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In this paper, we focus on the application of oculometric patterns extracted from raw eye movements during a mental workload task to assess changes in cognitive performance in healthy youth athletes over the course of a typical sport season. Oculometric features pertaining to fixations and saccades were measured on 116 athletes in pre- and post-season testing. Participants were between 7 and 14 years of age at pre-season testing. Due to varied developmental rates, there were large interindividual performance differences during a mental workload task consisting of reading numbers. Based on different reading speeds, we classified three profiles (slow, moderate, and fast) and established their corresponding baselines for oculometric data. Within each profile, we describe changes in oculomotor function based on changes in cognitive performance during the season. To visualize these changes in multidimensional oculometric data, we also present a multidimensional visualization tool named DiViTo (diagnostic visualization tool). These experimental, computational informatics and visualization methodologies may serve to utilize oculometric information to detect changes in cognitive performance due to mild or severe cognitive impairment such as concussion/mild traumatic brain injury, as well as possibly other disorders such as attention deficit hyperactivity disorders, learning/reading disabilities, impairment of alertness, and neurocognitive function.

There is a need for a practical objective measure to detect mild changes in cognitive performance as early signs of concussion in youth or other special populations. In this paper, we propose a novel correlation model that establishes the relationship between oculometrics extracted from raw eye movements during a mental workload task and cognitive performance. We assessed differences in cognitive performance in terms of age for youth athletes based on oculometrics pertaining to fixations and saccades. In this cross-sectional study, oculometrics were measured on 440 healthy youth athletes aged 7 to 15 years. Oculometrics pertaining to fixations (fixation time, fixation size, and surface area of fixation) and saccades (total saccadic amplitude, average saccadic amplitude, and saccadic velocity) were measured and compiled into a multivariate oculometric database by age. We discovered that the combined power of fixations and saccades provided the strongest correlation with cognitive performance—a finding that is evident across all ages as well as all levels of mental workload difficulty. Specifically, the combined observations of fixation time, saccadic velocities, and saccadic amplitudes provided us an understanding of cognitive performance during different levels of mental workload difficulty across all age groups. This study is the first step towards establishing normative, multi-dimensional oculometrics for fixations and saccades in young athletes (7 to 15 years) who are at risk for concussion in sports and recreational activities.

High-Altitude High Opening (HAHO) is a military operational procedure in which parachute jumps are performed at high altitude requiring supplemental oxygen, putting personnel at risk of acute hypoxia in the event of oxygen equipment failure. This study was initiated by the Norwegian Army to evaluate potential outcomes during failure of oxygen supply, and to explore physiology during acute severe hypobaric hypoxia. A simulated HAHO without supplemental oxygen was carried out in a hypobaric chamber with decompression to 30,000 ft (9,144 m) and then recompression to ground level with a descent rate of 1,000 ft/min (305 m/min). Nine subjects were studied. Repeated arterial blood gas samples were drawn throughout the entire hypoxic exposure. Additionally, pulse oximetry, cerebral oximetry, and hemodynamic variables were monitored. Desaturation evolved rapidly and the arterial oxygen tensions are among the lowest ever reported in volunteers during acute hypoxia. PaO2 decreased from baseline 18.4 (17.3–19.1) kPa, 138.0 (133.5–143.3) mmHg, to a minimum value of 3.3 (2.9–3.7) kPa, 24.8 (21.6–27.8) mmHg, after 180 (60–210) s, [median (range)], N = 9. Hyperventilation with ensuing hypocapnia was associated with both increased arterial oxygen saturation and cerebral oximetry values, and potentially improved tolerance to severe hypoxia. One subject had a sharp drop in heart rate and cardiac index and lost consciousness 4 min into the hypoxic exposure. A simulated high-altitude airdrop scenario without supplemental oxygen results in extreme hypoxemia and may result in loss of consciousness in some individuals. NEW & NOTEWORTHY This is the first study to investigate physiology and clinical outcome of oxygen system failure in a simulated HAHO scenario. The acquired knowledge is of great value to make valid risk-benefit analyses during HAHO training or operations. The arterial oxygen tensions reported in this hypobaric chamber study are among the lowest ever reported during acute hypoxia.

Introduction Simulator sickness causes vestibulo-autonomic responses that increase sympathetic activity and decrease parasympathetic activity. The purpose of the study was to quantify these responses through electrogastrography and cardiac interbeat intervals during flight simulation. Methods There were 29 subjects that were randomly assigned to 2 parallel arms: (1) oculovestibular recoupling, where galvanic vestibular stimulation was synchronous with the visual field; and (2) control. Electrogastrography and interbeat interval data were collected during baseline, simulation, and post-simulation periods. A simulator sickness questionnaire was administered. Results Statistically significant differences were observed in percentage of recording time with the dominant frequency of electrogastrography in normogastric and bradygastric domains between the oculovestibular recoupling and control groups. Normogastria was dominant during simulation in the oculovestibular recoupling group. In the control group, the percentage of recording time with the dominant frequency decreased by 22% in normogastria and increased by 20% in bradygastria. The percentage change of the dominant power instability coefficient from baseline to simulation was 26% in the oculovestibular recoupling group vs. 108% in the control group. The power of high-frequency components for interbeat intervals did not change significantly in the oculovestibular recoupling group and was decreased during simulation in the control group. Discussion Electrogastrography and interbeat intervals are sensitive indices of autonomic changes in subjects undergoing flight simulation. These data demonstrate the potential of oculovestibular recoupling to stabilize gastric activity and cardiac autonomic changes altered during simulator and motion sickness.

The value of epicardial adipose tissue (EAT) thickness as determined by echocardiography in cardiovascular risk assessment is not well understood. The aim of this study was to determine the associations between EAT thickness and Framingham risk score, carotid intima media thickness, carotid artery plaque, and computed tomographic coronary calcium score in a primary prevention population.Patients presenting for cardiovascular preventive care (n = 356) who underwent echocardiography as well as carotid artery ultrasound and/or coronary calcium scoring were included.EAT thickness was weakly correlated with Framingham risk score. The prevalence of carotid plaque was significantly greater in those with EAT thickness ≥ 5.0 mm who either had low Framingham risk scores or had body mass indexes ≥ 25 kg/m(2), compared with those with EAT thickness5.0 mm. No significant association between EAT thickness and carotid intima-media thickness or coronary calcium score existed.EAT thickness ≥ 5.0 mm may identify an individual with a higher likelihood of having detectable carotid atherosclerosis.

BACKGROUND: Commercial spaceflight participants on orbital flights typically are older than career astronauts and they often have medical conditions that have not been studied at high g or in microgravity. This is a case report of a 56-yr-old orbital spaceflight participant with essential tremor and frequent premature ventricular contractions that occurred at rates up to 7000 per day. Before training and spaceflight, he was required to complete extensive clinical investigations to demonstrate normal cardiac structures and the absence of cardiac pathology. The evaluation included signal averaged ECG, transthoracic stress echocardiography, exercise tolerance tests, electrophysiological studies, cardiac MRI, electron beam CT, Holter monitoring, and overnight oximetry. While no cardiac pathology was demonstrated, the Russian medical team required that the PVCs be treated prior to training and spaceflight. For the initial flight, a selective beta-1 receptor beta blocker was used and for the second a calcium channel blocker was used in combination with a nonselective beta blocker for tremor control. Analogue environment testing assured that this combination of medications was compatible. CONCLUSION: The spaceflight participant's PVCs were incompletely suppressed with a low-dose selective beta-1 blocker, but were well suppressed by a calcium channel blocker. He tolerated in-flight periodic use of a nonselective beta blocker in combination with a calcium channel blocker. In-flight ECG and blood pressure monitoring results were normal, and an ECG obtained midmission and on landing day showed successful PVC suppression. He did not have any cardiac difficulty with launch, on-orbit operations, entry, or recovery

Background: We aim to provide data on a diabetes technology simulation course (DTSC) that instructs internal medicine residents in the use of continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring system (CGMS) devices. Methods: The DTSC was implemented during calendar year 2012 and conducted in the institution's simulation center. It consisted of a set of prerequisites, a practicum, and completion of a web-based inpatient CSII-ordering simulation. DTSC participants included only those residents in the outpatient endocrinology rotation. Questionnaires were used to determine whether course objectives were met and to assess the satisfaction of residents with the course. Questionnaires were also administered before and after the endocrine rotation to gauge improvement in familiarity with CSII and CGMS technologies. Results: During the first year, 12 of 12 residents in the outpatient endocrinology rotation completed the DTSC. Residents reported that the course objectives were fully met. The mean satisfaction score with the course ranged from 4.0 to 4.9 (maximum, 5), with most variables rated above 4.5. Self-reported familiarity with the operation of CSII and CGMS devices increased significantly in the postrotation survey compared with that on the prerotation survey (both p < .01). Conclusions: In this pilot program, simulation-based education increased the perceived familiarity of residents with CSII and CGMS technologies. In light of these preliminary findings, the course will continue to be offered, with further data accrual. Future work will involve piloting the DTSC approach among other types of providers, such as residents in other specialties or inpatient nursing staff.

A 27-year-old flight instructor experienced 5 to 10 minutes after a scuba-dive to 29 m, which lasted totally 50 minutes, dizziness, nausea and severe vertigo. The symptoms lasted about an hour. The patient vomited several times and noted sudden onset headache and vertigo lasting the following three days. Hyperbaric oxygen therapy was started 30 hours after the event because decompression sickness was suspected. Transthoracic echocardiographic evaluation showed a patent foramen ovale. Diving accidents may be caused by decompression sickness, the formation of a free intravascular gas phase (bubbles) may result in transatrial shunting in the presence of a patent foramen ovale and may lead to neurological signs and symptoms. In this context the diver was advised to undergo closure of the atrial septal defect. Five months after the incident the patient underwent successful transcatheter occlusion of the PFO.

Introduction Despite improvement in the computational capabilities of visual displays in flight simulators, intersensory visual-vestibular conflict remains the leading cause of simulator sickness (SS). By using galvanic vestibular stimulation (GVS), the vestibular system can be synchronized with a moving visual field in order to lessen the mismatch of sensory inputs thought to result in SS. Methods A multisite electrode array was used to deliver combinations of GVS in 21 normal subjects. Optimal electrode combinations were identified and used to establish GVS dose-response predictions for the perception of roll, pitch, and yaw. Based on these data, an algorithm was then implemented in flight simulator hardware in order to synchronize visual and GVS-induced vestibular sensations (oculo-vestibular-recoupled or OVR simulation). Subjects were then randomly exposed to flight simulation either with or without OVR simulation. A self-report SS checklist was administered to all subjects after each session. An overall SS score was calculated for each category of symptoms for both groups. Results The analysis of GVS stimulation data yielded six unique combinations of electrode positions inducing motion perceptions in the three rotational axes. This provided the algorithm used for OVR simulation. The overall SS scores for gastrointestinal, central, and peripheral categories were 17%, 22.4%, and 20% for the Control group and 6.3%, 20%, and 8% for the OVR group, respectively. Conclusions When virtual head signals produced by GVS are synchronized to the speed and direction of a moving visual field, manifestations of induced SS in a cockpit flight simulator are significantly reduced.

HypothesisTo help establish institution baseline measurements and compare resuscitation performance in different simulation and clinical (live) environments.MethodsWe retrospectively compared GWTG-R metrics for ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) resuscitation perf

Altitude-related illnesses are a frequent cause of morbidity and occasional mortality in travelers to high altitudes in the United States and throughout the world. The primary altitude illnesses are acute mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema. The pathogenesis of these syndromes remains unclear despite considerable research. Altitude also has potential deleterious effects on common medical conditions including coronary artery disease, pulmonary disease, hemo globinopathies, and pregnancy. Most of these problems are primarily preventable with appropriate information before travel. Education should include information about rate of ascent, diet, alcohol intake, physical activity, and preventive medications, including acetazolamide, nifedipine, and dexamethasone in selected circumstances.

Objective: To report results of human VEEP studies in normal controls compared to patients with peripheral or central vestibular dysfunction. Background The VEEP has been described in animal models (cat and guinea pig) and more recently in humans. In contrast to other evoked potentials, a unique linear relationship between current strength and latency has been reported with VEEP responses in normal individuals. Design/Methods: Normal control subjects (n=5) and patients with vestibular dysfunction (n=3) were studied with electrical stimulation over the mastoid in one mA increments from threshold to no higher than 20 mA. Evoked potentials were recorded with standard signal averaging techniques. Results: In normal controls, mastoid stimulation at 2.5mA yielded Cz-A1/2 VEEP responses of median latency 10.2ms (range 6.0-13.3; SD 4.9). These responses progressively increased in latency from 8.6 to 22.6ms (mean latency increase of 1.3ms/mA) as current strength was increased in 10 steps (1mA/step) from threshold. VEEP responses differed significantly in stimulation threshold, morphology, amplitude and latency from mastoid dermatomal somatosensory evoked potentials (SEPs), great auricular sensory nerve action potentials (SNAPs), and frontalis compound muscle action potentials (CMAPs). Neither acoustic stimuli nor white noise masking affected the VEEP. In 3 patients with vestibular dysfunction (one each with acoustic neuroma, Meniere disease and multiple sclerosis as the cause) VEEP late response latencies were absent or markedly asymmetric, with recordable responses showing a median latency of 12.2ms (range 11.2-12.7; SD 0.4); none demonstrated the linear increasing current strength-latency pattern seen in normals. Conclusions: 1) VEEP studies produced reproducible responses in normal controls; 2) VEEP responses cannot be attributed to auditory or somatic sensory nerve responses; 3) VEEP current strength-latency curves showed a linear increase in normals in contrast to absent, flat, and/or decreasing patterns in patients with vestibular dysfunction. Supported by: Mayo Foundation. Disclosure: Dr. Smith has nothing to disclose. Dr. Cevette has nothing to disclose. Dr. Stepanek has nothing to disclose. Dr. Cocco has nothing to disclose. Dr. Pradhan has nothing to disclose. Dr. Brookler has nothing to disclose. Dr. Zapala has nothing to disclose. Dr. Ross has nothing to disclose.