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Results for “Simulation Training”

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PubMed1990

Carbohydrate-electrolyte replacement during a simulated triathlon in the heat.

Effects of a 7% carbohydrate-electrolyte drink (CE) or a flavored water placebo (P) on physiological function and performance were compared during a simulated triathlon (ST) in the heat. Ten trained male triathletes performed two STs, consisting of 1.5 km swimming, 40 km cycling, and 10 km running in an environmentally controlled area at self-selected race pace. Subjects consumed 2 ml.kg-1 (130-174 ml) of CE or P following the swim, at 8.0-km intervals during cycling, and at 3.2-km intervals during running. Sweat rate, rectal and mean skin temperatures, perceived exertion, heart rate, plasma osmolality, percent change in plasma volume, total protein, Na+, K+, and lactate were similar during the ST under both drink conditions, but RER and plasma glucose were higher (P less than 0.05) with CE. During the last 4 km of running, VO2 was significantly higher with CE. Mean run time and total ST time were faster with CE (by 1.4 and 1.2 min) although not significantly different (P less than 0.06 and P less than 0.10) from P. Subjects reported no significant difference in nausea, fullness, or stomach upset with CE compared to P. General physiological responses were similar for each drink during 2 h of multi-modal exercise in the heat; however, blood glucose, carbohydrate utilization, and exercise intensity at the end of a ST may be increased with CE fluid replacement.

Bicycling↗

PubMed2004

Altered cardiac function and minimal cardiac damage during prolonged exercise.

PURPOSE: The purpose of the present study was to examine markers of cardiac function and cardiac damage during a simulated half-ironman triathlon in highly trained athletes. METHODS: Nine highly trained male triathletes volunteered for the study (mean +/- SD; age: 33 +/- 3 yr; height: 1.8 +/- 0.1 m; body mass: 77.7 +/- 3.2 kg). The subjects completed a half-ironman triathlon; 1.9-km swim in an indoor 20-m pool, followed by a laboratory-based 90-km cycle and 21.1-km run. Venous blood samples were drawn and echocardiographic assessment completed before the start of exercise, immediately after each stage, and 24 h postexercise. Serum was analyzed for total creatine kinase activity (CK), creatine kinase isoenzyme MB(mass) (CK-MB(mass)), and cardiac troponin T (cTnT). Left ventricular systolic (stroke volume, and systolic blood pressure/end systolic volume ratio (SBP/ESV)) and diastolic (ratio of early [E] to late [A], ventricular filling E:A) measurements were derived from echocardiographic assessment. RESULTS: The mean completion time of the half-ironman triathlon was 301 +/- 28 min. Left ventricular contractility (SBP/ESV) was significantly reduced after the half-ironman triathlon (P < 0.05). A significant reduction in E:A was observed after the run phase of the half-ironman triathlon (P < 0.05). Significant increases in CK and CK-MB(mass) were observed during and after the half-ironman triathlon (P < 0.05), and cTnT was elevated in four subjects over the course of the half-ironman triathlon. CONCLUSIONS: The physiologic stress imposed by the half-ironman triathlon resulted in a reduced left ventricular contractility and altered diastolic filling, coupled with minimal cardiac damage in a number of highly trained male triathletes. The mechanisms behind such altered cardiac function and cardiac damage after prolonged exercise are yet to be elucidated.

Adult↗

PubMed2003

Noise amplification during supercontinuum generation in microstructure fiber.

Supercontinua generated by femtosecond pulses launched in microstructure fiber can exhibit significant low-frequency (<1-MHz) amplitude noise on the output pulse train. We show that this low-frequency noise is an amplified version of the amplitude noise that is already present on the input laser pulse train. Through both experimental measurements and numerical simulations, we quantify the noise amplification factor and its dependence on the supercontinuum wavelength and on the energy and duration of the input pulse. Interestingly, the dependence differs significantly from that of the broadband white-noise component, which arises from amplification of the input laser shot noise.

Journal Article↗

PubMed2006

Selective attenuation of afferent synaptic transmission as a mechanism of thalamic deep brain stimulation-induced tremor arrest.

Deep brain stimulation (DBS) of the ventrolateral thalamus stops several forms of tremor. Microelectrode recordings in the human thalamus have revealed tremor cells that fire synchronous with electromyographic tremor. The efficacy of DBS likely depends on its ability to modify the activity of these tremor cells either synaptically by stopping afferent tremor signals or by directly altering the intrinsic membrane currents of the neurons. To test these possibilities, whole-cell patch-clamp recordings of ventral thalamic neurons were obtained from rat brain slices. DBS was simulated (sDBS) using extracellular constant current pulse trains (125 Hz, 60-80 micros, 0.25-5 mA, 1-30 s) applied through a bipolar electrode. Using a paired-pulse protocol, we first established that thalamocortical relay neurons receive converging input from multiple independent afferent fibers. Second, although sDBS induced homosynaptic depression of EPSPs along its own pathway, it did not alter the response from a second independent pathway. Third, in contrast to the subthalamic nucleus, sDBS in the thalamus failed to inhibit the rebound potential and the persistent Na+ current but did activate the Ih current. Finally, in eight patients undergoing thalamic DBS surgery for essential tremor, microstimulation was most effective in alleviating tremor when applied in close proximity to recorded tremor cells. However, stimulation could still suppress tremor at distances incapable of directly spreading to recorded tremor cells. These complementary data indicate that DBS may induce a "functional deafferentation" of afferent axons to thalamic tremor cells, thereby preventing tremor signal propagation in humans.

Afferent Pathways↗

PubMed2003

Fundamentals of force feedback and application to a surgery simulator.

Force feedback increases the effectiveness of virtual-reality surgery training systems. An overview of the fundamentals of applying force feedback is presented. An impedance control technique and data processing methods for stability preservation are illustrated. A flexible interface for general force-feedback applications has been developed. This interface is capable of controlling several different force-feedback hardware systems, including the SensAble PHANTOM, the Laparoscopic Impulse Engines from Immersion, and the VS-One virtual endoscopic surgery trainer. The findings are evaluated using the main simulation system, KISMET, and the modeling tools KISMO and VESUV. Within the scope of a cooperative project called HapticIO (funded by the German Ministry of Education and Research [BMBF]), new haptic devices have been designed for virtual neuroendoscopy and laparoscopy. The concept and implementations presented in this paper have been found to be flexible, stable and suitable for universal use. The impedance method, combined with the open-loop feed-forward control technique, is well suited and appropriate for the task.

Computer Simulation↗

PubMed2004

Human factors of powered flight: the Wright brothers' contributions.

Orville and Wilbur Wright of Dayton, OH, not only were the first to fly a powered aircraft, but also pioneered many human factors considerations. While others tried to develop aircraft with a high degree of aerodynamic stability, the Wrights intentionally designed unstable aircraft with "cerebralized" control modeled on bird flight. During 1901-03, the brothers worked with large gliders at Kill Devil Hills, near Kitty Hawk, NC, to develop the first practical human-interactive controls for aircraft pitch, roll, and yaw. On December 17, 1903, they made four controlled, powered flights over the dunes at Kitty Hawk with their Wright Flyer. During the next 2 yr, the Wrights made numerous flights in the Wright Flyers II and III at Huffman Prairie near Dayton. They later developed practical in-flight control of engine power, plus an angle-of-attack sensor and stick-pusher that reduced pilot workload. The brothers' flight demonstrations in the U.S. and Europe during 1908-09 awakened the world to the new age of controlled flight. Orville was the first aviator to use a seat belt. He also introduced a rudder boost/trim control that gave the pilot greater control authority. The Wrights' flight training school in Dayton included a flight simulator of their own design. The Wrights patented their practical airplane and flight control concepts, many of which are still in use today.

Aerospace Medicine↗

PubMed2004

A virtual clinic: telemetric assessment and monitoring for rural and remote areas.

This article reports the establishment of a pilot 'virtual clinic' in a rural region of Victoria, Australia. Using low-cost videophones that work across ordinary phone lines, together with off-the-shelf (mostly automatic) clinical tools, local volunteers have been trained to mediate a virtual consultation between simulated patients and local GPs. This system has the potential to save long trips into town by such patients since the traditional 'home visit' is not feasible, as well as to provide regular home monitoring for those with chronic conditions. This in turn should impact favourably on ambulance deployment, sometimes enabling patients to avoid going to hospital or allowing them to come home sooner than otherwise would be the case, and generally to offer a sense of medical security to those living in isolated regions.

Journal Article↗

PubMed2006

[Statokinesiometric assessment of equilibrium system function in military pilots subjected to angular accelerations].

THE AIM: Evaluation of military flight personnel is of paramount importance in categories both flight safety and combat effectiveness. Assessment of equilibrium system in military pilots is very important part of fitness to fly evaluation. One of the assessment methods is statokinesiometry which can be used complementary to standard ENT evaluation methods. MATERIAL AND METHODS: 18 instructor pilots volunteered to take part in experiment. Age of participants was in range 22 to 47 years (mean 31 +/- 7.78), flight experience (240-4300 flying hours, mean 1408.13 +/-1054 h). All participants had current fitness to fly certificate. Each of participants underwent three expositions on GYRO Instrumental Physiological Trainer and consecutive statokinesiometric assessment in three conditions: "eye open" and "eye closed". RESULTS: Analysis of recorded parameters revealed individual variations in vestibular organ sensitivity. Capacity of vestibular system to cope an adapt to accelerations evoked in conditions similar to real flight is considered as important factor determining spatial disorientation susceptibility. CONCLUSIONS: Therefore it can be used as determinant whether certain individual is capable to perform military flight duties. Proposed method allows for objective and precise assessment of these qualities. Results obtained can be used as an objective complementation to flight personnel training efficiency assessment with use of aviation simulators.

Acceleration↗

PubMedDate not supplied

Selected predictors of health promotion counseling by three groups of allied health professionals.

Three groups of allied health professionals, including dental hygienists, dietitians, and certified nurse-midwives, were surveyed to determine current practice, beliefs, and attitudes regarding health promotion and disease prevention. The study aimed to explore the power of selected variables drawn from social learning theory in predicting self-reported level of counseling. We conducted separate analyses for 10 areas of health promotion and disease prevention: high blood pressure, smoking, lack of exercise, overweight, high-fat diet, alcohol abuse, illicit drug use, stress, isolation and loneliness, and nonuse of safety belts. The predictor variables were respondents' professional group membership, confidence that they possess appropriate skills and knowledge to counsel patients (self-efficacy), belief that patients will follow through on recommendations (adherence expectation), and belief that reduction of risk will improve patients' health status (expectation of health impact). The level of counseling activity varied markedly across the risk areas, with blood pressure and weight receiving the most emphasis on average and isolation and loneliness and nonuse of safety belts receiving markedly less attention. There also was variation across the professional groups. Certified nurse-midwives had higher mean counseling scores in all topics except those related to diet, where the dietitians' mean scores were approximately the same. Of all the areas about which counseling might be increased, use of safety belts stands out as having the lowest reported prevalence, the least complexity in terms of implementation, and the most relevance to at least two of the professional groups. These findings suggest the importance of skills training, including the provision of actual or simulated counseling experience and modeling by others in the same professional group.(ABSTRACT TRUNCATED AT 250 WORDS)

Allied Health Personnel↗

PubMed1981

Instructor pilot teaching behavior and student pilot stress in flight training.

The purpose of this study was to investigate the relationship between instructor pilot behavior and student pilot stress. Six instructor pilots and 12 undergraduate pilot training students served as subjects. Two students were assigned to each instructor. Ten categories of instructor pilot behavior were coded from audio cassette tapes made during four sorties from the initial instrument phase of undergraduate pilot training in the T-50 Instrument Flight Simulator. Behaviors were tallied and converted to a rate per minute; inter-recorder agreement was 87%. Instructors who relied heavily on acceptance and praise behaviors were placed in a positive group (N = 4), while those relying on criticism and scolding were placed in a negative group (N = 2). Student stress was estimated from timed urine samples used to quantify catecholamine excretion. Results indicated that missions in the T-50 Instrument Flight Simulator produced a significant stress response in the subjects and that the stress response was greater in lessons taught by the instructor pilots in the negative group.

Aviation↗

PubMed1980

Effects of different body positions on the Eustachian tube function in the selection of airmen.

The Eustachian tube function of 52 applicants accepted for flight training had earlier been comprehensively tested during simulated flights in a pressure chamber in the sitting position. Despite the fact that all were otologically healthy, the wide range of pressure-equilibrating capacity in the sitting position was even more pronounced when they were rested in recumbency, and in every type of test the pressure-equilibrating capacity was reduced. For instance, 17% of the recumbent subjects could not equilibrate at all during simulated descent as compared to 8% in the sitting position; 81% of the ears were Toynbee positive in the sitting position and only 69% in recumbency. The advantages of the recumbent compared to the seated test position are discussed.

Aerospace Medicine↗

PubMed1997

Virtual reality and telepresence for military medicine.

For decades, warfighters have been putting in place a sophisticated "digital battlefield", an electronic communication and information system to support advanced technology. Medicine is now in a position to leverage these technologies to produce a fundamental revolution, and the keystone is the digital physician. Today nearly all information about a patient can be acquired electronically, and with the new technologies of teleoperation and telesurgery we can provide remote treatment and even surgery through telemedicine. The following framework for military medicine will leverage upon the current electronic battlefield. A personnel status monitor (PSM) will have a global positioning locator to tell the position of each soldier and a suite of vital signs sensors. When a soldier is wounded, the medic will instantly know the location of the soldier, and how serious is the casualty. This will permit the medic to locate the most critically wounded soldier. Once stabilised, he will be placed in a critical care pod, a fully automated intensive care unit in a stretcher, which will monitor his vital signs, administer fluids and medications and provide environmental protection. If immediate surgery is needed, a remote telepresence surgery vehicle will come to the wounded soldier, the medic will place him in the vehicle, and a surgeon will operate remotely using telepresence surgery from a distant Mobile Advance Surgical Hospital (MASH) to the combat zone. Also, the expertise from any specialist will be available from the rear echelons as far back as the home country. For education and training in combat casualty care, virtual reality simulators are being implemented. This same scenario can be utilised in civilian health care, especially in providing care to patients in remote areas who do not currently have access to simple, let alone sophisticated, health care.

Computer Simulation↗

PubMed2001

Development of a multi-modal virtual human knee joint for education and training in orthopaedics.

Due to limited simultaneous access to a greater pool of patients an effective training of medical students or young orthopedic physicians is difficult. A knee joint simulator that comprises the properties of a healthy or pathological knee can support medical education and training. In this paper a mechatronic system is presented that provides visual, acoustic, and haptic (force) feedback so that it allows a user to touch and move a virtual shank, bones or muscles within the leg, and simultaneously observe the generated movement, feel the contact force, and hear sounds. These and further features enable the user to study and assess the properties of the knee, e.g. by testing the joint laxity and end-point stiffness in six degrees-of-motion (DOF) and by grasping and pulling at muscles, rupturing ligaments or changing muscle/ligament paths. Such a tool can support training of physical knee evaluation required for diagnosis and therapeutic planning, since any kind of pathology of any subject type can be tested at any time. Furthermore, it can provide a better understanding of functional anatomy, e.g. for the education of medical students.

Computer Simulation↗

PubMed2001

Experimental exposure to propylene glycol mist in aviation emergency training: acute ocular and respiratory effects.

OBJECTIVES: Propylene glycol (PG) (1-2 propanediol; CAS No 57-55-6) is a low toxicity compound widely used as a food additive, in pharmaceutical preparations, in cosmetics, and in the workplace-for example, water based paints, de-icing fluids, and cooling liquids. Exposure to PG mist may occur from smoke generators in discotheques, theatres, and aviation emergency training. Propylene glycol may cause contact allergy, but there is sparse information on health effects from occupational exposure to PG. METHODS: Non-asthmatic volunteers (n=27) were exposed in an aircraft simulator to PG mist over 1 minute, during realistic training conditions. Geometric mean concentration of PG was 309 mg/m3 (range 176-851 mg/m3), with the highest concentrations in the afternoon. The medical investigation was performed both before and after the exposure (within 15 minutes). It included an estimate of tear film stability break up time, nasal patency by acoustic rhinometry, dynamic spirometry, and a doctor's administered questionnaire on symptoms. RESULTS: After exposure to PG mist for 1 minute tear film stability decreased, ocular and throat symptoms increased, forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) was slightly reduced, and self rated severity of dyspnoea was slightly increased. No effect was found for nasal patency, vital capacity (VC), FVC, nasal symptoms, dermal symptoms, smell of solvent, or any systemic symptoms. Those exposed to the higher concentrations in the afternoon had a more pronounced increase of throat symptoms, and a more pronounced decrease of tear film stability. In four subjects who reported development of irritative cough during exposure to PG, FEV1 was decreased by 5%, but FEV1 was unchanged among those who did not develop a cough. Those who developed a cough also had an increased perception of mild dyspnoea. CONCLUSION: Short exposure to PG mist from artificial smoke generators may cause acute ocular and upper airway irritation in non-asthmatic subjects. A few may also react with cough and slight airway obstruction.

Adult↗

PubMed1993

A method for constructing data-based models of spiking neurons using a dynamic linear-static nonlinear cascade.

This paper describes a general nonlinear dynamical model for neural system identification. It describes an algorithm for fitting a simple form of the model to spike train data, and reports on this algorithm's performance in identifying the structure and parameters of simulated neurons. The central element of the model is a Wiener-Bose dynamic nonlinearity that ensures that the model is able to approximate the behaviour of an arbitrary nonlinear dynamical system. Nonlinearities associated with spike generation and transmission are treated by placing the Wiener-Bose system in cascade with pulse frequency modulators and demodulators, and the static nonlinearity at the output of the Wiener-Bose system is decomposed into a rectifier and a multinomial. This simplifies the model without reducing its generality for neuronal system identification. Model elements can be characterised using standard methods of dynamical systems analysis, and the model has a simple form that can be implemented and simulated efficiently. This model bears a structural resemblance to real neurons; it may be regarded as a connectionist "neuron" that has been generalized in a realistic way to enable it to mimic the behaviour of an arbitrary nonlinear system, or conversely as a general nonlinear model that has been constrained to make it easy to fit to spike train data. Tests with simulated data show that the identification algorithm can accurately estimate the structure and parameters of neuron-like nonlinear dynamical systems using data sets containing only a few hundred spikes.

Animals↗

PubMed2006

Leadership in multiteam systems.

This study examined 2 leader functions likely to be instrumental in synchronizing large systems of teams (i.e., multiteam systems [MTSs]). Leader strategizing and coordinating were manipulated through training, and effects on functional leadership, interteam coordination, and MTS performance were examined. Three hundred eighty-four undergraduate students participated in a laboratory simulation modeling a 3-team MTS performing an F-22 battle simulation task (N = 64 MTSs). Results indicate that both leader training manipulations improved functional leadership and interteam coordination and that functional leader behavior was positively related to MTS-level performance. Functional leadership mediated the effects of both types of training on interteam coordination, and interteam coordination fully mediated the effect of MTS leadership on MTS performance.

Cooperative Behavior↗

PubMed2003

Simulators, first experiences.

It is increasingly being recognized that laparoscopic surgery poses specific strains on the surgical novice. Specific psychomotor skills are required, which cannot easily be acquired by extrapolation from open surgery. Also, limited teaching time in the strict surgical training curricula makes it difficult to acquire such skills. Two surgical simulation platforms, the Advanced Dundee Psychomotor Tester (ADEPT(R)), and the Xitact LS500(R), are objects of study in our hospital for the training and objective assessment of laparoscopic task performance. Multiple validation studies, both at our center and at other institutions, are ongoing. Face-construct and content validity of the two systems under investigation have been established at our skills laboratory. This article highlights the most important findings of our studies using simulative surgical lapraoscopic technologies.

Journal Article↗

PubMed1994

Perceived exertion during submaximal G exposures before and after physical training.

Ratings of perceived exertion (RPE) were registered at submaximal levels in G endurance tests of a combined strength and endurance training program in 17 pilots. After 12 months of physical training, the endurance G tolerance (time to exhaustion during simulated aerial combat maneuver), increased by a mean of 40% (p < 0.001), while the mean RPE at 5 min submaximal G exposure decreased by 1.2 units (p < 0.02). Following 12 months of physical training, a significant relationship was observed between the improvement of the endurance G tolerance and the decrease of the RPE at 5 min (p = 0.05). Mean SaO2 at 5 min increased from 84 to 90% (p < 0.01) after training, while heart rate responses to G stress did not change. It is concluded that mean RPE and, to some extent, mean SaO2 during submaximal G exposures may be used as indicators of shifts in endurance G tolerance. The procedure may reduce the need for exhaustive G tolerance tests with associated risks and discomfort.

Aerospace Medicine↗