外科急诊创伤(英文)-贯通伤.ppt
合集下载
相关主题
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
▪ Velocity ▪ Profile ▪ Stability ▪ Expansion & Fragmentation ▪ Secondary Impacts ▪ Shape
Energy Dissipation
Drag:
▪ wind resistance
Cavitation:
▪ formation of a partial vacuum and cavity within a semi-fluid medium
Bullet spins as it travels down barrel
▪ Riflinቤተ መጻሕፍቲ ባይዱ in barrel
▪ Allows bullet to travel straight with slight yaw
Bullet departs barrel, spinning with a
slight wobble or yaw
Stability
▪ Allows for straighter trajectory ▪ Decreases after striking object results in tumbling
Aspects of Ballistics
Velocity
▪ Causes Trajectory
damage than large and slow.
▪ Different bullets of different weights traveling at different speeds cause
Low Energy/Low Velocity
• Knives and arrows
Medium Energy/Medium Velocity Weapons
▪ Greater the speed the greater the energy
Double speed = 4x increase KE
(continued)
Physics of Penetrating Trauma
Small & Fast bullet can cause greater
Faster = straighter trajectory Slower = more curved due to gravity
Aspects of Ballistics
Profile
▪ Portion of bullet you see as it travels towards you
Trauma
Introduction to
Penetrating Trauma
38,000 Deaths in US annually due to shootings.
Mechanisms of penetrating trauma
▪ Knives, Arrows, Nails, etc
Understanding principles of energy exchange increase the Index of Suspicion associated with the MOI
Larger profile = greater energy exchange
▪ Caliber
Diameter of a bullet (ID of gun)
• 0.22 caliber = 0.22 inches
▪ Bullets become unstable as they pass from one medium to another.
Weapon forced backward and absorbs energy
▪ Recoil
(continued)
Physics of Penetrating Trauma
Remainder of energy propels bullet forward at a high rate of speed.
Penetrating Trauma
Sections
Introduction to Penetrating Trauma
Physics of Penetrating Trauma Specific Tissue/Organ Injuries Special Concerns with Penetrating
Trajectory is curved due to gravity As bullet strikes object, it slows and
energy is transferred to object.
▪ Law of Conservation of Energy
Ballistics
• Handguns, shotguns, low-powered rifles • 250-400 mps
High Energy/High Velocity
• Assault Rifles • 600-1,000 mps
(continued)
Physics of Penetrating Trauma
Physics of Penetrating Trauma
Recall Kinetic Energy Equation
Ma (wsesi) gVhetl(osc pie)t2e yd K E
2
▪ Greater the mass the greater the energy
Double mass = double KE
Profile:
▪ Size and shape of a projectile as it contacts a target ▪ Larger the profile=greater energy exchange ▪ Expansion and fragmentation results in damage
Study of the characteristics of projectiles in motion and effects upon objects impacted
Factors affecting energy exchange between a projectile and body tissue
Energy Dissipation
Drag:
▪ wind resistance
Cavitation:
▪ formation of a partial vacuum and cavity within a semi-fluid medium
Bullet spins as it travels down barrel
▪ Riflinቤተ መጻሕፍቲ ባይዱ in barrel
▪ Allows bullet to travel straight with slight yaw
Bullet departs barrel, spinning with a
slight wobble or yaw
Stability
▪ Allows for straighter trajectory ▪ Decreases after striking object results in tumbling
Aspects of Ballistics
Velocity
▪ Causes Trajectory
damage than large and slow.
▪ Different bullets of different weights traveling at different speeds cause
Low Energy/Low Velocity
• Knives and arrows
Medium Energy/Medium Velocity Weapons
▪ Greater the speed the greater the energy
Double speed = 4x increase KE
(continued)
Physics of Penetrating Trauma
Small & Fast bullet can cause greater
Faster = straighter trajectory Slower = more curved due to gravity
Aspects of Ballistics
Profile
▪ Portion of bullet you see as it travels towards you
Trauma
Introduction to
Penetrating Trauma
38,000 Deaths in US annually due to shootings.
Mechanisms of penetrating trauma
▪ Knives, Arrows, Nails, etc
Understanding principles of energy exchange increase the Index of Suspicion associated with the MOI
Larger profile = greater energy exchange
▪ Caliber
Diameter of a bullet (ID of gun)
• 0.22 caliber = 0.22 inches
▪ Bullets become unstable as they pass from one medium to another.
Weapon forced backward and absorbs energy
▪ Recoil
(continued)
Physics of Penetrating Trauma
Remainder of energy propels bullet forward at a high rate of speed.
Penetrating Trauma
Sections
Introduction to Penetrating Trauma
Physics of Penetrating Trauma Specific Tissue/Organ Injuries Special Concerns with Penetrating
Trajectory is curved due to gravity As bullet strikes object, it slows and
energy is transferred to object.
▪ Law of Conservation of Energy
Ballistics
• Handguns, shotguns, low-powered rifles • 250-400 mps
High Energy/High Velocity
• Assault Rifles • 600-1,000 mps
(continued)
Physics of Penetrating Trauma
Physics of Penetrating Trauma
Recall Kinetic Energy Equation
Ma (wsesi) gVhetl(osc pie)t2e yd K E
2
▪ Greater the mass the greater the energy
Double mass = double KE
Profile:
▪ Size and shape of a projectile as it contacts a target ▪ Larger the profile=greater energy exchange ▪ Expansion and fragmentation results in damage
Study of the characteristics of projectiles in motion and effects upon objects impacted
Factors affecting energy exchange between a projectile and body tissue