The effect of the periosteum and strain gages on the structural response of human ribs - biomed 2009.

The purpose of this study was to determine if the removal of the periosteum or the application of a strain gage has any significant effect on the structural response of human ribs. A total of 32 three-point bending tests were performed on 16 matched whole rib sections obtained from the left and right sides of five male human thoraces. For one test group, matched specimens were tested to determine the effect of removing the soft tissue and periosteum versus leaving it intact.

Development of an improved injury device for neural cell cultures.

Traumatic Brain Injury is hypothesized to occur as a function of the strain and strain rate experienced by neural tissues during a traumatic event. In vitro studies of TBI at the cellular level have used a variety of methods to subject neural cell cultures to potentially injurious strains and strain rates. A device used in previous investigations of neural cell injury was limited in its ability to control strain and strain rate independently or simulate quick repetitive loading.

Modeling of transdermal transport of alcohol effect of body mass and gender.

TThis paper investigates the effect that body weight and gender have on the transdermal transport of ethanol observed after the ingestion of an alcohol beverage. The approach is to use a computational model which combines a multi-compartment ethanol metabolism model with a transdermal transport model. Males have a larger proportion of alcohol soluble body mass when compared to females of the same weight allowing for greater dilution of the same dose of alcohol, and lower resultant blood alcohol concentrations.

The use of acoustic emission in facial fracture detection.

This study describes a method for utilizing Acoustic Emission (AE) in facial fracture detection and demonstrates the association between fracture and acoustic emission magnitude. AE sensors were mounted to the frontal bone and mandible of cadaver skulls (n=14) exposed to impacts to the frontal bone, nasal bone, maxilla and mandible. The presence of AE during fracture and non-fracture tests necessitated the development of a threshold to distinguish AE associated with fracture.

Mechanical properties of polytetraflouroethylene elastomer membrane for dynamic cell culture testing.

A wide body of existing research on cellular injury has been conducted using cell cultures grown on flexible elastomer membranes deformed by a transient pressure pulse. However, there has been little published information on the material properties of these elastic membranes. In order to facilitate the development of a finite element model of cellular injury, the material properties of the underlying membrane must first be known.

The influence of arm position on thoracic response in side impacts.

The purpose of this study was to investigate the influence of arm position on thoracic response and injury severity in side impacts. A total of sixteen non-destructive side impact tests and four destructive side impact tests were preformed using four human male cadavers. Single-axis strain gages were placed on the lateral and posterior regions of ribs three through eight on the impacted side, and the lateral region of ribs three through eight on the non-impacted side.

Dynamic biaxial tissue properties of pregnant porcine uterine tissue.

Automobile crashes are the largest single cause of death for pregnant females and the leading cause of traumatic fetal injury mortality in the United States. Current research for pregnant occupant safety utilizing computational models is limited by available pregnant tissue data. The purpose of this study is to collect experimental data from biaxial tissue tests on pregnant uterine tissue at a dynamic rate.

Biomechanical analysis of football neck collars.

Objective: To determine the load-limiting capabilities of protective neck collars used in football through dynamic impact testing.

Design: A 50th-percentile male Hybrid III dummy was used in 48 dynamic impact tests comparing The Cowboy Collar, Bullock Collar, and Kerr Collar. A control and each collar were tested at two velocities (5 m/s and 7 m/s), three impact locations (front, top, and side of the helmet), and two shoulder pad positions (normal and raised).

Quantification of age-related shape change of the human rib cage through geometric morphometrics.

The aim of this study is to quantify patterns of age-related shape change in the human thorax using Procrustes superimposition. Landmarks (n=106) selected from anonymized computed tomography (CT) scans of 63 adult males free of skeletal pathology were used to describe the form of the rib cage. Multivariate linear regression was used to determine a relationship between landmark location and age.

Comparison of roadside crash injury metrics using event data recorders.

The occupant impact velocity (OIV) and acceleration severity index (ASI) are competing measures of crash severity used to assess occupant injury risk in full-scale crash tests involving roadside safety hardware, e.g. guardrail.

Development and validation of a synthetic eye and orbit for estimating the potential for globe rupture due to specific impact conditions.

The Facial and Ocular CountermeasUre Safety (FOCUS) headform is intended to aid safety equipment design in order to reduce the risk of eye and facial injuries. The purpose of this paper is to present a three part study that details the development and validation of the FOCUS synthetic eye and orbit and the corresponding eye injury criteria. The synthetic eye and orbit were designed to simulate the force-deflection response to in-situ dynamic impacts.

Utilizing cryogenic grips for dynamic tension testing of human placenta tissue.

Computational models are used to investigate placental abruption in motor vehicle crashes, which is the leading cause of traumatic fetal injury mortality in the United States. Material parameters for computational modeling of pregnant occupant kinematics come from early research on placenta tissue at quasi-static loading rates. The purpose of this research is to develop a methodology for using cryogenic grips to test placenta specimens in uniaxial tension at a rate normally seen in a motor vehicle crash.

Assessment of dermal ethanol emission sensors: experimental design.

This paper discusses methods that will be used to experimentally determine the limitations of transdermal ethanol alcohol sensors when used on human subjects. Transdermal ethanol sensors are used to measure the concentration of ethanol emitted by the surface of the skin. The maximum concentration of ethanol in the skin is proportional to the concentration of ethanol in the blood stream but is offset temporally because of the diffusion delay intrinsic to body tissue.

Methodology for dynamic biaxial tension testing of pregnant uterine tissue.

Placental abruption accounts for 50% to 70% of fetal losses in motor vehicle crashes. Since automobile crashes are the leading cause of traumatic fetal injury mortality in the United States, research of this injury mechanism is important. Before research can adequately evaluate current and future restraint designs, a detailed model of the pregnant uterine tissues is necessary.

Thoracic and lumbar spine accelerations in everyday activities.

The purpose of this study was to quantify thoracic and lumbar spine accelerations for men and women of different body sizes during daily activities. Measured spine accelerations were compared to determine if there were significant differences in peak accelerations based on gender, size, and spine location. Each subject performed seven activities, which included sitting in a chair, sitting quickly in a chair, walking at 1.

Development of point mass occupant injury criteria using event data recorders.

This paper presents an estimate of the probability of serious occupant injury in frontal crashes based on vehicle kinematics information. Occupant injury risk is developed by modeling the human as a point mass and computing the occupant impact velocity (OIV) using the flail space model. Event Data Recorder data provide vehicle kinematics information for real world crashes with known injury outcomes.

Predicting zygoma fractures from baseball impact.

The purpose of this study is to develop injury risk functions that predict zygoma fracture based on baseball type and impact velocity. Zygoma fracture strength data from published experiments were mapped with the force exerted by a baseball on the orbit as a function of ball velocity. Using a normal distribution, zygoma fracture risk functions were developed.

The effect of gender and body size on linear accelerations of the head observed during daily activities.

The purpose of this study was to determine the effect of gender and body size on peak linear head accelerations during daily activities. Head accelerations were measured for 18 volunteers using a biteplate system. Each subject performed seven activities: sitting in a chair, sitting quickly in a chair, walking at 1.

Prevention of facial fractures from night vision goggle impact.

Facial bone fractures in the military can result from direct loading of night vision goggles on the orbital region. Facial fracture research has shown that increasing the area over which the load is applied increases the load tolerance. The purpose of this study is to apply this concept to reducing the risk of facial bone fracture from night vision goggle impacts.

Determination of significant parameters for eye injury risk from projectiles.

Background: Eye injuries affect a large proportion of the population and are expensive to treat. This article presents a parametric analysis of experimental data to determine the most significant factors for predicting ocular injuries or tissue lesions.

Methods: Using logistic regression, statistical values were generated to determine significant projectile characteristics for predicting ocular injury in published studies.

Regional variation in the structural response and geometrical properties of human ribs.

By incorporating material and geometrical properties into a model of the human thorax one can develop an injury criterion that is a function of stress and strain of the material and not a function of the global response of the thorax. Previous research on the mechanical properties of ribs has focused on a limited set of specific ribs. For this study a total of 52 rib specimens were removed from four cadaver subjects.

Blunt trauma of the aging eye: injury mechanisms and increasing lens stiffness.

Objective: To investigate possible injury mechanisms in the eyes of elderly individuals and the effects of lens stiffness on model outputs indicative of injury as a function of age.

Methods: Three separate frontal impact scenarios, a foam particle (30 m/s), steering wheel (15 m/s), and air bag (67 m/s), were simulated with a validated finite-element model to determine the effects of changing lens stiffness on the eye when subjected to blunt trauma. The lens stiffness of the model was increased with increasing age using stiffness values determined from the literature for 3 age groups.

Analysis of real-time head accelerations in collegiate football players.

Objective: To measure and analyze head accelerations during American collegiate football practices and games.

Methods: A newly developed in-helmet 6-accelerometer system that transmits data via radio frequency to a sideline receiver and laptop computer system was implemented. From the data transfer of these accelerometer traces, the sideline staff has real-time data including the head acceleration, the head injury criteria value, the severity index value, and the impact location.