Presentation Dr Bir


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Presentation Dr Bir

  1. 1. Less Lethal Devices in Riot Control
  2. 2. Wayne State University <ul><li>Located in Detroit, Michigan </li></ul><ul><li>Founded in 1868 as Detroit Medical College </li></ul><ul><li>College of Engineering established in 1933 </li></ul><ul><li>Approximately 30,000 students enrolled </li></ul><ul><li>15 colleges and schools </li></ul>
  3. 3. WSU Bioengineering Center <ul><li>Bioengineering Center established in 1939 </li></ul><ul><li>Lissner and Gurdjian formed together to study skull fracture </li></ul><ul><li>BioMedical Engineering degree program initiated under Mechanical Engineering in 1998 </li></ul><ul><li>BioMedical Engineering Department established in October 2002 </li></ul>
  4. 4. Ballistic Impact Research Laboratory <ul><li>Established in 2000 within the Bioengineering Center at Wayne State University </li></ul><ul><li>Ability to fire non-lethal kinetic energy rounds </li></ul><ul><li>Renovated to “full range” </li></ul><ul><li>Ability to fire up to 30 caliber rounds </li></ul>
  5. 6. 30 g 60 m/s 40 g 90 m/s 35 g 50 m/s 140 g 60 m/s
  6. 7. Field Experience in the US <ul><li>12 gauge bean bag-type rounds accounted for 65% of munitions fired </li></ul><ul><li>37 mm plastic baton rounds accounted for 28% </li></ul>2006-01-1128 Bean Bag Rounds 37 – 40 mm Rounds 65% 28%
  7. 8. Common rounds of “today”
  8. 9. Regions of blunt impact testing Blunt ballistic impacts: impactor mass of 20-200 g impact velocity of 20 -250 m/s
  9. 10. Impact Biomechanics <ul><li>How does the human body respond to a given impact? </li></ul><ul><li>What injuries are the result of that impact? </li></ul><ul><li>How can we predict these injuries? What tolerance level are we going to set? </li></ul>
  10. 11. Ritchie (1992) <ul><li>123 patients treated in general hospital in Belfast </li></ul><ul><li>38 patients required admission </li></ul><ul><li>One death due to arrhythmia </li></ul>
  11. 12. Steele et al. (1999) <ul><li>One week in Northern Ireland </li></ul><ul><li>8,165 plastic batons deployed </li></ul><ul><li>173 injuries treated </li></ul><ul><li>42 hospitalized </li></ul><ul><li>3 admitted to ICU </li></ul>
  12. 13. Attenuated Energy Projectile <ul><li>Maguire et al., 2007 </li></ul><ul><ul><li>14 patients reportedly injured by new Attenuated Energy Projectile (AEP) </li></ul></ul><ul><ul><li>18 injuries </li></ul></ul><ul><ul><li>6 of 18 (33%) injuries were to head, face and neck </li></ul></ul><ul><ul><li>Reduction of head injuries not apparent with AEP </li></ul></ul>2006-01-1128
  13. 14. Field Information <ul><li>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 </li></ul><ul><ul><li>373 separate incidents </li></ul></ul><ul><ul><li>Type of rounds known in 962/969 firings </li></ul></ul>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.
  14. 15. 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.
  15. 16. 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.
  16. 17. Fatalities US- Hubbs (2004) <ul><li>Fatality rate by region struck </li></ul><ul><ul><li>Chest 5 out of 6 </li></ul></ul><ul><ul><li>Neck 1 out of 6 </li></ul></ul><ul><li>Two were result of mislabeled round </li></ul><ul><li>Two had multiple regions involved </li></ul>
  17. 18. Fatalities US - Ijames (1997) <ul><li>Five reported deaths in United States </li></ul><ul><li>First occurred in 1970’s </li></ul><ul><li>Four resulted from chest impacts </li></ul><ul><li>3 of the 4 fatalities resulted from structural damage, the fourth was due to arrhythmia </li></ul><ul><li>Beanbag and ARWEN rounds </li></ul>
  18. 19. Fatalities Europe -Metress and Metress (1987) <ul><li>14 deaths have been attributed to KE rounds in Europe since 1973 </li></ul><ul><li>All attributed to impacts to the head or chest </li></ul>2006-01-1128
  19. 20. Injury Mechanisms <ul><li>Tolerance of tissue to loading </li></ul><ul><ul><li>Ability of tissue to absorb impact energy without failure </li></ul></ul><ul><li>Deformation and stretching of tissues </li></ul><ul><li>Injury is dependent on area loaded, rate of loading and tissue properties (age) </li></ul>
  20. 21. Abbreviated Injury Scale (AIS) <ul><li>AIS 1 – minor </li></ul><ul><li>AIS 2 – moderate </li></ul><ul><li>AIS 3 – serious </li></ul><ul><li>AIS 4 – severe </li></ul><ul><li>AIS 5 – critical </li></ul><ul><li>AIS 6 – virtually unsurvivable </li></ul>2006-01-1128
  21. 22. Injury Tolerance Criteria <ul><li>Quantification of human tolerance levels </li></ul><ul><li>Empirically derived </li></ul><ul><li>Related to biomechanical parameters collected experimentally </li></ul>
  22. 23. Logistic regression analysis <ul><li>Provides ability to determine the probability of event occurring given the value of an independent variable. </li></ul><ul><li>Dichotomous state of occurrence vs. nonoccurrence </li></ul><ul><li>P(x) = 1/(1+exp(-a-bX)) </li></ul>
  23. 24. Areas of concern <ul><li>Thorax </li></ul><ul><li>Abdomen </li></ul><ul><li>Head/face </li></ul><ul><li>Eye </li></ul><ul><li>Penetration </li></ul>What do we know and what data is available?
  24. 25. Thorax
  25. 26. Non-penetrating injury to thorax <ul><li>Rib fractures </li></ul><ul><li>Pulmonary contusion </li></ul><ul><li>Cardiac injuries-structural </li></ul><ul><ul><li>cardiac contusion, laceration, rupture </li></ul></ul><ul><li>Commotio Cordis </li></ul><ul><ul><li>arrhythmias leading to fatal outcome without gross structural damage </li></ul></ul>
  26. 27. Thorax <ul><li>Area above diaphragm contained in bony structure of rib cage </li></ul><ul><li>Fractures and contusions </li></ul>Preliminary data indicates 19.1% of impacts occur to the thorax resulting in 19.28% of injuries. -Hubbs et al.
  27. 28. Viscous Injury <ul><li>Viscoelastic properties of soft tissue are essential in impacts > 3 m/s </li></ul><ul><li>Viano and Lau (1988) develop viscous response or VC </li></ul><ul><li>VC is defined as product of velocity of deformation V and compression C </li></ul>
  28. 29. Human Injury Tolerance
  29. 30. Thoracic Impacts <ul><li>Best predictor of injury based on logistic regression </li></ul><ul><li>Severe injury (lung contusion) </li></ul><ul><ul><li>VC max of 3.5 m/s will result in a 50% chance </li></ul></ul><ul><ul><li>VC max of 2.8 m/s will result in a 25% chance </li></ul></ul><ul><li>Moderate injury (rib fracture) </li></ul><ul><ul><li>VC max of .8 m/s will result in a 50% chance </li></ul></ul><ul><ul><li>VC max of .6 m/s will result in a 25% chance </li></ul></ul>
  30. 31. Abdomen
  31. 32. Abdomen <ul><li>Each area of abdomen gives unique response </li></ul><ul><li>Spleen, liver, bowel </li></ul>Preliminary data indicates 33.1% of impacts occur to the abdomen resulting in 33.15% of injuries. -Hubbs et al.
  32. 33. Blunt Criterion Model (BC) <ul><li>BC = ln( ½ MV 2 /W 2/3 kD) </li></ul><ul><ul><li>Where: </li></ul></ul><ul><ul><li>M = projectile mass (kg) </li></ul></ul><ul><ul><li>V = projectile velocity (m/s) </li></ul></ul><ul><ul><li>W = mass of the specimen (kg) </li></ul></ul><ul><ul><li>D = projectile diameter (cm) </li></ul></ul><ul><ul><li>k = 0.711 for males and 0.593 for females </li></ul></ul>
  33. 34. Abdominal Impact <ul><li>Best predictors of injury based on logistic regression </li></ul><ul><li>Upper abdominal (liver) injury </li></ul><ul><ul><li>Blunt Criterion </li></ul></ul><ul><ul><li>Maximum Force </li></ul></ul><ul><li>Lower abdominal (bowel) injury </li></ul><ul><ul><li>Maximum energy dissipated </li></ul></ul><ul><ul><li>Impact velocity </li></ul></ul>
  34. 35. Head Injury
  35. 36. Head Injury <ul><li>Several levels of injury – some mechanisms still being determined </li></ul><ul><li>Injuries </li></ul>Preliminary data indicates 2.4% of impacts occur to the head resulting in 2.64% of injuries. -Hubbs et al.
  36. 37. Head Injury <ul><li>Head Injury Criteria (HIC) </li></ul><ul><li>Severity Index (SI) </li></ul><ul><li>Rotational Acceleration </li></ul>
  37. 38. Head Injury ongoing <ul><li>50% chance of skull fracture using Head Injury Criterion (HIC) </li></ul><ul><ul><li>Temporal parietal impacts – 841 </li></ul></ul><ul><ul><li>Frontal impacts – 940 </li></ul></ul>
  38. 39. Facial Fracture <ul><li>Several bones make up face </li></ul><ul><li>Each bone has specific tolerance level </li></ul>
  39. 40. Facial Fracture
  40. 41. Biomechanical Surrogates
  41. 42. Eye
  42. 43. Eye <ul><li>Once the eye is impacted, hard to prevent injuries </li></ul><ul><li>Injuries </li></ul><ul><ul><li>Chamber angle injury </li></ul></ul><ul><ul><li>Fundus Injury </li></ul></ul><ul><ul><li>Penetrating Injury </li></ul></ul>
  43. 44. Eye 11/2/05
  44. 45. Skin Anatomy <ul><ul><li>Epidermis </li></ul></ul><ul><ul><ul><li>Outermost layer </li></ul></ul></ul><ul><ul><ul><li>Consists mainly of keratinocytes </li></ul></ul></ul><ul><ul><li>Dermis </li></ul></ul><ul><ul><ul><li>Tough, highly elastic layer </li></ul></ul></ul><ul><ul><ul><li>Contains elastic fibers and a fine network of collagen fibers </li></ul></ul></ul><ul><ul><li>Panniculus Adiposus </li></ul></ul><ul><ul><ul><li>Fatty subcutaneous layer </li></ul></ul></ul><ul><ul><ul><li>Consists of collagen and fat cells </li></ul></ul></ul><ul><li>Skin is a multilayered protective barrier for underlying tissue </li></ul>Epidermis Dermis
  45. 46. Significance <ul><li>Skin penetration heightens risk of serious injury </li></ul><ul><li>38% of reported deaths due to impact munitions were the result of penetration (Hubbs and Klinger, 2001) </li></ul><ul><li>Fatality resulting from penetration of a 12 gauge non-lethal round into the heart (Dahlstrom et al, 1999) </li></ul>
  46. 47. Penetration Risk <ul><li>Current data </li></ul><ul><ul><li>DiMaio, Copeland et al. (1982) </li></ul></ul><ul><ul><ul><li>12.75 J/cm 2 - .22 air gun pellet @ 75 m/s </li></ul></ul></ul><ul><ul><ul><li>19.03 J/cm 2 - .38 caliber @ 58 m/s </li></ul></ul></ul><ul><ul><ul><ul><li>Skin and muscle </li></ul></ul></ul></ul><ul><li>Fresh cadaveric specimens </li></ul><ul><ul><li>Paired testing </li></ul></ul><ul><ul><li>12 gauge round </li></ul></ul><ul><ul><li>400 – 600 fps </li></ul></ul>
  47. 48. Evaluation of penetration <ul><ul><li>Skin thickness varies with region of body </li></ul></ul><ul><ul><li>Multiple points of impact </li></ul></ul><ul><ul><ul><li>Areas where bone lies directly under the skin </li></ul></ul></ul><ul><ul><ul><li>Fleshy areas devoid of bone </li></ul></ul></ul>
  48. 49. Non- Penetrating Wound
  49. 50. Penetrating Wound
  50. 51. Results ‡ p < 0.01, † p < 0.05
  51. 52. <ul><li>Testing procedure comparable to cadaver test </li></ul><ul><li>Universal receiver with 12-gauge barrel for projectile launch </li></ul><ul><li>Chronograph to determine velocity of projectile </li></ul><ul><li>12-gauge fin stabilized rubber rocket round used as impactor </li></ul>Surrogate Assessment
  52. 53. Surrogate Assessment *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
  53. 54. Anterior Torso Recommendations <ul><li>Cadaver testing results: </li></ul><ul><ul><li>Area overlying ribs- 23.99 J/cm 2 </li></ul></ul><ul><ul><li>Area between ribs- 33.30 J/cm 2 </li></ul></ul><ul><li>Lower number of primary concern </li></ul><ul><li>Recommendation: </li></ul><ul><ul><li>LAL- natural chamois and 0.60cm thick closed cell foam </li></ul></ul><ul><ul><li>PAL- 20% gelatin </li></ul></ul><ul><ul><li>E/A- 23.88 J/cm 2 </li></ul></ul>
  54. 55. Things to consider <ul><li>Injuries </li></ul><ul><ul><li>Blunt Trauma </li></ul></ul><ul><ul><li>Penetrating Trauma </li></ul></ul><ul><li>Accuracy </li></ul><ul><li>Effectiveness </li></ul><ul><li>Cost </li></ul><ul><li>Utility of technology </li></ul>
  55. 56. Accuracy
  56. 57. Things to consider <ul><li>Effectiveness </li></ul><ul><ul><li>Based on pain compliance </li></ul></ul><ul><ul><li>Person dependent </li></ul></ul><ul><li>Cost issues </li></ul><ul><ul><li>Usually cheaper than Taser type device </li></ul></ul><ul><ul><li>Can ‘equip’ more officers since already used platform </li></ul></ul><ul><ul><li>One time use </li></ul></ul>
  57. 58. Things to consider <ul><li>Utility of technology </li></ul><ul><ul><li>Range of use </li></ul></ul><ul><ul><li>Limitations due to environment </li></ul></ul><ul><ul><li>Training involved </li></ul></ul>
  58. 59. 12 gauge versus 40 mm <ul><li>12 gauge </li></ul><ul><li>Lighter mass </li></ul><ul><li>Higher velocity </li></ul><ul><li>Smaller area of contact </li></ul><ul><li>Higher risk of penetration of skin and eyes </li></ul><ul><li>40 mm </li></ul><ul><li>Heavier mass </li></ul><ul><li>Slower velocity </li></ul><ul><li>Larger area of contact </li></ul><ul><li>Lower risk of penetration of skin and eyes </li></ul><ul><li>“ More effective” elicits “visceral pain” </li></ul>
  59. 60. Questions/Discussion <ul><li>Cynthia Bir, PhD </li></ul><ul><li>Wayne State University </li></ul><ul><li>818 W. Hancock </li></ul><ul><li>Detroit, MI 48201 </li></ul><ul><li>313-577-3830 </li></ul><ul><li>[email_address] </li></ul>