Tactile cues for orienting pilots during hover over moving targets.

INTRODUCTION: Providing information via the tactile sensory system allows the pilot to increase awareness without further taxing the visual and auditory perceptual systems. In this study, tactile cues were presented to pilots for target orientation during a simulated helicopter extraction over a moving target. The efficacy of the cues provided by the tactile system was assessed under various conditions (rested vs. fatigued, clear vs. degraded visual environment). METHODS: This study employed a mixed-model 2(4) factorial design, including one between-subjects variable (training amount: minimal, additional) and three within-subjects variables (state: rested, fatigued; visual environment: clear, degraded; tactile cue belt: active, inactive). Across 2 d under the 4 test conditions, 16 UH-60 rated, healthy aviators completed 8 sessions of 10-min stabilized hovering maneuvers over a moving target. All flights were conducted in a UH-60 flight simulator. RESULTS: Subjects were able to stay closer to the target when the tactile cuing system was active (M = 31.14 ft, SE = 3.17 ft) vs. inactive (M = 36.33 ft, SE = 2.84 ft). Likewise, subjects rated their situation awareness as greater when the tactile system was active vs. inactive. DISCUSSION: The results support the efficacy of the tactile system in providing directional cues for maintaining pilot performance during a hover maneuver over a moving target.

Modafinil as a potential motion sickness countermeasure.

INTRODUCTION: Motion sickness adversely affects military air and sea operations. Medications help prevent motion sickness but are frequently associated with side effects. Better medications or combinations of medications are needed. Dextroamphetamine has documented anti-motion sickness effects but also has a potential for abuse. Modafinil is a relatively new central nervous system stimulant that has none of the drawbacks of dextroamphetamine, but has not been evaluated for the treatment of motion sickness. METHODS: This double-blind, placebo-controlled study evaluated the anti-motion sickness efficacy of modafinil, alone or in combination with oral scopolamine. Moderate nausea was induced via a Coriolis cross-coupling stimulus. There were 60 participants who were assigned randomly to 1 of 3 conditions: 1) 2 placebo pills (DP); 2) modafinil plus placebo (MP); or 3) modafinil plus oral scopolamine (MS). The primary measure of drug efficacy was the number of head tilts tolerated upon reaching moderate nausea for 1 min without abatement. RESULTS: The combination of modafinil and scopolamine (MS) allowed subjects to tolerate significantly more head tilts than placebo, but modafinil alone (MP) failed to differ significantly from placebo (DP). No significant cognitive performance decrements were observed among the three experimental conditions. CONCLUSION: Modafinil was not found to be more effective than placebo. Further testing is recommended to determine whether the potentially promising combination of modafinil and scopolamine provides better efficacy or fewer side effects than scopolamine administered alone.

Defining Normal Balance for Army Aviators.

INTRODUCTION: One challenge clinicians face is determining when a military Service Member (SM) can return to duty after an injury that affects the postural control. The gold standard to measure postural control is the Sensory Organization Test (SOT). This test measures the amount of sway present in an individual's static stance that may be used to examine range of function and monitor recovery from injury. Normative values currently available were developed using a sample of clinically normal adults from the general population (i.e., civilian non-aviator). Previous research suggests that these values should not be used as a comparative cohort for high-performing populations in the military. However, normative values, specific to military SMs, do not exist. The aim of this study was to develop a normative clinical database for functional balance (i.e., the SOT) for military-trained aviators, an occupational specialty that may consist of high performers. MATERIALS AND METHODS: Forty-three U.S. Army trained aviators, between 23 and 40 years old with medical clearance for flight operations from the Fort Rucker, Alabama area community consented and participated in this study. The SOT was delivered using the NeuroCom SMART EquiTest Clinical Research System with the Data Acquisition Toolkit (version 9.3). RESULTS: A statistically significant (p < 0.01) difference between the study cohort of Army-trained aviators and the publically available general civilian normative values was found for the more challenging conditions, in which the force plate was not fixed (i.e., conditions four through six). The study cohort of Army-trained aviators were found to have a higher equilibrium score in each of these three conditions. Similarly, a significant difference (p < 0.01) between the two cohorts was found on the visual and vestibular sensory analysis ratios, and the visual preference scores (i.e., greater reliance upon visual information in the maintenance of balance). The study cohort were found to have a higher ratios (i.e., greater dependence upon these sensory cues) in each of these conditions. CONCLUSION: Army-trained aviators are high-functioning performers whose SOT scores differ from that of the general civilian population, particularly for the more challenging test conditions. New normative values were developed from this study population. Use of the developed normative values could be used as a comparative cohort in screening aviators who are recovering from injuries that affect postural stability.