Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Decompression sickness”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,531 records · Page 85Linked to original sources

Calculations of acoustic scattering from ellipsoidal voids: bends, krill and fish.

The T-matrix approach is used to calculate the scattering of sound waves by an ellipsoidal void in a fluid. Results are presented for the total cross-section of a sphere as a function of frequency; this is related to the detection of the onset of bends in divers. Results are also presented for the angular variation in scattered amplitude when a plane wave is incident on an ellipsoidal cavity in water; this is related to the target strength of euphausiids and teleostean. It is concluded that the model is a useful representation of the scattering from such marine organisms.

Animals↗

Subatmospheric decompression: neurological and behavioural studies.

Several studies in animals over the past decade have shown that prolonged exposures to pressures within the range 226 mm Hg to 160 mm Hg (30,000 to 37,500 ft) are likely to lead to brain damage. This often results in neurological and behavioural disturbance, which may be subtle and reversible or gross and ultimately fatal. The appearance of these impairments is often delayed until several hours or even days after exposure. Immediate survival does not necessarily ensure recovery. In contrast, decompression to pressures below 160 mm Hg or above 226 mm Hg are unlikely to have adverse effects if the exposure is survived. The most probable outcomes of such decompressions are death or uneventful recovery.

Aerospace Medicine↗

The European space suit, a design for productivity and crew safety.

In order to fulfill the two major mission objectives, i.e. support planned and unplanned external servicing of the COLUMBUS FFL and support the HERMES vehicle for safety critical operations and emergencies, the European Space Suit System baseline configuration incorporates a number of design features, which shall enhance the productivity and the crew safety of EVA astronauts. The work in EVA is today--and will be for several years--a manual work. Consequently, to improve productivity, the first challenge is to design a suit enclosure which minimizes movement restrictions and crew fatigue. It is covered by the "ergonomic" aspect of the suit design. Furthermore, it is also necessary to help the EVA crewmember in his work, by giving him the right information at the right time. Many solutions exist in this field of Man-Machine Interface, from a very simple system, based on cuff check lists, up to advanced systems, including Head-Up Displays. The design concept for improved productivity encompasses following features: easy donning/doffing thru rear entry, suit ergonomy optimisation, display of operational information in alpha-numerical and graphical form, and voice processing for operations and safety critical information. Concerning crew safety the major design features are: a lower R-factor for emergency EVA operations thru increased suit pressure, zero prebreath conditions for normal operations, visual and voice processing of all safety critical functions, and an autonomous life support system to permit unrestricted operations around HERMES and the CFFL. The paper analyses crew safety and productivity criteria and describes how these features are being built into the design of the European Space Suit System.

Communication↗

Design to safety: experience and plans of the Russian space suit programme.

The paper presents the analysis of the Russian experience gained in the operations of Salyut-6, 7 and Mir orbital stations. The main factors determining their effectiveness and safety are considered and the main requirements to the EVA suit, as the most important tool for the EVA, are formulated.

Aerospace Medicine↗

The EVA space suit development in Europe.

The progress of the European EVA space suit predevelopment activities has resulted in an improved technical reference concept, which will form the basis for a start of the Phase C/D development work in 1992. Technology development work over the last 2 years has resulted in a considerable amount of test data and a better understanding of the characteristics and behaviour of individual parts of the space suit system, in particular in the areas of suits' mobility and life support functions. This information has enabled a consolidation of certain design features on the one hand, but also led to the challenging of some of the design solutions on the other hand. While working towards an improved situation with respect to the main design drivers mass and cost, the technical concept has been improved with respect to functional safety and ease of handling, taking the evolving Hermes spaceplane requirements into consideration. Necessary hardware and functional redundancies have been implemented taking the operational scenario with Hermes and Columbus servicing into consideration. This paper presents the latest design status of the European EVA space suit concept, with particular emphasis on crew safety, comfort and productivity, in the frame of the predevelopment work for the European Space Agency.

Aerospace Medicine↗

U.S. prebreathe protocol.

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.

Aerospace Medicine↗

EVA: European plans.

The current status of European EVA (extravehicular activity) plans is reviewed. The major difference to already existing EVA scenarios in U.S.A. and Soviet Union consists in the adoption of a higher suit pressure, namely 500 hPa. The results of a study concerned with the physiological consequences of this adoption are presented, including recommendations for protective procedures and their necessary experimental validation. A certain discrepancy between laboratory experimental decompression data and EVA operational results is discussed, leading to the identification of several items which may influence space decompression. Microgravity and the influence of the space suit itself are most likely factors in the explanation of this discrepancy, and both experimental procedures and technological developments are proposed to clarify their role for the future design of EVA procedures.

Aerospace Medicine↗

Application of the mechanical oscillator technique to the investigation of EVA decompression.

The ultrasonic bubble detection technique has been used as a versatile tool in the investigation of hypobaric decompression procedures for the last two decades. However, this method can only detect relatively large bubbles > 30-50 micrometers (usually in venous blood) and not the very first stages of bubble formation. Recently, the mechanical oscillator technique has been applied in air diving trials in order to detect small blood density changes due to hypothetical fluid shifts. However, sharp density drops were found in the decompression process, and these have been attributed to gas bubble formation. In this study, this method was applied together with Doppler controls to a series of altitude decompressions to 300 and 500 hPa, which represents the range of EVA operational pressures currently used or planned. Six subjects participated in both series; the oscillator sample tube could be pressurized. By the application of pressure on a blood sample containing questionable gas bubbles, these are reduced in volume, like in recompression therapy, and thus the density of the sample is increased. This effect has been shown in all 6 subjects undergoing decompression to 300 hPa, whereas in the 500 hPa series only 3 out of 6 subjects corresponded with gas phase formation immediately after decompression. Typically, Doppler bubbles appeared only after some latency time between 20 and 60 min; after this time, the density effect had nearly vanished. It is concluded that the mechanical oscillator technique represents a complementary research instrument to the Doppler method, because it is able to deliver a quantitative resolution of the early stage of gas phase formation.

Aerospace Medicine↗

Bends in fish.

Explore the source record for details and available documents.

Air↗

A method for investigating specialised accidents with special reference to diving.

This paper describes a format for the investigation of complicated accidents which result in diving deaths. It emphasises the necessity for communication between technical, medical and legal personnel to arrive at a reasoned appreciation of factors leading to an accident. Properly applied this can result in a meaningful accumulation of data, which can be periodically analysed and be used in formulating Regulations for prevention of further accidents.

Decompression Sickness↗

Dysbarism. A review.

This review of dysbarism outlines the development of the knowledge of the effects of pressure changes on tissues and organs, which is related to a complex of physical, physiological and pharmacological changes. It also shows that with the ever increasing pressures to which man is subject the effects can be regarded as total body rather than the traditional concept of a few target organs.

Acute Disease↗