Fighter pilot cognitive effectiveness during Exercise Wolf Safari

http://pubs.drdc.gc.ca/inbasket/michel.paul.070219_0956.Toronto_TR_2007_020.pdf


Introduction. On recommendations from 1 Canadian Air Division surgeon, DRDC Toronto
received a tasking from 4 Wing to develop models of cognitive effectiveness of CF18 pilots during Exercise Wolf Safari (an ‘around the clock’ air-to-ground bombing exercise prior to possible deployment of CF-18 aircraft to support our troops in Afghanistan). Methods. During work-ups prior to Wolf Safari as well as during the exercise, six CF18 pilots wore wrist actigraphs for up to 28 days in order to allow quantification of their daily sleep. Their daily duty times and daily sleep data were inputted to FASTTM (Fatigue Avoidance Scheduling Tool) in order to generate models of cognitive assessment for each of the participating pilots. Results.
Four of the 6 pilots showed that the Wolf Safari Op Tempo caused a fatigued-induced impact on modelled cognitive effectiveness similar to or worse than the impact caused by being intoxicated to a blood alcohol level of 0.08%. The remaining 2 pilots showed a moderate impact on cognitive effectiveness. Discussion. Some degradation in cognitive effectiveness is inevitable during stressful and complex military operations, especially when conducted at night. To some extent,these performance degradations can be mitigated by ensuring the best possible opportunities for sleep, by sustaining nocturnal alertness with caffeinated gum, and by exploiting the new CF aeromedical policy for the short-term flight supervised prescription of selected sleep-inducing medications.

Effects of Extreme Sleep Deprivation on Human Performance

http://www.isu.edu/ias/documents/24_Tran.pdf

Sleep is a fundamental recuperative process for the nervous system. Disruption of this homeostatic drive can lead to severe impairments of the operator’s ability to perceive, recognize, and respond to emergencies and/or unanticipated events, putting the operator at risk. Therefore, establishing a comprehensive understanding of how sleep deprivation influences human performance is essential in order to counter fatigue or to develop mitigation strategies. The goal of the present study was to examine the psychological effects of prolonged sleep deprivation (approx. 75 hrs) over a four-day span on a general aviation pilot flying a fixed-based flight simulator. During the study, a series of tasks were employed every four hours in order to examine the pilot’s perceptual and higher level cognitive abilities. Overall, results suggest that the majority of cognitive and perceptual degradation occurs between 30-40 hours into the flight. Limitations and future research directions are also discussed.

Road Safety Research Report No. 78 Motorcycle Rider Fatigue:

http://www.dft.gov.uk/pgr/roadsafety/research/rsrr/theme2/riderfatigue.pdf


EXECUTIVE SUMMARY
The Department for Transport commissioned the Transport Research Laboratory
(TRL) to undertake a literature review of motorcycle rider fatigue. The aims of the
review were to:
• investigate the incidence of fatigue-related accidents among riders;
• investigate the causes, symptoms and effects of fatigue on riders;
• assess the impact of fatigue in riders on possible accident causation; and
• explore possible countermeasures to combat the effects of fatigue and review
campaign strategies that have addressed fatigue and its dangers.The term ‘fatigue’ is defined and interpreted in many different ways in the literature. For the purpose of this review, it is used as an umbrella term encompassing internal states and performance decrements associated with:
• a need for sleep (sleepiness/drowsiness);
• tasks/environments that are mentally or physically demanding (excessive task
demands or ETDs); and
• tasks/environments that are insufficiently stimulating (under-stimulation).
However, due to the nature of the motorcycle riding task (which includes exposure
to noise and vibration, and the need for the rider to maintain physical balance),the
final component is not generally a major problem for riders. The review covered data from a wide variety of sources,including publications in the open literature and ongoing work by major transport research centres. Overall, it found that there have been few studies investigating the causes and effects of rider fatigue. Where they do exist, they tend not to provide a definition for fatigue and also not to separate the definition into the above three components of fatigue, namely sleepiness, ETDs and effects due to under-stimulation, which may have quite different effects on performance. Additionally, there tends to be a reliance on self-report questionnaires rather than on directly observed effects of task performance or safety. Similarly, the literature does not provide much evidence for the effectiveness of potential countermeasures or campaign strategies specifically to
combat the effects of rider fatigue. However, information from the literature about
driver fatigue and fatigue in general has, with careful interpretation, provided some
insight into the possible causes of fatigue and the likely effects that it can have on motorcycle riders.
5
The main findings from the literature review are as follows:
• There is very little direct research evidence or information concerning motorcycle rider fatigue and, therefore, it is difficult to draw firm conclusions on the incidence of rider fatigue.
• Some of the causes and effects of rider fatigue are shared with those of driver
fatigue and fatigue in general. These include lack of prior sleep or time of day of
riding. However, there are strong reasons to focus specifically on motorcycle
rider research, mainly because the motorcycle riding task makes different demands of people from the car driving task, and riders are exposed to a far more hostile environment than drivers. These differences may have important consequences for the way fatigue develops and affects drivers and riders.
• Three main studies investigating rider fatigue have been identified. A pilot study
conducted in Australia examined the effects of a recreational day ride on reported fatigue and performance. A much older UK study examined riders’ reaction times after riding a test route before and after a night’s rest. Finally, in a brief qualitative internet study of riders, a questionnaire was sent to American motorcyclists. The questions in this questionnaire all related directly to motorcycle fatigue and ranged from riders’ concepts of fatigue to preparation prior to rides, detection of fatigue and countermeasures to fatigue.
• In the questionnaire study, riders commonly reported insufficient breaks, long
riding hours and monotonous roads as possible causes of rider fatigue. Elsewhere in the literature, heat stress, stress from cold, noise or vibration,
posture/discomfort stress and night-time riding were identified as causes of rider
fatigue.
• Few countermeasures or campaign strategies with a firm scientific basis have
been developed specifically to help riders avoid riding when fatigued, or to combat the effects of fatigue on riders. However, remedial measures to combat fatigue in drivers have been extensively discussed in the literature. The most common are: formal fatigue management programmes; taking regular breaks; ingesting caffeine; setting realistic targets for the journey; and taking ‘power naps’.
• Measures suggested specifically for minimising rider fatigue focus on reducing
the physical and mental demands of the (riding) task and include: having a windshield on the motorbike; correct configuration of the motorcycle; and using
hearing protection. However, hard evidence of their effectiveness is lacking.The investigation of the incidence of rider fatigue in UK accidents was carried out
by identifying fatigue-related motorcycle accidents in four accident databases (‘On
the Spot’, STATS19, ‘Fatals’ and ‘Motorcycle Accident In Depth Study’). The main
findings were:
Motorcycle Rider Fatigue: A Review
6
• fatigue was identified as a factor in only a relatively small proportion of the
motorcycle accidents in the databases;
• the small number of fatigue-related motorcycle accidents for study meant that it
was not possible to draw conclusions about any associations with other factors
(time of day, etc.); and
• it is likely that the small number of fatigue-related motorcycle accidents
identified is due, at least in part, to the practical difficulty of gathering
information about the fatigue state of accident-involved motorcyclists, either at
the scene or retrospectively. Taken as a whole, the available literature and accident data provide very little scientific information specifically on the subject of rider fatigue. The knowledge gaps found are introduced at the end of this report, and it is recommended that the first step should be to establish much more clearly the importance of motorcyclist fatigue as a road safety problem – for example, by more precisely quantifying the level of involvement of fatigue in motorcycle accidents (including through the use of rider self-report survey data). This should provide a firmer basis for justifying research expenditure on the other aspects of motorcyclist fatigue.

REASSESSMENT OF HUMAN PERFORMANCE PARAMETER ESTIMATES FOR RESPIRATORY PROTECTION DESIGN AND DEVELOPMENT

http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA477008&Location=U2&doc=GetTRDoc.pdf



The key to ensuring that rational respirator technology solutions are possible and acceptable to the user community is the knowledge that each option has a sound scientific basis. Historical mask wear human performance research offers useful, albeit limited, insights on the relationships between design parameters and performance. The purposes of the current task
were to review and revise the existing human performance capabilities and mask design parameters databases and to derive new algorithms to more accurately define human performance capabilities related to respirator wear. The results reaffirm that
much of the basic psychophysiological data needed to enhance respirator design requirements remains elusive. The main data gaps across all performance capabilities include little or no knowledge concerning the relationships among respirator design components and performance and the impacts of design parameters on task performance across different work
intensities. The impacts of mask design on subjective comfort and subsequent task performance is the capability area with the least amount of reliable information. In this regard, research needs to continue to advance the knowledge base to ensure that next generation respirator designs can be based on robust human factors data.

Impact of a protective vest and spacer garment on exercise heat strain

http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA477047&Location=U2&doc=GetTRDoc.pdf


Protective vests worn by global security personnel,
and weighted vests worn by athletes, may increase
physiological strain due to added load, increased clothing
insulation and vapor resistance. The impact of protective
vest clothing properties on physiological strain, and the
potential of a spacer garment to reduce physiological
strain, was examined. Eleven men performed 3 trials of
intermittent treadmill walking over 4 h in a hot, dry environment
(35C, 30% rh). Volunteers wore the US Army
battledress uniform (trial B), B + protective vest (trial P),
and B + P + spacer garment (trial S). Biophysical clothing
properties were determined and found similar to many law
enforcement, industry, and sports ensembles. Physiological
measurements included core (Tc), mean skin (Tsk) and chest
(Tchest) temperatures, heart rate (HR), and sweating rate
(SR). The independent impact of clothing was determined
by equating metabolic rate in all trials. In trial P, HR was
+7 b/min higher after 1 h of exercise and +19 b/min by the
fourth hour compared to B (P\0.05). Tc (+0.30C), Tsk
(+1.0C) and Physiological Strain Index were all higher in
P than B (P\0.05). S did not abate these effects except to
reduce Tsk (P[S) via a lower Tchest (-0.40C) (P\0.05).
SR was higher (P\0.05) in P and S versus B, but the
magnitude of differences was small. A protective vest
increases physiological strain independent of added load,
while a spacer garment does not alter this outcome.

Tympanic Membrane Perforation and Hearing Loss From Blast Overpressure in Operation Enduring Freedom and Operation Iraqi Freedom Wounded

http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA480371&Location=U2&doc=GetTRDoc.pdf

Primary blast injury is tissue destruction caused by the blast wave of high-pressure air that travels outward from an explosion. Tympanic membrane (TM) rupture is the most common form of primary blast injury. Since the ear is, by design, the body's most sensitive pressure transducer, it is the organ most commonly affected by the dramatic changes in ambient air pressure that occur close to an explosion. Studies of service members injured in combat have demonstrated that TM perforation occurs in approximately 9% of patients wounded by explosives. (Ritenour AE, Blackbourne LH, Kelly JF, et al. Primary blast injury in OEF/OIF: 2003 2006. Unpublished data.) TM rupture occurs more frequently when an explosion takes place in a closed space and when victims are in close proximity to the detonation center. The lowest pressure necessary to perforate a TM is about 5 psi; approximately 50% of TMs will rupture at 15 psi. Various factors have proven to positively or negatively affect an individual's susceptibility to TM rupture. Studies have demonstrated that disease or previous injury, increased age, inadequate pneumatization, and TM position perpendicular to the incident wave all increase the likelihood of perforation. Conversely, plugs of cerumen may exert a protective effect when loose in the external auditory canal, but may serve as a ramrods increasing injury if they are in contact with the TM at the time of the explosion. Simple ear plugs are very effective in reducing the incidence of TM rupture, but are impractical in situations, such as combat, where accurate understanding of quiet verbal communication is critical. Investigators have demonstrated that up to 80% of all perforated TMs heal spontaneously with relatively few requiring operative intervention. Large size of perforation (high grade) and peripheral location of the defect have both been associated with lower rates of spontaneous healing.

En-Route Care in the Air: Snapshot of Mechanical Ventilation at 37,000 Feet

http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA480473&Location=U2&doc=GetTRDoc.pdf

Evacuation of seriously wounded service members requiring mechanical ventilation in aircraft where low light, noise, vibration, and barometric pressure changes create a unique clinical environment. Our goal was to evaluate ventilatory requirements, oxygenation, and oxygen use in flight and assess the feasibility of a computer interface. A personal computer was integrated with the pulse oximeter and ventilator data port used in aeromedical evacuation from Iraq to Germany. Ventilator settings, inspired oxygen (FiO2), tidal volume (VT), respiratory rate (RR), minute ventilation (VE), monitored values, heart rate (HR), and oxygen saturation (SpO2), were recorded continuously. Additional data was obtained through the U.S. Air Force (USAF) Transcom Regulation and Command/Control Evacuation System (TRAC2ES) and the U. S. Army Institute of Surgical Research Joint Theater Trauma Registry databases. During a 4 month time frame 117 hours of continuous recording was accomplished in 22 patients. All patients survived transport. There were 32 changes to FiO2, 18 changes to PEEP, 26 changes to RR, and 20 changes to VT during flight. Five patients underwent no recorded changes in flight. Three desaturation events (<90%) were recorded lasting 35, 115, and 280 seconds. Recorded ventilatory changes averaged less than 1 (0.82) per hour of recorded flight with FiO2 being the most common. Conclusions: A computer interface is feasible in the austere aeromedical environment. Implications to military operations and civilian homeland defense include understanding casualty oxygen requirements for resource planning in support of aeromedical evacuation. Portable oxygen generation systems may be able to provide adequate oxygen flow for transport, reducing the need for compressed gas. Future studies of oxygen conservation systems including closed loop control of FiO2 are warranted.

Human Performance

http://www.fas.org/irp/agency/dod/jason/human.pdf

The fields of neuroscience, psycho-pharmacology, and cognition are in
rapid flux because new scientific tools have provided the capability to develop
fundamental understanding of linkages among brain activity, electrical and
chemical stimulation, and human behavior. Applications to human performance
modification are being driven primarily by medical needs, e.g., “cognitive
repair,” and there are significant new technological developments in
this area. As a result, there is popular excitement about, and thus commercial
markets for possible applications in “cognitive enhancement.” This area
is certain to be investigated extensively over the next decade. Awareness
of developments in cognitive performance enhancement, including cultural
differences in adoption, will be important because these may affect the behavior
and effectiveness of opposing military forces in both symmetric and
asymmetric warfare. The findings and recommendations of our study fall
under three categories, evaluation of military effectiveness, brain plasticity,
and brain-computer interface.

Sleep Impacts of Nighttime Training Noise from Large Weapons on Residents Living Near a Military Installation

http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=A476918&Location=U2&doc=GetTRDoc.pdf


Abstract: Training during the hours of darkness is a necessity for the Army and other branches of the Department of Defense (DoD). Nighttime training is needed to ensure military forces are ready for combat, but in-stallations also endeavor to minimize community noise disturbance and resulting negative public reaction. As a result, most installations restrict nighttime training or enforce training curfews to reduce the negative im-pact of the nighttime training noise on local residents. There is, however, little research-based guidance on the types of restrictions and curfews needed to effectively reduce the negative impact. Consequently, current training restrictions may sacrifice more training capability than necessary.
During the fall of 2004 a field study was conducted adjacent to a military installation to determine if there are preferred times to conduct nighttime training. The results of this research project clearly and strongly indicate that community disturbance is more effectively reduced by conducting training between 0000 and 0200 hours, and avoiding noisy training dur-ing the evening hours before midnight. These findings suggest that night-time training should be postponed until after midnight in order to effec-tively reduce the negative impact of nighttime training on local residents and to preserve nighttime training capabilities throughout DoD