Transfusion medicine illustrated. Novel management of cold agglutinin disease.
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This paper identifies and describes the prebreathe protocol currently used by the U.S. Space Shuttle Program to provide astronauts the capability to safely perform extravehicular activity. A comparison of planned vs actual prebreathe experience through the STS-37 Mission is also provided.
In today's fiscally constrained environment, it can be expected that systems designed for one space program will increasingly be used to support other programs. The example of the U.S. extravehicular mobility unit (EMU), designed for use with the Space Shuttle, and now part of the baseline for the International Space Station (ISS) program, illustrates the adaption process. Certifying the Shuttle's EMU for use aboard ISS requires addressing three fundamental issues: Identifying new ISS requirements to be imposed on the EMU. Extending Shuttle's EMU on-orbit service interval to meet ISS's longer missions. Certifying Shuttle's EMU to meet new environments unique to ISS. Upon completion of the certification process, Shuttle's EMU will meet all requirements for supporting both the Shuttle and ISS program. This paper discusses the processes for addressing these issues and progress to date in achieving resolution.
In the 36 years between June 1965 and February 2001, the US human space flight program has conducted 100 spacewalks, or extravehicular activities (EVAs), as NASA officially calls them. EVA occurs when astronauts wearing spacesuits travel outside their protective spacecraft to perform tasks in the space vacuum environment. US EVA started with pioneering feasibility tests during the Gemini Program. The Apollo Program required sending astronauts to the moon and performing EVA to explore the lunar surface. EVA supported scientific mission objectives of the Skylab program, but may be best remembered for repairing launch damage to the vehicle and thus saving the program. EVA capability on Shuttle was initially planned to be a kit that could be flown at will, and was primarily intended for coping with vehicle return emergencies. The Skylab emergency and the pivotal role of EVA in salvaging that program quickly promoted Shuttle EVA to an essential element for achieving mission objectives, including retrieving satellites and developing techniques to assemble and maintain the International Space Station (ISS). Now, EVA is supporting assembly of ISS. This paper highlights development of US EVA capability within the context of the overarching mission objectives of the US human space flight program.
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Role of individual reactions of thermal and water-electrolyte metabolism and their relation to the mechanisms of hormonal control were studied during suited immersion (SI). The investigation consisted of 177 man/exposures from 3 hrs up to 3 days of 46 male volunteers. Parameters of mass, heat and water-electrolyte metabolism, and hormonal control were determined on a background of monitoring consumption of special ratios. Based on the complex evaluation of tolerance of weight-free SI for 1 to 3 days, parameters of thermal and hydroionic homeostasis were found to be the predictor variables. Extreme types of reactions to SI were in the ratio of 1:4 (tolerant/intolerant subjects). An extreme reaction appears to be an individual constitutional characteristic of the body the dimensions of which are equal during repeated immersion. As for the water-electrolyte parameters, extreme levels of SI tolerance were significantly different in the amount and velocity of renal excretion of liquids and liquid losses due to perspiration (897 +/- 253 ml and 2010 +/- 218 ml in SI tolerant and intolerant subjects, serotonin variability in everyday life and serotonin dynamics during SI (significant increase in tolerant subjects and no dynamics in intolerant subjects after 24 hrs in SI). The complex evaluation of the reaction showed nonstationary thermal state and reduction of oral temperature by 1 degree C in SI intolerant subjects after initial 1-1.5 days of exposure. In the course of 3 days, the negative water balance showed an increase; body mass losses were in parallel with the development of motion sickness and hyperventilation, and disturbance in the rhythm of the sympathoadrenal activity. The renin-aldosterone system reacted most actively out of all the hormonal systems and did not adapt to SI within a day and a half. Thermal state of SI tolerant subjects was stationary during 1-1.5-d immersion; oral temperature dropped by 0.2-0.4 degree C, liquid losses and AP deviations were relatively small and blood osmolality remained unchanged on a background of stable adaptive reactions of various components of the neuroendocrine system. Adaptation to SI occurred in the period from one day to a day and a half.
The recent biomedical investigations conducted on the Space Shuttle and Spacelab have provided a wealth of biomedical information, including the ability to test the efficacy of proposed countermeasures. This achievement was made possible by the ability to conduct mechanistic and control-interventive studies simultaneously with a large number of individuals over a relatively brief period and to compare these data with results obtained from the Skylab missions. Comparisons between short- and long-duration results were limited to establishing trends or extrapolating from short-duration missions. To date, we have evaluated several protocols involving the lower-body negative pressure (LBNP) device, the bicycle-ergometer, the treadmill and preparations for body-fluid replenishment. In many instances, the traditional means of applying these protocols were not sufficient to protect against space-related deconditioning. This paper will review current countermeasures and compare their efficacy to that of existing protocols. Results from in-flight and ground-based experiments will be presented to illuminate the recommended protocols and procedures.
Exposure of crew, equipment, and experiments to the ambient space radiation environment in low Earth orbit poses one of the most significant problems to long-term space habitation. Accurate dose measurement has become increasingly important during the assembly (extravehicular activity (EVA)) and operation of space stations such as on Space Station Mir. Passive integrating detector systems such as thermoluminescent dosemeters (TLDs) are commonly used for dosimetry mapping and personal dosimetry on space vehicles. The well-known advantages of passive detector systems are their independence of power supply, small dimensions, high sensitivity, good stability, wide measuring range, resistance to environmental effects, and relatively low cost. Nevertheless, they have the general disadvantage that for evaluation purposes they need a laboratory or large--in mass and power consumption--terrestrial equipment, and consequently they cannot provide time-resolved dose data during long-term space flights. KFKI Atomic Energy Research Institute (KFKI AEKI) has developed and manufactured a series of thermoluminescent dosemeter systems for measuring cosmic radiation doses in the 10 microGy to 10 Gy range, consisting of a set of bulb dosemeters and a compact, self-contained, TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A detailed description of the system is given and the comprehensive results of these measurements are summarised.
This paper provides an overview and summary of U.S. extravehicular activity accomplishments of the last 26 years, Space Shuttle missions having scheduled extravehicular activities to be performed over the next several years, extravehicular activities expected to be necessary to support Space Station Freedom assembly tasks and operations, and potential extravehicular activity roles of the NASA Space Exploration Initiative Program.
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Since 1977, EVA suits of the semi-rigid type have been used to support sorties from Russian orbiting stations. Currently, within the MIR station program, the Orlan-DMA, the latest modification of the Orlan semi-rigid EVA suit is used by crewmembers. Quite some experience has been gained by Russia in operations of the Orlan type suits. It has proved the advantages of the EVA suit of a semi-rigid configuration, featuring donning/doffing through a hinged backpack door with a built-in life support system. Meanwhile there were some wishes and comments from the crewmembers addressed to the enclosure design and some LSS components. Currently a number of ways and methods are being developed to improve operational characteristics of the suit as well as to enhance its reliability and lifetime. The forthcoming EVAs to be performed by the STS-MIR crewmembers and future EVAs from the common airlock of the International Space Station Alpha make implementation of the planned improvements even more consistent. The paper analyzes the experience gained in the Orlan-DMA operation and discusses planned improvements in light of the forthcoming activities. In particular the Orlan enhancement program is aimed to make the donning/doffing easier, enhance enclosure mobility, improve the condensate removal unit, increase the CCC (Contamination Control Cartridge) operation time and simplify the onboard subsystem design concept.
A dual mode pressure regulator has been successfully completed by Intertechnique. This regulator provides the regulated oxygen pressure required for the extra vehicular activity suit for Hermes. This regulator also enables high purge flow during suit donning. New technologies have been successfully developed by Intertechnique in order to provide a very high level of safety.
Significant changes of thermogomeostatic parameters was obtained by thermotopometric method using the techniques simulate of microgravity effects: bed rest, pressurized isolation, suit immersion (SI). However, each of ground models made rectal temperature (T) trend downward. The autothermometric study (24 and 12 sessions, 2-13th and 6-174th flight days) was carried out onboard "Mir" by two flight engineers who had preliminary tested at SI (1-2 days). Studies of German investigators onboard "Mir" confirmed: rectal T must be higher in space flight as compared to the normal environment (n=4). Comparative studies suggest that microgravity is a key factor for the human body surface T raise and abolishment of the external/internal T-gradient. T-homeostasis was not really changing during missions and could be regarded as acute effect of microgravity. After delineation of changes in body surface T--by Carnot's thermodynamic law--rectal T raise should have been anticipated. Facts pointing to the excess entropy of human body must not be passed over.
Additional energy expenses due to stretching of the elastic elements of anti-loading suit (ALS) "Penguin" as a whole (shoulders-feet) or only its lower part (waist-feet) in the course of cyclic leg movements were measured in five female and five male volunteers. ALS design enabled tensometric monitoring of efforts applied to specific elastic elements, and total efforts applied to the shoulder or pelvic girdles separately. Energy spend were determined with the indirect calorimetric techniques from the data of the expired air analysis. Registered were electromyograms of m. longus spinae, femoral extensor (m. biceps femoris) and femoral flexor (m. rectus femoris), and m. gastrocnemius. On the first stage, bicycle ergometer was pedaled w/o loading with a frequency of 60 cycles/min. The next stage included testing by incremental loading in which pedaling ceased at the pulse rate of 150/min. Results of the experiments that did not require stretching elastic parts of the suit and in which the total strain effort made up 20 to 25 kg and 15 to 16 kg by males and females, respectively, were compared. It was ascertained that ALS enhanced metabolism during motion by 20 to 30%; however, there was no significant difference in energy expenses when loaded by the whole suit or only its lower part.
OBJECTIVE: To study effect of simulated weightlessness on non-evaporative heat dissipation from different parts of the human body. METHOD: Body surface temperature distribution of five subjects was measured under -6 degrees head down bedrest for 7 d with HR-II infrared thermography. Non-evaporative heat dissipation was calculated with the heat exchange equations based on surface temperature. RESULT: The temperature difference between torso and extremities increased during bed rest, and the largest was 6.7 degrees C higher than the control on the 3rd day of bed rest. The part of non-evaporative heat dissipation from the torso increased about 6% and that from head-neck increased 2%. At the same time, the parts of heat dissipation from the upper and lower extremities decreased about 3% and 5% respectively. CONCLUSION: The parts of non-evaporative heat dissipation from different areas of the human body changed during simulated weightlessness. This result provided a basis for the flow distribution design of liquid cooling garment of EVA suit.
Objective. To discuss the necessity that human mechanics and its physiological basis as applied to the research of human motion in many areas. Method. The motion performance of two aerospace [correction of areospace] pressure suit were studied. Human mechanics and its physiological basis was applied in the design of one suit only. Result. The result showed that good performance was obtained with the suit designed according to this principle which the stipulated actions couldn't be well performanced when wearing the suit not so designed. Conclusion. The research of the application of human mechanics and its physiological basis is necessary and it has better reality and is more scientific than applying biomechanics and robotics.
The paper discussed the results of stabilographic examination of the children suffered from the spastic form of child cerebral paralysis (CCP) treated by means of graded wearing of "Adel" suit which is a modification of the "Penguin" spacesuit. There has been studied the state of 30 children before treatment with the use of "Adel" suit and after the treatment as well as following the several courses of wearing the suit. Besides the patients, eleven healthy volunteer subjects (control group) were examined. There have been obtained the results pointing to the fact that in the healthy persons when they try to achieve the standing posture the leading role pertains to visual analyzer, at the same time, in the patients with spastic form of CCP the realization of standing posture depends upon the severity of the motor function disorders. When in the process of control stabilographic examination the patients suffered from spastic form of CCP demonstrate the significant role of the visual analyzer in achieving the standing posture, the use of the "Adel" suit is most desirable. The use of the "Adel" suit in the CCP patients with a decreased role of visual analyzer in achieving the standing pose as it was found under control examination enhances its significance in controlling the position of the center of gravity of the body.
Effects of 2- or 4-month bedrest in -6 degrees head-down tilt position with or without countermeasures on the histochemical properties of fiber phenotype and cross-sectional area (CSA) were studied in human soleus. The CSAs in slow fibers decreased approximately 32% during 4-month bedrest. This reduction was normalized after 1-month recovery. Although the reduction of percent slow fibers was not significant statistically, the percent intermediate fibers was significantly elevated 4 months after bedrest. Such shift in fiber type was not normalized following 1-month recovery. Effects of wearing an anti-g Penguin suit which has a modest, but continuous resistance at the knee and ankle (Penguin-1) or with knee resistance without loading on the ankle (Penguin-2) for 10 consecutive hours daily were also investigated during approximately 2 months of bedrest. The subjects performed knee extension and flexion for the last 15 min of each hour while in a supine position in bed. Bedrest-induced fiber atrophy was prevented in the Penguin-1 group but not the Penguin-2 group. Transformation of fiber type was not prevented in either Penguin suit group. It is suggested that long-term bedrest causes an atrophy and a shift of fiber phenotype toward fast-twitch type in human soleus. Data also indicated that loading on the muscle is an effective countermeasure for prevention of fiber atrophy but not fiber-type transformation.