Suchergebnisse

This ABC introduces medicine in areas of conflict or natural disaster responding to the growing number of regions affected. Chapters deal with subjects such as earthquakes and landslides as well as nuclear incidents and biological warfare both nationally and internationally. It covers both logistical planning and medical aid as well as post-conflict recovery, offering psychological as well as medical and public health support. It prepares aid workers for a range of roles in all possible situations

The aim of this work was to further develop a synthetic model of ballistic head injury by the addition of skin and soft tissue layers to an anatomically correct polyurethane skull filled with gelatine 10% by mass. Six head models were impacted with 7.62 x 39 mm full metal jacket mild steel core (FMJ MSC) bullets with a mean velocity of 652 m/s. The impact events were filmed with high-speed cameras. The models were imaged pre- and post-impact using computed tomography. The models were assessed post impact by two experienced Home Office pathologists and the images assessed by an experienced military radiologist. The findings were scored against real injuries. The entry wounds, exit wounds and fracture patterns were scored positively, but the synthetic skin and soft tissue layer was felt to be too extendable. Further work is ongoing to address this.

Intro -- Foreword -- Preface -- Contents -- Part I: Basic Science and Engineering -- 1: Section Overview -- 2: The Fundamentals of Blast Physics -- 2.1 Explosives and Blast: A Kinetic Effect -- 2.2 Explosive Systems: The Explosive Train -- 2.3 Energy Levels and Energy Distribution -- 2.4 Formation and Velocity of Fragments -- 2.5 Shock and Stress Transmission -- 2.5.1 Wave Type -- 2.5.2 Magnitude of the Wave -- 2.5.3 Impedance: A Property of the Material -- 2.5.4 Wave Transmission Across Interfaces -- 2.5.5 The Solid-Air Interface -- 2.6 Blast Waves -- 2.6.1 Change in Impedance of a Gas in a Blast Wave -- 2.6.2 Reflected Waves -- 2.6.3 Temperature Rise -- 2.7 Comparing Explosive Scenarios: Scaled Distance and TNT Equivalence -- 2.8 The Three-Dimensional World and the Physical Basis of Blast and Fragment Injury -- 2.9 Summary/Conclusion -- References -- Further Reading -- 3: Biomechanics in Blast -- 3.1 Overview -- 3.2 Terminology in Biomechanics -- 3.2.1 Biomechanics of Motion -- 3.2.2 Forces -- 3.2.3 Newton's Laws and Kinetics -- 3.2.4 Functional Anatomy -- 3.3 Biomechanics of Force Transmission -- 3.3.1 Muscle Forces -- 3.3.2 Forces in Joints -- 3.4 Bringing it All Together: Forensic Biomechanics of Blast -- References -- Further Reading -- 4: Behaviour of Materials -- 4.1 Introduction -- 4.2 Materials -- 4.2.1 Metals -- 4.2.1.1 Microstructure -- 4.2.1.2 Imperfections -- 4.2.1.3 Hardening -- 4.2.1.4 Main Industrial Alloys -- Steel -- Cast Iron -- Copper Alloys -- Alloys of Light Metals -- 4.2.2 Ceramics -- 4.2.3 Polymers -- 4.2.3.1 Thermoplastics -- 4.2.3.2 Thermosets -- 4.2.3.3 Elastomers or Rubbers -- 4.2.4 Composites -- 4.2.5 Biological Materials -- 4.2.5.1 Biological Fluids -- Protoplasm -- Mucus -- Synovial Fluid -- 4.2.5.2 Biological Solids -- Actin and Elastin -- Collagen -- 4.3 Stress Analysis.

Ballistic head injury remains a significant threat to military personnel. Studying such injuries requires a model that can be used with a military helmet. This paper describes further work on a skull-brain model using skulls made from three different polyurethane plastics and a series of skull 'fills' to simulate brain (3, 5, 7 and 10% gelatine by mass and PermaGel™). The models were subjected to ballistic impact from 7.62 × 39 mm mild steel core bullets. The first part of the work compares the different polyurethanes (mean bullet muzzle velocity of 708 m/s), and the second part compares the different fills (mean bullet muzzle velocity of 680 m/s). The impact events were filmed using high speed cameras. The resulting fracture patterns in the skulls were reviewed and scored by five clinicians experienced in assessing penetrating head injury. In over half of the models, one or more assessors felt aspects of the fracture pattern were close to real injury. Limitations of the model include the skull being manufactured in two parts and the lack of a realistic skin layer. Further work is ongoing to address these.