Euro NCAP Whiplash Rating Toyota Position & Proposal … · 3 Schedule 2011 7 14 21 28 February...
Transcript of Euro NCAP Whiplash Rating Toyota Position & Proposal … · 3 Schedule 2011 7 14 21 28 February...
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Euro NCAP Whiplash Rating -
Toyota Position & Proposal
May 2011
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Content
• Background and Priority
• J-NCAP
• Extended Review
• Overall Conclusion
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Schedule 2011
2821147
February
Folksam
Chalmers
TNO
BASt (15.03)
TRL (11.05)
June
B. Fildes (ESV)
Euro NCAP (TBC)
ADAC
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Background:Past TOYOTA presentation
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Marginal ratingGood real-life effectiveness
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1st Priority Improvement
– Remove HRCT, T1Gmax, RV– No relevance in real life safety– Design restrictive
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J-NCAP
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J-NCAP criteria and thresholds are based on the work of Ono et al.
Evaluation Criteria for the Reduction of Minor Neck Injuries during Rear-end Impacts Based on Human Volunteer Experiments and Accident Reconstruction Using Human FE Model Simulations Koshiro Ono1), Susumu Ejima1), Kunio Yamazaki1), Fusako Sato1), Jonas Aditya Pramudita2), Koji Kaneoka3), and Sadayuki Ujihashi 2) 1) Japan Automobile Research Institute , 2) Tokyo Institute of Technology, Japan , 3) Waseda University, Japan
13New Car Assessment Japan 2010, page 7http://www.nasva.go.jp/mamoru/en/panf_2010_en.pdf
J-NCAP criteria and point generation
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J-NCAP thresholds: sliding scale between 5% and 95% WAD 2+ risk
5% WAD2+ risk
95% WAD2+ risk
JAPAN NEW CAR ASSESSMENT PROGRAM FOR MINOR NECK INJ URY PROTECTION IN REAR-END COLLISIONSTakahiro IKARI, Kenichi KAITO National Agency for Automotive Safety and Victims’ Aid (NASVA), JAPANTaichi NAKAJIMA, Kunio YAMAZAKI, Koshiro ONO Japan Automobile Research Institute (JARI), JAPANESV Paper Number 09-0364
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Extended Criteria Review
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Extended Criteria Review
(1) gtr7(2) Biomechanics of Whiplash(3) Real life data analysis
(4) Criteria proposal (5) Implications
(6) Threshold proposal (7) Implications
(8) New rating scheme
(9) Evaluation of real life relevance
Today’s Agenda
For a later day
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Whiplash Regulation , Assessmentstarted under making
~2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
GTR
JP
EU
US
JP
EU
US
Korea
China
Ass
ess
ment
Regu
ration
FMVSS202a(FR)
(RR)
★GTR-Phase1 ☆GTR-Phase2 (Step1)?
☆GTR-Phase2 (Step2)?
ECE17-10?
ECE17-10?
New FMVSS202a?
J-NCAP
E-NCAP
IIHS
K-NCAP
C-NCAP?
Folksam
Thatcham
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Purpose and situation of Head Restraint GTR makingPurpose and situation of Head Restraint GTR making
1.Evaluation by Injury Criteria・ Japan proposed the assessment based on Ono 2009 (completed). ・ An original research that uses PMHS is being conducted in the United
States (until end of 2011). → Injury Criteria of GTR7 is to be considered by a joint research of
JARI(Ono) and NHTSA.
Solving the following problem of the Whiplash evaluation of the current state is necessary. Governments and the industry are jointly working on it withinWP29/GRSP. .
Japan proposal NHTSA study
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2.Guarantee of Repeatability・Reproducibility・ The Cause of variability is studied in each country. ・ Improvement of BioRID Ⅱ calibration is studied by Humanetics Co..・ Reduction of dummy setting tolerance (Completed at GTR7-Phase1).
→When establishing the regulation, improvement of Repeatability・Reproducibility is requested and necessary.
PDB studyHumanetics Co.Calibration study
Dummy set proposal(Fixed at GTR7-Phase1. )
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3. Test method to reflect the real world・ Seat back angle to be set (and tested) at design angle is considered in
each country.・ Test speed appropriate for permanent injury reduction is considered in each country.
・ Large stature (AM95-three dimensional manikin) is considered by the Netherlands &TNO.
Small design torso angle Dummy setting study
Test speed for injury reduction study
High height person study
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Extended Criteria Review
(1) gtr7(2) Biomechanics of Whiplash(3) Real life data analysis
(4) Criteria proposal (5) Implications
(6) Threshold proposal (7) Implications
(8) New rating scheme
(9) Evaluation of real life relevance
Today’s Agenda
For a later day
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Biomechanics of Whiplash injuries – Injury criteria review
“None of the proposed injury criteria were found to have a definite biomechanical basis and their validity in predicting the risk needs to be established. None of the criteria can be recommended on a strictly biomechanical basis.”
Considered were main injury criteria proposed in literature: Nij, Nkm, LNL, IV-NIC, NDC, NIC, other: Head RV and Seatbelt load.
Dummy Requirements and Injury Criteria for a Low-speed Rear Impact Whiplash Dummy. EEVC WG12 report, p.29, September 2007
However, some valuable insight can gained from a biomechanical review of Whiplash injuries.
On the following pages, “Mainstream findings” will be presented, Controversial research findings are not included.
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Biomechanics of Whiplash injuries
The biomechanical evidence for Whiplash injuries
Symptoms (short and long term)
Physiological damage(injury)
Injury mechanism
Injury criterionthresholds
corr
elat
ion
Injury criterion with thresholds
Classic injury criteria development For whiplash
Effe
ctiv
enes
s re
view
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Biomechanics of Whiplash injuriesWhiplash
Injuries
Injury mechanism
Criteria
Thresholds
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Biomechanics of Whiplash injuries
Symptoms
Neck pain, headache, vision disorder, dizziness, unconsciousness, neurological symptoms and other
EEVC WG12 report, p.24, September 2007Schmitt, K.U. Trauma Biomechanics, 2nd Edition, p.91
Syptoms and injuries are related:“Nociceptors have been shown to exist in various
components of spinal tissues, namely the muscle (Bogduk & Marsland 1988), disc annulus and facet joint ligaments (McLain 1994). Consequently, injury to any of these tissues has the potential to cause neck pain.”
Whiplash associated disorders: a comprehensive review, p. 31. Anderson et al. Centre for Automotive Safety Research. University of Adelaide. April 2006
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Biomechanics of Whiplash injuries
Physiological damage (injuries)
Yoganandan et al. (2000) reported injuries to several ligaments, the intervertebral discs and the facet joint structures.
Taylor et al. (1998) and Svensson et al. (2000) reported damage in cervical spinal root ganglia
Brault et al. (2000) reported muscle injuriesEEVC WG12 report, p.24, September 2007
But muscle stiffness following the impact typically last only a few days
Whiplash associated disorders: a comprehensive review, p. 31. Anderson et al. Centre for Automotive Safety Research. University of Adelaide. April 2006.
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Biomechanics of Whiplash injuries
Physiological damage (injuries)
“The structures most likely to be injured in whiplash are the facet capsule, the intervertebral discs and the upper cervical ligaments. Injuries to other structures may occur but the available evidence appears to suggest that these are less common”
Whiplash associated disorders: a comprehensive review, p. 31.
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Biomechanics of Whiplash injuriesWhiplash
Facet joint Disc Ligaments Muscles Spinal root ganglia Injuries
Injury mechanism
Criteria
Thresholds
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Biomechanics of Whiplash injuries
Injury mechanism
Hyperextension of the neck – not relevant any moreMuscle strains – unlikely and pain only last for a few daysSpinal column pressure pulses – could cause ganglion
damageCervical spine motion (local hyperextension/flexion) - has
been shown to be able to lead to facet joint impingement Neck shear force can cause excessive facet joint strain.Neck compression can cause the facet capsules to stretch
and possibly torn, resulting in inflammation and pain.
Whiplash associated disorders: a comprehensive review, p. 36-38
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Biomechanics of Whiplash injuries
Injury mechanism
“Many causes for soft tissue neck injuries are hypothesised, … In practice, the S-shape deformation is regarded to play a crucial role when discussing possible injury mechanism”
Schmitt, K.U. Trauma Biomechanics, 2nd edition p.94
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Biomechanics of Whiplash injuriesWhiplash
Facet joint Disc Ligaments Muscles
local hyperextension
/ flexionMuscle strain
Spinal root ganglia
Pressure pulseNeck shearNeck
compression
Injuries
Injury mechanism
Criteria
Thresholds
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Biomechanics of Whiplash injuries – Injury criteria review
Several injury criteria (response measurement)
Associated injury mechanismItem Who? Year Where?
NIC Bostrom '96 IRCOBI Pressure pulses in spinal ganglia
Nkm Schmitt '01 ESV Excessive load (some relation with facet injury)Combination of Fx and My
LNL Heitplatz '03 ESV
MIX Kullgren '03 ESV - (combination of NIC and Nkm)
WIC Muñoz '05 ESV - (excessive load?)
Excessive load (some relation with facet injury)Combination of lower Neck Fx, Fz, My
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Biomechanics of Whiplash injuries
Several injury criteria (response measurement) contd.
Associated injury mechanismItem Who? Year Where?
T1G - (Seat design parameter)
Fx (upper) Facet injury (via cervical strain)
Fz (upper)
Fx (lower)
Fz (lower)
My (lower)
'07 IRCOBIStemper
My (upper)
'07 IRCOBIStemper
'09 IRCOBIOno
'09 IRCOBIOno
Facet injury (excessive load and/or motion)
Facet injury (via cervical strain)
Facet injury (via cervical strain)
Facet injury (via cervical strain)
Facet injury (excessive load and/or motion)
'07 IRCOBIStemper
'09 IRCOBIOno
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Biomechanics of Whiplash injuries
Several injury criteria (kinematic measurement)
Associated injury mechanismItem Who? Year Where?
IV-NIC Panjabi '99 IRCOBI Facet joint, Disc and ligament (excessive rotation)
VT1 Muser '00 IRCOBI - (excessive load in rebound phase)
NDC Viano '02 SAE - (Kinematic measurement for excessive load)
PWI Mallory '05 ESV - (Head rotation)
Head RV - (excessive load in rebound phase)
T-HRC - (Head to headrest contact timing)
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Biomechanics of Whiplash injuries – Injury criteria review
Whiplash
Facet joint Disc Ligaments Muscles
local hyper-extension/
flexionMuscle strain
Spinal root ganglia
Pressure pulse
NIC
Neck shearNeck
compression
Injuries
Injury mechanism
Criteria
Thresholds
Fx, Fz, My, IV- NICNkm, LNL as combination
MIX, NDC T1G, T-HRC, Head RV, VT1
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Biomechanics of Whiplash injuries
Ono 2009
Injury-risk curves for thresholds derivation
Kullgren 2003
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Injury criteria thresholds with correlation to Whiplash injuries
Derived thresholdsItem Who? Year Where?
NIC
Nkm
BostromKullgren
20002003
BookESV 15 m/s2 (20% risk for long term injuries) (1)
8/30 (5%/95% risk of WAD2+)
Kullgren 2003 ESV 0.8 (20% risk for long term injuries) (2)1Schmitt 2001 ESV
Fx (upper)
Fz (upper)
Fx (lower)
Fz (lower)
My (lower)
My (upper)
Kullgren 2003 ESV5Nm (20% risk for long term injuries) (3)(recommended to use NIC and Nkm only)
Ono 2009 IRCOBI 340/730N (5%/95% risk of WAD2+)
475/1130N
12/40Nm
340/730N
257/1480N
12/40Nm
“
Ono 2009 IRCOBI
Ono 2009 IRCOBI
Values for 5%/95% risk of >1m symptoms are approx. (1) 11/28 (2) 0,5/1,7 (3) 3/8
Fairly old findings. Nkm might correlate because Fxand My do. Thus, Fx and My should be used
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Biomechanics of Whiplash injuries – Injury criteria review
Whiplash
Facet joint Disc Ligaments Muscles
local hyper-extension/
flexionMuscle strain
Fx: 340-730N
Spinal root ganglia
Pressure pulse
NIC
NIC8-30
15
Neck shear Neck compr.
My: 12-40Nm
Fz: 475-1130N
Injuries
Injury mechanism
Criteria
Thresholds
(Nkm), (LNL), Fx, Fz, My, IV- NICMIX, NDC T1G, T-HRC, Head RV, VT1
MIX: 3.2
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Biomechanics of Whiplash injuries – Injury criteria reviewSummary (1): Injury criteria based on an underlying injury
mechanism and are correlated with whiplash injuries exist
12/40Nm
5Nm (recommended not to use)
Ono ’09
Kullgren ’03
Facet injury (via cervical strain)
Ono ’09Stemper ‘07
My lower
12/40NmOno ’09Facet injury (via cervical strain)
Ono ’09My upper
340/730N475/1130N
Ono ’09Facet injury (via cervical strain)
Stemper ‘07Ono ’09
Fx (lower)Fz (lower)
340/730N475/1130N
Ono ’09Facet injury (via cervical strain)
Ono ’09Fx (upper)Fz (upper)
10.8
Schmitt ‘01Kullgren ’03
Excessive load (some relation with facet injury)
Schmitt ‘01Nkm
15 m/s28/30 m/s2
Bostrom ’00Kullgren ’03Ono ‘09
Pressure pulses in spinal ganglia
Bostrom ‘96NIC
ThresholdsCorrelationMechanismEstablishedItem
Nkm might correlate because Fx and My do. Thus, Fx and
My should be used
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Biomechanics of Whiplash injuries
Summary (2) : Any other injury criterion should only be used after further thorough evaluation
-Ono ’09--Head RV
--- (excessive load in rebound)
Muser ‘00VT1
---Viano ’02NDC
---Mallory ’05PWI
----T-HRC
--Facet, disc and ligament injury (excessive rotation)
Panjabi ’99IV-NIC
----T1G
---Muñoz ’05WIC
3.2Kullgren ’03-Kullgren ’03MIX
--Excessive load (some relation with facet injury)
Heitplatz '03LNL
ThresholdsCorrelationMechanismEstablishedItem
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Biomechanics of Whiplash injuries – Injury criteria review
Whiplash
Facet joint Disc Ligaments Muscles
local hyper-extension/
flexionMuscle strain
Fx: 340-730N
Spinal root ganglia
Pressure pulse
NIC
NIC8-30
15
Neck shear Neck compr.
My: 12-40Nm
Fz: 475-1130N
Injuries
Injury mechanism
Criteria
Thresholds
(Nkm), (LNL), Fx, Fz, My, IV- NICMIX, NDC T1G, T-HRC, Head RV, VT1
MIX: 3.2
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Extended Criteria Review
(1) gtr7(2) Biomechanics of Whiplash(3) Real life data analysis
(4) Criteria proposal (5) Implications
(6) Threshold proposal (7) Implications
(8) New rating scheme
(9) Evaluation of real life relevance
Today’s Agenda
For a later day
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0.0640.071 0.07
0.092
0.146
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
Good Acceptable Marginal Poor Not tested
W/O, Cars after 97 With Anti_whiplash System
W/O, Cars before 97
With Anti Whiplash System
IIWPG rating & injury risk
Slight differences
Rel
ativ
e LT
Ris
k (%
)
Kullgren et al. (ESV 2007)
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Pro
port
ion
of L
Tin
jurie
s(%
)
Farmer et al. (Traffic Injury Prevention 2007)
3.8%
4.7%
3.6%
5.8%
4.6%
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
6.0%
7.0%
good acceptable marginal poor all
IIWPG rating & injury risk
“Good” significantly better than “poor”
Only “marginal” significantly better than “all”
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IIWPG rating & injury risk
Not all questions are answeredIt is still a valuable exercise to compare rating and real-life risk
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Injury and seat performance criteria versus injury risk
Methods:
- Analysing real life risk from Swedish insurance data (1995-2008) of rear impacts with filed Whiplash claim-Taking proportions of Symptoms > 1 month and permanent disability
-Grouping similar seats (e.g. all Volvo Whips seats)-Taking representative test values (medium pulse) for injury and seat performance measurements
EEVC WG12 Report Document Number 578Evaluation of Seat Performance Criteria for Rear-end Impact Testing (Interim report) January 2011Johan Davidsson, Chalmers University of TechnologyAnders Kullgren, Folksam Research
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Injury and seat performance criteria versus injury risk
Findings: Some injury and seat performance criteria correlate with injury risk
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Injury and seat performance criteria versus injury risk
Findings: Some injury and seat performance criteria do not correlate with injury risk
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Injury and seat performance criteria versus injury risk
Findings: Some injury and seat performance criteria correlate with injury risk some do not
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Injury and seat performance criteria versus injury risk
Conclusion
NIC, Fx (upper), Head to T1 rotation and Nkm are suggested to be included in performance evaluation of seat systems in rear-end impact.
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Injury and seat performance criteria versus injury risk
Findings: Some injury and seat performance criteria have limited correlation with injury risk (after removal of outliers)
Conclusion
Fz (lower) , My (lower) are candidates for performance evaluation of seat systems in rear-end impact.
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Effectiveness of different seat concepts
Kullgren and Krafft, IRCOBI 2010GENDER ANALYSIS ON WHIPLASH SEAT EFFECTIVENESS: RESULTS FROM REAL-WORLD CRASHES
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Effectiveness of seat concepts for malesRelative risk of permanent medical impairment for m ales
0
1
2
3
4
5
6
7
8
standard seat RHR Saab other RHR WhiPS WIL
%
All concepts are effective
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Relative risk of permanent medical impairment for f emales
0
2
4
6
8
10
12
14
standard seat RHR Saab other RHR WhiPS WIL
%
Effectiveness of seat concepts for females
Do RHR protect females?
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Extended Criteria Review
(1) gtr7(2) Biomechanics of Whiplash(3) Real life data analysis
(4) Criteria proposal (5) Implications
(6) Threshold proposal (7) Implications
(8) New rating scheme
(9) Evaluation of real life relevance
Today’s Agenda
For a later day
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Current J-NCAP
Current Euro NCAP
( )**My upper
My lower
Head - T1 rotation
T1 x-acceleration
Head restraint contact time
( )**
( )*
Ideas for Euro NCAP(open discussion)
Real-life justification
Biomechanical justification
Criterion
NIC
Nkm
Head RV
Fx upper
Fz upper
Seatback opening
Fz lower
Fx lower
Head RV used to measure violence of rebound.- Head velocity relative to T1 (early phase) or Neck Forces (late phase with Seatbelt interaction) seem more appropriate.-Difficult to measure (video tracking problems)-No injury-risk curves available
Seatback rotation used to measure seatback stability for high impact loads. (no biomechanical criterion)
Head – T1 rotation difficult to measure(video tracking problems). Correlation with My exists. Rotation rate might be more important than amount
WrongGood / use
CandidateNot used
Dou
ble
eval
uatio
n
*further research needed. Fx might be more appropriate.Ono et al. conclude no correlation with facet strain. Should be excluded to avoid double evaluation**further research needed.Ono et al. showed correlation with facet strain, butKullgren and Davidsson showed no correlation to real-life risk
(EEVC WG12)
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Extended Criteria Review
(1) gtr7(2) Biomechanics of Whiplash(3) Real life data analysis
(4) Criteria proposal (5) Implications
(6) Threshold proposal (7) Implications
(8) New rating scheme
(9) Evaluation of real life relevance
Today’s Agenda
For a later day
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Removal of T1 acceleration, head restraint contact time, Head rebound velocity
0
1
2
3
4
0 1 2 3 4
current rating score
calc
ulat
ed ra
ting
scor
e w
ithou
t T1g
, T-H
RC
, HR
VUnchanged performance limits
59-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120 127 134 141 148 155 162 169 176 183 190 197 204 211 218 225
chan
ge in
sco
re
On average, score increases by 0.12 when T1G, T-HRC, HRV are excludedThis could be compensated for setting good-average-poor limits up by 0.12(High increase when HRV exceeded capping value before)
Removal of T1 acceleration, head restraint contact time, Head rebound velocity
Unchanged performance limits
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0
1
2
3
4
0 1 2 3 4
current rating score
calc
ula
ted
ratin
g sc
ore
with
out T
1g, T
-HR
C, H
RV
0
1
2
3
4
0 1 2 3 4
current rating score
calc
ula
ted
ratin
g sc
ore
with
out T
1g, T
-HR
C, H
RV
0
1
2
3
4
0 1 2 3 4
current rating score
calc
ulat
ed r
atin
g s
core
with
out
T1g
, T-H
RC
, HR
V
0
1
2
3
4
0 1 2 3 4
current rating score
calc
ulat
ed r
atin
g s
core
with
out
T1g
, T-H
RC
, HR
V
Toyota Volvo & Saab
PSA BMW &Mercedes
Removal of T1 acceleration, head restraint contact time, Head rebound velocitySome implications by OEM
Unchanged performance limits
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Extended Criteria Review
(1) gtr7(2) Biomechanics of Whiplash(3) Real life data analysis
(4) Criteria proposal (5) Implications
(6) Threshold proposal (7) Implications
(8) New rating scheme
(9) Evaluation of real life relevance
Today’s Agenda
For a later day
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0.8
15
Kullgren 200320% risk symptoms >1month
270/610 – 360/750 –470/770
30/110 – 30/190 –30/210
0.12/0.35 – 0.15/0.55 – 0.22/0.47
9/15 – 11/24 – 13/23
Current Euro NCAP(low-mid-high)
12-40My upper
12-40My lower
Ono 20095%-95% risk WAD2+
Davidson and Kullgren 2010<6% risk of permanent injuries given initial symptoms
Criterion
8-3020NIC
0.35Nkm
340-730150Fx upper
475-1130Fz upper
257-1480Fz lower
340-730Fx lower
Thresholds
J-NCAP
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Extended Criteria Review Summary
From the presented evidence, it is recommended to• Continue using criteria with biomechanical and real life justification
– NIC, [Nkm], (Upper Fz), Upper Fx• Discontinue using criteria without justification
– T1G, T-HRC, Head RV• Consider introducing additional criteria with have a justification
– (Lower Fx), Lower Fz, Lower My, (Upper My)• Consider introducing
- Injury-risk based thresholds to effectively prevent injury and not to only benchmark seats
() further research for real-life effect needed[] discontinuation suggested as Fx and My should be measured
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• Toyota recommends to harmonise with J-NCAP– A good step towards a scientifically founded
rating can be achieved.
– J-NCAP’s criteria have the best scientific justification of the ratings available and can be adopted easily.
• Toyota recommends to follow gtr phase 2 developments and consider harmonising
Conclusion
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Thank you!