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Results for “Life Support Systems”

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At least 19 recordsLinked to original sources
PubMed1992

Controlled ecological life-support system. Use of plants for human life-support in space.

Scientists and engineers within NASA are conducting research which will lead to development of advanced life-support systems that utilize higher plants in a unique approach to solving long-term life-support problems in space. This biological solution to life-support, Controlled Ecological Life-Support System (CELSS), is a complex, extensively controlled, bioengineered system that relies on plants to provide the principal elements from gas exchange and food production to potable water reclamation. Research at John F. Kennedy Space Center (KSC) is proceeding with a comprehensive investigation of the individual parts of the CELSS system at a one-person scale in an approach called the Breadboard Project. Concurrently a relatively new NASA sponsored research effort is investigating plant growth and metabolism in microgravity, innovative hydroponic nutrient delivery systems, and use of highly efficient light emitting diodes for artificial plant illumination.

Aerospace Medicine↗
PubMed1990

A human breathing simulator designed to test the life support system of a hyperbaric tent.

A self contained life support system which can maintain a breathable atmosphere for up to eight hours was recently developed for use with a portable hyperbaric tent. To facilitate further life support system studies, the practicality of a human breathing simulator (HBS), which would remove oxygen and release carbon dioxide at the same rate as a human, was tested. The HBS consists of a cylinder of carbon dioxide bled into the chamber via a flow regulator and a Vanadous bubbler to chemically remove oxygen from the chamber. First experiments show that the HBS works, but that a larger chemical system is needed to remove oxygen at the desired rate. Scale up calculations have been completed.

Ecological Systems, Closed↗
PubMed1976

Life-support system: emergency medical care for conventions.

The life-support system described provides on-site emergency medical care for a designated group of people. It consists of a fixed subunit, a back-up emergency department; a temporary subunit, a life support station, and a mobile subunit, an ambulance and mobile medical personnel. A proposal for a life-support system for indoor conventions is presented with specifications of personnel, communications, supplies, registrant education and life-support team function. Results, critique, and discussion of a life-support station at the 1974 Annual ACEP/EDNA Scientific Assembly are presented.

Adult↗
PubMed1992

Cardiovascular responses to positive pressure breathing using the tactical life support system.

The improved protection afforded by the Tactical Life Support System (TLSS) vs. other partial pressure ensembles has not been reported with respect to the cardiovascular effects of positive pressure breathing (PPB). Nine seated subjects wearing TLSS were exposed to 30, 50, and 70 mm Hg PPB (breathing air) with four times this pressure in the G-suit. Experiments were conducted at ground-level in order, separated by 4 min rest and preceded by a 1-min control period. Stroke volume and cardiac output (SV, CO) and indexes (SI, CI) were determined by impedance cardiography. Mean arterial pressure (MAP) was directly related to PPB level, increasing by 23%, 32%, and 47% for each PPB level, respectively (p less than 0.01). HR, SV, and CO were unaffected after 4 min of 30, 50, and 70 mm Hg PPB. The results indicate that cardiovascular function decay is less severe than that reported using other PPB ensembles at similar PPB levels. Improved protection is most likely due to the greater pressurization of the G-suit and the 45% greater bladder volume in the leg bladders, leading to restored venous return and SV.

Adult↗
PubMedDate not supplied

[Habitability and biological life support systems for man].

This paper discusses general concepts and specific details of the habitability of space stations and planetary bases completely isolated from the Earth for long periods of time. It emphasizes inadequacy of the present-day knowledge about natural conditions that provide a biologically acceptable environment on the Earth as well as lack of information about life support systems as a source of consumables (oxygen, water, food) and a tool for waste management. The habitability of advanced space vehicles is closely related to closed bioregenerative systems used as life support systems.

Ecological Systems, Closed↗
PubMedDate not supplied

[Control of mineral nutrition of higher plants in biological life support systems].

Control of mineral nutrition of higher plants is one of the problems involved in the development of life support systems. The experiments on carrots cultivated aeroponically have demonstrated that mineral nutrition of plants can be controlled by means of a correction solution applied in accordance with the protocols derived from experimental studies of increase in the plant dry biomass.

Culture Media↗
PubMed1977

Life support systems in intensive care: a review of history, ethics, cost, benefit and rational use.

This paper outlines the development of life support systems, i.e. artificial support systems for failing essential organs such as heart, lungs, kidneys and gastrointestinal tract. The current status of organ support is discussed, particularly in relation to intensive care units. Ethical problems posed by the availability of these systems are presented, cost and cost/benefit ratios are discussed, and proposals are made for the rational use of life support systems in the intensive care situation.

Cost-Benefit Analysis↗
PubMedDate not supplied

[Study of the possibility of utilizing the transpired mositure condensate from sweet potato for growing plants in biological life support systems].

The effect of nonpurified condensate obtained during prolonged cultivation of batata in a sealed chamber upon batata cuttings and seedlings of garden cress, radish and Chinese cabbage was studied. It was shown that nonpurified condensate produced an inhibitory effect on the formation of roots in batata cuttings and on the growth of previously developed roots of batata cuttings and seedlings. The studies which used a chemical model of 3,4-dihydroxy phenylalanine indicated that the condensate contained biologically active substance of organic origin. However, only experiments with the real continuous culture of batata, using real dilutions of the condensate that depend on the size of the greenhouse and the amount of the nutrient solution would clarify wheather condensate of transpiration water of batata plants can be repeatedly utilized in life support systems.

Ecological Systems, Closed↗
PubMedDate not supplied

[Microbiological aspects of the performance of life support systems during prolonged operation].

The environmental control system using superoxides, sillicagels or synthetic ceolites is capable of purifying the atmosphere from microorganisms. The air conditioning system is another means for air purification from microorganisms. The possibility of microbial build-up and multiplication in the atmospheric condensate makes it necessary to assume that an air conditioning system may contribute to the transfer of conditionally pathogenic microorganisms in a space cabin. The reliability of a life support system may degrade due to an accumulation of microorganisms in its components. Further extensive studies are needed to clarify this problem.

Air Conditioning↗
PubMedDate not supplied

[Possibility of using higher plants in a life-support system on the moon].

The paper discusses the possibility of repeated termination of plant vegetation by prolonged darkness approximating the lunar night. This may be helpful for the incorporation of higher plants into the life support system of lunar bases, the solar light being used for illumination. In this connection vegetables (beet Bordeaux, turnip Petrovskaya, carrot Chantanet, dill, radish Virovsky white) and wheat (variety Sonora) were cultivated during the lunar light-dark cycle (i. e. 15 day light: 15 day dark). The experiments demonstrated that traditional plant products can be obtained under the conditions of lunar photoperiod. Grain of wheat grown during the lunar photoperiod were tested as seed material for further cultivation under similar conditions.

Ecological Systems, Closed↗
PubMedDate not supplied

[The role of higher plants in the human biological life support system].

This paper discusses the functional characteristics of the man-plant-mineralization system and the environment it forms when it is supplemented with a photoautotrophic component including higher plants and algae. The functional characteristics of the higher plant component were studied when it operated first in an independent cultivation mode, then coupled with a biological system of human and biocomplex waste mineralization, and finally with a human gas exchange system and Chlorella containing photosynthetic reactors. This approach demonstrated for the first time that Chlorella and higher plants can normally work in a common autosphere. The paper also presents quantitative data about the use of higher plants in a biological life support system. Data analysis shows that the total plant yield did not diminish when the system was closed and man, mineralization system and algal reactors were connected. However although the total photosynthetic productivity remained unchanged, the yield of useful crops decreased. This points to a complex nature of the above effects, the causes of which remain so far inexplicable and require further study.

Aerospace Medicine↗
PubMedDate not supplied

[Characteristics of the proteins of unicellular organisms as potential components of ecological life-support systems].

A comparative characterization of the biological value of proteins from green and blue-green algae, bacteria, and microbial coenosis of straw mineralizing active sludge is given with respect to the fractional composition of total protein, its amino acid composition, and affinity for proteolytic enzymes in vitro. The above microorganisms have an adequate amino acid composition, a high content of essential amino acids, and differ in their content of readily soluble proteins. The presence of protein complexes with other cellular components, for instance lipids and carbohydrates, seems to be responsible for a poor digestibility of these proteins.

Amino Acids↗
PubMed1992

Medical command errors in an urban advanced life support system.

STUDY OBJECTIVE: The aim of this study was to assist in focusing educational efforts for command physicians by identifying the most common types of errors made by on-line medical command. DESIGN: Retrospective survey of prehospital advanced life support (ALS) trip sheets. SETTING: An urban ALS paramedic service with on-line physician medical command rotating on a monthly basis among three hospitals. PARTICIPANTS: From September 1988 through December 1990, all ALS run sheets were reviewed as part of an ongoing quality assurance program. Cases were identified as deviating from regional emergency medical services protocols as judged by agreement of three physician reviewers. Cases were excluded if all three reviewers did not agree that the command rendered was inappropriate. INTERVENTIONS: Command errors were identified from the prehospital ALS run sheets and categorized. RESULTS: One hundred ninety-four command errors in 167 cases were identified from 3,839 runs (4.4% of all runs). Six types of errors accounted for 80% of the total errors, with the most common error (34%) being failure to address the possibility of hypoglycemia with altered level of consciousness. Error rate decreased from 7.9% to 2.6% of total runs during the study period. CONCLUSION: To reduce the medical command error rate, physician education should be directed at the six problem areas identified. Ongoing quality assurance review of medical command may result in a decrease of the command error rate.

Diagnostic Errors↗
PubMed1977

Survival test of submersible life support systems.

An experiment to validate predictions concerning submersible survivability was performed in December, 1975, by members of the Canadian Forces in the CF Submersible Lockout Vehicle SDL-1 in Halifax Harbour in water of 4 degrees C temperature at a depth of 40 ft. Data was collected relevant to the life support equipment to determine if it would operate for a simulated 6-h mission followed by a 24-h immobility period, at the end of which rescue was presumed to have occurred. Physiological data was collected from the submersible occupants in order to assess the degree of thermal stress experienced in this exercise. The experiment was terminated after a duration of approximately 25 h at 1 atm internal pressure due to exhaustion of two of the three on-board power supplies, causing the CO2 scrubbers to be inoperative and the CO2 content in the breathing gas to increase to toxic levels. Only two of the three submersible occupants experienced cold stress, one in the forward sphere and one in the aft sphere. At the end of 24 h, the core temperatures of both individuals had decreased by 0.5 degrees C and, during this time, skin temperatures, particularly of the extremities, had steadily and slowly decreased. Neither individual was hypothermic, but it was considered likely that after a 3-d exposure, at least two of the crew members would have had core temperatures of 35 degrees C or lower, assuming that CO2 poisoning had not occurred earlier.

Air↗