFl.ICT SIGNALS

(MonON SlCt<N ESS)

DOME SP!.ICE SICt<NESS

HOP/DROP PLATFORM RAILS

DOME" CH A IR

SLED ORI E NTAnON

SPACE SICt< N ESS

Ft:. 1. Scope o f the M:rf/Canadian Spacdab 1 expc:rimenu. by experiment shon name. relative to a schematic representation of the role of the vestibular and other senses in control of posture , eye movements and perceplion of orientarion . Experiment shan names are keyed to Table 1

Young et aI. , Exp Brain ReSt 1986

Insertion into orbit removes the fundam ental eNS spatial reference and triggers neuro-

Return to Earth. reintroduces this reference

and triggers neuro­adaptive processes that return peljonnance to

terrestrial norms.

adaptive processes that optimize peljormance for the microgravity environment.

o

Adaptive Neural Control of Upright Stance

Desired Moro r Output

Orientation Vestibu lar

Visual

.:::

, Cor rel3lion

Slor~l ge

(in ternal mod els)

Proprioceptive

Sensory Feedback

based on Hein and Held (1962)

Pelformance Distributions Following l80-day Missions

_ Preflight I :_ R+12 HOUrs !

_R+1 I' _ R+2

I _ R+4

_R+8 i

20 40 60 80 100

Latent =Q Score (SOT 6)

26 I

J

0.5

0.4

0.3

0.2

_ 0.1

ro ~ 0.0 a..

0.4

0.3

0.2

0.1

0.0

SOT 6 Pelformance: Falls

I . -'Session A

r----- - - r-

--,

J Session B] ;

-

,

I

I --. !

o 10 20

,,-

/ V

/ v

..---V r--I

II Female (n=101) i I I

II Male (n=89) I I I I !

! I

I

i 30

I I I I I

I , I I

I I I

, ------+----:: I

40 50

Age

60

j

I I I

I v i I

I

~ i --1 -----r-----I I

70 80 90 100

r--

I

. .

II

Forward work to facilitate the next steps in human exploration of space ...

• Identify sites and mechanisms of sensorymotor adaptation. • Determine interactions betviTeen sensory-motor adaptation,

autonomic system function, and musculo-Bkeletal function. • Assess functional risk of sensory-motor adaptation to the

success of future missions. • Develop adequate countermeasures to mitigate the untowar

functional risks.

Ground-based venues are unlikely to serve as adequate analogs. Space-based experiment platforms will be required, possibly

including animal and human centrifuges to provide artificial gravity.

----I

I

28