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.

[MODERN INSTRUMENTS FOR EAR, NOSE AND THROAT RENDERING AND EVALUATION IN RESEARCHES ON RUSSIAN SEGMENT OF THE INTERNATIONAL SPACE STATION].

The paper reports the results of testing some diagnostic video systems enabling digital rendering of TNT teeth and jaws. The authors substantiate the criteria of choosing and integration of imaging systems in future on Russian segment of the International space station kit LOR developed for examination and download of high-quality images of cosmonauts' TNT, parodentium and teeth.

Adaptive data filtering of inertial sensors with variable bandwidth.

MEMS (micro-electro-mechanical system)-based inertial sensors, i.e., accelerometers and angular rate sensors, are commonly used as a cost-effective solution for the purposes of navigation in a broad spectrum of terrestrial and aerospace applications. These tri-axial inertial sensors form an inertial measurement unit (IMU), which is a core unit of navigation systems. Even if MEMS sensors have an advantage in their size, cost, weight and power consumption, they suffer from bias instability, noisy output and insufficient resolution. Furthermore, the sensor's behavior can be significantly affected by strong vibration when it operates in harsh environments. All of these constitute conditions require treatment through data processing. As long as the navigation solution is primarily based on using only inertial data, this paper proposes a novel concept in adaptive data pre-processing by using a variable bandwidth filtering. This approach utilizes sinusoidal estimation to continuously adapt the filtering bandwidth of the accelerometer's data in order to reduce the effects of vibration and sensor noise before attitude estimation is processed. Low frequency vibration generally limits the conditions under which the accelerometers can be used to aid the attitude estimation process, which is primarily based on angular rate data and, thus, decreases its accuracy. In contrast, the proposed pre-processing technique enables using accelerometers as an aiding source by effective data smoothing, even when they are affected by low frequency vibration. Verification of the proposed concept is performed on simulation and real-flight data obtained on an ultra-light aircraft. The results of both types of experiments confirm the suitability of the concept for inertial data pre-processing.

Generating genius: how an Alzheimer's drug became considered a 'cognitive enhancer' for healthy individuals.

BACKGROUND: Donepezil, an acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease, has been widely cited in media and bioethics literature on cognitive enhancement (CE) as having the potential to improve the cognitive ability of healthy individuals. In both literatures, this claim has been repeatedly supported by the results of a small study published by Yesavage et al. in 2002 on non-demented pilots (30-70 years old). The factors contributing to this specific interpretation of this study's results are unclear. METHODS: We examined print media and interdisciplinary bioethics coverage of this small study, aiming to provide insight into how evidence from research may be shaped within different discourses, potentially influencing important policy, ethics, and clinical decisions. Systematic qualitative content analysis was used to examine how this study was reported in 27 media and 22 bioethics articles. Articles were analyzed for content related to: (1) headlines and titles; (2) colloquialisms; and, (3) accuracy of reporting of the characteristics and results of the study. RESULTS: In media and bioethics articles referencing this small study, strong claims were made about donepezil as a CE drug. The majority of headlines, titles, and colloquialisms used enhancement language and the majority of these suggest that donepezil could be used to enhance intellectual ability. Further, both literatures moved between reporting the results of the primary study and magnifying the perceived connection between these results and the CE debate that was alluded to in the primary study. Specific descriptions of the results overwhelmingly reported an improvement in performance on a flight simulator, while more general statements claimed donepezil enhanced cognitive performance. Further, a high level of reporting accuracy was found regarding study characteristics of the original study, but variable levels of accuracy surrounded the presentation of complex characteristics (i.e., methods) or contentious properties of the CE debate (i.e., initial health status of the study subjects). CONCLUSIONS: Hyped claims of CE effects cannot be completely accounted for by sheer inaccuracy in reporting. A complex interaction between the primary and secondary literature, and expectations and social pressures related to CE appears to drive enthusiastic reports.

Physiological monitoring and analysis of a manned stratospheric balloon test program.

INTRODUCTION: The Red Bull Stratos Project consisted of incremental high altitude parachute jumps [maximum altitude 127,852 ft (38,969 m)] from a pressurized capsule suspended from a stratospheric helium-filled balloon. A physiological monitoring system was worn by the parachutist to provide operational medical and acceleration data and to record a unique set of data in a supersonic environment. METHODS: Various physiological parameters, including heart rate (HR), respiratory rate (RR), skin temperature, and triaxial acceleration, were collected during the ascent, high altitude float, free fall, and parachute opening and descent stages of multiple low- and high altitude jumps. Physiologic data were synchronized with global positioning system (GPS) and audiovisual data for a comprehensive understanding of the environmental stressors experienced. RESULTS: HR reached maximum during capsule egress and remained elevated throughout free fall and landing. RR reached its maximum during free fall. Temperature data were unreliable and did not provide useful results. The highest accelerations parameters were recorded during parachute opening and during landing. During each high altitude jump, immediately after capsule egress, the parachutist experienced a few seconds of microgravity during which some instability occurred. Control was regained as the parachutist entered denser atmosphere. DISCUSSION: The high altitude environment resulted in extremely high vertical speeds due to little air resistance in comparison to lower altitude jumps with similar equipment. The risk for tumbling was highest at initial step-off. Physiological responses included elevated HR and RR throughout critical phases of free fall. The monitoring unit performed well despite the austere environment and extreme human performance activities.

Forgotten hardware: how to urinate in a spacesuit.

On May 5, 1961, astronaut Alan Shepard became the first American to fly in space. Although National Aeronautics and Space Administration (NASA) had discounted the need for him to urinate, Shepard did, in his spacesuit, short circuiting his electronic biosensors. With the development of the pressure suit needed for high-altitude and space flight during the 1950s, technicians had developed the means for urine collection. However, cultural mores, combined with a lack of interagency communication, and the technical difficulties of spaceflight made human waste collection a difficult task. Despite the difficulties, technicians at NASA created a successful urine collection device that John Glenn wore on the first Mercury orbital flight on February 20, 1962. With minor modifications, male astronauts used this system to collect urine until the Space Shuttle program. John Glenn's urine collection device is at the National Air and Space Museum and has been on view to the public since 1976.

[Spatial orientation of pilot using a cockpit exterior surveillance system].

Spatial orientation of pilots using a cockpit exterior surveillance system was tested in real nighttime helicopter flights. Major factors complicating adequate spatial orientation and provoking visual illusions in pilots are lack of information for spatial depth (relation) perception in two-dimensional TV images altering their position along the horizontal and vertical lines of trajectory and simultaneous piloting and target search-identification operations. Reliability of pilot's spatial orientation could be improved by displaying on the exterior imaging screen also relevant flight navigation parameters.

An independent, objective calibration check for the reduced oxygen breathing device.

INTRODUCTION: Normobaric hypoxia, which does not entail an altitude chamber, but reduces the fraction of inspired oxygen (02) by diluting air with nitrogen, is finding increased use. The reduced oxygen breathing device (ROBD-2) is one of several commercial devices for generating such normobaric hypoxia. Reported here are results of a procedure to check the calibration of the ROBD-2 using methods that may be readily available in physiology and psychophysiology facilities. METHODS: The %O2 output by the ROBD-2 was measured concurrently in two ways for altitudes from mean sea level (MSL) to 34,000 ft above MSL at 2000-ft intervals five times over 2 d. One measurement method used was the one built into the ROBD-2, which reports the %O2 the device is delivering at the selected target altitude. The other method diverted a sample of the ROBD-2's output gas to the paramagnetic O2, sensor of a metabolic measuring system via its sampling line. The %O2, measured with the two techniques was compared using Bland-Altman statistical procedures. RESULTS: The two measurement methods produced %O2 readings differing by no more than 0.18% O2 from MSL to 34,000 ft (from 20.95 to about 4.40% oxygen, respectively), the full operating range of the device. Calculating altitude from the measured %O2 showed the ROBD-2 operated within its design error margins over its whole operational range. DISCUSSION: The purpose for which the ROBD-2 is used should determine whether the reliability of its output in normobaric equivalent altitude is adequate. Differences between devices and device stability over time and with use have yet to be assessed. Our assessment does not address the accuracy of the algorithm the ROBD-2 uses to provide an equivalent target altitude under normobaric conditions.

Surgery in space: the future of robotic telesurgery.

BACKGROUND: The origins of telemedicine date back to the early 1970s, and combined with the concept of minimally invasive surgery, the idea of surgical robotics was born in the late 1980s based on the principle of providing active telepresence to surgeons. Many research projects were initiated, creating a set of instruments for endoscopic telesurgery, while visionary surgeons built networks for telesurgical patient care, demonstrated transcontinental surgery, and performed procedures in weightlessness. Long-distance telesurgery became the testbed for new medical support concepts of space missions. METHODS: This article provides a complete review of the milestone experiments in the field, and describes a feasible concept to extend telemedicine beyond Earth orbit. With a possible foundation of an extraplanetary human outpost either on the Moon or on Mars, space agencies are carefully looking for effective and affordable solutions for life-support and medical care. The major challenges of surgery in weightlessness are also discussed. RESULTS: Teleoperated surgical robots have the potential to shape the future of extreme health care both in space and on Earth. Besides the apparent advantages, there are some serious challenges, primarily the difficulty of latency with teleoperation over long distances. Advanced virtualization and augmented-reality techniques should help human operators to adapt better to the special conditions. To meet safety standards and requirements in space, a three-layered architecture is recommended to provide the highest quality of telepresence technically achievable for provisional exploration missions. CONCLUSION: Surgical robotic technology is an emerging interdisciplinary field, with a great potential impact on many areas of health care, including telemedicine. With the proposed three-layered concept-relying only on currently available technology-effective support of long-distance telesurgery and human space missions are both feasible.

In-flight urine collection device: efficacy, maintenance, and complications in U-2 pilots.

INTRODUCTION: Urine collection systems for in-flight use have gradually improved over the past 50 yr; however, current management of urine evacuation remains suboptimal. This is a cross-sectional survey-based study on the current urine collection device employed in the U.S. Air Force's U-2S airframe, examining efficacy, problems with wear, device maintenance, and complaint reporting. METHODS: An anonymous survey consisting of 18 questions was generated inquiring about problems with wear of the urine collection system, care of the device, and education. The survey was offered at Beale AFB and overseas U-2 locations to pilots with at least 180 h of flying experience with the airframe. RESULTS: There were 57 subjects who completed the survey with 62.5% reporting complications, including mechanical dysfunction, pain and poor fit, skin irritation, allergic reaction, embarrassment, and urethral issues. Variation was seen in the degree of problem reporting and care of the device. Discussion and literature review is provided on in-flight and space urine collection and evacuation systems, sheath catheters, urine and contact dermatitis, urethritis, external catheter sizing methods, and psychological aspects of catheter use. CONCLUSIONS: The majority of surveyed pilots experienced various problems associated with wear of their urine collection device. Also, variation in reporting and care of the device exists. Potential improvements include standardization of fitting procedures and device maintenance, increased catheter draining capacity, use of skin barriers to urine, enhanced privacy measures, and incorporation of less injurious structural materials such as silicone.

Medical issues associated with commercial flights.

Almost 2 billion people travel aboard commercial airlines every year. Health-care providers and travellers need to be aware of the potential health risks associated with air travel. Environmental and physiological changes that occur during routine commercial flights lead to mild hypoxia and gas expansion, which can exacerbate chronic medical conditions or incite acute in-flight medical events. The association between venous thromboembolism and long-haul flights, cosmic-radiation exposure, jet lag, and cabin-air quality are growing health-care issues associated with air travel. In-flight medical events are increasingly frequent because a growing number of individuals with pre-existing medical conditions travel by air. Resources including basic and advanced medical kits, automated external defibrillators, and telemedical ground support are available onboard to assist flight crew and volunteering physicians in the management of in-flight medical emergencies.

[Some approaches to the countermeasure system for a mars exploration mission].

In article discussed physiological and methodical principles of the organization of training process and his (its) computerization during Martian flight in conditions of autonomous activity of the crew, providing interaction with onboard medical means, self-maintained by crew of the their health, performance of preventive measures, diagnostic studies and, in case of necessity, carrying out of treatment. In super long autonomous flights essentially become complicated the control of ground experts over of crew members conditions, that testifies to necessity of a computerization of control process by a state of health of crew, including carrying out of preventive actions. The situation becomes complicated impossibility of reception and transfer aboard the necessary information in real time and emergency returning of crew to the Earth. In these conditions realization of problems of physical preventive maintenance should be solved by means of the onboard automated expert system, providing management by trainings of each crew members, directed on optimization of their psychophysical condition.

[On-board medical support system (MSS) of flights of promising aerospace sets (design)].

It was suggested as the main compositive fractions MSS to consider the base system of automated evaluation of blood redistribution (BR) in body means of crew members protection and prophylaxis (CMPP) of unfavourable effects of flight factors to organism and also the automated circuit of CMPP' control. The advanced MSS includes 4 original measuring channels for registration of the base physiologic indices (electrocardiogram, venous-arterial pulsegram of neck vessels, reogram of head, earlap vessels pulsegram) the dynamic of which allows to determine with the help of computer the BR-integral parameter. The CMPP automated control circuit unites the separate protecting means in common system and executes the individual selection of regimes and CM PP-composition in accord with, first of all, body reactions manifestation and, secondly, individual physiologic status of spaceman. As CMPP was selected the negative pressure production around lower body part. Approlation of constructed active laboratory engineering mock-up MSS has performed investigations with participation of 29 subjects (Volunteers) under the modeling of hemodynamic shifts, developing in human body in short-term antiorthostatic hypokinesia (-10 degrees), as well as, in combined effect of antiorthostatic hypokinesia (-10 degrees), Coriolis acceleration and optokinetic stimulation. Results of investigations have showed, that the use of advanced MSS gives the indices of operator professional activity on the average of 17-32% under the decrease of hemodynamic stressful.

Hemodynamic Responses and G Protection Afforded by Three Different Anti-G Systems.

BACKGROUND: UK Royal Air Force fast jet aircrew use three different anti-G systems, however, little objective comparison of the G protection they provide exists. The G-protection afforded by each system and associated hemodynamic responses were investigated.METHODS: Ten subjects performed centrifuge acceleration exposures using Mk-10 (S1) and Mk-4 (S2) five-bladder anti-G trousers (AGT) and full coverage AGT plus pressure breathing for G-protection (PBG; S3). Measurements of relaxed G tolerance (RGT), eye-level blood pressure (BPeye), lower body blood volume (LBV), stroke volume (SV) and total peripheral resistance (TPR) were made during gradual onset runs (GOR) and rapid onset runs (ROR). The subjective effort required to maintain clear vision at +7 and +8 Gz provided an indication of the protection provided by the system.RESULTS: All systems moderated decreases in SV and BPeye and increases in LBV under increased +Gz. S3 provided the greatest mean RGT during GOR (+6.2 Gz) and ROR (+6 Gz), reduced the effort required to maintain clear vision at up to +8 Gz, prevented venous pooling and afforded the greatest rise in TPR. The majority of indices revealed no difference between S1 and S2 although RGT during the ROR was greater with S2 (+0.25 Gz).DISCUSSION: S3 effectively prevented pooling of blood in the lower limbs under +Gz, despite the use of PBG, and offers an advantage over five-bladder AGT. Given the similarities of S1 and S2, it was unsurprising that the majority of indices measured were similar. The objective measurement of hemodynamic parameters provides useful information for comparing the G-protection provided by anti-G systems.Pollock RD, Firth RV, Storey JA, Phillips KE, Connolly DM, Green NDC, Stevenson AT. Hemodynamic responses and G protection afforded by three different anti-G systems. Aerosp Med Hum Perform. 2019; 90(11):925-933.

High Altitude Performance of Loudspeakers and Potential Impact on Audiometric Findings.

BACKGROUND: The evaluation of how air rarefaction can affect a loudspeaker performance at altitude implies the need for characterization of earphones during hypobaric conditions. The aim of this study was phonometric analysis at different altitudes of the acoustic output of a widely used earphone model, along with its consequences on audiological investigations conducted under such environmental conditions.METHODS: The transfer function of a TDH-39P earphone was analyzed with an artificial ear under nine different altitude levels, from sea level up to 35,000 ft, inside a hypobaric chamber. A specific phonometric system not sensitive to environmental pressure changes was used. Other potentially confounding factors, such as environmental temperature and humidity, were continuously monitored.RESULTS: No relevant temperature or humidity changes were detected. The sound pressure level generated by the earphone under hypobaric conditions was found considerably affected by air density changes. These data produced a correction table aiming at recalibrating the earphone's output at each audiometric octave test frequency within the 250-8000 Hz range. Quite different characteristics of response were observed at different audiometric frequencies. Such findings were particularly evident for altitudes exceeding 12,000 ft.DISCUSSION: The development of a frequency-selective and altitude-related correction factor for acoustic stimuli is an essential aspect when hearing threshold measurements in hypobaric environments are performed.Lucertini M, Botti T, Sanjust F, Cerini L, Autore A, Lucertini L, Sisto R. High altitude performance of loudspeakers and potential impact on audiometric findings. Aerosp Med Hum Perform. 2019; 90(7):655-659.

Gender Differences in Dry-EEG Manifestations During Acute and Insidious Normobaric Hypoxia.

INTRODUCTION: Prior research suggests there may be gender differences with regards to hypoxia resilience. Our study was designed to determine whether there were differences between genders in neuronal electrical activity at simulated altitude and whether those changes correlated with cognitive and aviation performance decrements.METHODS: There were 60 student Naval Aviators or Flight Officers who completed this study (30 women, 30 men). Participants were exposed to increasing levels of normobaric hypoxia and monitored with dry EEG while flying a fixed-base flight simulation. Gender differences in brainwave frequency power were quantified using MATLAB. Changes in flight and cognitive performance were analyzed via simulation tasks and with a cognitive test validated under hypoxia.RESULTS: Significant decreases in theta and gamma frequency power occurred for women compared to men with insidious hypoxic exposures to 20K, with an average frequency power decrease for women of 19.4% compared to 9.3% for men in theta, and a 42.2% decrease in gamma for women compared to 21.7% for men. Beta frequency power correlated highest between genders, with an average correlation coefficient of r = 0.95 across seven channels.DISCUSSION: Results of this study suggest there is identifiable brain wave suppression for both men and women with hypoxic exposure and, moreover, there are significant differences in this suppression between genders. Beta frequency power was most sensitive for both genders and highly correlative compared to other brainwave frequencies. The implications of these findings are important considerations for next-generation aviation helmets, which may employ this technology as an early warning mechanism.Rice GM, Snider D, Drollinger S, Greil C, Bogni F, Phillips J, Raj A, Marco K, Linnville S. Gender differences in dry-EEG manifestations during acute and insidious normobaric hypoxia. Aerosp Med Hum Perform. 2019; 90(4):369-377.

Evaluation of Aircrew Low-Intensity Threat Laser Eye Protection.

Prototype low-intensity threat laser eye protection (LIT-LEP) spectacles were evaluated for US Coast Guard (USCG) cockpits and night vision goggle compatibility. The impetus for interest in aviation LIT-LEP is driven in part by the fact that easily accessible 0.5-2.0 W high-power laser pointers exceed safety standards for direct on-axis viewing. A repeated-measures experimental design was used to assess LIT-LEP performance relative to a no-LEP control for the following tasks: Near- and far contrast acuity, night vision goggle far-contrast acuity, emissive and non-emissive light source color-vision screening, and USCG multifunctional display color symbol discrimination reaction time and accuracy. Near- and far-contrast acuity results demonstrated good LIT-LEP performance for typical in- and out-of-cockpit lighting conditions. Night vision goggle performance suffered marginally at only one contrast level (85%; 20/30 acuity line). Color vision test results showed good color balance in that S-, M-, and L-cone performance did not demonstrate a clinical diagnostic color defect for emissive or non-emissive light sources when wearing LIT-LEP. Color symbol discrimination reaction-time-task results based on inverse efficiency scores revealed that some non-primary flight display colors exhibited a combination of slower speed and decreased accuracy. The findings will contribute to an acquisition decision as well as guide future LEP designs.

Continuous Glucose Monitoring for In-Flight Measurement of Glucose Levels of Insulin-Treated Pilots.

INTRODUCTION: Due to the risk of hypoglycemia-related incapacitation, diabetic pilots requiring insulin are assessed as unfit according to the International Civil Aviation Organization and most national authorities. Some authorities, such as those from Canada, the United Kingdom, and the United States, permit selected insulin-treated pilots (ITDM-pilots) to fly subject to a protocol requiring pre- and in-flight capillary glucose measurements to show safe levels (>100-<300 mg · dl-1). Critics of such permission question the practicability of these in-flight measurements and whether clinically desired glycemic targets can be achieved while keeping glucose levels in the safe range. Subcutaneous continuous glucose monitoring (CGM) has recently been approved by the FDA as a stand-alone method to provide accurate glucose levels and treatment decision guidance in patients. This commentary considers that use of CGM by ITDM pilots facilitates practicability and recording of in-flight glucose measurements and facilitates achievement of clinically desired glycemic targets without increasing hypoglycemia risks.Strollo F, Simons R, Mambro A, Strollo G, Gentile S. Continuous glucose monitoring for in-flight measurement of glucose levels of insulin-treated pilots. Aerosp Med Hum Perform. 2019; 90(8):735-737.