Publications by authors named "E M Spratley"

Though energy attenuating (EA) seats for air and spacecraft applications have existed for decades, they have not yet been fully characterized for their energy attenuation capability or resulting effect on occupant protection in vertical underbody blast. EA seats utilize stroking mechanisms to absorb energy and reduce the vertical forces imparted on the occupant's pelvis and lower spine. Using dynamic rigid-body modeling, a virtual tool to determine optimal force and deflection limits was developed to reduce pelvis and lower spine injuries in underbody blast events using a generic seat model.

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Military vehicle underbody blast (UBB) is the cause of many serious injuries in theatre today; however, the effects of these chaotic events on the human body are not well understood. The purpose of this research was to replicate UBB loading conditions on the human pelvis and investigate the resulting response in a controlled laboratory setting. In addition to better understanding the response of the human pelvis to high rate vertical loading, this test series also aimed to identify high rate injury thresholds.

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Article Synopsis
  • Underbody blast (UBB) attacks can cause serious pelvic injuries to military vehicle occupants, prompting a study to assess how different seated postures impact these injuries.
  • A 3D finite element model of the pelvis was created and validated against tests on human cadaveric pelves to analyze the biomechanical responses to vertical loading during UBB-like events.
  • Results indicated that sitting in an upright posture can lessen the severity of pelvic fractures compared to other seated positions, suggesting a proactive approach to reduce injury risk during such attacks.
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Three laboratory simulated sub-injurious under-body blast (UBB) test conditions were conducted with whole-body Post Mortem Human Surrogates (PMHS) and the Warrior Assessment Injury Manikin (WIAMan) Technology Demonstrator (TD) to establish and assess UBB biofidelity of the WIAMan TD. Test conditions included a rigid floor and rigid seat with independently varied pulses. On the floor, peak velocities of 4 m/s and 6 m/s were applied with a 5 ms time to peak (TTP).

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Identifying native femoral version from proximal femoral landmarks would be of benefit both for preoperative assessment as well as intraoperatively. To identify potential markers for femoral anteversion, an empirical framework was developed for orientation-independent analysis of the proximal femur from pelvic CT to allow for segmentation of the proximal femur into five constituent regions: Femoral head, femoral neck, greater trochanter, lesser trochanter and femoral shaft. The framework is based on the identification of differences in the radius of curvature at anatomic zones of transition between regions of the proximal femur, followed by non-linear geometric shape fitting.

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