1、raising standards worldwide NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BSI Standards Publication PD CEN/TR 16148:2011 Head and neck impact, burn and noise injury criteria A Guide for CEN helmet standards committeesPD CEN/TR 16148:2011 PUBLISHED DOCUMENT National foreword
2、This Published Document is the UK implementation of CEN/TR 16148:2011. The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e P H / 6 , H e a d p r o t e c t i o n . A list of organizations represented on this committee can be obtained on request to its secretar
3、y. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 71865 6 ICS 13.340.20 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was p
4、ublished under the authority of the Standards Policy and Strategy Committee on 30 June 2011. Amendments issued since publication Date T e x t a f f e c t e dPD CEN/TR 16148:2011TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 16148 March 2011 ICS 13.340.20 English Version Head and neck
5、impact, burn and noise injury criteria - A Guide for CEN helmet standards committees Critres relatifs au traumatisme cervico-facial et aux lsions dues aux brlures et au bruit - Guide destin aux comits des normes sur les casques de protection du CEN Kriterien fr Verletzungen durch Einwirkung auf Kopf
6、 und Hals, Verbrennungen und Lrmverletzungen - Leitfaden fr Arbeitsgruppen, die europische Helmnormen erarbeiten This Technical Report was approved by CEN on 27 December 2010. It has been drawn up by the Technical Committee CEN/TC 158. CEN members are the national standards bodies of Austria, Belgiu
7、m, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMIT
8、TEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 16148:2011: EPD CEN/TR 16148:2011 C
9、EN/TR 16148:2011 (E) 2 Contents Page Foreword 3 Introduction .4 1 Abbreviated injury scale, AIS .5 2 Peak linear acceleration (A.3.1 & A.4) .9 3 Head injury criterion HIC (A.4) 9 4 Rotational motion (A.2.6, A.3.2 & A.4.3) . 10 4.1 Peak Rotational Acceleration 10 4.2 Tangential force at the helmet su
10、rface . 10 5 Skull crushing and penetration force (A.2.2 & A.3.3) 11 5.1 Crushing force 11 5.2 Penetration force 11 6 Neck injury . 11 7 Noise (Appendix section A5.0) 12 8 Heat: burns and fatigue (A.6) . 12 8.1 Burns 12 8.2 Heat fatigue . 13 9 References . 14 Annex A Biomechanics of head injury from
11、 impact, noise and heat . 15 A.1 General . 15 A.2 Head injuries . 16 A.3 Head injury mechanisms . 24 A.4 Head injury criteria . 29 A.5 Noise 31 A.6 Heat: burns and fatigue 35 A.7 Conclusions 41 Bibliography . 42 PD CEN/TR 16148:2011 CEN/TR 16148:2011 (E) 3 Foreword This document (CEN/TR 16148:2011)
12、has been prepared by Technical Committee CEN/TC 158 “Head protection”, the secretariat of which is held by BSI. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any o
13、r all such patent rights. PD CEN/TR 16148:2011 CEN/TR 16148:2011 (E) 4 Introduction Members of helmet Standards committees frequently need to define limits for test procedures. Such limits relate to test values that indicate the potential for injury and yet it is often difficult for members to know
14、the type and severity of injury that is represented by a given test value. Over the years, criteria have been developed for different body regions and usually these have been derived from a combination of accident and casualty data, and tests on cadavers, cadaver body parts, animals and human volunt
15、eers. However, such criteria are often used by the automotive industry as pass/fail values without a clear understanding of human tolerance to injurious forces. This sometimes leads to the mistaken belief that any value below the stated limit implies uninjured and all values above imply a serious or
16、 fatal injury. This misconception gives very little freedom to choose values that are different from the often inappropriate automotive value. This is particularly true for head injury criteria for which values for a helmeted head may be different to those for the unhelmeted head. Many accidents to
17、wearers of helmets, which cover a wide range of activities from horse riding to downhill skiing, result in a closed head injury. This is when the brain is damaged without any skull or external tissue damage. Conversely, head injuries in automotive accidents are much more frequently open head injurie
18、s with skull fracture and soft tissue lesions. Other misconceptions arise because of the failure to understand that human response to a given dose or injurious parameter varies across a range of the population. The dose response curve tends to be “S“ (sigmoid) shaped such that as the magnitude of th
19、e injurious parameter increases so does the percent of the population that sustains an injury of a given severity. Thus, a family of “S“ curves can be generated for a range of injury severity such as AIS and a measurement or criterion such as HIC, the Head Injury Criterion. Unfortunately, the data f
20、or such an analysis is generally difficult to obtain because measurements generated by test apparatus do not relate directly to injury severity because a headform for example does not respond in an impact like a human head. Hence, it is necessary to find a relationship between these test measurement
21、s and injury severity. This paper is designed to provide information to convenors that will help in choosing test limits in relation to a particular injury type and severity. It is worth noting that accident investigators use a scale known as the Abbreviated Injury Scale, AIS (AAAM). This was develo
22、ped (in the USA) so that injury severity could be recorded in databases regardless of the body region and type of injury thus avoiding lengthy medical terms that were unfamiliar and difficult to interpret. This paper begins by reviewing the AIS scale and its application to head and neck injuries and
23、 burn injuries. Thereafter, each measurement type is reviewed and the severity of injury for given values is identified where possible. A section on burn injuries and fatigue related to heat exposure has been included to assist with Standards for equipment to protect firefighters. The Appendix descr
24、ibes the skin structure and the category and consequence of burn injuries. Premature deafness because of high noise levels and the converse problem of over attenuation of auditory warnings was also considered. Suggested levels have been included with details of test methods in Annex A. PD CEN/TR 161
25、48:2011 CEN/TR 16148:2011 (E) 5 1 Abbreviated injury scale, AIS This is a scale that extends from 0 to 6 where 0 is uninjured and 6 is unsurviveable. Each level can be applied to any body region according to a coding manual developed by the Association for the Advancement of Automotive Medicine (AAA
26、M). Tables 1 and 2 give the scale and injury severity and an indication of the head and neck injuries that would be classified at each level. Table 3 gives similar information for burn injuries by degree, surface area and region of the body. PD CEN/TR 16148:2011 PD CEN/TR 16148:2011 CEN/TR 16148:201
27、1 (E) 6 Table 1 AIS scale with head injury severity AIS 0 uninjured AIS 1 minor AIS 2 slight AIS 3 moderate AIS 4 serious AIS 5 severe AIS 6 unsurviveable Scalp superficial abrasions, contusions, lacerations X major laceration or minor blood loss X blood loss 20% or total scalp loss X Intracranial v
28、essels (arteries) laceration X X Cranial nerves contusion, laceration, loss of function X Brain swelling, contusions, haemorrhage X haematoma, large 15cc contusion X massive 30cc contusions, diffuse axonal injury, large haematoma X crush, penetrating injury X Loss of consciousness 24 hours, or 6-24
29、hours with neurological deficit X Skull Fracture simple X compound X complex, open, loss of brain tissue X PD CEN/TR 16148:2011 PD CEN/TR 16148:2011 CEN/TR 16148:2011 (E) 7 Table 2 AIS scale with neck injury severity AIS 0 uninjured AIS 1 minor AIS 2 slight AIS 3 moderate AIS 4 serious AIS 5 severe
30、AIS 6 unsurviveable Whole area Skin superficial abrasions, contusions, lacerations X major laceration or minor blood loss X blood loss 20% X Decapitation X Vessels (arteries) carotid, jugular and vertebral laceration minor X carotid jugular and vertebral laceration major X Nerves vagus injury X phre
31、nic injury X Spine hyoid fracture X cord contusion X incomplete cord syndrome X complete cord syndrome or laceration C-4 or below X complete cord syndrome or laceration C-3 or above X disc injury without nerve root damage X disc injury with nerve root damage X PD CEN/TR 16148:2011 PD CEN/TR 16148:20
32、11 CEN/TR 16148:2011 (E) 8 Table 3 AIS scale with burn injury severity AIS 0 uninjured AIS 1 minor AIS2 slight AIS 3 moderate AIS 4 serious AIS 5 severe AIS 6 unsurviveable 1st degree unspecified X 2nd degree 10% TBS (Total Body Surface) X 3rd degree 10% TBS X 10% TBS with face, hand or genitalia in
33、volvement X 2nd or 3rd degree 10% to 19% TBS X 10% to 19% TBS with face, hand or genitalia involvement X 20% to 29% TBS X 20% to 29% TBS with face, hand or genitalia involvement X 30% to 39% TBS X 30% to 39% TBS with face, hand or genitalia involvement X 40% to 89% TBS X 90% X TBS = Total Body Surfa
34、ce PD CEN/TR 16148:2011 CEN/TR 16148:2011 (E) 9 2 Peak linear acceleration (A.3.1 & A.4) This is the most frequently used parameter in helmet testing and is derived usually from a tri-axial accelerometer mounted in the headform unless the headform is rigidly supported and then the source is a single
35、 axis accelerometer. In both types, the helmet is mounted onto the headform and then the apparatus allowed to fall unimpeded onto a rigid anvil. Table 4 is a scale published by Newman (1980) and is supported by research that is more recent. Table 4 Peak acceleration and typical AIS Equivalent Peak A
36、cceleration AIS 300 g AIS 6 Although not specifically stated in the original research paper it should be considered that the above values represent 50th percentile, which means that 50 percent of the population would sustain an injury of a given AIS severity for the corresponding range of accelerati
37、on. It is interesting to note that historically, values have been set which correspond to AIS 5 and that this has resulted in helmets that have given reasonable protection. In some standards, the helmet is mounted onto a fixed headform and then a mass is dropped onto the helmet. Values given in Tabl
38、e 4 may be used with caution provided the falling mass is approximately 5 kg and the headform is attached to an appropriate neck. Replacing the fixed headform test by a falling headform, guided or free-fall, should be considered. 3 Head injury criterion HIC (A.4) Annex A gives details of the derivat
39、ion of HIC and the formula is given below. () max 1 2 5 , 2 1 2 2 1 1 = t t dt a t t HIC t t resThe benefit of HIC over peak linear acceleration is that HIC is related to time and it is known that pulses with the same peak value but different duration can give a different injury outcome. Unfortunate
40、ly, HIC and AIS values have never been satisfactorily correlated. Although, recent research (COST 327) has provided tentative values for AIS 2 and AIS 3, see below. Nevertheless, researchers have provided an assessment of the probability of death for HIC ranges. A summary of the various findings is
41、given in Table 5. PD CEN/TR 16148:2011 CEN/TR 16148:2011 (E) 10 Table 5 Probability of death for HIC ranges HIC Probability of death AIS (where known) 1000 10 % - 15 % 2 1500 35 % 3 2000 35 % - 50 % 3000 55 % 4000 60 % - 65 % It should be noted that where a range is given, this is indicative of more
42、 than one source. It should also be noted that HIC is derived from the GSI (Gadd Severity Index) (see A.4.2) used in some Standards. GSI and HIC are potentially interchangeable but only for regular pulse shapes. Therefore, it is recommended that GSI be replaced by HIC. 4 Rotational motion (A.2.6, A.
43、3.2 & A.4.3) 4.1 Peak Rotational Acceleration This is a parameter that is known to contribute substantially to brain injury but the relationship with injury is difficult to quantify. It is also a parameter that is considered by test authorities to be difficult to measure because it requires a nine-a
44、ccelerometer array in the headform and complex interpretation. Nevertheless, the research shows, Table 6, that concussion AIS 1-2 can occur at 5 000 rad/sec 2and fatal injury AIS 5-6 can potentially occur at 10 000 rad/sec 2 . This correlates with data that indicates that there is a 35 % risk of a b
45、rain injury of AIS 3 - 6 at 10 000 rad/sec 2 . Table 6 Probability of brain injury Peak rotational acceleration AIS Probability of injury 5 000 rad/s 21 - 2 10 000 rad/s 23 - 6 35 % 4.2 Tangential force at the helmet surface This parameter is measured in motorcycle helmet Standards BS 6658 and Regul
46、ation.22-05. It is not directly related to rotational acceleration at the centre of a headform but is a function of helmet geometry. Thus, the following information in Table 7 which was obtained from motorcycle accident reconstruction data needs to be interpreted with care. Table 7 Injury related to
47、 peak tangential force on a motorcycle helmet Peak tangential force AIS Probability of injury 1 000 N 1 - 2 000 N 2 - 3 500 N (Reg 22-05) 3 50 % 4 000 N 3 50 % 7 000 N 4 - PD CEN/TR 16148:2011 CEN/TR 16148:2011 (E) 11 5 Skull crushing and penetration force (A.2.2 & A.3.3) 5.1 Crushing force Resistan
48、ce to crushing and a means of measuring the crush force transmitted to the skull are frequently discussed in helmet Standards committees. Below in Table 8 is a dynamic force that is typically required to fracture the facial bones and the skull. The information is from different sources hence the ran
49、ge and suggested tolerance values. Table 8 Typical fracture forces Bone Fracture Force Range (N) Mean Tolerance Value (N) Zygoma 614 - 3 470 1 000 Zygomatic arch 925 - 2 110 1 500 Maxilla 623 - 1 980 900 Mandible centre 1 890 - 4 110 3 000 Mandible lateral 818 - 3 405 1 900 Mandible midbody 1 290 - 1 445 NA
