Differences Between Crash Dummy Responses and Real-World Injury

Frank A. Pintar Frank A. Pintar N. Yoganandan N. Yoganandan Dale HallowayDale Halloway

Dennis J. MaimanDennis J. Maiman

Wisconsin CIREN Milwaukee, Wisconsin USA

DEPARTMENT OF VETERANS AFFAIRS

RESEARCH SERVICE

Introduction

Anthropomorphic Test Devices (ATD)ya. k. a. crash test dummies yUsed to design modern safety systemsyUsed to evaluate modern safety systems8NHTSA Regulatory testing8NHTSA NCAP star rating8IIHS ratings8Euro-NCAP, Japan-NCAP, etc

yDesigned to represent the living humanyAssess injury potential without getting injured8Non-frangible

How human-like is an ATD?

Biofidelity

Purpose

Crash test dummy characteristicsyBiofidelityyInjury criteria

US-DOT-NHTSA RegulationsVehicle-related injuries in the real-worldyCIREN identifies emerging trends

Discuss areas of development

Dummy Characteristics - BiofidelityHybridHybrid--III III

Frontal Impact DummyFrontal Impact DummyGMGM--designed 1970designed 1970’’ss

Dummy Characteristics - BiofidelityHybridHybrid--III Frontal Impact DummyIII Frontal Impact Dummy

Chest ComplianceChest Compliance

Lobdell 1972

Force (lb)

Deflection (in)

Force (lb)

Deflection (in)

Dummy Characteristics - BiofidelityHybridHybrid--III Frontal Impact DummyIII Frontal Impact Dummy

Neck ComplianceNeck Compliance

Military personnel volunteersMilitary personnel volunteers

Dummy Characteristics – Injury Criteria

MatchedMatched--pair testing withpair testing withEuroSIDEuroSID--2re Side Impact Dummy2re Side Impact Dummy

PMHS tests PMHS tests –– full Instrumentationfull Instrumentation

F(t)

x(t)a(t)a(t)

a(t)

Various Various boundary boundary

conditions:conditions:Rigid wallRigid wall

Padded wallPadded wallOffset wallOffset wall

Dummy Characteristics – Injury Criteria

Tests with InjuriesTests with Injuries

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 10 20 30 40 50 60 70 80Max%CTests without InjuriesTests without Injuries

Derive Probability of Injury

Dummy Characteristics – Injury Criteria

Probability of Serious Chest Injury forProbability of Serious Chest Injury forEuroSIDEuroSID--2re Side Impact Dummy2re Side Impact Dummy

Normalized to 45 year oldNormalized to 45 year old

00.10.20.30.40.50.60.70.80.9

1

0 10 20 30 40 50 60 70 80 90 100Max. Rib Defl. (mm)

Prob

. of I

njur

yAIS3+ AIS4+

0

100

200

300

400

500

600

0 0.002 0.004 0.006 0.008 0.01 0.012Time [s]

Acc

eler

atio

n [g

]WSTC1960 CurveIsolated headIntact cadaverCorrected data

Dummy Characteristics – Injury Criteria

GurdjianGurdjian, 1960s PMHS, 1960s PMHS““hand droppinghand dropping”” techniquetechnique

HIC15 = [1/(t2-t1) ∫ a dt]2.5 (t2-t1)

where t2-t1 is chosen to maximize HIC, t2-t1 < 15 msa is resultant acceleration measured at head center of gravity

Head Injury Criteria

Dummy Characteristics – Injury Criteria

Accelerometers in the dummy Accelerometers in the dummy head record head record translational accelerationtranslational acceleration

Head Injury Criteria

-20

-10

0

10

20

30

40

50

60

0 30 60 90 120 150

Time (ms)

Tran

slat

iona

l Acc

eler

atio

n (g

)

XYZXY

Z

Federal Motor Vehicle Safety Standards

Part 571: Includes Crashworthiness Standardsy 571.208 – Frontal Impact Occupant Protectiony 571.213 – Child Restraint Systemsy 571.214 – Side Impact Occupant Protection

Part 572: Anthropomorphic Test Devices used in 200-series of part 571

US DOT-NHTSA RegulationsFrontal Impact Crashworthiness FMVSS 208

Front outboard seats Two belted dummiesStationary barrierMoving vehicleTrauma toyHeadyNeckyChestyThigh 35 mph (belted)

25 mph (unbelted)

Rigid Barrier

US DOT-NHTSA RegulationsFrontal Impact CrashworthinessHybrid-III 50th Male Dummy Injury Criteria

Head Injury Criteria (HIC15) – 700 (15 ms)Chest Acceleration – 60 gChest Deflection – 63 mmNeck Injury Criteria Nij < 1.0Femur Criteria – 10 kN

US DOT-NHTSA RegulationsSide Impact Crashworthiness FMVSS 214

Two Belted dummies

Left side seating

Stationary vehicle

Moving deformable barrier “crabbed”

NHTSA-SID Trauma toy Chest

y Pelvis

33.5 miles per hour

US DOT-NHTSA RegulationsSide Impact FMVSS 214 UPGRADE

Test Configurations Dummies

BOTH mid-size male & small female

Oblique vehicle to pole impact

MDB--to-vehicle side impact

ES-2re SIDIIs

US DOT-NHTSA RegulationsSide Impact CrashworthinessES-2re 50th Male Dummy Injury Criteria

Head Injury Criteria (HIC36) – 1000 (36 ms)Lower Spine Acceleration – 82 gRib Deflection – 40 mmAbdomen Force – 2500 NPubic Force – 6000 N

US DOT-NHTSA RegulationsChild Restraint Systems FMVSS 213

Newborn, 12-mo, 3-yo, 6-yoHead Injury Criteria (HIC36) – 1000 (36 ms)Chest Acceleration – 60 gHead Excursion LimitKnee Excursion Limit

Real-World TraumaInjuries that dummies don’t tell you about

Types of Abdominal Trauma

Upper Extremity Trauma

Real-World TraumaInjuries that dummies don’t tell you about

Types of lower extremity trauma Some spine trauma

Vascular trauma

Real-World TraumaPelvic Fractures

Frontal impact of 1999 Jeep CherokeeRt acetabular Fx induced by knee contact with knee bolster

Frontal impact of 1997 Lexus LX450

Acetabular Fxs induced by knee contact with knee bolster

Developments in UnderstandingPelvic Fractures

Knee-Thigh-Hip trauma Knee contact – knee bolsterEffect of loading rateEffect of position

Rupp & Schneider, Orthop Clin N Am, 2004

Developments in UnderstandingPelvic Fractures

Translate PMHS response data to dummy responseTranslate PMHS injury criteria to dummy criteria

Rupp, et al, ESV 2005

Real-World TraumaBrain Injuries

Right Occipital Skull FxCerebellar contusion DAI, IVH, SAH IVH, SAH

Developments in UnderstandingBrain Injuries

FocalFocal MotionMotion

Translational AccelerationTranslational Acceleration Rotational AccelerationRotational Acceleration

Developments in UnderstandingBrain Injuries

Skull

Dura-CSF

Brain

Falx Cerebri

Bridging Veins

Skull

Dura-CSF

Brain

Falx Cerebri

Bridging Veins

Rotational motion induces Rotational motion induces deep brain traumadeep brain trauma

SIMonSIMonComputation Computation

ModelModel

Developments in Advanced Dummies

THORTHORFrontal Impact DummyFrontal Impact Dummy

WorldSIDWorldSIDSide Impact DummySide Impact Dummy

~150 sensors~150 sensors3X3X--4X biofidelity4X biofidelityInjury Criteria ?Injury Criteria ?

Summary

Dummies are valuable tools

Great improvements to human safety

Dummy biofidelity is advancing

Dummy-based injury criteria needed

Dummies don’t measure every type of injury

Development of dummy with computer models

This research was supported by

US Dept. of Transportation NHTSA,Dept. of Veterans Affairs Medical Research

Acknowledgment

Differences Between Crash Dummy Responses and Real-World InjuryIntroductionHow human-like is an ATD?PurposeDummy Characteristics - BiofidelityDummy Characteristics - BiofidelityDummy Characteristics - BiofidelityDummy Characteristics – Injury CriteriaDummy Characteristics – Injury CriteriaDummy Characteristics – Injury CriteriaDummy Characteristics – Injury CriteriaDummy Characteristics – Injury CriteriaFederal Motor Vehicle Safety StandardsUS DOT-NHTSA Regulations�Frontal Impact Crashworthiness FMVSS 208US DOT-NHTSA Regulations�Frontal Impact Crashworthiness�Hybrid-III 50th Male Dummy Injury CriteriaUS DOT-NHTSA Regulations�Side Impact Crashworthiness FMVSS 214US DOT-NHTSA Regulations�Side Impact FMVSS 214 UPGRADEUS DOT-NHTSA Regulations�Side Impact Crashworthiness�ES-2re 50th Male Dummy Injury CriteriaUS DOT-NHTSA Regulations�Child Restraint Systems FMVSS 213Real-World Trauma�Injuries that dummies don’t tell you aboutReal-World Trauma�Injuries that dummies don’t tell you aboutReal-World Trauma�Pelvic FracturesDevelopments in Understanding�Pelvic FracturesDevelopments in Understanding�Pelvic FracturesReal-World Trauma�Brain InjuriesDevelopments in Understanding�Brain InjuriesDevelopments in Understanding�Brain InjuriesDevelopments in Advanced DummiesSummary