Less Lethal Devices in Riot Control
Jan 17, 2015
Less Lethal Devices in Riot Control
Wayne State University
Located in Detroit, Michigan Founded in 1868 as Detroit Medical
College College of Engineering established in
1933 Approximately 30,000 students enrolled 15 colleges and schools
WSU Bioengineering Center
Bioengineering Center established in 1939 Lissner and Gurdjian formed together to study
skull fracture BioMedical Engineering degree program
initiated under Mechanical Engineering in 1998 BioMedical Engineering Department
established in October 2002
Ballistic Impact Research Laboratory
Established in 2000 within the Bioengineering Center at Wayne State University
Ability to fire non-lethal kinetic energy rounds
Renovated to “full range” Ability to fire up to 30 caliber rounds
30 g60 m/s
40 g90 m/s
35 g50 m/s
140 g60 m/s
7
Field Experience in the US 12 gauge bean bag-type rounds
accounted for 65% of munitions fired 37 mm plastic baton rounds accounted
for 28%
2006-01-1128
Bean Bag Rounds 37 – 40 mm Rounds
65%28%
Common rounds of “today”
Regions of blunt impact testing
Ve
loci
ty (
m/s
)
1
10
100
1000
10 100 1000 10000 100000
Automotive
Mass (g)
Non-lethal 12 gageRegion of BluntBallistic Impacts
United Kingdom Baton
Baseball
Blunt ballistic impacts:impactor mass of 20-200 gimpact velocity of 20 -250 m/s
Impact Biomechanics
How does the human body respond to a given impact?
What injuries are the result of that impact?
How can we predict these injuries? What tolerance level are we going to set?
Ritchie (1992)
123 patients treated in general hospital in Belfast
38 patients required admission One death due to arrhythmia
17%
20%
9%22%
31%
1%Head
Chest
Maxillofacial
Upper limbs
Low er limbs
Groin
Steele et al. (1999)
One week in Northern Ireland 8,165 plastic batons deployed 173 injuries treated 42 hospitalized 3 admitted to ICU
13
Attenuated Energy Projectile
Maguire et al., 2007– 14 patients reportedly injured by new
Attenuated Energy Projectile (AEP)– 18 injuries– 6 of 18 (33%) injuries were to head, face
and neck– Reduction of head injuries not apparent
with AEP
2006-01-1128
Field Information
Hubbs & Klinger (2004) gathered information regarding the use and effects of less-lethal kinetic energy rounds via a survey of North American law enforcement agencies – 373 separate incidents – Type of rounds known in 962/969
firings
Hubbs, K., Klinger, D., 2004. Impact munitions database of use and effects. National Institute of Justice, Department of Justice. Award Number 98-LB-VX-K006.
Distribution by body region
Hubbs, K., Klinger, D., 2004. Impact munitions database of use and effects. National Institute of Justice, Department of Justice. Award Number 98-LB-VX-K006.
Types of injuries
Hubbs, K., Klinger, D., 2004. Impact munitions database of use and effects. National Institute of Justice, Department of Justice. Award Number 98-LB-VX-K006.
Fatalities US- Hubbs (2004)
Fatality rate by region struck– Chest 5 out of 6– Neck 1 out of 6
Two were result of mislabeled round Two had multiple regions involved
Fatalities US - Ijames (1997)
Five reported deaths in United States First occurred in 1970’s Four resulted from chest impacts 3 of the 4 fatalities resulted from
structural damage, the fourth was due to arrhythmia
Beanbag and ARWEN rounds
Fatalities Europe -Metress and Metress (1987)
14 deaths have been attributed to KE rounds in Europe since 1973
All attributed to impacts to the head or chest
2006-01-1128
Injury Mechanisms
Tolerance of tissue to loading– Ability of tissue to absorb impact
energy without failure
Deformation and stretching of tissues Injury is dependent on area loaded,
rate of loading and tissue properties (age)
21
Abbreviated Injury Scale (AIS)
2006-01-1128
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1 2 3 4 5 6
AIS
Pro
bab
ilit
y (%
)
Survival
Mortality
AIS 1 – minor AIS 2 – moderate AIS 3 – serious AIS 4 – severe AIS 5 – critical AIS 6 – virtually
unsurvivable
Injury Tolerance Criteria
Quantification of human tolerance levels
Empirically derived Related to biomechanical parameters
collected experimentally
Logistic regression analysis
Provides ability to determine the probability of event occurring given the value of an independent variable.
Dichotomous state of occurrence vs. nonoccurrence
P(x) = 1/(1+exp(-a-bX))
Areas of concern
Thorax Abdomen Head/face Eye Penetration
What do we know and what data is available?
Thorax
Non-penetrating injury to thorax
Rib fractures Pulmonary contusion Cardiac injuries-structural
– cardiac contusion, laceration, rupture
Commotio Cordis– arrhythmias leading to fatal outcome
without gross structural damage
Thorax
Area above diaphragm contained in bony structure of rib cage
Fractures and contusions
1 superficial penetrating chest injury2 sternum fracture3 penetrating chest injury with > 20% blood loss by volume4 severe heart contusion; bilateral lung contusion5 lung laceration with tension pneumothorax6 heart laceration with ventricular rupture
THORAX Preliminary data indicates19.1% of impacts occurto the thorax resultingin 19.28% of injuries.
-Hubbs et al.
Viscous Injury
Viscoelastic properties of soft tissue are essential in impacts > 3 m/s
Viano and Lau (1988) develop viscous response or VC
VC is defined as product of velocity of deformation V and compression C
Human Injury Tolerance
Thoracic Impacts
Best predictor of injury based on logistic regression
Severe injury (lung contusion)– VCmax of 3.5 m/s will result in a 50% chance– VCmax of 2.8 m/s will result in a 25% chance
Moderate injury (rib fracture)– VCmax of .8 m/s will result in a 50% chance– VCmax of .6 m/s will result in a 25% chance
Abdomen
Abdomen
Each area of abdomen gives unique response
Spleen, liver, bowel
1 superficial penetrating injury
2minor spleen laceration (<= 3 cm deep); no major vessel involvement
3 colon perforation4 major kidney laceration (main renal vessel involvement)
5massive liver laceration (disruption of > 50% of hepatic vascular system)
6 hepatic avulsion
ABDOMEN Preliminary data indicates33.1% of impacts occurto the abdomen resultingin 33.15% of injuries.
-Hubbs et al.
Blunt Criterion Model (BC)
BC = ln(½MV2/W2/3kD)– Where:– M = projectile mass (kg)– V = projectile velocity (m/s)– W = mass of the specimen (kg)– D = projectile diameter (cm)– k = 0.711 for males and 0.593 for females
Abdominal Impact
Best predictors of injury based on logistic regression
Upper abdominal (liver) injury– Blunt Criterion– Maximum Force
Lower abdominal (bowel) injury– Maximum energy dissipated– Impact velocity
Head Injury
Head Injury
Several levels of injury – some mechanisms still being determined
Injuries
1 scalp contusion or laceration2 major scalp laceration3 superficial penetrating injury (<= 2 cm below entrance)4 basilar skull fracture (open or comminuted)5 major penetrating injury (> 2 cm penetration)6 crush--destruction of skull and brain
HEAD Preliminary data indicates2.4% of impacts occurto the head resultingin 2.64% of injuries.
-Hubbs et al.
Head Injury
Head Injury Criteria (HIC) Severity Index (SI) Rotational Acceleration
Head Injury ongoing
50% chance of skull fracture using Head Injury Criterion (HIC)– Temporal parietal impacts – 841– Frontal impacts – 940
Facial Fracture
Several bones make up face Each bone has specific tolerance
level
1 mandible fracture (location not specified)2 zygoma fracture
3maxilla fracture in which maxilla and one or more facial bones are separated from the skull
4 maxilla fracture with > 20% blood loss5 none6 none
FACE
Facial Fracture
Cadaver # Imp Loc Vel (m/s) En (J) Fx Peak F (N) Max P(mm)UM001 Front 69.26 84.40 No 3190 1UM007 Front 37.90 17.72 No 1787 828292 Front 33.21 13.60 No 1647 1UM002 Front No 2450
AVE Front 46.79 38.57 2269 3
UM001 Zygo 53.54 50.44 Yes 1668 7UM007 Zygo 38.30 18.09 Yes 1179 2328292 Zygo 28.43 9.97 Yes 985 13UM002 Zygo Yes 972
945 Zygo Yes 1510AVE Zygo 33.37 14.03 1263 14
UM001 Mand Yes 3920O30 Mand 47.14 27.41 No 1552 25
UM007 Mand 44.90 24.87 No 1873 828292 Mand 35.92 15.92 No 943 19UM002 Mand No 1816
945 Mand No 2278
AVE Mand 40.41 20.39 2064 17
Biomechanical Surrogates
Mandible
Maxilla(Left & Right)
Frontal Bone(Left & Right)
Zygoma(Left & Right)
Nasal Bone
Mandible
Maxilla(Left & Right)
Frontal Bone(Left & Right)
Zygoma(Left & Right)
Nasal Bone
Eye
Eye
Once the eye is impacted, hard to prevent injuries Injuries
– Chamber angle injury– Fundus Injury– Penetrating Injury
11/2/05
Eye
Skin Anatomy
Epidermis Outermost layer Consists mainly of keratinocytes
Dermis Tough, highly elastic layer Contains elastic fibers and a fine network of
collagen fibers
Panniculus Adiposus Fatty subcutaneous layer Consists of collagen and fat cells
Epidermis
Dermis
Skin is a multilayered protective barrier for underlying tissue
Significance
Skin penetration heightens risk of serious injury
38% of reported deaths due to impact munitions were the result of penetration (Hubbs and Klinger, 2001)
Fatality resulting from penetration of a 12 gauge non-lethal round into the heart (Dahlstrom et al, 1999)
Penetration Risk
Current data– DiMaio, Copeland et al. (1982)
• 12.75 J/cm2 - .22 air gun pellet @ 75 m/s• 19.03 J/cm2 - .38 caliber @ 58 m/s
– Skin and muscle
Fresh cadaveric specimens– Paired testing– 12 gauge round– 400 – 600 fps
Evaluation of penetration
Skin thickness varies with region of body
Multiple points of impact–Areas where bone lies directly under the skin –Fleshy areas devoid of bone
Non- Penetrating Wound
Penetrating Wound
Results
Location 50% Risk Chi- Squared P-value
Sternum 32.88 1.820 0.177 -1.907 0.058
On Anterior Rib 23.99 16.636 0.000‡ -126.513 5.274 Between Anterior
Rib 33.30 3.563 0.059 -2.731 0.082
Liver 39.88 2.885 0.089 -3.789 0.095 Lateral to Umbilicus
34.34 2.842 0.092 -3.424 0.098
Proximal Femur 26.13 9.747 0.002‡ -5.147 0.197
Distal Femur 28.13 8.397 0.004‡ -4.895 0.174
Scapula 50.60 5.336 0.021† -5.262 0.104
On Posterior Rib 52.74 10.964 0.001‡ -10.021 0.190
Lower back 38.13 7.746 0.005‡ -4.004 0.105
‡ p < 0.01, † p < 0.05
Surrogate Assessment
Testing procedure comparable to cadaver test
Universal receiver with 12-gauge barrel for projectile launch
Chronograph to determine velocity of projectile
12-gauge fin stabilized rubber rocket round used as impactor
Surrogate Assessment
LAL* PAL α β (E/a)
None Gelatin -66.12 4.67 14.46
C Gelatin -107.28 6.24 17.18
C-C Gelatin -77.38 4.25 18.19
C-F1 Gelatin -156.78 6.56 23.88
C-F3 Gelatin -188.22 7.77 24.24
C-F3-C Gelatin -103.18 3.24 31.84
L-F3 Gelatin N/A N/A Over 44.03
C-F1-D-F2 Gelatin -78.56 1.83 43.02
C-F4 Gelatin -109.57 4.13 26.54
C-F4-C Gelatin -21.089 0.556 37.93
C-F5 Gelatin -321.46 9.19 34.99
Vinyl Gelatin N/A N/A Below 14.98
PVA Gelatin N/A N/A Below 16.62
*C- Chamois, L- Leather, F1- 0.6 cm foam, F2- 0.3 cm foam, F3- 0.93 cm foam,
F4- 3-4 lb/ft3 foam, F5- 7-8 lb/ft3 foam
Anterior Torso Recommendations
Cadaver testing results:- Area overlying ribs- 23.99 J/cm2
- Area between ribs- 33.30 J/cm2
Lower number of primary concern Recommendation:
- LAL- natural chamois and 0.60cm thick closed cell foam
- PAL- 20% gelatin- E/A- 23.88 J/cm2
Things to consider
Injuries– Blunt Trauma– Penetrating Trauma
Accuracy Effectiveness Cost Utility of technology
Accuracy
Things to consider
Effectiveness – Based on pain compliance– Person dependent
Cost issues – Usually cheaper than Taser type device– Can ‘equip’ more officers since already
used platform– One time use
Things to consider
Utility of technology– Range of use– Limitations due to environment– Training involved
12 gauge versus 40 mm
12 gauge
Lighter mass Higher velocity Smaller area of
contact Higher risk of
penetration of skin and eyes
40 mm
Heavier mass Slower velocity Larger area of contact Lower risk of
penetration of skin and eyes
“More effective” elicits “visceral pain”
Questions/Discussion
Cynthia Bir, PhD
Wayne State University
818 W. Hancock
Detroit, MI 48201
313-577-3830