Biomedical Engineering Fundamentals

53.1 Introduction
Injury is caused by energy transfer to the body by an impacting object. It occurs when sufficient force is
concentrated on the chest or abdomen by striking a blunt object, such as a vehicle instrument panel or
side interior, or being struck by a baseball or blunt ballistic mass. The risk of injury is influenced by the
object’s shape, stiffness, point of contact, and orientation. It can be reduced by energy absorbing padding
or crushable materials, which allow the surfaces in contact to deform, extend the duration of impact, and
reduce loads. The torso is viscoelastic, so reaction force increases with the speed of body deformation.
The biomechanical response of the body has three components, (1) inertial resistance by acceleration of
body masses, (2) elastic resistance by compression of stiff structures and tissues, and (3) viscous resistance
by rate-dependent properties of tissue. For low-impact speeds, the elastic stiffness protects from crush
injuries; whereas, for high rates of body deformation, the inertial and viscous properties determine the
force developed and limit deformation. The risk of skeletal and internal organ injury relates to energy
stored or absorbed by the elastic and viscous properties. The reaction load is related to these responses
and inertial resistance of body masses, which combine to resist deformation and prevent injury. When
tissues are deformed beyond their recoverable limit, injuries occur.
53.2 Chest and Abdomen Injury Mechanisms
The primary mechanism of chest and abdomen injury is compression of the body at high rates of loading.
This causes deformation and stretching of internal organs and vessels. When torso compression exceeds
53-1

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Document Outline

• Introduction and Preface
• Editor-in-Chief
• Contributors
• Contents
• 1. An Outline of Cardiovascular Structure and Function
• 2. Endocrine System
• 3. Nervous System
• 4. Vision System
• 5. Auditory System
• 6. Gastrointestinal System
• 7. Respiratory System
• 8. Modeling Strategies and Cardiovascular Dynamics
• 9. Compartmental Models of Physiologic Systems
• 10. Cardiovascular Models and Control
• 11. Respiratory Models and Control
• 12. Neural Networks for Physiological Control
• 13. Methods and Tools for Identification of Physiologic Systems
• 14. Autoregulating Windkessel Dynamics May Cause Low Frequency Oscillations
• 15. External Control of Movements
• 16. The Fast Eye Movement Control System
• 17. A Comparative Approach to Analysis and Modeling of Cardiovascular Function
• 18. Cardiopulmonary Resuscitation: Biomedical and Biophysical Analyses
• 19. Basic Electrophysiology
• 20. Volume Conductor Theory
• 21. The Electrical Conductivity of Tissues
• 22. Membrane Models
• 23. Computational Methods and Software for Bioelectric Field Problems
• 24. Principles of Electrocardiography
• 25. Principles of Electromyography
• 26. Principles of Electroencephalography
• 27. Biomagnetism
• 28. Electrical Stimulation of Excitable Systems
• 29. History and Overview of Neural Engineering
• 30. Electrical Stimulation of the Central Nervous System
• 31. Transcutaneous FES for Ambulation: The Parastep System
• 32. Comparing Electrodes for Use as Cortical Control Signals: Tiny Tines, Tiny Wires, or Tiny Cones on Wires: Which Is Best?
• 33. Development of a Multi-Functional 22-Channel Functional Electrical Stimulator for Paraplegia
• 34. An Implantable Bionic Network of Injectable Neural Prosthetic Devices: The Future Platform for Functional Electrical Stimulation and Sensing to Restore Movement and Sensation
• 35. Visual Prostheses
• 36. Interfering with the Genesis and Propagation of Epileptic Seizures by Neuromodulation
• 37. Transcranial Magnetic Stimulation of Deep Brain Regions
• 38. Metallic Biomaterials
• 39. Ceramic Biomaterials
• 40. Polymeric Biomaterials
• 41. Composite Biomaterials
• 42. Biodegradable Polymeric Biomaterials: An Updated Overview
• 43. Biologic Biomaterials: Tissue-Derived Biomaterials (Collagen)
• 44. Soft Tissue Replacements
• 45. Hard Tissue Replacements
• 46. Controlling and Assessing Cell–Biomaterial Interactions at the Micro- and Nanoscale: Applications in Tissue Engineering
• 47. Mechanics of Hard Tissue
• 48. Musculoskeletal Soft Tissue Mechanics
• 49. Joint-Articulating Surface Motion
• 50. Joint Lubrication
• 51. Analysis of Gait
• 52. Mechanics of Head/Neck
• 53. Biomechanics of Chest and Abdomen Impact
• 54. Cardiac Biomechanics
• 55. Heart Valve Dynamics
• 56. Arterial Macrocirculatory Hemodynamics
• 57. Mechanics of Blood Vessels
• 58. The Venous System
• 59. Mechanics, Molecular Transport, and Regulation in the Microcirculation
• 60. Mechanics and Deformability of Hematocytes
• 61. Mechanics of Tissue/Lymphatic Transport
• 62. Modeling in Cellular Biomechanics
• 63. Cochlear Mechanics
• 64. Vestibular Mechanics
• 65. Exercise Physiology
• 66. Factors Affecting Mechanical Work in Humans
• 67. Rehabilitation Engineering, Science, and Technology
• 68. Orthopedic Prosthetics and Orthotics in Rehabilitation
• 69. Wheeled Mobility: Wheelchairs and Personal Transportation
• 70. Externally Powered and Controlled Orthoses and Prostheses
• 71. &#