Submarine medicine: An overview of the unique challenges, medical concerns, and gaps.

Submariners face many challenges. For example, they "live where they work" and can be called to duty anytime. They have limited access to open space, natural settings, fresh air, fresh food, sunlight, privacy, exercise, and outside communication. They support a wider range of missions than occur aboard most other Navy vessels. At sea or on shore, submariners work long hours under conditions with little margin for error. They may traverse remote or disputed areas of the ocean far from rescue assets, and must remain vigilant for potential encounters with hostile forces, onboard fires, anomalies in the breathing atmosphere, leaks, undersea collisions, or radiation exposures. If any of these factors cause casualties, the Independent Duty Corpsman (with intermittent advice from shore-based medical personnel), must be ready to provide aid as long as necessary. The challenges of submarine service led to the growth of the unique field of submarine medicine, which has maintained an excellent record of health and safety. This review introduces the field of submarine medicine as practiced in the U.S. Navy, describing its major concerns, giving an overview of the operation of a submarine medical department, and identifying several medical gaps that researchers are working to fill. Submarine medicine already has a stellar record in terms of radiation and atmospheric safety and has made strides in fatigue management. Ongoing work will deliver improved psychological screening and support tools. This report summarizes developments in these and other areas of submarine medicine.

Motion sickness diagnostic criteria: Consensus Document of the Classification Committee of the Bárány Society.

We present diagnostic criteria for motion sickness, visually induced motion sickness (VIMS), motion sickness disorder (MSD), and VIMS disorder (VIMSD) to be included in the International Classification of Vestibular Disorders. Motion sickness and VIMS are normal physiological responses that can be elicited in almost all people, but susceptibility and severity can be high enough for the response to be considered a disorder in some cases. This report provides guidelines for evaluating signs and symptoms caused by physical motion or visual motion and for diagnosing an individual as having a response that is severe enough to constitute a disorder.   The diagnostic criteria for motion sickness and VIMS include adverse reactions elicited during exposure to physical motion or visual motion leading to observable signs or symptoms of greater than minimal severity in the following domains: nausea and/or gastrointestinal disturbance, thermoregulatory disruption, alterations in arousal, dizziness and/or vertigo, headache and/or ocular strain. These signs and/or symptoms occur during the motion exposure, build as the exposure is prolonged, and eventually stop after the motion ends. Motion sickness disorder and VIMSD are diagnosed when recurrent episodes of motion sickness or VIMS are reliably triggered by the same or similar stimuli, severity does not significantly decrease after repeated exposure, and signs/symptoms lead to activity modification, avoidance behavior, or aversive emotional responses.   Motion sickness/MSD and VIMS/VIMSD can occur separately or together. Severity of symptoms in reaction to physical motion or visual motion stimuli varies widely and can change within an individual due to aging, adaptation, and comorbid disorders. We discuss the main methods for measuring motion sickness symptoms, the situations conducive to motion sickness and VIMS, and the individual traits associated with increased susceptibility. These additional considerations will improve diagnosis by fostering accurate measurement and understanding of the situational and personal factors associated with MSD and VIMSD.

Computerized Tests of Team Performance and Crew Coordination Suitable for Military/Aviation Settings.

INTRODUCTION: The coordination of team effort on shared tasks is an area of inquiry. A number of tests of team performance in challenging environments have been developed without comparison or standardization. This article provides a systematic review of the most accessible and usable low-to-medium fidelity computerized tests of team performance and determines which are most applicable to military- and aviation-relevant research, such as studies of group command, control, communication, and crew coordination. METHODS: A search was conducted to identify computerized measures of team performance. In addition to extensive literature searches (DTIC, Psychinfo, PubMed), the authors reached out to team performance researchers at conferences and through electronic communication. RESULTS: Identified were 57 potential tests according to 6 specific selection criteria (e.g., the requirement for automated collection of team performance and coordination processes, the use of military-relevant scenarios). The following seven tests (listed alphabetically) were considered most suitable for military needs: Agent Enabled Decision Group Environment (AEDGE), C3Conflict, the C3 (Command, Control, & Communications) Interactive Task for Identifying Emerging Situations (NeoCITIES), Distributed Dynamic Decision Making (DDD), Duo Wondrous Original Method Basic Awareness/Airmanship Test (DuoWOMBAT), the Leader Development Simulator (LDS), and the Planning Task for Teams (PLATT). Strengths and weaknesses of these tests are described and recommendations offered to help researchers identify the test most suitable for their particular needs. DISCUSSION: Adoption of a few standard computerized test batteries to study team performance would facilitate the evaluation of interventions intended to enhance group performance in multiple challenging military and aerospace operational environments.Lawson BD, Britt TW, Kelley AM, Athy JR, Legan SM. Computerized tests of team performance and crew coordination suitable for military/aviation settings. Aerosp Med Hum Perform. 2017; 88(8):722-729.

The Neurovestibular Challenges of Astronauts and Balance Patients: Some Past Countermeasures and Two Alternative Approaches to Elicitation, Assessment and Mitigation.

Astronauts and vestibular patients face analogous challenges to orientation function due to adaptive exogenous (weightlessness-induced) or endogenous (pathology-induced) alterations in the processing of acceleration stimuli. Given some neurovestibular similarities between these challenges, both affected groups may benefit from shared research approaches and adaptation measurement/improvement strategies. This article reviews various past strategies and introduces two plausible ground-based approaches, the first of which is a method for eliciting and assessing vestibular adaptation-induced imbalance. Second, we review a strategy for mitigating imbalance associated with vestibular pathology and fostering readaptation. In discussing the first strategy (for imbalance assessment), we review a pilot study wherein imbalance was elicited (among healthy subjects) via an adaptive challenge that caused a temporary/reversible disruption. The surrogate vestibular deficit was caused by a brief period of movement-induced adaptation to an altered (rotating) gravitoinertial frame of reference. This elicited adaptation and caused imbalance when head movements were made after reentry into the normal (non-rotating) frame of reference. We also review a strategy for fall mitigation, viz., a prototype tactile sway feedback device for aiding balance/recovery after disruptions caused by vestibular pathology. We introduce the device and review a preliminary exploration of its effectiveness in aiding clinical balance rehabilitation (discussing the implications for healthy astronauts). Both strategies reviewed in this article represent cross-disciplinary research spin-offs: the ground-based vestibular challenge and tactile cueing display were derived from aeromedical research to benefit military aviators suffering from flight simulator-relevant aftereffects or inflight spatial disorientation, respectively. These strategies merit further evaluation using clinical and astronaut populations.

Military Occupations Most Affected by Head/Sensory Injuries and the Potential Job Impact of Those Injuries.

OBJECTIVE: Identifying Department of Defense (DoD) occupations affected by injuries to the head and sensory systems. METHODS: We explored the Defense Medical Epidemiology Database to identify occupations with the highest incidence of injured personnel, then ranked how frequently they occurred in a top 10 list for each of four injury categories (head/brain, visual, auditory, vestibular) encompassing 25 injury codes. Across all four categories, the most affected occupations were identified, among which we chose three Army combat-related military occupational specialties (MOSs) for detailed study. We identified skills needed to perform these MOSs and explored whether MOS-critical deficits could be expected following the injuries. RESULTS: Some DoD occupations are more likely to suffer from these injuries, including Infantry, Combat Operations Control, Artillery/Gunnery, Motor Vehicle Operator, Combat Engineering, and Armor/Amphibious. Within these DoD occupations, we explored three Army combatant MOSs: Infantry (11B), Cavalry Scout (19D), and Artillery (13B), confirming that these jobs are likely to be disrupted by injuries within the four categories. CONCLUSIONS: Head and sensory injuries disproportionately affect certain military occupations. Relatively few injuries disrupt combat-related abilities that are job critical (e.g., firearms operation) and job specific (e.g., Artillery gunnery problems); these should be the focus of efforts to improve rehabilitation and RTD outcomes.

Motion sickness and sopite syndrome associated with parabolic flights: a case report.

OBJECTIVE: The purpose of this paper was to provide an extensive description of a case of sopite syndrome, a manifestation of motion sickness scarcely described in the literature. DESIGN: The following questionnaires were used to assess sopite syndrome symptoms pre, during and post parabolic flight; Misery Scale rate, Positive and Negative Affect Scale, the Motion Sickness Assessment Questionnaire and the Epworth Sleepiness Scale. STUDY SAMPLE: Case report of a 35-year old female compared to a control group (n = 26). RESULTS: We describe of sopite syndrome during parabolic flight. The subject reported drowsiness and she noted mood changes such as irritation and annoyance. Furthermore, she was not able to perform her assigned task. Her symptoms escalated into extreme fatigue and the inability to stay awake. Nauseogenic symptoms improved, but soporific symptoms persisted for several hours after the motion stimulus (i.e. parabolic flight). CONCLUSIONS: This case points towards the need for controlled studies to assess the prevalence of this syndrome among the general population and select groups. Future research should focus on developing tests for personnel screening and explore treatment options.

Functional screening for vestibular and balance problems soon after head injury: options in development for the field or aid station.

Vestibular balance dysfunction has been documented as a military problem after duty-related barotrauma and/ or traumatic head acceleration. We are fostering the development of rapid, portable, fieldable tests of balance function after such vestibular insults. We consulted on military-relevant tests with more than 50 vestibular researchers, scientific advisors, clinicians, and biomedical engineers working for government agencies, universities, clinics, hospitals, or businesses. Screening tests and devices appropriate for early (post-injury) military functional assessment were considered. Based on these consultations, we recommend that military field tests emphasize dynamic, functional, and duty-relevant aspects of standing balance, gait, visual acuity, perception of visual vertical, and vertigo. While many current tests are useful for the clinic, they often require modification before they are suitable for military field and aid station settings. This report summarizes likely future military testing needs, giving priority to testing approaches in development that promise to be rapid, portable, fieldready, semiautomated, usable by a nonspecialist, and suitable during testing and rehabilitation.