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Technical Reports
Technical Reports
A technical report is a technical document that records and disseminates methods and results from research studies and research,
development, test, and evaluation (RDT&E) activities. Technical reports are USAARL's principal method of in-depth reporting on
technical subjects that are of interest not only to the department, agency, or command sponsoring the work, but also to external
groups and laboratories in government, academia, and industry. Technical reports may vary in type, to include technical reports
that present the findings of research or analyses or that provide guidance or instruction on matters important to the DoD, journal
articles (open access and embargoed text) that have been published under an open access agreement with the publisher or published
under a Creative Commons license, conference proceedings that include whole collections of papers presented at a symposium or
workshop, and conference papers that could include an individual paper, briefing charts, or a poster presented at a workshop or
symposium. For inquiries related to USAARL's technical report(s), contact
usarmy-usaarl-library@health.mil.
Featured Reports
For more reports, please visit the technical reports archive page.
SIZE:948 KB
DTIC #:AD1329027
TITLE:Unmanned Aerial Systems Injury Risks in Military Applications
AUTHOR(s):Gleason, A. J., Brozoski, F., Rooks, T., Johnson, B. A., Rhodes, D., McEntire, B. J., & Chancey, V. C.
ABBREVIATED ABSTRACT:The U.S. Army Aeromedical Research Laboratory received a request from the Unmanned Aerial Systems (UAS) branch of the U.S. Army Aviation Center of Excellence for information on impact characteristics, energy transfer mechanics, and human injury risks associated with UAS use in military applications. This report summarizes findings reported in a briefing given by the Injury Biomechanics and Protection Group at the 2025 Army Aviation Unmanned Aircraft Systems/Launched Effects Summit along with additional discussion on currently available UAS safety standards and injury criteria. Currently available civilian UAS safety standards are discussed along with their origins and associated limitations. There have been recent efforts to update the injury risk limits in current standards to reflect the specific mechanics of UAS to human impacts, but results from those efforts are still limited in their applicability. Large scale efforts in other areas (i.e., automotive, sports, military) have developed a wealth of injury criteria that may be useful in the UAS space, but work is needed to determine applicability to military UAS exposures. This effort has revealed the need for a military-specific UAS safety standard. Collection of military-specific epidemiological data on UAS injuries, and creation of a test methodology to determine the risk UAS pose to personnel in training and operational environments are the next steps toward creating that standard.
KEYWORDS:unmanned aircraft systems, unmanned aerial systems, UAS, drone, injury risk curve, Abbreviated Injury Scale, anthropomorphic test device, FAA 14 CFR 107, ASTM F3389/3389M, Range Commanders Council
SIZE:1.8 MB
DTIC #:AD1329024
TITLE:Optimizing Adaptive Automation in Aviation: A Literature Review on Dynamic Automation System Interaction
AUTHOR(s):Atchley, J. A., Vogl, J., Ranes, B., Mackie, R., McCurry, C., & Bommer, S.
ABBREVIATED ABSTRACT:A current goal of operator state monitoring research is developing models that predict an operator's cognitive workload (CWL) in real-time to support adaptive automation. It is common in the literature for researchers to create different demand levels for studies involving workload as a manipulation; however, the implementation of automation invalidates these demand levels. The U.S. Army Aeromedical Research Laboratory Multi-Attribute Task Battery (USAARL MATB; a desktop aviation simulator) was utilized because of its inclusion of controllable demand levels and automation functionality. The approach to calculating computational Multiple Resource Theory (cMRT) interference scores and Improved Performance Research Integration Tool (IMPRINT) scores provided by Wickens (2002) and Mitchell (2000), respectively, were applied to the USAARL MATB to calculate theoretical workload values for each possible task combination and automation status. Findings indicate that the scores generated by both approaches were related to performance, subjective workload, and heart rate, supporting the idea that these scores are reflective of CWL and could be a viable replacement for demand levels in research manipulating workload.
KEYWORDS:cognitive workload, operator state monitoring, aviation, USAARL MATB, IMPRINT, cMRT
SIZE:2.4 MB
DTIC #:AD1325426
TITLE:Comparing Visual Outcomes of Keratorefractive Lenticule Extraction, PRK, and LASIK Procedures in the Military Population (Reprint)
AUTHOR(s):Evangelista, C., Harris, J., Trinh, T., Kohler, P., Mackie, R., Turovets, S., Aden, J., & Capo-Aponte, J.
ABBREVIATED ABSTRACT:Purpose: To assess the 6-month visual and refractive outcomes of keratorefractive lenticule extraction (KLEx) as compared with laser in situ
keratomileusis (LASIK) and photorefractive keratectomy (PRK) in a military population at a Joint Warfighter Refractive Surgery Center.
Setting: Joint Warfighter Refractive Surgery Center (JWRSC), Lackland Air Force Base, San Antonio, Texas.
Design: Retrospective study.
Methods: Patients who underwent KLEx, PRK, or LASIK between 2019 and 2022 were included. Anonymized data collected included demographics, preoperative and postoperative uncorrected and corrected visual acuity, and manifest refraction.
Results: Of the 4466 treated eyes, 737 (16.5%) underwent the KLEx, 2801 (62.7%) underwent PRK, and 928 (20.8%) underwent LASIK treatment. Regarding efficacy, there was no statistically significant difference at postoperative month (POM) 6 between the percentage of eyes reaching an uncorrected distance visual acuity of 20/20 or better between the three procedures. At POM1 (P <.001) and POM3 (P < .001), there were a greater number of eyes in the KLEx group that achieved the same or one line better of distance visual acuity than the PRK group. The efficacy indices of KLEx, PRK, and LASIK at POM6 were 1.09, 1.10, and 0.97, respectively. The safety indices for KLEx, PRK, and LASIK at POM6 were 0.96, 1.01, and 0.81, respectively.
Conclusions: After the initial recovery period, KLEx demonstrates comparable outcomes in efficacy, safety, and accuracy as compared with LASIK and PRK.
KEYWORDS:keratorefractive lenticule extraction, KLEx, PRK, LASIK, military vision
SIZE:1.1 MB
DTIC #:AD1325407
TITLE:Investigating the Benefits and Operational Gaps of 3D Spatial Audio Technology in Aircraft
AUTHOR(s):Noetzel, J., & Brunner, L.
ABBREVIATED ABSTRACT:Three-dimensional spatial audio technology, commonly known as 3D audio, has emerged as a promising tool to enhance communication, situational awareness, and optimize pilot performance in military aircraft. This technology creates a realistic sound environment by allowing listeners to perceive sound as if it is coming from different directions and distances. The implementation of a 3D audio system (3DAS) in military aircraft can improve communication in multi-channel environments, mitigate challenges associated with hearing in noisy settings, and reduce cognitive workload for pilots. Previous research has shown that a 3DAS leads to increased understanding of verbal messages, quicker target acquisition, and aids in threat and collision avoidance.
To gather feedback on the benefits and limitations of 3D spatial audio technology, a 28-question survey was administered to A-10 aircraft pilots who have operational experience using a 3DAS. The survey collected demographic information and asked about the benefits of 3D audio, training experiences, operational gaps, and key mission areas where 3D audio was beneficial. The survey had 16 respondents.
Overall, there was general acceptance and benefits were noted by users. Radio separation emerged as notable benefit in both multiple choice and open text responses. Pilots annotated customizable radio placement and volume adjustments for different channels, as well as the need for noise reduction. Training experiences were varied, including classroom instruction, hands-on training, simulator training, and briefings. Proper fitting of the ear cups in the helmet was emphasized for optimal performance as well. The primary operational gap of the 3D audio system identified is its susceptibility to failure, which can lead to potential performance degradation. Issues included the system entering fallback mode, loss of noise canceling features, and audio loss from certain sources, making it a single point of failure that affects overall effectiveness and focus.
Overall, the survey provided valuable insights into the utilization, benefits, training experiences, and operational gaps of 3D audio technology in military aircraft operations. Majority of respondents found the technology to be beneficial, although there were some limitations and individual preferences regarding customization and adjustability. Further research should explore the integration of 3D audio and active noise reduction technologies to optimize their effectiveness. Additionally, investigations are needed to assess the efficacy of 3D audio in pilots with hearing loss and explore customization options for individual hearing needs, using real-world experiences and feedback to guide future research and development.
KEYWORDS:three-dimensional audio, 3D audio, 3D audio system, 3DAS, A-10, aviation communication
SIZE:1.3 MB
DTIC #:AD1325443
TITLE:U.S. Army Syphilis Testing
ABBREVIATED ABSTRACT:This study determined the prevalence of syphilis among military populations and compared the Centers for Disease Control's (CDC) two screening algorithms, traditional (i.e., nontreponemal) and reverse (i.e., treponemal), for syphilis serological testing to make informed policy recommendations regarding screening practices. A retrospective descriptive study of the prevalence of syphilis in the Department of Defense (DoD), specifically the Army aviator and Navy diver communities, was completed using the Defense Medical Epidemiological Database (DMED). Overall, the prevalence of syphilis in the DoD was higher from 2016 to 2018 when compared to the national population. No statistically significant correlation was found between a reported diagnosis of syphilis and occupational status, specifically the military occupational specialties (MOS) of Army aviator and Navy diver. These communities had a notably lower reported prevalence of syphilis when compared to the larger DoD. The Army branch of service and Army Aviation community were also found to have a reduced risk of reported disease (i.e., protective factors), especially compared to the Navy branch of Service from odds ratios (OR) calculated in the study. The traditional algorithm is the most appropriate screening method in the DoD and specific military occupations, such as Army aviator and Navy diver.
KEYWORDS:syphilis, reverse algorithm, traditional algorithm, nontreponemal, treponemal, serological testing, defense medical epidemiological database (DMED), military occupational specialties (MOS), prevalence
SIZE:1.3 MB
DTIC #:AD1325398
TITLE:Relationships between Individual Differences, Physiological Measures, Cognitive Workload, and Task Performance: Implications for Operator State Monitoring
AUTHOR(s):Kelley, A. Yue, X., Aura, C., Feltman, K., Mackie, R., & Brooks, J.
ABBREVIATED ABSTRACT:The potential to monitor operator states and predict future performance deficits in real-time using physiological metrics continues to expand. Technological advancements continue to drive operator state monitoring (OSM) forward in terms of wearable sensors, data synchronization, and feasibility of use in applied settings. Likewise, advancements in understanding the relationships between physiological measurements, performance, and cognitive states are key to the development of a predictive model with acceptable levels of accuracy and classification. Individual differences, both within- and between-operators, introduce error into the model and need to be accounted for during computation in order to boost model performance. The main objective of this study was to identify and control for both stable (e.g., demographics) and dynamic (e.g., baseline physiology) sources of variance. Results indicated support for electroencephalogram derived measures of cognitive workload, demographic information (education level), and differences in perceived workload as predictors of performance deficits. The resultant sample size limited the analyses and thus further research is warranted.
KEYWORDS:operator state monitoring, cognitive workload, performance, electroencephalogram
SIZE:1.1 MB
DTIC #:AD1318262
TITLE:An Evaluation of tDCS Intensities for Aviator Performance Enhancement: Comparison of 1 mA, 1.5 mA, and 2mA
AUTHOR(s):Feltman, K. A., Mackie, R., Basso, J., & Yue, X.
ABBREVIATED ABSTRACT:Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that has been shown to impact performance. In using tDCS, a researcher must select a number of parameters that can each impact the effects tDCS has on behavioral outcomes. One such parameter is the selection of the stimulation intensity. Previous research within our laboratory has demonstrated the utility of tDCS in improving aviator performance using an intensity of 2 milliamperes (mA). However, recent research suggests that lower intensities such as 1 or 1.5 mA may have greater effects on performance. Additionally, a number of individual differences can impact the effectiveness of tDCS. To determine which intensity to use in an upcoming study, a pilot study was conducted where six Army aviators experienced each of the following three intensity values (on separate days): 1 mA, 1.5 mA, and 2 mA. Stimulation was applied during a simulated flight scenario and a number of individual difference measures were collected. Results determined that 1.5 mA demonstrated consistent trends of improving performance. Additionally, individual difference measures such as intelligence and behavioral inhibition were found to have an effect on the outcomes.
KEYWORDS:performance enhancement, transcranial direct current stimulation, aviation
SIZE:2.6 MB
DTIC #:AD1318260
TITLE:The Physical Basis of Spatial Disorientation in Flight: A Scoping Review
AUTHOR(s):Sharma, K., Petrassi, F., D'Alessandro, M., Temme, L., Billock, V., & Campbell, B.
ABBREVIATED ABSTRACT:Spatial disorientation (SD) directly interferes with an aviator's ability to maintain proper flight metrics and often results in devastating consequences. To avoid SD, the aviator must be aware of the obstacles and challenges they may encounter in flight that could cause SD. A deeper understanding of the physical and physiological phenomenon resulting in SD may increase the aviator's ability to respond appropriately when the illusion(s) impact cognition, reasoning/decision making, and general awareness. The vestibular system plays a vital role in the balance and regulation of spatial awareness. We have applied a multidisciplinary approach, including physics, physiology, and state of perception, to bridge many fundamental concepts of how the vestibular system physiologically functions (creating perceptions and responses) and how external forces and variables affect those functions. From a physical standpoint, we explain how the kinematics of aircraft motion can create perceptual illusions that contribute to SD. We provide relevant flight review examples from the aerospace environment. We integrated the physics of those phenomena with perceptual and physiological effects to give a synoptic framework for understanding SD.
KEYWORDS:spatial disorientation, aviation, vestibular, aerospace
SIZE:4.1 MB
DTIC #:AD1314714
TITLE:Holistic Situational Awareness and Decision Making Operator State Monitoring Final Report
AUTHOR(s):Godfroy-Cooper, M., Miller, J. D., Alicia, T. , Yue, X., Bachelder, E., Turovets, S., Mackie, R., Feltman, K., Mielcarek, N., Szoboszlay, Z., Takahashi, M., Whalley, M., Goerzen, C., Lusardi, J., Fujizawa, B., & Shivers, M.
ABBREVIATED ABSTRACT:The Operator State Monitoring (OSM) study is one component of the Holistic Situational Awareness and Decision Making (HSA-DM) program. The HSA-DM program is focused on identifying cognitive workload (WL) drivers and developing cognitive workload management capabilities. The OSM effort was utilized to explore the validity and reliability of metrics selected for the monitoring of pilot WL and to provide recommendations for operationalization in future Army aircraft. The U.S. Army Combat Capabilities Development Command (DEVCOM) Aviation & Missile Center (AvMC) recruited 24 volunteer participants with relevant experience to complete challenging aeromedical evacuation (MEDEVAC) scenario vignettes in reconfigurable rotary-wing flight simulators. Over the course of two evaluations utilizing advanced cueing and autonomy design solutions, the pilots' workload was assessed using a variety of techniques. The findings indicate strengths and limitations of each assessment in an operational setting and recommend a hybrid approach of complementary assessment techniques to provide a holistic view of workload and the subsequent impact on Warfighter performance.
KEYWORDS:operator state, situation awareness, cognitive workload, workload models, autonomy
SIZE:1.1 MB
DTIC #:AD1313907
TITLE:Optimizing Adaptive Automation in Aviation: A Literature Review on Dynamic Automation System Interaction
AUTHOR(s):Vogl, J., D'Alessandro, M., Wilkins, J., Ranes, B., Persson, I., McCurry, C. D., & Bommer, S.
ABBREVIATED ABSTRACT:This literature review examines the evolution of adaptive automation in aviation, comparing foundational research with modern advancements (2013-2023) to identify best practices for future automated systems. Automation has been pivotal in reducing pilot workload and enhancing safety; however, it also introduces challenges such as over-reliance, disengagement, and diminished situational awareness. With the growing complexity of modern military aircraft systems and increasingly dynamic operational environments, adaptive automation offers a promising solution by dynamically adjusting to the pilot's workload and environmental conditions. Key areas explored include automation activation processes-static, adaptable, and adaptive-and their respective impacts on safety and operator performance. Literature review findings emphasize the importance of maintaining situational awareness, particularly during automation handoffs. Transparency in automation interfaces is crucial, ensuring pilots remain informed about system decisions and actions both in real-time and in near-future projections. This is especially important in high-stakes environments, where failure to properly manage automation transitions can lead to catastrophic outcomes.
KEYWORDS:adaptive automation, operator state monitoring, aviation
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Last Modified Date: 2023-04-14
