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%

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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

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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

cbir@wayne.edu