Development of a Procedure

The human toll from AP mines is large. The United Nations estimates that there are over 100 million AP mines deployed worldwide (U.N. 2000). An estimated 20,000 civilians die each year from landmine explosions.Thousands more are wounded and maimed. As there is still no inexpensive and reliable mechanical technique for removing AP mines, human deminers will be used in the foreseeable future to protect the general population from the menace of landmines

Redesign of the double hand rim modification of the "Whirlwind" Wheelchair for manufacture in developing nations

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 32).In this thesis, I investigate possible improvements to the design of a wheelchair for manufacture in a developing nation, specifically one designed for use by persons with hemiplegia. Ralf Hotchkiss's "Whirlwind" Wheelchair is currently manufactured with local materials in many developing nations. It provides both an affordable source of quality wheelchairs for the populace as well as a source of employment. J.A. van Alphen and D.R. Arbib made modifications to the original Wheelchair design so that it would be usable by hemiplegics. However, on manufacture in Duranguito, Mexico, the chair was deemed unusable due to certain flaws. After analyzing the design of the chair, potential solutions for the two most critical problems are suggested, taking care to avoid undue increases in cost or complexity of manufacture.by Cameron M. Bass.S.B

Efficacy of Medical Operations and Layout Planning Onboard Nontraditional US Navy Vessels at High Seas

The article of record as published may be found at http://dx.doi.org/10.1093/milmed/usz227Introduction: Attempting to expedite delivery of care to wounded war fighters, this study aimed to quantify the ability of medical and surgical teams to perform lifesaving damage control and resuscitation procedures aboard nontraditional US Navy Vessels on high seas. Specifically, it looked at the ability of the teams to perform procedures in shipboard operating and emergency rooms by analyzing motion of personnel during the procedures. Methods: One hundred and twelve damage control and resuscitation procedures were performed during a voyage of the US Naval Ship Brunswick in transit from Norfolk, Virginia, to San Diego, California. The ability of personnel to perform these procedures was quantified by the use of motion link analysis designed to track the movement of each participant as they completed their assigned tasks. Results: The link analysis showed no significant change in the number of movements of participants from the beginning to the end of the study. However, there was a learning effect observed during the study, with teams completing tasks faster at the end of the study than at the beginning. Conclusion: This shows that the working conditions aboard the US Naval Ship Brunswick were satisfactory for the assigned tasks, indicating that these medical operations may be feasible aboard nontraditional US Navy vessels.This specific study was a part of a major three-phase investigation entitled �Effect of High Deck Accelerations on Surgical Tasks� funded by the following organizations for each phase: Phase I�Office of Naval Research, Phase II�Office of the Chief of Naval Operations (OPNAV) N81, and Phase III�Advanced Medical Development and OPNAV N81.This specific study was a part of a major three-phase investigation entitled �Effect of High Deck Accelerations on Surgical Tasks� funded by the following organizations for each phase: Phase I�Office of Naval Research, Phase II�Office of the Chief of Naval Operations (OPNAV) N81, and Phase III�Advanced Medical Development and OPNAV N81

A Multiscale Approach to Blast Neurotrauma Modeling: Part I – Development of Novel Test Devices for in vivo and in vitro Blast Injury Models

The loading conditions used in some current in vivo and in vitro blast-induced neurotrauma models may not be representative of real-world blast conditions. To address these limitations, we developed a compressed-gas driven shock tube with different driven lengths that can generate Friedlander-type blasts. The shock tube can generate overpressures up to 650 kPa with durations between 0.3 and 1.1 ms using compressed helium driver gas, and peak overpressures up to 450 kPa with durations between 0.6 and 3 ms using compressed nitrogen. This device is used for short-duration blast overpressure loading for small animal in vivo injury models, and contrasts the more frequently used long duration/high impulse blast overpressures in the literature. We also developed a new apparatus that is used with the shock tube to recreate the in vivo intracranial overpressure response for loading in vitro culture preparations. The receiver device surrounds the culture with materials of similar impedance to facilitate the propagation of a single overpressure pulse through the tissue. This method prevents pressure waves reflecting off the tissue that can cause unrealistic deformation and injury. The receiver performance was characterized using the longest helium-driven shock tube, and produced in-fluid overpressures up to 1500 kPa at the location where a culture would be placed. This response was well correlated with the overpressure conditions from the shock tube (R2 = 0.97). Finite element models of the shock tube and receiver were developed and validated to better elucidate the mechanics of this methodology. A demonstration exposing a culture to the loading conditions created by this system suggest tissue strains less than 5% for all pressure levels simulated, which was well below functional deficit thresholds for strain rates less than 50 s−1. This novel system is not limited to a specific type of culture model and can be modified to reproduce more complex pressure pulses

A Multiscale Approach to Blast Neurotrauma Modeling: Part II: Methodology for Inducing Blast Injury to in vitro Models

Due to the prominent role of improvised explosive devices (IEDs) in wounding patterns of U.S. war-fighters in Iraq and Afghanistan, blast injury has risen to a new level of importance and is recognized to be a major cause of injuries to the brain. However, an injury risk-function for microscopic, macroscopic, behavioral, and neurological deficits has yet to be defined. While operational blast injuries can be very complex and thus difficult to analyze, a simplified blast injury model would facilitate studies correlating biological outcomes with blast biomechanics to define tolerance criteria. Blast-induced traumatic brain injury (bTBI) results from the translation of a shock wave in-air, such as that produced by an IED, into a pressure wave within the skull–brain complex. Our blast injury methodology recapitulates this phenomenon in vitro, allowing for control of the injury biomechanics via a compressed-gas shock tube used in conjunction with a custom-designed, fluid-filled receiver that contains the living culture. The receiver converts the air shock wave into a fast-rising pressure transient with minimal reflections, mimicking the intracranial pressure history in blast. We have developed an organotypic hippocampal slice culture model that exhibits cell death when exposed to a 530 ± 17.7-kPa peak overpressure with a 1.026 ± 0.017-ms duration and 190 ± 10.7 kPa-ms impulse in-air. We have also injured a simplified in vitro model of the blood–brain barrier, which exhibits disrupted integrity immediately following exposure to 581 ± 10.0 kPa peak overpressure with a 1.067 ± 0.006-ms duration and 222 ± 6.9 kPa-ms impulse in-air. To better prevent and treat bTBI, both the initiating biomechanics and the ensuing pathobiology must be understood in greater detail. A well-characterized, in vitro model of bTBI, in conjunction with animal models, will be a powerful tool for developing strategies to mitigate the risks of bTBI

Assessing Surgical Task Load and Performance: A Comparison of Simulation and Maritime Operation

The article of record as published may be found at http://dx.doi.org/10.1093/milmed/usz297This study examined the effects of simulated and actual vessel motion at high seas on task load and surgical performance. Methods: This project was performed in phases. Phase I was a feasibility study. Phase II utilized a motion base simulator to replicate vessel motion. Phase III was conducted aboard the U.S. Naval Ship Brunswick. After performing surgical tasks on a surgical simulation mannequin, participants completed the Surgical Task Load Index (TLX) designed to collect workload data. Simulated surgeries were evaluated by subject matter experts. Results: TLX scores were higher in Phase III than Phase II, particularly at higher sea states. Surgical performance was not significantly different between Phase II (84%) and Phase III (89%). Simulated motions were comparable in both phases. Conclusions: Simulated motion was not associated with a significant difference in surgical performance or deck motion, suggesting that this simulator replicates the conditions experienced during surgery at sea on the U.S. Naval Ship Brunswick. However, Surgical TLX scores were dramatically different between the two phases, suggesting increased workload at sea, which may be the result of time at sea, the stress of travel, or other factors. Surgical performance was not affected by sea state in either phase.Bureau of Medicine USN; OPNAV N-81 Assessments Division, Medical Analysis Branch; Navy Advanced Medical Development; Naval Surface Warfare Center, PC.Phase I of this study was sponsored by the Office of Naval Research. Phase II was sponsored by the Office of the Chief of Naval Operations (OPNAV) N-81 Assessments Division, Medical Analysis Branch (N813). Phase III was sponsored by the OPNAV N-81 (N813) and Navy Advanced Medical Development (AMD).Bureau of Medicine USN; OPNAV N-81 Assessments Division, Medical Analysis Branch; Navy Advanced Medical Development; Naval Surface Warfare Center, PC.Phase I of this study was sponsored by the Office of Naval Research. Phase II was sponsored by the Office of the Chief of Naval Operations (OPNAV) N-81 Assessments Division, Medical Analysis Branch (N813). Phase III was sponsored by the OPNAV N-81 (N813) and Navy Advanced Medical Development (AMD)

Porcine Head Response to Blast

Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300–2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G’s and were well correlated with peak incident overpressure (R2 = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are presented to provide experimental data for computer model validation

Labelling of electronic cigarettes : regulations and current practice.

More stringent enforcement of regulations is needed to ensure not only the user's safety and awareness, but also the safeguarding of the environment

'If you had only listened carefully...':the discursive construction of emerging leadership in a UK all-women management team

Increasingly, feminist linguistic research has adopted a discursive perspective to learn how women and men 'do' leadership in gendered ways. 'Women' as a social category is made relevant to this study by virtue of the lack of female senior leaders in UK businesses (Sealy and Vinnicombe, 2013). Much previous research has analysed leadership discourse in mixed gender groups, relying on theories that imply comparisons between men and women. Using an Interactional Sociolinguistic approach, this study aims to learn more about how women perform leadership in the absence of men by analysing the spoken interactions of a women-only team who were engaged in a competitive leadership task. The analysis reveals that the women accomplish leadership in multiple and complex ways that defy binary gendered classifications. Nonetheless, there is a distinctive gendered dynamic to the team's interactions which, it is argued, might be disadvantageous to women aspiring to senior positions