Assessment of Head and Neck Injury Potential During Aircraft Longitudinal Impacts

Transcription

1 DOT/FAA/AM-17/9 Office of Aeospce Medicine Wshington, DC Assessment of Hed nd Neck Inju Potentil Duing Aicft Longitudinl Impcts Richd L. DeWeese 1 Dvid M. Moocoft 1 M.M.G.M. Philippens 2 1 Civil Aeospce Medicl Institute Fedel Avition Administtion Oklhom Cit, OK TNO Defense, Secuit nd Sfet 2600 JA Delft The Nethelnds Febu 2017 Finl Repot

2 NOTICE This document is disseminted unde the sponsoship of the U.S. Deptment of Tnspottion in the inteest of infomtion echnge. The United Sttes Govenment ssumes no libilit fo the contents theeof. This publiction nd ll Office of Aeospce Medicine technicl epots e vilble in full-tet fom the Civil Aeospce Medicl Institute s publictions website:

3 Technicl Repot Documenttion Pge 1. Repot No. 2. Govenment Accession No. 3. Recipient's Ctlog No. DOT/FAA/AM-17/9 4. Title nd Subtitle 5. Repot Dte Assessment of Hed nd Neck Inju Potentil Duing Aicft Longitudinl Impcts Febu Pefoming Ognition Code 7. Autho(s) 8. Pefoming Ognition Repot No. DeWeese R, 1 Moocoft D, 1 Philippens MMGM 2 9. Pefoming Ognition Nme nd Addess 10. Wok Unit No. (TRAIS) 1 FAA Civil Aeospce Medicl Institute P.O. Bo 25082, Oklhom Cit, OK Contct o Gnt No. 2 TNO Defense, Secuit, & Sfet, The Nethelnds 12. Sponsoing Agenc nme nd Addess 13. Tpe of Repot nd Peiod Coveed Office of Aeospce Medicine Fedel Avition Administtion 800 Independence Ave., S.W. 14. Sponsoing Agenc Code Wshington, DC Supplementl Notes 16. Abstct The isk of hed-neck injuies ws evluted fo cetin icft set nd inteio configutions in icft longitudinl impcts. Two loding scenios fo the hed-neck sstem wee investigted: inetil (noncontct) loding in posteio-nteio nd ltel diection using fowd fcing set nd side fcing couch, espectivel, nd contct loding though impcts of the hed with tpicl icft inteio components. The sled tests simulte n impct long the longitudinl is of the icft; howeve, the set oienttion cuses eithe fowd o ltel occupnt loding. The FAA Hbid III ws used in the occupnt-fowd impcts, nd the ES-2 Anthopomophic Test Device (ATD) ws used in the occupnt-ltel impcts. The ATDs utilied unique 9-cceleomete (NAP) bcket. Techniques wee pplied to deive ottionl cceletion nd velocit fom the NAP. Hed ottionl velocities wee coss-vlidted using photometic techniques. Both ATDs wee lso equipped with uppe nd lowe neck 6-is lod cells. The estint configutions investigted fo inetil loding wee fowd fcing pilot set with 4-point estint, fowd fcing pssenge set with lp belt estint, nd side fcing pssenge set with 3-point estint. The contct lod configutions utilied fowd fcing pssenge set with lp belt estint with eithe pssenge set bck o simulted clss divide s impct sufces. The neck inju potentil ws evluted b the Fedel Moto Vehicle Sfet Stndds Nij citeion, using the neck lods t the occipitl condle level. The NAP dt wee used to evlute hed inju potentil with multiple vesions of the Hed Inju Citei (HIC), Skull Fctue Coelte, nd the Bin Inju Citei (BIC). Neck inju ws not significnt isk in most of the fowd fcing configutions tested; the onl test with Nij vlue bove the limit lso eceeded the HIC limit. Fo the side fcing test configutions, neck inju ws significnt isk, pticull fo seting sstems tht did not povide effective uppe bod suppot. Fo hed inju isk, significnt diffeences wee seen between the vition nd utomotive vesions of HIC. In sevel tests, vition HIC ws not clculted becuse thee ws no contct, but the utomotive vesions of HIC nd BIC suggest isk of hed inju. Ovell, these esults indicte tht using both HIC nd BIC to evlute seting sstems could povide sfet benefit b diectl evluting the isk of skull fctue nd tumtic bin inju. 17. Ke Wods 18. Distibution Sttement HIC, BIC, Nij, Hed Inju, Neck Inju, Aicft Csh Document is vilble to the public though the Intenet: Secuit Clssif. (of this epot) 20. Secuit Clssif. (of this pge) 21. No. of Pges 22. Pice Unclssified Unclssified 37 Fom DOT F (8-72) Repoduction of completed pge uthoied i

4 ACKNOWLEDGMENTS The wok would not hve been completed without the full suppot of the technicl stff t CAMI: Dvid DeSelms, Ronnie Minnick, nd Bn Povine. Eik Tkhounts t NHTSA supplied the SIMon softwe nd ssisted the uthos in implementing it. Robet Timble of Webe Aicft supplied the test sets, nd Joe McEntie of the U.S. Am Aeomedicl Resech Lboto supplied the 4-point estint sstems. ii

5 Contents BACKGROUND... 1 METHODS... 2 Fowd-Fcing Set Configution... 3 Inetil Loding Test Configution... 4 Row-to-Row Test Configution... 5 Wll Test Configution... 7 Side-Fcing Set Configution... 9 Test Device FAA Hbid III Euo SID Instumenttion Electonic Instumenttion Video Covege Inju Evlutions Hed Inju Citei (HIC) Skull Fctue Coelte (SFC) Bin Inju Citei (BIC) Neck Inju RESULTS Fowd-Fcing Set Configution Inetil Loding Test Configution Row-to-Row Test Configution Side-Fcing Set Configution Cente Test Configution Wll Test Configution Amest Test Configution DISCUSSION Neck Inju Hed Inju Bin Inju LIMITATIONS CONCLUSION REFERENCES APPENDIX... A-1 Angul Velocit Deivtion... A-1 NAP Clcultions... A-1 NAP Coections... A-3 iii

6 ASSESSMENT OF HEAD AND NECK INJURY POTENTIAL DURING AIRCRAFT LONGITUDINAL IMPACTS BACKGROUND Cuent icft set dnmic qulifiction tests utilie the Hed Inju Citei (HIC) to evlute hed potection. HIC ws selected fo use becuse it ws the most widel ccepted mens of hed inju ssessment when the dnmic set equiements wee dopted in 1988 [1, 2]. The oiginl vesion of HIC cited in the utomotive sfet stndds, efeed to s HIC Unlimited, consideed the entie cceletion time histo of the impct event nd hd pss/fil limit of A subsequent evision to the Ntionl Highw Tffic Sfet Administtion (NHTSA) ule cpped the clcultion t 36 ms [3]. The vition vesion of the clcultion disegds n hed cceletion pio to contct with sufce. This djustment ws the Fedel Avition Administtion s (FAA) mens of compensting fo the tendenc fo HIC to oveestimte the inju isk fo long peiods of eltivel low cceletion (s cn occu duing occupnt flil pio to hed contct). Since HIC hd been oiginll vlidted fo shot dution impcts (less thn o equl to 13 ms) tht esulted in skull fctue, ecluding non-contct cceletion seemed to be esonble ppoch t the time. A vesion tht compensted fo this tendenc b limiting the length of time consideed b the clcultion to 15 milliseconds ws lte dopted in the uto sfet stndds [4]. This vesion of HIC, efeed to s HIC15, hd lowe pss/fil limit of 700. While the defined level of sfet povided b HIC hs evolved since its intoduction, cuent pobbilit methods define HIC36 vlue of 1000 s 23% chnce of seious inju [5]. Tht level of hed inju cn esult in unconsciousness fom 1-6 hous, which mens tht occupnts m not be let nd ble to ssist with thei own evcution fte csh. This concen bout the bilit to self-evcute, nd the emegence of technologies nd citei to ssess bin inju isk, ws pt of the motivtion behind completing poject to detemine the bseline hed inju isk fo tpicl icft sets. Cuent icft set qulifiction tests do not ssess neck inju potentil fo sevel esons. The oiginl citei wee selected to potect occupnts duing epected impct scenios (pimil longitudinl nd veticl impct vectos eltive to the icft) when seted in the most common tpes of sets (fowd nd ft fcing). The citei focused on contolling the most seious injuies tht wee likel to esult fom those combintions of set tpes nd impct scenios. Neck inju ws not identified s high isk in those impct scenios. Neck inju ssessment ws lso not included fo one ve pcticl eson, the technolog to mesue neck loding nd n ccepted inju citei to detemine neck inju isk did not eist t the time of the ule s doption. Since tht time, technolog nd inju citei hve been developed to ssess neck injuies. The significnt neck fleion obseved in some impct scenios is one of the motivting fctos fo conducting this neck inju isk ssessment. Anothe fcto ws concen tht HIC eduction methods such s eneg bsobing set bcks nd ibgs could hve the unintended consequences of inducing injuies to the neck. 1

7 METHODS Hed nd neck inju potentil duing fowd impcts fo occupnts of tpicl icft sets nd inteio configutions ws ssessed in 26 tests coss 6 configutions (Tble 1). Two pim loding scenios wee investigted: inetil (non-contct) loding in the posteionteio nd ltel diection using, espectivel, fowd-fcing set nd side-fcing couch, nd contct loding though impcts of the hed with tpicl icft inteio components (setbcks nd wlls). The icft longitudinl impcts wee simulted b sled tests conducted t the FAA Civil Aeospce Medicl Institute (CAMI) using n FAA Hbid III nd n ES-2 Anthopomophic Test Device (ATD). The ATDs utilied unique 9-cceleomete (NAP) bcket developed b the Nethelnds Ognistion fo Applied Scientific Resech (TNO, the Nethelnds). The estint configutions investigted fo inetil loding wee fowd-fcing pilot set with 4-point estint, fowd-fcing pssenge set with 2-point belt estint, nd side-fcing pssenge set with 3-point estint. The contct lod configutions utilied pssenge set bcks, simulted clss divides, nd igid wlls s impct sufces. Tble 1: Test Mti Test Numbe Set Oienttion Configution Nominl G Pek ATD Restint A05044 Fowd No Contct 26 G FAA Hbid III 4-pt A05045 Fowd No Contct 26 G FAA Hbid III 4-pt A05046 Fowd No Contct 26 G FAA Hbid III 4-pt A05047 Fowd Toso Contct 16 G FAA Hbid III Lp A05048 Fowd Toso Contct 16 G FAA Hbid III Lp A05049 Fowd Set Bck 16 G FAA Hbid III Lp A05050 Fowd Set Bck 16 G FAA Hbid III Lp A05051 Fowd Set Bck 16 G FAA Hbid III Lp A05052 Fowd Set Bck 16 G FAA Hbid III Lp A05054 Fowd Wll 16 G FAA Hbid III Lp A05055 Fowd Wll 16 G FAA Hbid III Lp A05056 Fowd Wll 16 G FAA Hbid III Lp A05057 Fowd Wll + Ledge 16 G FAA Hbid III Lp A05058 Fowd Wll + Ledge 16 G FAA Hbid III Lp A05066 Side Cente 16 G ES-2 3-pt A05068 Side Cente 16 G ES-2 3-pt A05067 Side Cente 16 G ES-2 Infltble A05070 Side Cente 16 G ES-2 Infltble A05065 Side Close Wll 16 G ES-2 3-pt A05071 Side F Wll 16 G ES-2 3-pt A05072 Side F Wll 16 G ES-2 3-pt A05075 Side Amest 16 G ES-2 3-pt A05076 Side Amest 16 G ES-2 3-pt A05073 Side Amest 16 G ES-2 Infltble A05074 Side Amest 16 G ES-2 Infltble A06004 Side Amest 16 G FAA Hbid III 3-pt 2

8 Fowd-Fcing Set Configution Fouteen tests wee completed with fowd-fcing set nd n FAA Hbid III ATD. Tpicl seting configutions found in both tnspot nd genel vition wee chosen bsed on likelihood of hed nd/o neck inju. Thee configutions wee tested: inetil loding tht esulted in no contct o dumm-to-dumm contct, ow-to-ow which esulted in contct with setbck, nd simulted font ow set with wll impct. The inetil loding configutions with onl lp belt esulted in toso contct with the uppe leg nd hed contct with the lowe leg. Thiteen tests used igid lunch set nd no w to educe vibilit nd simplif nlsis of esults (Figue 1). The set bck ngle ws 13 degees to veticl nd hd no bck cushion. The set pn ws 5 degees fom hoiontl, with bottom cushion mde fom 1 inch of ve fim closed cell fom (IV3) coveed with cloth. Fowd sliding of the cushion ws minimied b positive stop t the font edge of the set pn. This cushion thickness nd stiffness ws chosen to mimie test epetbilit nd is not necessil epesenttive of n ctul icft set cushion. To ensue consistent initil position, hedest ws positioned to suppot the hed t the nominl (un-fleed) position. The hedest ws constucted of 4.25-inch thick block of polethlene fom. The ATD ws tied bck ginst the hedest with two stnds of 4 pound beking stength sting to pevent motion duing the sled cceletion phse (Figue 2). The ms wee plced few inches futhe bck thn wht is used fo tpicl cetifiction test in n ttempt to limit the obscution of the hed photometic tgets. The fouteenth test ws pt of n nnul tining clss tught t CAMI nd included el lunch set, 10 degees of w, nd floo mislignment unde the impcted set. Figue 1: Schemtic of Rigid Set (dimensions in inches) 3

9 Inetil Loding Test Configution Figue 2: Bekw Sting Instlltion Tests A05044 A05046: 4-point estined occupnt subjected to 14 CFR pilot set 26 G, 42 ft/s fowd deceletion [2]. The igid set ws configued to emulte the seting position nd belt ncho loction of tpicl Pt 23 pilot set (Figue 3). The ATD s feet wee plced on simulted udde pedls nd 4-point UH-1 (milit helicopte) hness with no ineti eel ws used. The lp belt potion ws 3 inches wide, nd the shoulde stps wee 1.75 inches wide nd meged into single stp behind the neck. The lp belt nchos wee 20 inches pt nd wee 0.1 inch ft nd 1.2 inches below the intesection of the set pn nd set bck plnes. The shoulde belt guide ws 10.3 inches ft nd 29.3 inches bove the pn/bck intesection. All slck ws emoved fom the lp belt, nd the shoulde belts wee djusted to povide 1 inch of slck (to emulte tpicl I-eel pout). Figue 3: 4-point Belt Test Setup 4

10 Tests A05047 nd A05048: Lp belt estined occupnt subjected to 14 CFR G, 44 ft/s fowd deceletion [1]. The igid set ws configued to emulte the seting position nd belt ncho loction of n econom clss pssenge set (Figue 4). The floo ws 15.6 inches below the pn/bck intesection. The belt nchos wee 16 inches pt nd locted 1.15 inches fowd nd 0.6 inch bove the pn/bck intesection. A new nlon icft pssenge lp belt ws used fo ech test. Fo test A05047, the ATD feet wee plced flt on the floo with the toes ginst veticl stop 30 inches fowd of the pn-bck intesection. This test ws to detemine the unesticted hed pth, fo use in the subsequent ow-to-ow tests. Fo test A05048, the sme set configution nd ATD position ws used, but the foot stop ws not. A tiple plce pssenge set ws plced well fowd of igid set, to detemine the kinemtics of the set bck fo use in the subsequent ow-to-ow tests. Figue 4: Lp Belt Test Setup Row-to-Row Test Configution Tests A05049 A05051: Lp belt estined occupnt subjected to 14 CFR G, 44 ft/s fowd deceletion impcting n econom-clss set bck (Figue 5). The sme igid set configution nd ATD position s in A05048 ws used. A new nlon icft pssenge lp belt ws used fo ech test. The tget set ws tiple plce pssenge set fme with full dessed set bck in the cente position. The set fme ws einfoced to withstnd multiple impcts without defomtion, nd it ws inspected fo dmge fte ech test. The bck hd povisions fo instlltion of video sceen just bove the t tble. In lieu of the ctul sceen, wooden suogte sceen of the sme sie nd shpe ws instlled. This set bck is designed to bsob hed impct eneg b sequentill sheing pi of bolts in the hinge mechnism. The eneg bsobing (EA) bolts wee tightened pe the mnufctue s specifictions. The gol of these tests ws to hve the hed stike the cente of the set bck, just bove the t tble. ATD hed pth nd setbck fleion dt detemined fom photometic nlsis of pevious tests wee used to select the stuck set bck foe/ft position tht would give the highest pobbilit 5

11 of chieving the impct gol. This esulted in the tget set bck hinge point locted 32.7 inches fowd of the igid set pn/bck intesection. The top of the t tble ws 25.8 inches fowd nd 20.4 inches bove the pn/bck intesection. Figue 5: Row-to-Row Test Setup Test 05052: Lp belt estined occupnt subjected to 14 CFR G, 44 ft/s fowd deceletion impcting n econom-clss set eneg bsobing set (Figue 6). The ATD ws seted in cente plce of pssenge tiple set wed 10 degees counte clockwise fom the icft centeline. A new nlon icft pssenge lp belt ws used fo ech test. The stuck set ws full occupied pssenge tiple set tht incopoted stoking e set legs intended to limit lods on the set tck duing fowd impct. The set bcks incopoted eneg bsobing hinge mechnisms simil to the set bcks stuck in the pevious tests. The sets wee instlled t pitch of 30 inches. The ATDs wee seted ccoding to stndd cetifiction testing methods, including the plcement of the ms [6]. 6

12 Figue 6: Row-to-Row Test with Yw Wll Test Configution Lp belt estined occupnt subjected to 14 CFR G, 44 ft/s fowd deceletion impcting wll (Figue 7). These five tests used the sme set nd ATD position s in the pevious igid set ow-to-ow tests. A new nlon icft pssenge lp belt ws used fo ech test. The wll consisted of 1-inch thick, 24-inch wide b 48-inch tll, fibeglss fced Nome honecomb coe pnel of the tpe used in tpicl icft inteio wlls. Wll pnel ws clmped coss the bottom 3 inches of the pnel, nd simpl suppoted b olles coss the top. The unsuppoted height of the pnel ws inches fom the top the bottom clmp edge to the middle of the fowd olle suppot. The bottom of the pnel ws inches bove the floo. The wll ws plced 35 inches fowd of the pn/bck intesection, which is common instlltion distnce. A septe floo stop pnel ws povided t the sme plne s the wll. This pnel mteil nd mounting configution ws intended to emulte the stiffness of seting clss divide pnel. 7

13 Figue 7: (L) Wll Test Setup, (R) Close-up of Rolle Suppot Tests A05054 A05056: These thee tests used the sme wll configution ecept fo the loction of the ft olle (Figue 7). In tests A05055 nd A05056, the olle ws ised 1 inch with espect to the fowd olle to incese the stiffness of the uppe end condition. Tests A05057 nd A05058: These two tests with the sme wll configution s A A igid sufce ws plced in the pth of the hed such tht fte the hed intection with the wll ws ove, the hed would stike the sufce (Figue 8). The gol of this test ws to evlute the effect of two successive hed impcts. Fo test A05057, the second stike sufce ws 4-inch wide, 0.25-inch thick steel ngle pdded with 2 inches of IV3 fom, pllel to the wll with the top inches fom the floo. The ft olle ws ised 4 inches with espect to the font olle to futhe incese the stiffness of the uppe end condition. Fo test A05058, the second stike sufce ws n 8-inch wide, 4-inch deep hoiontl sufce pdded with 2 inches of IV3 fom. Top sufce ws 18.5 inches fom the floo. The ft olle ws plced t the sme level s the font olle, minimiing the stiffness of the uppe pnel end condition. 8

14 Figue 8: Wll Test with Second Stike Sufce Side-Fcing Set Configution Eleven tests wee completed with side-fcing set s pt of poject to evlute the ES-2 side-impct dumm [7]. Thee configutions wee tested: cente position (non-contct), seted net to igid wll, nd seted net to n mest (Figue 9). All tests wee subjected to the 14 CFR G, 44 ft/s fowd deceletion. Ech configution included bod centeed 3- point set belt, si tests with conventionl belt nd five tests with n infltble toso estint. Some tests wee epeted to ssess dt sped. Ten tests used the ES-2 ATD nd the eleventh test used the FAA Hbid III. Figue 9: ES-2 Test Setups with Conventionl Restints 9

15 Test Device FAA Hbid III The FAA Hbid III diffes fom the stndd Hbid III used in utomotive testing becuse it hs been modified to bette emulte the moe upight postue of n occupnt in n iline set nd povide kinemtic nd veticl esponse equivlent to the Hbid II [8]. The modifiction consists of sevel Hbid II pts substituted into the stuctue including the lumb spine, bdominl inset, chest jcket, nd uppe leg bone. FAA egultions equie cetifiction tests be pefomed with the Hbid II o n equivlent nd the FAA Hbid III hs been deemed equivlent [9]. The FAA Hbid III ws selected becuse it is cpble of mesuing neck lods while the Hbid II cnnot. Euo SID 2 The ES-2 ATD is specill designed to evlute inju in test conditions with significnt ltel loding. This ATD is cited in FAA polic PS-ANM R1 fo side fcing sets nd 49 CFR fo use in utomotive side impct tests [10, 11]. The dumm ehibits good biofidelit when used to evlute tpicl vition set configutions [7]. While the polic nd egultion bove cite the 49 CFR Pt 572 subpt U [12], efeed to s the ES-2e, the esech cited heein ws conducted with n ES-2 build level E2.AI. The ES-2e hs set of ib etensions tht etend fom the ends of the ibs to the bck plte, filling gp tht hd eisted in the pevious vesion. These etensions impoved the consistenc of the intection with contoued set bck upholste common in utomobiles [13]. Since the bck upholste used in the FAA esech test sets ws not contoued, it is unlikel tht using the ES-2e in these tests would hve poduced diffeent esponse thn the oiginl ES-2. Instumenttion Electonic Instumenttion Both the FAA Hbid III nd ES-2 wee instumented with nine-cceleomete pckge (NAP) to llow fo the clcultion of ngul hed cceletion nd velocit. The mount nd computtionl lgoithm wee povided b TNO. The mount, shown in Figue 10, ws designed to educe esonnt esponses nd dnmic loction inccucies found in some othe NAP ngements. The ngul cceletion nd velocit wee deived using mesued diffeentil line cceletions nd the NAP geomet vi computtionl lgoithm implemented in Mtlb [See Appendi]. This mount weighed 0.46 pound (without cceleometes) vesus the 0.28 pound weight of the stndd cceleomete block tht it eplced. The ATDs wee lso instumented with uppe nd lowe 6-is neck lod cells. 10

16 Figue 10: NAP - Left: Isometic View, Right: Embedded Acceleometes Sevel dditionl chnnels wee ecoded but e not ll epoted in this ppe due to its focus on hed nd neck inju. Fo the fowd-fcing set, the FAA Hbid III ws instumented with chest nd pelvis X nd Z cceleometes, nd lumb lod cell mesuing F, F, nd M. The igid set incopoted lod cell unde the set pn tht mesued the foces nd moments eeted on the pn b the ATD (F, F, nd M). These foces wee te compensted using dt gtheed fom test with no ATD. The tensions on both sides of the lp belt wee mesued between the pelvis of the ATD nd the belt ncho with webbing tnsduces. Fo the side fcing set, the dditionl instumenttion nd mesuements e documented in the test epot [7]. All test dt wee gtheed nd filteed pe the equiements of SAE J211/1 [14]. The sign convention of the ecoded signls confomed to SAE J1733 [15]. The electonic dt wee ecoded fo 400 ms. Video Covege High-speed (1000 fmes pe second), high esolution ( piels) colo video ws cptued fom the side nd ovehed b Phntom cmes (Vision Resech, Stut, FL), imed pependicul to the sled tvel. Tgets wee plced t ke points on the ATD nd set to fcilitte motion nlsis. The position nd velocit of selected tgeted points wee deived fom the videos using pocedues compling with the equiements of SAE J211/2 [16]. Fo fowdfcing set tests, 250 ms of video ws ecoded, while 400 ms ws etined fo the side-fcing set tests. Inju Evlutions Fo ech test, viet of hed nd neck inju metics wee evluted. These metics include vition egulto (HIC), utomotive egulto (such s HIC15 nd N ij ), nd esech inju citei (such s BIC). These inju metics hve n ssocited isk of specific level of inju, tpicll bsed on the Abbevited Inju Scle (AIS). The AIS is n ntomicl-bsed coding sstem developed b the Assocition fo the Advncement of Automotive Medicine tht clssifies nd nks the seveit of specific injuies [17]. It epesents the thet to life ssocited with the inju the thn the compehensive ssessment of the seveit of the inju. An AIS vlue of two is denoted s modete, vlue of thee is denoted s seious, nd vlue of fou is denoted s sevee. 11

17 Hed Inju Citei (HIC) HIC is used to evlute hed inju isk nd hs n FAA egulto limit of Fo HIC36, vlue of 1000 coesponds to 23% isk of n AIS-3 o gete hed inju o 47% isk of n AIS-2 o gete hed inju [5]. HIC evolved fom the clinicll obseved pevlence of concomitnt concussions in skull fctue cses to elte cdve impcts to bin inju [18]. It ws obseved tht 80% of ll concussion cses lso hd line skull fctues nd theefoe, b limiting the isk of skull fctue, the isk of bin inju is lso limited [19]. Psd nd Met nled the vilble dt nd detemined the eltionship between HIC nd injuies to the skull nd bin. Bsed on thei methodolog, the bin inju eltionship esulted in isk cuve nel identicl to the skull fctue inju isk [20]. The oiginl biomechnicl skull fctue dt ws bsed on shot dution impcts whee no specimen epeienced HIC dution gete thn 13 ms [3]. Additionll, humn voluntee tests demonstted tht the pobbilit of inju in long dution events ws low [3]. Despite this evidence, the oiginl implementtion of HIC did not limit the dution nd NHTSA ws cutious in subsequentl limiting the dution to 36 ms. With the polifetion of ibgs, the dution ws lte limited to 15 ms to compenste fo the tendenc fo HIC to oveestimte the inju isk fo the long peiods of eltivel low cceletion poduced b ibg contcts. Fou vesions of the HIC clcultion e included in this epot: vition HIC, HIC15, HIC36, nd HIC Unlimited. All fou use the sme eqution (below). The vition HIC clcultion nd the HIC Unlimited both hve n unlimited dution, but the vition clcultion cited in 14 CFR diffes fom the utomotive vesion in tht the esultnt hed cceletion includes onl the dt fte hed contct. Bod-to-bod contct is ecluded fom the vition clcultion due to the undmped esonnt esponse tht cn occu when eltivel igid pts of the ATD stike ech othe, which m give n tificill high HIC vlue. HIC15 uses ll the dt, but the time dution is limited to 15 ms, while HIC36 limits the time dution to 36 ms. whee t 1 is the initil integtion time in seconds, t 2 is the finl integtion time in seconds, nd (t) is the totl cceletion fo the hed in units of gvit. The vlues of t 1 nd t 2 e selected such tht the HIC vlue is the mimum possible fo the time peiod being evluted. Skull Fctue Coelte (SFC) The Skull Fctue Coelte ws developed b NHTSA nd the Medicl College of Wisconsin solel to evlute skull fctue [21]. It ws found to coelte bette to fctue thn n of the stndd HIC fomultions. The SFC is defined s the vege cceletion duing the HIC 15 intevl, with n SFC vlue of 120 g coesponding to 15% pobbilit of skull fctue. Bin Inju Citei (BIC) The Bin Inju Citei is kinemtic inju citeion developed b NHTSA s coelte to subset of tumtic bin injuies (TBI) in which hed ottionl velocit is believed to be 12

18 pim inju mechnism [22]. Duing its development, BIC ws coelted to two phsicl pmetes, Cumultive Stin Dmge Mesue (CSDM) nd m pinciple stin (MPS). These pmetes e indictos of inju clculted b finite element models of the skull nd bin. Two independent models, the Simulted Inju Monito (SIMon) nd the Globl Humn Bod Modeling Consotium (GHBMC) hed model, wee used in the citei s development. BIC is clculted using onl the mesued ngul velocit in ech othogonl is. The citicl vlues fo ngul velocit e diectionll dependent nd e independent of the ATD used fo mesuing them. whee ω, ω, nd ω e mimum ngul velocities (clculted iespective of the time it hs occued) bout the X-, Y-, nd Z-es espectivel, nd ωc, ωc, nd ωc e the citicl ngul velocities in thei espective diections. The citicl vlues bsed on CSDM nd MPS e d/s, d/s, nd d/s fo the X-, Y-, nd Z-es, espectivel. A BIC vlue of 1.0 coesponds to 50% pobbilit of AIS 4 o gete ntomic bin injuies. Neck Inju Fowd-Fcing Set Configution To limit the potentil fo neck inju in fowd utomotive cshes, 49 CFR defines the citei fo neck tension nd compession, s well s citei tht combines the effect of the neck bending moment nd il foce, clled N ij. This is not cuentl pss/fil citeion in vition but limit of 1.0 is clled out fo utomotive testing [4]. An Nij vlue of 1.0 epesents 22% isk of AIS-3 o gete inju fo ll occupnt sies [3]. The N ij clcultion uses foce nd moment dt mesued with n uppe neck lod cell (pojected to the occipitl condle loction). The utomotive egultion lso limits compession to 899 pounds nd the tension limit is 937 pounds [4]. F is the foce t the tnsition fom the hed to neck, F ZC is the citicl foce (1530 pounds), M OC is the totl moment, M c is the citicl moment (1200 in-lb). Side-Fcing Set Configution Neck inju citei fo side-fcing sets e defined in FAA polic PS-ANM R1 [10]. The il neck tension limit is 405 pound, which epesents 25% isk of n AIS-3 o gete neck inju. The il compession limit is lso 405 pound, which should povide simil level of sfet s the tension limit fo this loding condition [23]. Ltel bending moment (M) is limited to 1018 in-lb (mesued t the occipitl condle loction of the ES-2e), which cn be consideed theshold below which neck inju is not epected. A limit on the neck she lod of 185 pound epesents 25% isk of n AIS-3 o gete neck inju. 13

19 RESULTS The inju metics discussed bove wee clculted using 400 ms of electonic dt, ecept fo the ngul velocities, nd coesponding BIC, which wee clculted bsed on the fist 250 ms. The time peiod ws limited due to some dift issues, which e discussed in the limittions section nd the ppendi. In the tbles, vlues in itlicied ed tet denote pmete tht eceeds the inju citei limit. Fowd-Fcing Set Configution Inetil Loding Test Configution The 4-point belt configution ws un thee times (A05044 A05046), showing consistent esults fo most of the epoted vlues (Tble 2). Duing loding, the ATD neck bent fowd until the chin stuck the stenum, then the hed ebounded ginst the hedest. With the eception of BIC, the hed nd neck inju pmetes poduced wee bout hlf the limits, with BIC being close to the limit. The combined shoulde stp tension lods eceeded the 2000 pound citei limit in ll tests. Since high shoulde stp lods coespond to highe toso cceletion, it is likel tht these tests poduced moe hed-neck loding thn would be found in cetified set hving belt lods within limits. The esults fo this test configution suggest tht even t the high G impct condition of Pt 23 pilot set test, the isk of hed-neck inju esulting fom onl inetil loding is not ecessive fo well-estined occupnt. The lp belt onl, inetil loding configution ws un twice, once with the legs blocked (A05047) nd once with the legs fee to flil (A05048). In this configution, the ATD fliled fowd until the toso of the ATD impcted the thighs. Afte the motion of the toso ws ested, the hed continued to tvel between the legs in n c downwd, nd eventull ewd. In test A05047, the flil estiction of the lowe legs kept the uppe legs in thei nominl position, which esulted in significnt contct between them nd the uppe toso. This contct cused the hed to whip between the legs without stiking nthing. In test A05048, the toso lso contcted the uppe thighs, but lte thn in the pevious test. As the hed ws pssing between the legs, which hd fliled to nel hoiontl, it contcted the left shin, cusing high hed cceletion spikes in the X nd Y diections nd significnt ngul velocit bout ll thee es (Tble 2). The vition HIC ws not clculted since the ATD did not stike sufce othe thn itself. The limits fo HIC15, HIC Unlimited, nd BIC wee eceeded in both tests, while HIC36 ws eceeded in one of the two tests. The neck inju citei nd the Skull Fctue Coelte (SFC) wee below limits fo both tests. 14

20 Tble 2: Inetil Loding Test Configution Test Pmete Citei Test Numbe Limit A05044 A05045 A05046 A05047 A05048 Test Configution No Contct No Contct No Contct Toso Contct Toso Contct Restint 4-pt 4-pt 4-pt Lp Lp Impct Vel (ft/s) Sled Acc (g) Avition HIC 1000 None None None None None Dution (ms) N\A N\A N\A N\A N\A HIC HIC15 Dution (ms) HIC HIC36 Dution (ms) HIC Unlimited HIC Unl. Dution (ms) SFC Angul Vel X (d/s) Angul Vel Y (d/s) Angul Vel Z (d/s) BIC Nij Neck Tension (lb) Neck Compession (lb) Combined Shoulde Stp Lod (lb) (R) 1187 (L) 1055 (R) 1349 (L) 1039 (R) 1283 (L) N\A N\A Row-to-Row Test Configution The ow-to-ow configution using the igid set ws un thee times to evlute inju isk nd epetbilit. Up to the point of hed contct with the set bck, the ATD ovell kinemtics nd ecusion wee ve simil. The set bck fleion ws lso simil until the ATD s hnds contcted the set bck. In ech cse, the set bck fleion pio to hed impct diffeed somewht, likel due to diffeences in how much the hnds pushed on the set bck. This phenomenon hs been documented in simil loding scenios [24]. The vible set bck fleion ffected when nd whee the hed stuck the set bck in ech test. Fo test A05049, the foehed contcted the suogte sceen 3 inches bove the t tble. Fo test A05050, the foehed contcted the t tble just below the top edge of the tble. Fo test A05051, the foehed contcted the sceen 6 inches bove the top of the t tble. The diffeences in hed stike loction esulted in fi mount of sctte in the esults (Tble 3). Avition HIC vied fom 774 to 1350, nge tht spns low isk to high isk of sevee hed inju. HIC15 lso spns wide nge, but ll thee tests eceeded tht inju citei limit. The HIC36 nd HIC Unlimited vlues wee genell equl to the vition HIC vlues. In test A05049, hed contct with the igid suogte sceen poduced high cceletion spike in ll 15

21 thee of the X-is cceleometes. It lso poduced high spike in one of the thee Y-is cceleometes, which e oiented pependicul to the diection of impct. In test A05051, the hed contct with the sceen lso poduced high cceletion spike in ll thee of the X-is cceleometes but did not poduce simil Y-is esponse. The HIC intevl fo this impct ws onl 1 ms with n vege cceletion of 238 g (Figue 11). Although the HIC fo this impct ws less thn 1000, the SFC ws nel double the limit, suggesting tht skull fctue is likel. In ll thee cses, fte the initil contct, the hed slid down the set bck s it folded fowd. In test A05050, the intection with the setbck inteupted the downwd sliding of the hed sufficientl to poduce tension nd etension moments high enough to esult in n N ij just ove the limit (Figue 12). As seen in the fme gb, miniml neck etension is evident. BIC ws lso high in ll thee tests but did not eceed the limit. Tble 3: Row-to-Row Test Configution Test Pmete Citei Test Numbe Limit A05049 A05050 A05051 A05052 Test Configution Set Bck Set Bck Set Bck Set Bck Restint Lp Lp Lp Lp Impct Vel (ft/s) Sled Acc (g) Avition HIC Dution (ms) HIC HIC15 Dution (ms) HIC HIC36 Dution (ms) HIC Unlimited HIC Unl. Dution (ms) SFC Angul Vel X (d/s) Angul Vel Y (d/s) Angul Vel Z (d/s) BIC Nij Neck Tension (lb) Neck Compession (lb)

22 Figue 11: Hed Resultnt (HIC dution 1 ms) Figue 12: A05050 Uppe Neck Moment bout Y-is nd Neck Etension t Pek M (171 ms) The ow-to-ow configution using the el sets, test A05052, esulted in ve diffeent intection between the ATD nd the set bck. The ineti foce geneted b the thee ATDs of the fowd set cused the set e legs to stoke (s designed), which moved the entie set fme fowd. This moved the set bck hinge point fowd, esulting in the hed impcting t much lowe point (t the bottom of the t tble) thn would hve occued with set tht ws not occupied, o with one hving nel igid fme. Convesel, if both sets wee full loded nd stoked the sme distnce, then the hed impct point m be close to wht is poduced b igid fme sets. Contcting t lowe point povides less levege to ctute the eneg bsobing hinge mechnism, which inceses the contct foce nd, theefoe, the hed cceletion. Afte contct, the hed slid down onto the litetue pocket nd ehibited significnt ottion nd neck fleion. This intection is eflected in the mesued HIC of 1439 nd BIC of The neck inju citei, howeve, wee not eceeded which is somewht supising given the mount of neck etension obseved (Figue 13). This etension ws obseved ove n etended dution (195 ms ms). 17

23 Figue 13: A05052 Uppe Neck Moment bout Y-is nd Visul Pek of Etension ( ms) Wll Test Configution The wll impct configution using the igid set ws un thee times to ssess inju isk nd evlute epetbilit (A05044 A05046). Up to the point of hed contct with the wll, the ATD ovell kinemtics nd ecusion wee ve simil. As in the ow-to-ow tests, the foce of the hnds on the wll cused it to deflect fowd to ving degees, ffecting the test esults. These tests esulted in high vlues of HIC nd BIC, which genell eceed the defined limits (Tble 4). This loding lso esulted in high X-is hed cceletion esponse nd high Y-is esponse. The vlidit of tht high Y-is cceletion is suspect becuse thee is nothing in the video to coobote the high Y cceletions ecoded, unlike test A05048 whee high Y-is cceletion coincided with ltel movement of the hed due to contct with the leg. The mostl sliding contct with the wll in ech cse esulted in neck inju pmetes below the limits. Two second stike configutions wee un (A05057 nd A05058). Duing test A05057, the suppot ngles fo the second stike sufce intefeed with the noml m kinemtics of the ATD cusing the hed to miss the second stike tget. This esulted in simil kinemtics to the thee pevious wll impct tests; howeve, the ecoded X nd Z-is cceletion coinciding with wll contct ws much highe thn the pevious tests. Fo test A05058, the stike sufce ws modified to pevent this intefeence. Duing ll of the wll impct tests, the hed etined significnt velocit fte intection with the wll. In test A05058, this cused ve high hed cceletion spike of significnt dution when the hed stuck the stiff second sufce. This test esulted in eteme vlues fo HIC due to the solid hed stike on the ledge. Due to ve high (likel esonnt) esponse cused b the wll contct nd the second impct, the hed cceletion dt ws of such poo qulit tht no ngul velocit vlues wee clculted fo eithe of the second stike tests. 18

24 Tble 4: Wll Test Configution (Fowd-Fcing) Test Pmete Citei Test Numbe Limit A05054 A05055 A05056 A05057 A05058 Test Configution Wll Wll Wll Wll + Ledge Wll + Ledge Restint Lp Lp Lp Lp Lp Impct Vel (ft/s) Sled Acc (g) Avition HIC Dution (ms) HIC HIC15 Dution (ms) HIC HIC36 Dution (ms) HIC Unlimited HIC Unl. Dution (ms) SFC Angul Vel X (d/s) N\A N\A Angul Vel Y (d/s) N\A N\A Angul Vel Z (d/s) N\A N\A BIC N\A N\A Nij Neck Tension (lb) Neck Compession (lb) Side-Fcing Set Configution Cente Test Configution Fo the cente set configution, the ES-2 is in the middle set of tiple plce couch/sof (A05066 A05068 nd A05070). With the conventionl toso estint, the ATD ottes sufficientl fo the hed to contct the setbck though 4-inch cushion. This esulted in vlues of HIC, BIC, neck tension, nd neck she bove the espective limits (Tble 5). The dt fom these two tests (A05066 nd A05068) show consistent esults. The inclusion of n infltble toso estint pevents the ATD fom impcting the set, nd theefoe educed ll the mesued inju pmetes, lthough BIC is close to the limit (0.90 nd 0.88). 19

25 Tble 5: Cente Test Configution Test Pmete Citei Test Numbe Limit A05066 A05068 A05067 A05070 Test Configution Cente Cente Cente Cente Restint Conventionl Conventionl Infltble Infltble ATD ES-2 ES-2 ES-2 ES-2 Impct Vel (ft/s) Sled Acc (g) Avition HIC None None Avition HIC Dution (ms) N\A N\A HIC HIC15 Dution (ms) HIC HIC36 Dution (ms) HIC Unlimited HIC Unl. Dution (ms) SFC Angul Vel X (d/s) Angul Vel Y (d/s) Angul Vel Z (d/s) BIC Neck Tension (lb) Neck Compession (lb) Neck Bending M (in-lb) Neck She F (lb) Wll Test Configution In the close wll configution, A05056, the ES-2 ATD is seted 3 inches fom igid, pdded wll while weing conventionl 3-pt estint. Duing the test, the ATD emined completel upight nd ll the inju pmetes e fil low (Tble 6). The f wll configution ws identicl, ecept the ATD is 6 inches fom the wll (A05071 nd A05072). This llowed fo the hed to ccelete pio to contcting the wll, esulting in high HIC nd SFC vlues, lthough BIC ws low. The ATD did st upight, which kept the othe inju pmetes low. The inclusion of n infltble estint, A05072, did not pevent hed contct with the wll, but did slow the ATD down enough to getl educe the HIC scoes (145 vs. 2014). 20

26 Tble 6: Wll Test Configution (Side-Fcing) Test Pmete Citei Test Numbe Limit A05065 A05071 A05072 Test Configution Close Wll F Wll F Wll Restint Conventionl Conventionl Infltble ATD ES-2 ES-2 ES-2 Impct Vel (ft/s) Sled Acc (g) Avition HIC Avition HIC Dution (ms) HIC HIC15 Dution (ms) HIC HIC36 Dution (ms) HIC Unlimited HIC Unl. Dution (ms) SFC Angul Vel X (d/s) Angul Vel Y (d/s) Angul Vel Z (d/s) BIC Neck Tension (lb) Neck Compession (lb) Neck Bending M (in-lb) Neck She F (lb) Amest Test Configution The mest condition esulted in eteme flil, but essentill no hed contct (onl contct ws with shoulde). This is function of lck of suounding stuctue moe thn n othe cicumstnce. In the two tests with conventionl estint sstem, A05075 nd A05076, the utomotive HIC vlues suggest tht inju could occu (Tble 7). Likewise, BIC nd the neck pmetes suggest sevee inju. The FAA Hbid III ws lso tested in this configution (A06004). While the ATD toso hd simil kinemtics to the ES-2, the Hbid-III s neck is much stiffe nd less biofidelic in ltel bending, which esulted in educed hed kinetics. Theefoe, the FAA Hbid III HIC, BIC, nd neck lods e povided fo efeence onl. The defined neck citei limits e not pplicble to tht ATD, nd the lck of ltel bending biofidelit educes the confidence tht the HIC nd BIC esults mesued using this ATD eflect the ctul inju isk fo this occupnt loding condition. 21

27 Tble 7: Amest Test Configution Test Pmete Citei Test Numbe Limit A05075 A05076 A05073 A05074 A06004** Test Configution Amest Amest Amest Amest Amest Restint Cnv* Cnv* Infltble Infltble Cnv* ATD ES-2 ES-2 ES-2 ES-2 FAA HIII Impct Vel (ft/s) Sled Acc (g) Avition HIC 1000 None None None None None Avition HIC Dution N\A N\A N\A N\A N\A HIC HIC15 Dution (ms) HIC HIC36 Dution (ms) HIC Unlimited HIC Unl. Dution (ms) SFC Angul Vel X (d/s) Angul Vel Y (d/s) Angul Vel Z (d/s) BIC Neck Tension (lb) Neck Compession (lb) Neck Bending M (in-lb) Neck She F (lb) * Conventionl estint sstem ** HIII esponse povided fo efeence onl The infltble estint tests, A05073 nd A05074, did not esult in hed contct. The vious hed nd neck inju pmetes e ll well below the citei limits. Simil to the ow-to-ow emple (A05052), neck bending tht m ppe injuious does not lws esult in high lods (Figue 14). Figue 14: A05074 M Hed Ecusion (t=158 ms) 22

28 DISCUSSION Neck Inju Neck inju ws not significnt isk in most of the fowd fcing set configutions tested. The N ij eceeded the Fedel Moto Vehicle Sfet Stndds limit in onl one cse: ow-toow test whee the point of hed contct ws the t tble (A05050). In this cse the intection ws significnt enough to eceed ll of the HIC limits nd nel eceed the BIC limit. Pek tension nd compession vlues wee not eceeded in n of the tpicl loding scenios. The compession limit ws onl eceeded in the cse whee the ATD hit second ledge nd geneted HIC of These tests suggest tht s long s the hed is potected, the neck will be s well. Howeve, subsequent testing hs demonstted tht this is not tue if the ATD chin ctches on t tble o othe set fetue duing the occupnt s fowd flil [24]. Neck inju ws significnt isk in some of the side fcing configutions tested. The neck nd she foce limits defined in FAA polic PS-ANM R1 wee eceeded in mn of the set configutions. Essentill, n of the configutions tht did not povide suppot to the hed nd neck b mens of pdded wll o infltble estint geneted ecessive neck foces. Hed Inju Hed inju isk ws significnt in mn of the configutions, even though the sets incopoted fetues to educe the isk of hed inju. Some of the fctos contibuting to incesed hed inju isk wee: Lp belt estined occupnts inetil loding: Ecessive hed ottionl velocit s the hed whips downwd fte the chest impcts the uppe legs. Contct with lowe leg s the hed tvels between the etended legs. Row-to-ow impcts: Inconsistent pefomnce of eneg bsobing set bck due to intection with the ATD s ms. Ving impct point on set bck due to stoking of the tget set legs. Wll impcts: Insufficient eneg bsobed b the wll contct pemitted simil inju esponse s in the lp belt estined inetil loding cse. Intection with the ATD s ms contibuted to inconsistent hed intection with the wll. Side-fcing sets: Lck of uppe bod suppot esulted in contct with suounding sufces o ecessive hed ottion. Bin Inju In the ppe detiling BIC, the uthos obseved tht BIC is ottionl inju citeion, while HIC is tnsltionl inju citeion (clculted using tnsltionl cceletions onl), nd combining the two m bette cptue hed injuies. Howeve, humn hed is el epeiencing just ottionl o just tnsltionl motion. It usull is epeiencing both [22]. Using these citei to independentl ssess the two tpes of inju isk (skull fctue nd tumtic bin inju) m be big step fowd in pedicting hed inju; howeve, the m not cptue ll possible injuies, pticull if the inju is esult of combined loding condition. 23

29 To evlute the utilit of the two ssessments, pss o fil ws consideed fo ech test bsed on n vition HIC limit of 1000 nd BIC limit of 1.0 (Figue 15). In nine cses, the tests eithe pss both o fil both. In onl one test ws the vition HIC below the limit of 1000 while BIC ws ove the 1.0 limit. This ws wll impct (A05054), which hd n vition HIC of 974, BIC of 1.44, nd vlues of HIC15, HIC Unlimited, nd SFC bove the espective limits. This test ws un two moe times nd vition HIC nd BIC wee eceeded in ech. Bsed on this limited smple, BIC does not ppe to cptue isk of inju beond tht of the cuent egulto citei fo these configutions. Figue 15: Avition HIC vs. BIC The dded sfet benefit of the BIC clcultion m lie in the scenios whee vition HIC is not clculted. In the five fowd fcing set tests with no contct besides dumm-to-dumm, BIC ws eceeded in the two lp belt onl tests nd ws 0.85 o gete in the thee tests with 4-pt estint. Fo the side-fcing sets, the two tests in cente set plce with n infltble estint hd BIC ne the limit (0.88 o gete), while ll the othe inju citei wee low. Fo the side-fcing mest tests with conventionl belt, BIC ws well bove the limit, s wee the othe vesions of HIC nd the neck inju citei. This smple suggests tht vition HIC m miss some potentill injuious configutions, lthough this cn be ptill offset b the neck inju citei fo side-fcing sets. Consideing tht the deivtion of HIC ws pimil bsed on shot dution impcts (between 3 ms nd 12 ms) nd tht NHTSA hs dopted HIC15, vition HIC ws comped to HIC15 to see the impct of using HIC15 to detemine whethe test pssed o filed (Figue 16). In this evlution, two tests hd n vition HIC ove 1000 while HIC15 ws unde 700. Both of 24

30 these tests wee the wll impct configution. Inteestingl, this is the opposite esult of the othe test in this configution (A05054) which hd vition HIC below 1000, but HIC15 bove 700 (s discussed bove). In thee tests, HIC15 is bove 700 while vition HIC is below 1000, including two ow-to-ow setbck tests whee ll fou vesions of HIC poduced the sme esult (A05049 nd A05051), nd one of the wll impct tests (A05054). Not included in this compison e the twelve tests whee vition HIC is not clculted, of which thee fil HIC15. Bsed on this limited smple, it ppes tht switch fom vition HIC to HIC15 would esult in shift in the configutions tht meet the ule. Futhe esech is needed to undestnd the impct of this shift nd detemine if thee is sfet benefit to dopting diffeent HIC fomultion. Figue 16: Avition HIC vs. HIC15 LIMITATIONS As n eploto stud, the numbe of impct scenios investigted ws limited. The set configutions selected wee those tht wee commonl found in genel vition nd tnspot icft t the time of the stud. Howeve, thee m be configutions tht cn poduce impcts with diffeent inju isks. Specificll, ving pmetes such s set bck stiffness nd owto-ow spcing cn ffect both the hed nd neck injuies poduced. Intection with some ibg configutions m lso poduce injuies nd wnt futhe stud. The scope of this epot ws limited to evluting onl hed-neck injuies; othe inju citei m hve been eceeded in some tests even if the hed nd neck inju citei wee within limits. The nine-cceleomete pckge (NAP) uses diffeences between line cceleometes s detiled in the Appendi. The w ottionl velocities deived duing this poject hve cumultive eo (dift) coss thei time histo. The souce of this dift is the 12-bit esolution nlog-to-digitl convesion (A/D) dt cquisition sstem used in this stud. While methods wee emploed to significntl impove the ccuc b empiicll compensting fo the dift, 25

31 s detiled in the Appendi, the ngul velocities epoted, nd BIC vlues bsed on them, should be consideed estimtes onl. An futhe studies evluting bin inju should be conducted using newe nd moe ccute technolog such s ngul te sensos, o NAP connected to 16-bit o gete A/D dt cquisition sstem. Some of the hed contcts involving impcts onto locll igid sufces esulted in ve high, shot dution cceletion spikes, including ones egisteed b cceleometes tht wee oiented 90 degees to the impct diection. In poduct development tests, this tpe of esponse is often obseved duing impcts with set bck mounted video monitos. The mechnism poducing these dt spikes hs ecentl been ttibuted to the esonnt esponse of undmped cceleometes, which cn esonte duing impcts onto igid stuctues [14]. Even when whole bod cceletion is epected to be below 500 g, the esonnce cn poduce mplitudes much gete thn 500 g. When the dt cquisition sstem is set to nge of 500 g fo given tnsduce, esonnce cn cuse sevee dt distotion. Infomtion on this phenomenon ws included in the 2014 vesion of SAE J211, long with discussion of dmped vs. undmped cceleometes [14]. In this test seies, 2000 g cceleometes wee used in the hed, but the wee set to the tpicl 500 g nge, so esonnt esponse could ccount fo the high mgnitude, shot dution esponses mesued duing igid impcts. Cuentl, thee is no definitive nswe s to whethe ve shot dution impcts hve sufficient eneg content to poduce inju. Howeve, when Psd nd Met nled vilble test dt to detemine the eltionship between HIC nd injuies to the skull nd bin, the HIC dutions nged fom 0.9 to 10.1 msec [20]. Fom thei nlsis we cn infe tht HIC dutions of t lest 1 ms long wee consideed biomechnicll vlid. Futhe esech is needed to bette undestnd the ccuc of the mesued cceletions nd the inju isks posed b these tpes of contcts. CONCLUSION A seies of 26 tests coss 6 tpicl icft set nd inteio configutions duing icft fowd impct conditions wee conducted to ssess the potentil of hed nd neck inju. These tests used specilied instumenttion to evlute nge of metics tht include both egulto nd non-egulto (esech) inju citei. Neck inju ws not significnt isk in most of the fowd-fcing set configutions tested. This included cses whee the neck bending visull ppes injuious, but did not esult in high mesued lods. Fo the side-fcing set configutions, neck inju ws significnt isk, pticull fo seting sstems tht did not povide effective uppe bod suppot. The 2012 FAA polic fo side-fcing sets ws implemented, in pt, to ddess this isk. Fo hed inju, thee ws significnt ovelp between the vition HIC nd BIC pss/fil detemintions, suggesting tht BIC does not cptue isk of inju beond tht of the cuent egulto citei fo configutions whee the hed stikes setbck o monument. Howeve, BIC did suggest the potentil fo inju in sevel tests whee the ATD did not contct nthing othe thn itself. When comping vition HIC to HIC15, mn tests poduced diffeent pss/fil detemintion depending on which citei ws used. Pio to consideing n compehensive chnge in FAA polic, futhe esech is needed to undestnd the impct of this shift nd detemine if thee is sfet benefit to dopting diffeent HIC fomultion. Ovell, these esults indicte tht combining HIC nd BIC to evlute seting sstems could povide sfet benefit b diectl evluting the isk of skull fctue nd tumtic bin inju. 26

32 REFERENCES 1. US Code of Fedel Regultions, Title 14, Pt Aiwothiness Stndds: Tnspot Ctego Aiplnes, Emegenc Lnding Conditions. Wshington, DC: US Govenment Pinting Office, US Code of Fedel Regultions, Title 14, Pt Aiwothiness Stndds: Tnspot Ctego Aiplnes, Emegenc Lnding Conditions. Wshington, DC: US Govenment Pinting Office, Eppinge R, Sun E, Bndk F, Hffne M, Khewpong N, Mltese M, Kupp S, Nguen T, Tkhounts E, Tnnous R, Zhng A, Sul R. Development of Impoved Inju Citei fo the Assessment of Advnced Automotive Restint Sstems II. Wshington, DC: US Govenment Pinting Office, US Code of Fedel Regultions, Title 49, Pt Occupnt Csh Potection. Wshington, DC: US Govenment Pinting Office, Kupp S. Inju Citei fo Side Impct Dummies, Wshington, DC: DOT/Ntionl Highw Tffic Sfet Administtion; M FMVSS-214 NPRM docket: NHTSA SAE Intentionl. Aeospce Stndd 8049B. Pefomnce stndd fo sets in civil otocft, tnspot icft, nd genel vition icft. Wendle, PA: SAE Intentionl, DeWeese R, Moocoft D, Geen T, Philippens M.M.G.M. Assessment of Inju Potentil in Aicft Side-Fcing Sets Using the ES-2 Anthopomophic Test Dumm. Wshington DC: Fedel Avition Administtion M 2007; Repot No. DOT/FAA/AM-07/ Gowd V, DeWeese R, Beebe M, Wde B, Duncn J, Kell R, Blke J. A Lumb Spine Modifiction to the Hbid III ATD fo Aicft Set Tests. Wendle, PA: SAE Intentionl, Fedel Avition Administtion Polic AIR Use of Hbid III Anthopomophic Test Dumm in Set Dnmic Testing. Wshington, DC: Fedel Avition Administtion, Fedel Avition Administtion Polic ANM R1 - Technicl Citei fo Appoving Side-Fcing Sets. Wshington, DC: Fedel Avition Administtion, US Code of Fedel Regultions, Title 49, Pt Side Impct Potection. Wshington, DC: US Govenment Pinting Office, U.S. Code of Fedel Regultions, Title 49, Pt 572. Wshington, DC: U.S. GPO, Anthopomophic Test Devices Dumm 50th Pecentile Adult Mle nd SID IIs Side Impct Csh Test Dumm 5th Pecentile Adult Femle; Finl Rules; Fedel Registe / Vol 71, No. 240 pge 75304, Dec 14, Kupp S, Eppinge R, McKo F, Nguen T, Pint F, Yognndn N. Development of Side Impct Thocic Inju Citei nd thei Appliction to the Modified ES-2 Dumm with Rib Etensions (ES-2e), Stpp C Csh Jounl, Stpp Assocition, pp , Vol

33 14. SAE Intentionl. Instumenttion fo Impct Test Pt 1- Electonic Instumenttion. Wendle, PA: SAE Intentionl; 2014; Sufce Vehicle Recommended Pctice No: J211/ SAE Intentionl. Sign Convention fo Vehicle Csh Testing. Wendle, PA: SAE Intentionl; Dec. 1994; SAE Sufce Vehicle Infomtion Repot No: J SAE Intentionl. Instumenttion fo Impct Test Pt 2- Photogphic Instumenttion. Wendle, PA: SAE Intentionl; 2014; SAE Sufce Vehicle Recommended Pctice No: J211/ The Abbevited Inju Scle Updte 2008, Bington, Illinois, Assocition fo the Advncement of Automotive Medicine, Gudjin ES, Webste JE, nd Lissne HR. Obsevtions on the Mechnism of Bin Concussion, Contusion, nd Lcetion. Sug., Gnec., & Obstet. 101: , Melvin JW, Lighthll JW, nd Ueno K. Bin Inju Biomechnics, in Accidentl Inju: Biomechnics nd Pevention, Nhum nd Melvin, Editos. 1993, Spinge-Velg: New Yok. p , Psd P nd Met H. The Position of the United Sttes Delegtion to the ISO Woking Goup 6 on the Use of HIC in the Automotive Envionment. SAE Govenment/Indust Meeting nd Eposition, SAE ppe no , Vnde Vost M, Stuhmille J, Ho K, Yognndn N, nd Pint F. Sttisticll nd Biomechnicll Bsed Citeion fo Impct-Induced Skull Fctue. Annul Poceedings of the Assocition fo the Advncement of Automotive Medicine. 2003; 47: Tkhounts E,Cig M, Moohouse K, McFdden J, nd Hsij V. Development of bin inju citei (BIC). Stpp C Csh Jounl. 57, DeWeese R, Moocoft D, Abmowit A, Pellettiee J. Civil Aicft Side-Fcing Set Resech Summ. Wshington DC: Fedel Avition Administtion Nov. 2012; Repot No. DOT/FAA/AM-12/ Tlo AM, DeWeese RD, Moocoft DM. Effect of Pssenge Position on Csh Inju Risk in Tnspot-Ctego Aicft. Wshington DC: Fedel Avition Administtion Sept. 2015; Repot No. DOT/FAA/AM-15/ Pdgonk A, Kiege K, King A. Mesuement of ngul cceletion of igid bod using line cceleometes. Jounl of Applied Mechnics, pp

34 APPENDIX Angul Velocit Deivtion To evlute bin inju, ngul dt fom the hed CG is needed. Angul velocit dt is cquied in one of two methods: diect mesuement with ngul te sensos o deived fom set of 9 line cceletions. At the time of this test seies, ngul te sensos wee not edil vilble. To genete the necess dt, 9-cceleomete pckge (NAP) ws used. The 9 line cceletions wee then pocessed to genete ngul cceletions nd integted to poduce ngul velocit (line velocit ws lso clculted). A custom Mtlb scipt ws witten b M. Philippens, TNO, to pocess the dt. Filteed dt (CFC 1000) ws used fo ll inputs into the equtions. NAP Clcultions Rigid bod dnmics pinciples e used to convet line cceletions fom nine cceleometes plced in configution to ngul motion of igid bod. Fo igid bod, the 3D motion of point B mesued b n obseve locted t point A (Figue A1) is the sme s the motion of tht bod bout fied point. Instntneous is of ottion Z ω v /A A B B A O A Y X Figue A1: Rigid Bod Motion The bsolute cceletion of point B is: B = A + B/A + ω (ω B/A ) A-1

35 A-2 In component fom, this becomes: ( ) ( ) ( ) ( ) ( ) ( ) = A A A B B B ω ω ω ω ω ω ω ω ω ω ω ω ω ω ω The nine cceleomete pckge plced in configution is shown in Figue A2 whee is denoted s 1, is denoted 2, nd is denoted s 3. Figue A2: Nine Acceleomete A Configution Knowing the m lengths nd solving fo ngul cceletion, ields: = = = X, Z, Y,

36 Whee = inches, 1 = inches, 2 = inches nd = inches. In theo, onl single vlue is necess, howeve in the phsicl NAP used in this stud, the moment ms wee diffeent. These equtions e given in Pdgonk et l. nd cuentl seve s the bsis fo deivtion of ngul motion of igid bod fom set of nine line cceletions [24]. Since these line cceletions e function of time, the ngul velocities of the igid bod could be obtined b simpl integting with espect to time: NAP Coections Smll eos in the diffeence outines in the NAP lgoithm cn multipl the eos cusing signl dift. At the time of dt collection, the DAQ sstem used b CAMI ws n olde 12 bit Anlog to Digitl (A/D) convete (DTS TDAS 2, Sel Bech, CA). A 12 bit sstem hs 4096 steps (2 12 ), which is much lowe esolution thn cuent 16 bit A/D convetes, which hve 65,536 steps (2 16 ). This esults in eltivel high noise floo nd noticeble dift in ngul velocit clcultions (Figue A4). These eos wee compensted b setting bound conditions nd comping esults with photometic nlsis esults. Test video ws obseved to detemine time when the ATD hed hd eo ngul velocit. A outine in Mtlb (inte2.m) ws used to clculte the integl of the ngul cceletion while ppling the bound condition (i.e. ngul velocit equl eo t time t). Fo the tests epoted heein, the time selected ws eithe 45 ms fo fowd-fcing tests o 90 ms fo side-fcing tests. The bound condition ws defined fo ll thee diections. The outine outputs the coected ngul velocit nd the offset pplied to the ngul cceletion. This offset ws then dded to the oiginl ngul cceletion. Emple 1: Test A05044 (fowd fcing, 4-point belt) As seen in the video of the test (Figue A3), the ATD hed ottes fowd stting t bout 50 ms. Theefoe, 45 ms ws selected s n ppopite bound condition time. At ppoimtel 127 ms the fowd ottion of the hed stops nd eveses s the toso momentum is hlted b the shoulde stps. The hed ebounds bck until ppoimtel 220 ms when the hed mkes contct with the hed est. The hed then ottes fowd befoe coming to finl est t time gete thn 350 ms (the sved video ws limited to 250 ms). Figue A4 shows the clculted ngul velocit with no bound conditions pplied. The dift of the signl is cle s the finl -is ngul velocit of the hed is epoted to be ppoimtel 20 d/s. A-3

37 Figue A3: Test A05044 t 0 ms, 45 ms, 127 ms, nd 220 ms Figue A4: Rw Angul Velocit bout Y-is with Dift Figue A5 shows the coected hed ngul velocit bout the -is. In geement with the video, the dt cosses eo t ppoimtel 127 ms nd 220 ms. The figue lso shows the clculted ngul velocit fom photometics, which hs clculted ccuc of 0.05 inch pe SAE J Thee is good geement (5% eo pe the Spgue nd Gees Compehensive eo) between the two cuves suggesting tht the velocit coection ws ccute. A-4

38 Figue A5: Coected NAP dt vs Photometic Emple 2: Test A05046 (Fowd fcing, 4-point belt) Afte coection, some tests still demonstted signl dift. Most noticeble is the -is ngul velocit fo test A05046 (Figue A6). All thee es hve eo ngul velocit though 50 ms nd the X nd Y es e close to eo t 400 ms. Convesel, the -is hs nel 30 d/s of finl ngul velocit. The coesponding video does not show n twist of the hed, though 250 ms, to coobote the dt (Figue A7). Consideing tht the slope of the -is ngul velocit is essentill constnt fom 75 ms to 400 ms, this is consideed dift. Some othe tests demonstted simil esponse, leding the uthos to limit the ngul velocit clcultions to 250 ms, which coesponds to the length of the sved videos. A-5

39 Figue A6: Hed Angul Velocit fo A05046 Figue A7: Test A05046 t 250 ms A-6