The U.S. Army Aeromedical Research Laboratory Virtual Reality Vection System.

INTRODUCTION: Vection is a stationary individual's illusory experience of self-motion. This illusory self-motion is operationally important for aviation, particularly military aviation, since vection is a dramatic example of spatial disorientation (SD), which is an individual's failure to correctly sense the aircraft's position, motion, and/or attitude with respect to the fixed coordinate system of the Earth's surface and its gravitational vertical. Notably, SD is a major cause of fatal aviation mishaps, and the visual system is particularly prone to provoking vection. This article describes the Virtual Reality Vection System (VRVS), which uses computer-controlled virtual reality technology to induce vection under controlled conditions for training, demonstration, testing, and research. MATERIALS AND METHODS: The VRVS enables the precise specification of the number and appearance of visual stimulus elements intended to generate vection, including photorealistic images. The VRVS can present visual stimuli on any OpenXR-capable virtual reality headset. The VRVS currently records 2 types of behavioral responses, button presses to indicate the presence and duration of vection and the voltage of a handheld linear potentiometer to indicate the presence, duration, and magnitude of vection. RESULTS: An approved test plan helped guide, organize, document, and validate the VRVS during its development. Under this plan, a pair of tests guided hardware and software development of the VRVS system. Although the first test verified the ability of the VRVS to generate and measure vection, it also demonstrated that the VRVS can quickly manipulate the visual stimuli from one trial to the next so that the VRVS can support complex experimental designs. The second test used these capabilities to verify that the VRVS can characterize vection in a more analytic fashion using a masking paradigm. Specifically, the test assessed whether random stimulus elements injected into the vection-inducing stimulus disrupted vection in a quantifiable fashion. This work opens the door to studies that characterize the necessary and sufficient visual elements for vection-based SD. DISCUSSION: The VRVS is currently used to research, develop, test, and evaluate mitigation strategies targeting vection-related SD in degraded visual environments. Similarly, the VRVS is supporting research to develop methods to predict individual differences in visually induced motion sickness susceptibilities. The VRVS is currently being integrated with a precision motor-controlled rotating Barany chair for multisensory studies. It should be noted that since the VRVS was developed to support United States Army Aeromedical Research Laboratory projects, it is an Army product representing government intellectual property and may be freely available to other government institutions.

A Method to Determine Capabilities and Resources for Spacecraft Medical Systems.

INTRODUCTION: This paper describes the method for assigning medical diagnostic and treatment capabilities and resources to the database which assists with an updated probabilistic risk analysis (PRA) tool for exploration class medical system planning. The National Aeronautics and Space Administration has used PRA since 2011 to inform mission medical system design, but existing tools are designed only for low Earth orbit. An updated PRA tool was needed to assist with exploration class missions.METHODS: A team of medical experts with a wide range of expertise and experience, including Space Medicine, was assembled to build capability and resource tables for the new PRA tool. This team met over 8 mo and used practice guidelines, literature, and experience to build capability and resource tables (CRTs) for each condition in the new PRA tool database.RESULTS: This process led to CRTs for each condition and a total of 617 distinct capabilities and 839 discrete resources.CONCLUSION: The CRT method is an effective way to translate medical practice guidelines into capabilities and resources usable by PRA tools for exploration class medical system planning. This same method may be used in commercial space ventures and in other applications in which medical predictive analytics are informative.Levin DR, Nelson AM, Zahner C, Stratton ER, Anderson A, Steller J. A method to determine capabilities and resources for spacecraft medical systems. Aerosp Med Hum Perform. 2024; 95(7):403-408.

Approaches to Medical Emergencies on Commercial Flights.

In-flight medical incidents are becoming increasingly critical as passengers with diverse health profiles increase in the skies. In this paper, we reviewed how airlines, aviation authorities, and healthcare professionals respond to such emergencies. The analysis was focused on the strategies developed by the top ten airlines in the world by examining training in basic first aid, collaboration with ground-based medical support, and use of onboard medical equipment. Appropriate training of crew members, availability of adequate medical resources on board airplanes, and improved capabilities of dialogue between a flying plane and medical doctors on the ground will contribute to a positive outcome of the majority of medical issues on board airlines. In this respect, the adoption of advanced telemedicine solutions and the improvement of real-time teleconsultations between aircraft and ground-based professionals can represent the future of aviation medicine, offering more safety and peace of mind to passengers in case of medical problems during a flight.

Space Ultrasound: A Proposal for Competency-based Ultrasound Training for In-flight Space Medicine.

Space travel has transformed in the past several years. Given the burgeoning market for space tourism, in-flight medical emergencies are likely to be expected. Ultrasound is one of the few diagnostic and therapeutic modalities available for astronauts in space. However, while point-of-care ultrasound (POCUS) is available, there is no current standard of training for astronaut preparation. We suggest an organized and structured methodology by which astronauts should best prepare for space with the medical equipment available on board. As technology continues to evolve, the assistance of other artificial intelligence and augmented reality systems are likely to facilitate training and dynamic real-time needs during space emergencies. Summary: As space tourism continues to evolve, an organized methodology for POCUS use is advised to best prepare astronauts for space.

"Spaceflight-to-Eye Clinic": Terrestrial advances in ophthalmic healthcare delivery from space-based innovations.

The phrase "Bench-to-Bedside" is a well-known phrase in medicine, highlighting scientific discoveries that directly translate to impacting patient care. Key examples of translational research include identification of key molecular targets in diseases and development of diagnostic laboratory tests for earlier disease detection. Bridging these scientific advances to the bedside/clinic has played a meaningful impact in numerous patient lives. The spaceflight environment poses a unique opportunity to also make this impact; the nature of harsh extraterrestrial conditions and medically austere and remote environments push for cutting-edge technology innovation. Many of these novel technologies built for the spaceflight environment also have numerous benefits for human health on Earth. In this manuscript, we focus on "Spaceflight-to-Eye Clinic" and discuss technologies built for the spaceflight environment that eventually helped to optimize ophthalmic health on Earth (e.g., LADAR for satellite docking now utilized in eye-tracking technology for LASIK). We also discuss current technology research for spaceflight associated neuro-ocular syndrome (SANS) that may also be applied to terrestrial ophthalmic health. Ultimately, various advances made to enable to the future of space exploration have also advanced the ophthalmic health of individuals on Earth.

Cervical Disc Displacement in Military Pilots.

INTRODUCTION: Cervical disc displacement (CDD) may disqualify pilots from flying and have a profound impact on military unit capability. The objective of this retrospective database review is to characterize the incidence and demographic predictors of symptomatic cervical spine disc displacement in pilots of fixed- and rotary-wing aircraft and ground-based controls. MATERIALS AND METHODS: The Defense Military Epidemiology Database was queried for first-occurrence ICD-9 code 722.0: CDD cases from 2007 to 2015. Injury count rates among aircraft groups and overall incidence per 1,000 person-years were calculated and standardized for age, gender, and military rank, and 95% confidence intervals (CIs) were compared to determine significance. RESULTS: There were 934 new cases of CDD among active duty U.S. Military pilots during the study period. The overall incidence of CDD in all pilots during this time frame was 2.715 per 1,000 person-years (95% CI, 2.603-2.830). Helicopter pilots had a significantly higher incidence compared to all other aircraft pilots and crew at 3.79 per 1,000 person-years (95% CI, 3.48-4.13). This finding remained statistically significant after standardizing for age, gender, and rank. Among all military officers, increasing age was a risk factor for CDD. CONCLUSIONS: The U.S. Military helicopter pilots have an increased risk compared to fixed-wing pilots and non-pilot controls. CDD remains a rare, though career-threatening, condition. Increased education and awareness training are warranted for both helicopter pilots and flight physicians to recognize signs and symptoms of cervical pathology. Continued investigations into preventive measures to minimize injury and time unfit for flight are warranted.

Radiation protection and estimate of commercial aircrew effective doses in Bosnia and Herzegovina.

Cosmic rays are the primary source of the daily exposure of aircrew and passengers to ionising radiation. This study aims to estimate the effective doses of ionising radiation for aircraft crews in Bosnia and Herzegovina by taking into consideration factors such as flight duration and altitude, as well as the geographical position of airports. The CARI-7 algorithm and neural network method were used in the analysis of data obtained from the Sarajevo International Airport. The results show that the estimated annual effective doses in 2021 range from 0.06 to 10 mSv for flights to and from Belgrade and Dubai, respectively. Both linear regression and neural network models were developed to predict the effective dose based on flight duration, average altitude, latitude and maximum altitude. The findings reveal that flight duration is the most statistically significant factor, followed by average altitude, latitude and maximum altitude.

Crew Autonomy During Simulated Medical Event Management on Long Duration Space Exploration Missions.

OBJECTIVE: Our primary aim was to investigate crew performance during medical emergencies with and without ground-support from a flight surgeon located at mission control. BACKGROUND: There are gaps in knowledge regarding the potential for unanticipated in-flight medical events to affect crew health and capacity, and potentially compromise mission success. Additionally, ground support may be impaired or periodically absent during long duration missions. METHOD: We reviewed video recordings of 16 three-person flight crews each managing four unique medical events in a fully immersive spacecraft simulator. Crews were randomized to two conditions: with and without telemedical flight surgeon (FS) support. We assessed differences in technical performance, behavioral skills, and cognitive load between groups. RESULTS: Crews with FS support performed better clinically, were rated higher on technical skills, and completed more clinical tasks from the medical checklists than crews without FS support. Crews with FS support also had better behavioral/non-technical skills (information exchange) and reported significantly lower cognitive demand during the medical event scenarios on the NASA-TLX scale, particularly in mental demand and temporal demand. There was no significant difference between groups in time to treat or in objective measures of cognitive demand derived from heart rate variability and electroencephalography. CONCLUSION: Medical checklists are necessary but not sufficient to support high levels of autonomous crew performance in the absence of real-time flight surgeon support. APPLICATION: Potential applications of this research include developing ground-based and in-flight training countermeasures; informing policy regarding autonomous spaceflight, and design of autonomous clinical decision support systems.

Coronary Artery Disease Management in Military Aircrew.

INTRODUCTION: Coronary artery disease (CAD) is the leading cause of denial or withdrawal of flying privileges for aircrew. Screening for CAD is therefore crucial. The present study analyzed German military aircrew with diagnosed CAD and/or acute coronary syndrome despite close medical monitoring with the intention to further optimize individual outcomes and aeromedical disposition.METHODS: The digital information systems of the German Air Force Centre of Aerospace Medicine were searched for pilots and nonpilot aircrew with CAD and/or myocardial infarction (MI). They were retrospectively analyzed for age at initial diagnosis, body mass index, cardiovascular risk factors, diagnostic procedures, treatment, and aeromedical disposition.RESULTS: Between February 1987 and March 2023, 126 aircrew, 55% pilots and 45% nonpilot aircrew, were identified with CAD and/or MI. An accumulation of two to six risk factors was found in 77% of both groups. Most pilots (54%) received conservative treatment, 44% underwent percutaneous coronary intervention, and 3% coronary artery bypass grafting. In the group of nonpilot aircrew, conservative treatment was performed in 47%, coronary intervention in 37%, and bypass grafting in 16%. A total of 45 pilots (65%) returned to flying duties, albeit 39 (57%) with restrictions. In the group of nonpilot aircrew, 31 (54%) returned to flying duties.DISCUSSION: A small group of aircrew developed CAD over the years, some with severe coronary artery stenoses and MI. Further optimization of individual prognosis and aeromedical disposition should aim at appropriate CAD screening and risk factor elimination. CAD management needs a comprehensive approach regarding military aviation requirements and clinical guidance.Guettler N, Sammito S. Coronary artery disease management in military aircrew. Aerosp Med Hum Perform. 2023; 94(12):917-922.

Microgravity and Space Medicine.

This Special Issue (SI), "Microgravity and Space Medicine", covers research articles and reviews focusing on gravitational biology, cancer research and space medicine [...].

In-flight Medical Emergencies.

In 2018, approximately 2.8 million passengers flew in and out of U.S. airports per day. Twenty-four to 130 in-flight medical emergencies are estimated to occur per 1 million passengers; however, there is no internationally agreed-upon recording or classification system. Up to 70% of in-flight emergencies are managed by the cabin crew without additional assistance. If a health care volunteer is requested, medical professionals should consider if they are in an appropriate condition to render aid, and then identify themselves to cabin crew, perform a history and physical examination, and inform the cabin crew of clinical impressions and recommendations. An aircraft in flight is a physically constrained and resource-limited environment. When needed, an emergency medical kit and automated external defibrillator are available on all U.S. aircraft with at least one flight attendant and a capacity for 30 or more passengers. Coordinated communication with the pilot, any available ground-based medical resources, and flight dispatch is needed if aircraft diversion is recommended. In the United States, medical volunteers are generally protected by the Aviation Medical Assistance Act of 1998. There is no equivalent law governing international travel, and legal jurisdiction depends on the patient's and medical professional's countries of citizenship and the country in which the aircraft is registered.

The effects of 12 weeks of functional strength training on muscle strength, volume and activity upon exposure to elevated Gz forces in high-performance aircraft personnel.

BACKGROUND: Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel, including inducing neck and back pain. The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1) the volume and strength of the neck and shoulder muscles and 2) muscular activity upon exposure to helmets of different masses and elevated Gz forces in a long-arm centrifuge in high-performance aircraft personnel. METHODS: Eighteen participants underwent 12 weeks of functional strength training (n = 12) or the control protocol (n = 6) without additional strength training. Pre- and post-intervention tests included evaluations of isometric strength of the head extensor muscles, flexion, and lateral flexion and rotation, as well as magnetic resonance imaging (MRI) to measure the volume of the m. sternocleidomastoideus, m. trapezius, and deep neck muscles. Furthermore, during a long-arm centrifuge (+ 1.4 and + 3 Gz) protocol, the muscular activity levels of the m. sternocleidomastoideus, m. trapezius and m. erector spinae muscles were assessed without a flight helmet, with a helmet, and with a helmet and night vision goggles. Each participant's perception of muscular strain was noted immediately after the long-arm centrifuge protocol. RESULTS: The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group (P < 0.05). Relative muscle activity (%MVC) with a helmet decreased after the intervention in the training but not the control group (P = 0.01). Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group (P < 0.01). The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups. CONCLUSION: Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated Gz forces in a long-arm centrifuge.

Historic Firsts: Aeromedical Evacuation and the Transportation Isolation System.

This short communication highlights the US Air Force's recent success with having their aeromedical evacuation crews use the Transportation Isolation System for the first time operationally to transport patients positive for coronavirus disease 2019.

Novel method for evaluating the health condition of mice in space through a video downlink.

Clarification of the criteria for managing animal health is essential to increase the reliability of experiments and ensure transparency in animal welfare. For experiments performed in space, there is no consensus on how to care for animals owing to technical issues, launch mass limitation, and human resources. Some biological processes in mammals, such as musculoskeletal or immune processes, are altered in the space environment, and mice in space can be used to simulate morbid states, such as senescence acceleration. Thus, there is a need to establish a novel evaluation method and evaluation criteria to monitor animal health. Here, we report a novel method to evaluate the health of mice in space through a video downlink in a series of space experiments using the Multiple Artificial-gravity Research System (MARS). This method was found to be more useful in evaluating animal health in space than observations and body weight changes of the same live mice following their return to Earth. We also developed criteria to evaluate health status via a video downlink. These criteria, with "Fur condition" and "Respiratory" as key items, provided information on the daily changes in the health status of mice and helped to identify malfunctions at an early stage. Our method and criteria led to the success of our missions, and they will help establish appropriate rules for space experiments in the future.

Assessing Patients for Air Travel.

Advising patients before air travel is a frequently overlooked, but important, role of the physician, particularly primary care providers and pulmonary specialists. Although physiologic changes occur in all individuals during air travel, those with underlying pulmonary disease are at increased risk of serious complications and require a specific approach to risk stratification. We discuss the available tools for assessment of preflight risk and strategies to minimize potential harm. We also present a case discussion to illustrate our approach to assessing patients for air travel and discuss the specific conditions that should prompt a more thorough preflight workup.

Cardiopulmonary resuscitation (CPR) during spaceflight - a guideline for CPR in microgravity from the German Society of Aerospace Medicine (DGLRM) and the European Society of Aerospace Medicine Space Medicine Group (ESAM-SMG).

BACKGROUND: With the "Artemis"-mission mankind will return to the Moon by 2024. Prolonged periods in space will not only present physical and psychological challenges to the astronauts, but also pose risks concerning the medical treatment capabilities of the crew. So far, no guideline exists for the treatment of severe medical emergencies in microgravity. We, as a international group of researchers related to the field of aerospace medicine and critical care, took on the challenge and developed a an evidence-based guideline for the arguably most severe medical emergency - cardiac arrest. METHODS: After the creation of said international group, PICO questions regarding the topic cardiopulmonary resuscitation in microgravity were developed to guide the systematic literature research. Afterwards a precise search strategy was compiled which was then applied to "MEDLINE". Four thousand one hundred sixty-five findings were retrieved and consecutively screened by at least 2 reviewers. This led to 88 original publications that were acquired in full-text version and then critically appraised using the GRADE methodology. Those studies formed to basis for the guideline recommendations that were designed by at least 2 experts on the given field. Afterwards those recommendations were subject to a consensus finding process according to the DELPHI-methodology. RESULTS: We recommend a differentiated approach to CPR in microgravity with a division into basic life support (BLS) and advanced life support (ALS) similar to the Earth-based guidelines. In immediate BLS, the chest compression method of choice is the Evetts-Russomano method (ER), whereas in an ALS scenario, with the patient being restrained on the Crew Medical Restraint System, the handstand method (HS) should be applied. Airway management should only be performed if at least two rescuers are present and the patient has been restrained. A supraglottic airway device should be used for airway management where crew members untrained in tracheal intubation (TI) are involved. DISCUSSION: CPR in microgravity is feasible and should be applied according to the Earth-based guidelines of the AHA/ERC in relation to fundamental statements, like urgent recognition and action, focus on high-quality chest compressions, compression depth and compression-ventilation ratio. However, the special circumstances presented by microgravity and spaceflight must be considered concerning central points such as rescuer position and methods for the performance of chest compressions, airway management and defibrillation.

Nurses' responsibilities in the aerospace environment.

OBJECTIVES: to characterize the nurses who work in the aerospace environment and to identify their most frequent responsibilities during the pre-flight, flight, and post-flight periods. METHODS: a quantitative, exploratory-descriptive research, conducted using a survey through Google forms®, from January to April of 2018, with 50 nurses from aerospace services in Brazil. Data were analyzed using descriptive statistics. RESULTS: predominance of male participants (64%), mean age of 37 years, with a mean working time in the aerospace environment of six years, in helicopter (54%), and in the southern region (42%). The main pre-flight, flight, and post-flight activities were, respectively: verification/testing of equipment functionality, nursing care for patients, and replacement of supplies and equipment. CONCLUSIONS: In the aerospace environment, nurses' work are primarily organizational and victim care actions, during all phases of the flight.

Designing clinical trials for future space missions as a pathway to changing how clinical trials are conducted on Earth.

OBJECTIVE: The project aims to build a framework for conducting clinical trials for long-term interplanetary missions to contribute to innovation in clinical trials on Earth, especially around patient involvement and ownership. METHODS: We conducted two workshops in which participants were immersed in the speculative scenario of an interplanetary mission in which health problems emerged that required medical trials to resolve. The workshops used virtual reality and live simulation to mimic a zero-gravity environment and visual perception shifts and were followed by group discussion. RESULTS: Some key aspects for the framework that emerged from the workshops included: (a) approaches to be inclusive in the management of the trial, (b) approaches to be inclusive in designing the research project (patient preference trials, n-of-1 trials, designing clinical trials to be part of a future prospective meta-analysis, etc), (c) balancing the research needs and the community needs (eg, allocation of the participants based on both research and community need), (d) ethics and partnerships (ethics and consent issues and how they relate to partnerships and relationships). CONCLUSION: In identifying some key areas that need to be incorporated in future planning of clinical trials for interplanetary missions, we also identified areas that are relevant to engaging patients in clinical trials on Earth. We will suggest using the same methodology to facilitate more in-depth discussions on specific aspects of clinical trials in aerospace medicine. The methodology can be more widely used in other areas to open new inclusive conversations around innovating research methodology.