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In order to evaluate a human surrogate, the human and surrogate response must be defined. The purpose of this study was to evaluate the response of cadaver subjects to blunt impacts to the frontal bone, nasal bone and maxilla. Force-displacement corridors were developed based on the impact response of each region. Variation in the force-displacement response of the cadaver subjects due to the occurrence of fracture and fracture severity was demonstrated. Additionally, impacts were performed at matched locations using the Facial and Ocular CountermeasUre Safety (FOCUS) headform. The FOCUS headform is capable of measuring forces imposed onto facial structures using internal load cells. Based on the tests performed in this study, the nasal region of the FOCUS headform was found to be the most sensitive to impact location. Due to a wide range in geometrical characteristics, the nasal impact response varied significantly, resulting in wide corridors for human response.

Biomechanical data are often assumed to be doubly censored. In this paper, this assumption is evaluated critically for several previously published sets of data. Injury risk functions are compared using simple logistic regression and using survival analysis with 1) the assumption of doubly censored data and 2) the assumption of right-censored (uninjured specimens) and uncensored (injured) data. It is shown that the injury risk functions that result from these differing assumptions are not similar and that some experiments will require a preliminary assessment of data censoring prior to finalizing the experimental design. Some types of data are obviously doubly censored (e.g., chest deflection as a predictor of rib fracture risk), but many types are not left censored since injury is a force-limiting phenomenon (e.g., axial force as a predictor of tibia fracture). Guidelines for determining the censoring for various types of experiment are presented.

Computer simulations, dummy experiments with a new enhanced upper extremity, and small female cadaver experiments were used to analyze the small female upper extremity response under side air bag loading. After establishing the initial position, three tests were performed with the 5th percentile female hybrid III dummy, and six experiments with small female cadaver subjects. A new 5th percentile female enhanced upper extremity was developed for the dummy experiments that included a two-axis wrist load cell in addition to the existing six-axis load cells in both the forearm and humerus. Forearm pronation was also included in the new dummy upper extremity to increase the biofidelity of the interaction with the handgrip. Instrumentation for both the cadaver and dummy tests included accelerometers and magnetohydrodynamic angular rate sensors on the forearm, humerus, upper and lower spine.

The goal of this paper is to estimate near-side injury risk in vehicles with the best side impact performance in the U.S. New Car Assessment Program (NCAP). The longer-term goal is to predict the incidence of crashes and injury outcomes in the U.S. in a future fleet of the 2025-time frame after current active and passive safety countermeasures are fully implemented. Our assumption was that, by 2025, all new vehicles will have side impact passive safety performance equivalent to current U.S. NCAP five star ratings. The analysis was based on real-world crashes extracted from case years 2010-2015 in the National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) in which front-row occupants of late-model vehicles (Model Year 2011+) were exposed to a near-side crash.

The longitudinal motion of the head, thorax and lumbar spine of two test subjects was measured in low-speed rear-end collisions in order to understand the effect of the head-to-head restraint distance (backset) on the occupant kinematics. The two test subjects were exposed to three rear-end impacts at two crash severities, nominal changes in velocity (ΔV) of 1.11 (low ΔV) and 2.22 m/s (high ΔV). The backset was hypothesized to be an independent variable that would affect the head and neck motion and was set at 0, 5 or 10 cm. The x and z-axis accelerations of the impacted vehicle and the anatomical x and z-axis accelerations of each test subjects’ upper thorax and L5-S1 region were measured and then transformed to an earth-based coordinate system. Head accelerations were measured at the mouth and these accelerations were transformed to an earth-based coordinate system at the head center of gravity (CG).

The head motions of a human driver and a Hybrid III Anthropometric Test Device (ATD) right front passenger were measured in low-speed rearend impacts (velocity change (ΔV) ≤ 8 kph) with high speed film and accelerometers. Data were analyzed from three crashes with the same human driver (weight similar to ATD) at ΔV's of 3.9, 6.6 and 7.8 kph. The results indicate that the human's and ATD's head have roughly similar basic patterns of motion: a post-impact period where the head is stationary with respect to the earth (Phase I), a period where the head rotates rearward with respect to the vehicle (Phase II), a subsequent period where the head rotates forward with respect to the vehicle (Phase III) and a final period where the head settles into a post-impact rest position (Phase IV). The human's head motion tended to be more complex than the ATD's head motion during Phases II and III.

A second series of low speed rear end crash tests with seven volunteer test subjects have delineated human head/neck dynamics for velocity changes up to 10.9 kph (6.8 mph). Angular and linear sensor data from biteblock arrays were used to compute acceleration resultants for multiple points on the head's sagittal plane. By combining these acceleration fields with film based instantaneous rotation centers, translational and rotational accelerations were defined to form a sequential acceleration history for points on the head. Our findings suggest a mechanism to explain why cervical motion beyond the test subjects' measured voluntary range of motion was never observed in any of a total of 28 human test exposures. Probable “whiplash” injury mechanisms are discussed.

The objective of this study was to investigate potential for traumatic brain injuries (TBI) using a newly developed, geometrically detailed, finite element head model (FEHM) within the concept of a simulated injury monitor (SIMon). The new FEHM is comprised of several parts: cerebrum, cerebellum, falx, tentorium, combined pia-arachnoid complex (PAC) with cerebro-spinal fluid (CSF), ventricles, brainstem, and parasagittal blood vessels. The model's topology was derived from human computer tomography (CT) scans and then uniformly scaled such that the mass of the brain represents the mass of a 50th percentile male's brain (1.5 kg) with the total head mass of 4.5 kg. The topology of the model was then compared to the preliminary data on the average topology derived from Procrustes shape analysis of 59 individuals. Material properties of the various parts were assigned based on the latest experimental data.

A blast buck (Accelerative Loading Fixture, or ALF) was developed for studying underbody blast events in a laboratory-like setting. It was designed to provide a high-magnitude, high-rate, vertical loading environment for cadaver and dummy testing. It consists of a platform with a reinforcing cage that supports adjustable-height rigid seats for two crew positions. The platform has a heavy frame with a deformable floor insert. Fourteen tests were conducted using fourteen PMHS (post mortem human surrogates) and the Hybrid III ATD (Anthropomorphic Test Device). Tests were conducted at two charge levels: enhanced and mild. The surrogates were tested with and without PPE (Personal Protective Equipment), and in two different postures: nominal (knee angle of 90°) and obtuse (knee angle of 120°). The ALF reproduces damage in the PMHS commensurate with injuries experienced in theater, with the most common damage being to the pelvis and ankle.

The head, neck and trunk kinematic responses of four volunteer test subjects, recorded during a series of experimental low velocity motor vehicle collisions, have been measured and analyzed. Using data obtained from multiple high speed film, video and electronic accelerometer measurements of the test subjects, it was found that the actual kinematic responses of the human head, neck and trunk that occur during low velocity rearend collisions are more complex than previously thought. Our findings indicate that the time-honored description of the cervical “whiplash” response is both incomplete and inaccurate. Although the classic “whiplash” neck response to rearend collisions and the widely accepted hyperextension/hyperflexion cervical injury mechanism have been extensively written and speculated about, there have been little human experimental data available, especially for low velocity collisions.