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.

Download '2026-07' report PDF

SIZE:1.3 MB

DTIC #:AD1349413

TITLE:Real-Time Multi-Sensor Data Collection and Processing: Challenges, Opportunities, and Insights From an Expert Panel Survey

AUTHOR(s):Yue, X., Aura, C. J., Atchley, J. A.

ABBREVIATED ABSTRACT:Monitoring and evaluating aviator's cognitive states in real-time using neurophysiological and physiological signals recorded from wearable multi-sensor systems holds promise for enhancing flight safety and improving mission success. However, several key challenges must be addressed to realize this vision. These includes synchronizing signals across different modalities, implementing robust real-time data cleaning pipelines, developing effective methods for multi-sensor data fusion, and overcoming computational constraints associated with real-time processing and model inference. This report synthesizes expert insights gathered through the targeted survey, highlighting potential solutions to these challenges and outlining strategies for enhancing real-time cognitive state monitoring and performance prediction in operational cockpit settings.

KEYWORDS:multi-sensor recording, EEG, ECG, fNIRS, synchronization

Download '2026-06' report PDF

SIZE:1.4 MB

DTIC #:AD1349412

TITLE:Evaluation of a Commercial EEG System beneath the Aviator's Helmet: Data Quality and Comfortability

AUTHOR(s):Feltman, K. A., Wilkins, J., Andres, K., Basso, J., & Yue, X.

ABBREVIATED ABSTRACT:A non-research activity was conducted to assess the comfort and signal quality of a research electroencephalography (EEG) system beneath the aviator's helmet. Three aviators participated in the activity. The EEG system was evaluated using two helmet liner types to determine comfort and quality of the EEG signal. Each aviator wore the EEG beneath each liner type for a total of one hour of simulated flight. Activities to increase movement by the aviators occurred throughout the flights to further test signal quality. Subjective measures were taken to assess comfort. Overall, both liners resulted in significant discomfort after an hour of wear; however, one liner was preferred by two of the three aviators. Regarding signal quality, both liners resulted in usable EEG signals. In the current set up, it is not recommended to use the EEG beneath the helmet in research studies exceeding 30 minutes of wear. However, there may be ways to improve comfort, which should be further explored to determine whether the EEG can comfortably be worn beneath the helmet beyond 30 minutes.

KEYWORDS:EEG, helmet, aviation

Download '2026-05' report PDF

SIZE:3 MB

DTIC #:AD1349406

TITLE:Review of Post-Mortem Human Subject Thoracic Response of Blunt Non-Penetrating Ballistic Impact to Determine Surrogate Biofidelity Requirements

AUTHOR(s):Lynch, C., Conti, S. M., Rhodes, D., & McEntire, B. J.

ABBREVIATED ABSTRACT:When body armor successfully defeats a ballistic threat, the underlying surface experiences a dynamic deformation which creates a blunt insult to the wearer. Energy transmitted from the armor's local backface deformation (BFD) to the wearer can produce high loading rates with sufficient deformation to produce trauma to the underlying soft tissues and skeletal structures. Resulting BFD injuries are region-specific because of the anatomical structures in different areas of the thorax, thus selected surrogates may require varied material properties to properly mimic the diverse responses. Current test standards use Roma Plastilina #1 (RP1) clay to measure impact severity by indentation (Bolduc & Anctil, 2010; Shewchenko et al., 2020); however, the current standards are inadequate due to the homogeneous material used and their inability to assess injury to the thorax. Researchers at the U.S. Army Aeromedical Research Laboratory have highlighted the need for better thoracic biofidelity in ballistic scenarios because current models, while more sophisticated, still struggle to accurately replicate complex human responses in military scenarios. This report provides a review of published research in open literature describing the physical surrogates used to study behind armor blunt trauma (BABT) resulting from blunt ballistic impacts to the thoracic region with a focus on studies that developed biomechanical response corridors derived from post-mortem human subject data. Despite advancements, current surrogates often fall short in replicating the complex dynamic responses of human tissues, and the lack of standardized biofidelity metrics and testing protocols hinders comparison and reliability across studies. Additionally, establishing post-mortem human subject biofidelity corridors for regions beyond the thorax, such as the abdominal area, is crucial for developing a fully biofidelic surrogate. By advancing the development of highly biofidelic thoracic surrogates, researchers can enhance the testing and evaluation of protective equipment (such as body armor), deepen their understanding of thoracic injury mechanisms, and develop more effective strategies for preventing and mitigating ballistic injuries, ultimately contributing to improved safety and health outcomes in military and civilian contexts.

KEYWORDS:human thoracic biofidelity, biomechanical response corridors, ballistic, non-penetrating, behind armor blunt trauma

Download '2026-04' report PDF

SIZE:2.6 MB

DTIC #:AD1349405

TITLE:Injury Assessment Reference Values for the Hybrid III 95th Percentile Male Pedestrian Anthropomorphic Test Device Lumbar Spine under Vertical Loading

AUTHOR(s):Schlick, M., Rhodes, D., Johnson, B., Logsdon, K., Chancey, V. C., & McEntire, B. J.

ABBREVIATED ABSTRACT:The U.S. Army Aeromedical Research Laboratory (USAARL) developed injury assessment reference curves (IARCs) for the Hybrid III 95th percentile male pedestrian (HIII-95M-PED) anthropomorphic testing device (ATD) representing larger occupants. The HIII-95M-PED was used instead of the standard HIII-95M due to availability. The major differences between the two ATDs is that the pelvis of the pedestrian ATD has a sit-to-stand hip range of motion and a straight lumbar spine as opposed to the standard ATD that has a seated molded pelvis with limited hip range of motion and a curved lumbar spine. Male post-mortem human subject (PMHS) injury data were leveraged for this study from prior work by Lafferty et al. (2020). The HIII-95M-PED lumbar axial load cell performance IARV was determined for a 10% risk of thoracolumbar spinal injury (AIS 2+).

KEYWORDS:lumbar spine, vertical accelerative testing, lumbar injury, vertical loading, injury assessment reference values, IARV, Male, 95th percentile male, Hybrid III, HIII, pedestrian pelvis, thoracolumbar spinal injury, Abbreviated Injury Scale (AIS)

Download '2026-03' report PDF

SIZE:1.9 MB

DTIC #:AD1349404

TITLE:Identifying the Top Factors and Stressors Impacting Flight Performance: A Survey of Army Aviators

AUTHOR(s):Feltman, K. A., Wilkins, J., Duffy, M. J., Wolf, S., Wood, M., & Gerstner, J.

ABBREVIATED ABSTRACT:A descriptive survey of U.S. Army aviators was completed. The purpose of the survey was to identify the most prevalent occupational stressors impacting aviators' performance. In addition, female aviators were asked questions specific to health concerns. Forty-five aviators completed the survey, with the majority being UH-60 pilots. Fatigue, weather, and task saturation were most commonly identified as factors impacting performance. For females, genitourinary and anthropometric health issues were identified as being of concern. The outcomes of the survey will help shape future research.

KEYWORDS:Army aviation, performance, occupational stressors, female health

Download '2026-02' report PDF

SIZE:2.1 MB

DTIC #:AD1349400

TITLE:Designing Adaptive Automation for Aviation: Transparency and Handoff Effects on Cognitive Workload, Situational Awareness, and Trust

AUTHOR(s):Vogl, J., Atchley, A., Basso, J., Bommer, S. McCurry, C.

ABBREVIATED ABSTRACT:Military aviation increasingly depends on automation to manage complex missions, yet static or pilot-initiated systems risk misuse, disuse, or over-reliance. Adaptive automation offers a potential solution by dynamically adjusting autonomy in response to operator state. This study examined two foundational design features, system transparency (transparent vs. opaque displays of automation state and rationale) and handoff method (voluntary vs. forced activation), to examine their effects on pilot cognitive workload (CWL), situational awareness (SA), and trust in automation.

KEYWORDS:adaptive automation, operator state, cognitive workload, situational awareness

Download '2026-01' report PDF

SIZE:1.2 MB

DTIC #:AD1349399

TITLE:The Relationship Between Trust, Control, and Automation Reliance in High-Demand Aviation Tasks

AUTHOR(s):Ranes, B., Vogl, J., & Atchley, J. A.

ABBREVIATED ABSTRACT:Trust in automation (TIA) is a critical factor in aviation safety and performance, yet the extent to which self-reported trust aligns with actual automation use remains unclear. This study investigated relationships among trait, state, and behavioral measures of TIA in a simulated multitasking aviation environment. Seventeen active-duty military aviators completed four trials of the USAARL Multi-Attribute Task Battery-II (MATB-II), during which automation was available across four subtasks. Automation reliability (70-percent vs. 90-percent) and task load order were varied within subjects. Participants completed standardized self-report measures of trait TIA (Adapted Propensity to Trust in Technology Questionnaire), state TIA (Checklist for Trust between People and Automation), and workload, alongside behavioral indicators of automation engagement: Reliance (time automation was engaged), delegation (user-initiated use), and compliance (prompt-initiated use). Data were analyzed using linear and generalized linear mixed-effects models. Results showed that reliance on automation significantly improved task performance, with a 10-percent increase in automation use corresponding to a 1.06-point improvement in task score (p < .001). In contrast, reliance did not reduce perceived workload (p = .957). Trait TIA significantly predicted state TIA (?? = 1.38, p = .047), but neither predicted behavioral use of automation (all p > .48). Instead, contextual factors drove automation engagement: Delegation was more likely in dynamic subtasks such as resource management and tracking (both p < .001), whereas higher cognitive workload increased compliance (p < .001). Delegation exerted a stronger effect on sustained reliance than compliance (?? = 0.309 vs. ?? = 0.193, both p < .001), underscoring the importance of operator agency when considering automation use behaviors. These findings highlight a belief-behavior gap in TIA, suggesting that TIA self-report measures alone are insufficient to predict aviators' automation use. System designs that support operator autonomy while providing workload-sensitive prompting may better calibrate reliance and optimize human-machine teaming in aviation contexts.

KEYWORDS:trust in automation, cognitive workload, beliefs, attitudes, behavior, aviators

Download '2025-41' report PDF

SIZE:3.6 MB

DTIC #:AD1341106

TITLE:Evaluation of Patient-Specific Medical Device Alarms during Multi-Patient Medical Evacuation Scenarios

AUTHOR(s):Enzor, M. J., Kroening, L. R., Kinsler, R. E., Lloyd, A., Molles, J., Mackie, R., Jones, H., Fralish, V., Hale, J., Toelle, R., Ravelli, A., Snyder, S., Price, B., Owens, C.

ABBREVIATED ABSTRACT:The objective of this work was to evaluate three-dimensional (3D) audio alarms that may contribute to enhanced medical awareness of patients for care providers in the military medical evacuation environment. The specific effect examined was the alarm response time. Qualitative end-user feedback was also collected to evaluate the efficacy of the alarm configurations. Each subject participated in four 60-minute patient care scenarios, two scenarios with monaural alarms broadcasted over a simulated ICS and two scenarios with 3D audio alarms broadcasted over the simulated ICS. Each alarm type was used with two- and three-patient configurations. Although statistical significance was not achieved, trends in the reaction time data indicate that the implementation of 3D audio alarms may be beneficial in high workload environments. Average reaction times were reduced between 1-4 seconds in the configurations with the 3D audio alarms compared to the monaural alarms. Subject feedback indicated that 3D audio was well received and had a positive impact on reducing reaction time and directing attention to the necessary patient.

KEYWORDS:saliency, salient signal, integrated alarms, intercommunication set, ICS, communication ear plugs (CEP), CEPs, three-dimensional audio, spatial audio, helicopter, HH-60, medical evacuation, MEDEVAC

Download '2025-40' report PDF

SIZE:2.9 MB

DTIC #:AD1340435

TITLE:Pilot Performance in Multi-Talker Environments: Effects of 3D Audio and Active Noise Reduction

AUTHOR(s):Noetzel, J., Henry, P., Mackie, R., Stefanson, JR, Hale, J. K., Andres, K., McDermott, D., Brunner, L., & Jones, H.

ABBREVIATED ABSTRACT:This study investigates the impact of three-dimensional (3D) spatial audio and active noise reduction (ANR) on aviators' cognitive workload and flight performance when monitoring multiple radio channels. Laboratory experiments demonstrated that 3D audio significantly enhanced speech recognition, particularly under high auditory workload, and reduced perceived workload, as confirmed by pupil dilation measurements. While increased auditory workload negatively impacted speech recognition, simulator-based experiments revealed no statistically significant differences in speech recognition across listening conditions. However, pilots showed a strong preference for 3D audio, indicating its potential for improving aviator performance and reducing cognitive burden. The study recommends prioritizing the integration of 3D audio into aircraft and suggests further research into optimizing ANR technologies for aviator headsets.

KEYWORDS:spatial audio, 3-dimentional audio, active noise reduction (ANR), pupillometry, listening effort

Download '2025-38' report PDF

SIZE:1.6 MB

DTIC #:AD1340277

TITLE:Critical Review of Civilian and Military Crashworthy Aircraft Seat Performance Requirements

AUTHOR(s):Rhodes, D., McEntire, B. J., Willett, J. F., & Chancey, V. C.

ABBREVIATED ABSTRACT:U.S. Army rotary-wing seating system specifications, MIL-S-58095A (AV) (pilot and co-pilot) and MIL-S-85510 (AS) (crew and passenger) provide rigorous safety metrics with the goal of proper occupant protection. Although MIL-S-58095A (AV) has been canceled and MIL-S-85510 (AS) rendered inactive, they are still referenced by the active MIL-STD-1290A. Civilian standards provide an appealing alternative due to less rigorous testing conditions and off-the-shelf, mass-produced materiel for seating systems. Future Vertical Lift (FVL) designers are considering adopting civilian rotary-wing crew seat performance requirements due to a lack of adequate and active specifications requirements. Static and dynamic requirements of the seating system of the U.S. Army's pilot, crew, and troop seat and system requirements/guidance specified in MIL-S-85510, MIL-S-58095A, and JSSG-2010-7 were compared to those of the civilian requirements in SAE AS8049D and SAE AS8049/1 Rev. B. Researchers found that the testing conditions and performance metrics defined by the civilian rotary-wing seating standards are less rigorous than the legacy military seating specifications and, as such, will not replicate the exposures experienced in military operational environments and will likely result in increased occupant injury and mortality rates in severe but otherwise survivable military rotary-wing mishaps. As the rotary-wing seating system is the occupant's last line of defense against crash-induced injury, it is imperative that the military rotary-wing aircraft seating and occupant restraint systems be designed for and tested against stringent, military-relevant, performance and test standards.

KEYWORDS:Rotary-wing, rotorcraft seating systems, MIL-S-58095A, MIL-S-85510, SAE AS8049D, SAE AS8049/1 rev. B, crashworthiness, civilian crash standards, military crash standards

back to top