The T1G of Hybr id-III for Whiplash Injury Evaluation

JAPAN/　MLITApril 2006

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Neck Injury Evaluation Cr iter ia

• For neck injury evaluation, the S-shape curving of the neck must be considered. 　 Conventional view

Bostrom et al, A New Neck Injury Criterion Candidate Based on Injury Findings in the Cervical Spinal Ganglia After Experimental Neck Exteision Trauma,1996 IRCOBI Conference

Phase 1 Phase 2 Phase 3

Cited from Japan's presentation material

for 4th GTR Meeting

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Axial force

Bending moment

C5/6 open book-like motion

C5

C6

Facet impingement

Initial flexion S-shapeFull extension

initial flexion S-shape curvature full extension

Cited from Japan's presentation material

for 4th GTR Meeting

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Existing Neck Injury Evaluation Methods

All the methods using upper and lower neck cr iter ia– IIWPG – T1G, HRC, Fx, Fz– EuroNCAP – NIC, Nkm, Head rebound V,　（draft） Fx, Fz, T1G, HRC

T1G

MyFx

Fz

HrV

HRC

NIC: Calculated from acceleration/velocity of the head and T1

Nkm: Calculated from neck moment and neck shear force

HeadG

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To ver ify different biomechanical responses of HY-III and BioRID II

HY-III BioRID II

Biomechanical Responses of HY-III and BioRID II　Par t1Cited from Japan's presentation material

for ３rd GTR Meeting

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•BioRID II is closer in terms of S-shape deformation pattern of the neck and the head/neck angle relative to T1 of human volunteer than HY-III.

Kinematics

HA-TA

-60

-40

-20

0

20

0 50 100 150 200 250Time(ms)

Angle

(deg)

Ave.±1(S.D)

BioRID-II

Hybrid-III

T1-HP

-20

0

20

40

60

0 50 100 150 200 250Time(ms)

Dis

tance(m

m)

Ave.±1(S.D) BioRID-II Hybrid-III

HA-TAHA-TAT1-HP

HA: Head Angle,TA: Torso Angle T1-HP: Length change between T1 and Hip point

Cited from Japan's presentation material

for ３rd GTR Meeting

HY-IIIの挙動は人体と異なるが、ピークレベルは近い

HY-IIIの挙動、ピーク　レベル共に人体と異なる

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Hyge Sled TestTo ver ify the different biomechanical responses of HY-III

and BioRID II due to different seat character istics.

HY-III

BioRID II

Seat A : Normal Head Rest

Seat B : Active Head Rest

Seat C : Normal Head Rest

Seat D : Active Head Rest

Types of Tests

Cited from Japan's presentation material

for 3rd GTR Meeting

Biomechanical Responses of HY-III and BioRID II　Par t2HR-6-5

6

8

10

12

14

16

6 8 10 12 14 16

BioRID II T1G (G)

HY

-III

T1G

(G)

Seat ASeat BSeat CSeat D

T1G Compar ison between Hybr id-III and BioRID II

Because the T1G values of Hybr id-III and the more biofidelic BioRID II cor relate inversely, the T1G of Hybrid-III is inappropr iate as a neck injury evaluation cr iter ion.

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0

5

10

15

20

25

30

35

IIWPG rating

FMV

SS20

2a (h

ead

back

war

d in

clin

atio

n an

gle)

POOR MARGINAL ACCEPTABLE GOOD

12°

Seat A

Seat D

Seat BSeat C

5

7

9

11

13

15

IIWPG ratingT

1G (H

Y-I

II)

POOR MARGINAL ACCEPTABLE GOOD

Seat A

Seat D

Seat B

Seat C

Hybrid-III's head backward inclination angle vs BioRID-II's IIWPG rating

Hybrid-III's T1G vs BioRID-II'sIIWPG rating

Hybr id-III's Head Backward Inclination/T1G vs BioRID-II's IIWPG Rating

Roughly Fair correlation Inverse correlation

Hybr id-III の場合、T1G加速度よりも頭部後傾角の方が生体忠実性のより良いBioRID IIの評価指標と相関がある。

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Bio R ID2 v s HY-I I I

0

5

10

15

20

25

30

Ｂio ＲID2　IIHS SCORE

HY

-II

I (H

ead

Ro

tati

on

An

gle

)

Act2

Act3

Pas1

Pas2

Pas3

Pas4

Pas6

Pas7

Pas8POOR MARGINAL ACCEPTABL GOOD

FMVSS 202a (HY-III) vs IIWPG (BioRID-II) Evaluations

12

HY-III頭部後傾角要件の妥当性検証

頭部後傾角の要件は生体忠実性の低さから傷害低減効果を示す根拠が不十分であり、技術的実現性から決めるのが妥当と考えるが、

現提案[頭部後傾角≦12°]は IIHSアセスメント実力との相関性検証結果から厳しすぎると考えられる。

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ConclusionsS-shape curving of the neck is impor tant.Desirable to measure both upper /lower neck cr iter ia.Hybrid-III' s T1G is an inappropr iate cr iter ion for the

following reasons:　　-生体忠実性が低い

　　- Inversely correlates with biofidelic BioRID-II' s T1G.- Inversely correlates with IIWPG rating.

If Hybrid-III is to be used, head backward inclination angle is more reliable a neck injury evaluation cr iter ion than T1G.しかしながら、現要件 案[12°以下]の妥当性はさらに検証要と考える。

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Conclusions将来的には、ダミーだけでなくスレッド波形も含めて、より市場の事故実態と相関性のある、（オプションではない）本来のダイナミック要件とすることが必要であり、その旨gtrプレアンブルにフェーズ２で検討すべき事項と記載することが望まれる。

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