“Crashworthiness issues in

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“Crashworthiness issues in

EMS Asia 2012Symposium B, 12.00 – 13.00,

September 10, 2012

Nadine Levick, MD MPHResearch Director, EMS Safety FoundationCEO, Objective Safety, New York, USA

ambulance design”

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Integrating crashworthiness into Ambulance design, NAEMSP 2012

http://www.emssafetyfoundation.org/NAEMSP2012poster.pdf What does crashworthiness mean?

That a vehicle has been tested to meet standards that demonstrate that under crash circumstances occupants will be

Essentially… crashworthiness is -

crash circumstances occupants will be protectedBut….. to what standards and which crash circumstances???

Important…

Ergonomics and automotive safety issues are interrelatedCrashworthiness priorities override theCrashworthiness priorities override the ergonomic issues

Any testing that meets a standard – is only as valuable as the standards capacity to reflect the real world scenario

Important Concepts

p yComputer models are only as good as the data entered into them – garbage in.. garbage out!

60 kph into a tree or pole60 kph into a rocky wall60 kph into deformable roadside hardware60 kph roll into a soft shoulder

These are very different… but are all crashes….

60 kph roll into a soft shoulder

And in which vehicle, and what occupant configuration or restraint system use….

ALL are different G- forces and energy transfer and injury outcomes

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And will have very different vehicle and occupant

outcomesThe testing must be guided by:

Real world crash scenariosReal world vehicle and occupant

Key issues

Real world vehicle and occupant configurationsReal world crash injury mechanisms

What is a safe speed and how do we identify that?

What is a survivable impact ?

12 mph (20 km/hr)?IRMRC

What is a survivable impact?E= ½ mv2 v2 = 2as

IRMRC


IRMRC ~ 30 mph - survivable

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IRMRC ~ 60 mph – not survivable

Vehicle Safety Dynamic Testing Types

Deceleration Sled Tests (not usually a full vehicle) – no intrusionBarrier impact tests – intrusionBarrier impact tests intrusionFull vehicle to vehicle tests – intrusionComputer predictive modeling - must be based on real world injury and vehicle crashworthiness data

Deceleration Sled Tests (not usually a full vehicle) – no

intrusion

Deceleration Sled Crashworthiness testing

Europe - 2007 to meet CEN

Pre crash sled test configuration(view of captains chair and patient area)

Uninstrumentedrestrained CTD

Instrumented restrained child

CTD

Pre crash sled test configuration(view of squad bench)

Instrumented unrestrained SID

Uninstrumentedrestrained CTD

‘man saver’ device

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And this all takes place in 60 millisecs –the blink of an eye

Post impact (from rear door)

PPE from the stationary environment can be highly hazardous in the automotive setting

XXXXSystems safety failure AND dangerous

Overwhelming existing evidence these practices are HIGHLY dangerous

NO evidence whatsoever that these practices are NOT dangerous, let alone XXsafeXX

NOT new technical data…

Richardson S.A., et al, Int. J. of Crash., 4:3, 239 – 259, 1999Side facing 4-point harnesses demonstrated to be lethal, even at

slow ground vehicle speeds

Beware some provider restraint systems are dangerous

Side facing 4-point harnesses demonstrated to be lethal, even at slow ground vehicle speeds

Richardson S.A., et al, Int. J. of Crash., 4:3, 239 – 259, 1999

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Being seated IN an automotive seat is what will protect you

Anything that allows or encourages you to get up out of your seat will also encourage you to be injured or killed – it is potentially lethal to be out of your seat in any fashiony y4 or 5 point harnesses over both shoulders for sidefacing occupants are potentially lethal –and in NO WAY SUPPORTED BY ANY DATA OR INDEPENDENT AUTOMOTIVE SAFETY EXPERTISE

Dynamic Sled Testing

ofof Ambulance

Pediatric Restraints

Deceleration Sled test (upon impact) 24 G, 30mph

Levick NR, et al. Development and Application of a Dynamic Testing Procedure for Ambulance Pediatric Restraint Systems, SAE Australasia 1998;58:2:45-51

If we know this – and its published….

Why do we do this?ALL patients need shoulder straps!!

Barrier impact tests - intrusionSprinter v Ford Transit crash test

http://www.youtube.com/watch?v=C3kN6WF5vAA&feature=related

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Full vehicle to vehicle crashworthiness tests

Intrusion and occupant dynamics

Intersection crashes are associated with high injury and

fatality rates

And very Predictable…y

Intersections are lethal environments

So.. The real world for an EMS vehicle approaching a red light

You think they heard you…You know they must have seen you..And maybe they didAnd maybe they did….. But..There is NO way humanly possible that they could stop…..

The real worldIntersection passenger car stopping distance* at 40 mph dry

and wet

44 feet

P ti R ti ti V hi l B ki ti (d )

DryStopped at 176 feet

+

Perception + Reaction time Vehicle Braking time (dry)

40 mph

Wet Stopped at 220 feet

Perception + Reaction time Vehicle Braking time (wet)

* Stopping distance:Perception time + Reaction time + Vehicle braking time (varies with age, skill, agility, alertness + vehicle type, tire pressure, road etc)

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Testing the real worldTest 1 – Right side impact

1 2

What is actually happening during an ambulance crash

Johns Hopkins University

1 – Target vehicle, Type I ambulance

2 – Bullet vehicle, Type II ambulance

Closing speed 44 mph

Pre-impact CTD positioning

Preparation of test vehicles

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And this all takes place in 60 millisecs – the blink of an eye

Impact residue

CTD dynamics

During impact

Post impact

Computer predictive modeling -

must be based on real world injury and vehicle

h thi d tcrashworthiness data

Valuable that Malaysian ambulances are OEM vehicles – structurally unalteredKey importance of occupant restraint

Relevance

Key importance of occupant restraint use and configuration in determining safety outcome

Use of standard seat belts by providersUse the patients stretcher shoulder belts for ALL patients

Important!!!

ALL equipment must be secured If hazardous driving is deployed – ALL occupants and equipment MUST be optimally retrained during that time

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Vehicle StandardsVehicle– AMD– KKK– NFPA– ASTM– ASTM– FMVSS– SAE– International - CEN/ASA

International Ambulance Design Safety and Occupant Protection

Standards

In existence since 1999Australia – ASAEurope - CEN

“Restraint systems shall apply to all equipment and people carried in an

Australia & New Zealand Ambulance restraint standard

AS/NZS 4535:1999restraint systems only

q p p pambulance…” -Dynamic Testing - 50th & 95th percentile manikins24G in Forward and Rearward10G in Transverse

CEN – EN 1789:2007+A1 2010E*Medical vehicles and their equipment –

Road ambulances “Without exception, all persons, medical devices, equipment, and objects normally carried on the road ambulance shall be maintained to prevent them from becoming

j til h bj t t f ”a projectile when subject to a force…”Dynamic testing - 50th percentile manikins10 G in Forward, Rearward, Transverse, & Vertical directionsCertified by Notified Body & Ambulance Mfg*Also is EN-1865:2000, for stretchers and patient handling equipment used for road ambulances

SAE Ambulance Equipment mounting testing standards

Frontal Impact SAE 2917, published May 2010Side Impact SAE 2956, published June 2011

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USA KKK ambulance purchase specifications

GSA:KKK-A-1822F, Aug 2007to retire October 2013

Specifications for purchase of Star of Life AmbulanceStatic Pull test2200 Lbs static stretcher test in2200 Lbs. static stretcher test inlongitudinal, lateral & vertical No dynamic test for vehicle, occupants or equipmentNo automotive test manikinVoluntary

www.ntea.com/WorkArea/downloadasset.aspx?id=1352

USA Ambulance Manufacturing Division (AMD)

Ambulance Standards– August 2007

(being integrated into NFPA 1917)No dynamic or impact testNo automotive test manikinMandates NO ‘crumple zone’ No impact tested anchorages for occupant restraint or equipmentInternal, not independent & not a standardizing body

http://www.ntea.com/WorkArea/showcontent.aspx?id=1350

Current 2012 USA ambulance ‘safety testing’ – Is NOT consistent with accepted automotive

safety practice…!?!?No ‘a’… then NO ‘F’ !!!!!

F = ma

where F – forcem – massa – acceleration

Yes a “nationally recognized testing lab” – BUT - NOT an automotive/occupant

safety crash test lab!!

NFPA 1917, August 2012(based on KKK, AMD)

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AMD 2007 - 025 ‘static occupant safety testing’

Accepted automotive safety dynamic occupant

testing

- Compared with -

Meets CEN-1789 - High speed crash, rolled and the occupants (patient and medics) had only

minor scratches

this vehicle is safety crash tested by automotive experts

Unlike this vehicle

Which does meet KKK, and AMD…

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April 30, 2009 - Tennessee A survivable impact??

Just because it has been ‘Tested’ does not necessarily mean it has been crash tested – nor that it is crashworthy and/or going to protect you

Caution!!!

Even if it has been ‘Crash tested’ – it depends upon to which standard, whether or not it is actually safe under real world crash conditionsAppropriate technical expertise is key!!

Appropriate crashworthiness testing is the primary guide as to whether a vehicle and restraint configuration is actually safe Independent and specialized technical

ti i t ti f t i k t

Summary

expertise in automotive safety is key to guide interpretation of any manufacturer claimsUse of proven occupant safety design saves lives

Thank you! Any Questions??

Electronic handout and resources available onlinehttp://www.objectivesafety.net

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“Crashworthiness issues in