Biomechanics Part 6 Cadavers . Cadavers used for research are donated to science · Many advances in automotive safety are due to cadaver research 1.Windshields 2. Seat belts 3. Air bags 4. Padding in the occupant compartment · It is estimated that each cadaver tested has saved over 60 lives (King, 1995) Storing human tissue · Refrigerator: Fresh tissue 1. Important for soft tissue response 2. Rigor mortis 3. Test within three days of death · Freezer: Fresh frozen tissue 1. Allows for more time to plan testing 2. Can change soft tissue response 3. Best when interested in the skeletal response · Embalming: Preserved tissue 1. Necessary for anatomical preservation 2. Less commonly used in injury biomechanics research 3. Stiffens the response of the ligaments and muscles Cadaver testing Advantages · Human anatomy and anthropometry · Can be tested injuriously Limitations · Pressurization in the vessels and lungs
· No active musculature · Cannot maintain pre-impact position · Cadavers are often elderly · Testing is time and resource intensive · Studies use limited number of tests Anthropometric test devices (ATDs) Sensors measure force, acceleration, and deformation ATDs need to: · Be as biofidelic as possible · Be robust · Have repeatable responses
Limitations: · Cannot capture body kinematics fully · Not representative of diversity of occupants · Expensive ($100k+) · Designed for a specific impact scenario Computational models Multi-body (MB) models · Bones considered rigid bodies · Tissues modeled as springs and dampers · Good for whole body kinematics Finite element (FE) models · Bones and tissues divided into smaller elements to solve · Material properties are assigned to each element Advantages of Computational Models · Measure forces and deformations throughout model . Allow for many tests with a single model · Can include active musculature