Development and interactions of two inert gas bubbles during decompression.

Y Jiang; L D Homer; E D Thalmann

Home/Archive/PubMed

PubMed · 8931280

Development and interactions of two inert gas bubbles during decompression.

Y Jiang·L D Homer·E D Thalmann

View original source ↗Export metadata ↓

Abstract

A mathematical model has been developed to simulate the evolution of two inert gas bubbles in tissue. This is useful for understanding the dynamics of bubbles that presumably arise during decompression. It is assumed that they are spherical and that the tissue volume surrounding them is infinite. The total pressure in each bubble is determined by the barometric and metabolic gas pressures as well as the pressure due to surface tension. Bipolar coordinates are employed to determine the inert gas pressure distribution. Two coupled governing equations for bubble radii are then derived and solved numerically. The results demonstrate how bubble evolution is affected by the distance between bubbles and the initial bubble radii. The existence time and bubble surface flux of two equal-sized bubbles are calculated and compared with those of a single gas bubble model. The results indicate that when two bubbles are very close, it takes 20% more time for two bubbles to dissolve than for a single one, and the total surface flux of two bubbles is nearly 20% less than twice of a single bubble. When the center-to-center distance is 10 times of bubble radius, the effect of bubble interaction on bubble existence time and surface flux are about 6 and 9% changes, respectively. We conclude that if bubbles are not too small, the interactions among bubbles should be included in inert gas bubble models predicting bubble evolution.

Explore related subjects

Decompression Sickness Humans Models, Biological Models, Theoretical Noble Gases Pressure Surface Tension Journal Article Research Support, U.S. Gov't, Non-P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Y Jiang, L D Homer, E D Thalmann. 1996. Development and interactions of two inert gas bubbles during decompression.. https://pubmed.ncbi.nlm.nih.gov/8931280/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

[Decompression sickness in Darwin's kingdom].

Explore the source record for details and available documents.

Decompression Sickness↗

PubMed2006

Delayed treatment of decompression sickness with short, no-air-break tables: review of 140 cases.

INTRODUCTION: Most cases of decompression sickness (DCS) in the U.S. are treated with hyperbaric oxygen using U.S. Navy Treatment Tables 5 and 6, although detailed analysis shows that those tables were based on limited data. We reviewed the development of these protocols and offer an alternative treatment table more suitable for monoplace chambers that has proven effective in the treatment of DCS in patients presenting to our facility. METHODS: We reviewed the outcomes for 140 cases of DCS in civilian divers treated with the shorter tables at our facility from January 1983 through December 2002. RESULTS: Onset of symptoms averaged 9.3 h after surfacing. At presentation, 44% of the patients demonstrated mental aberration. The average delay from onset of symptoms to treatment was 93.5 h; median delay was 48 h. Complete recovery in the total group of 140 patients was 87%. When 30 patients with low probability of DCS were excluded, the recovery rate was 98%. All patients with cerebral symptoms recovered. Patients with the highest severity scores showed a high rate of complete recovery (97.5%). DISCUSSION: Short oxygen treatment tables as originally described by Hart are effective in the treatment of DCS, even with long delays to definitive recompression that often occur among civilian divers presenting to a major Divers Alert Network referral center.

Decompression Sickness↗

PubMed2006

[The heart and underwater diving].

Cardiovascular examination of a certain number of candidates for underwater diving raises justifiable questions of aptitude. An indicative list of contraindications has been proposed by the French Federation of Underwater Studies and Sports but a physiopathological basis gives a better understanding of what is involved. During diving, the haemodynamic changes due not only to the exercise but also to cold immersion, hyperoxaemia and decompression impose the absence of any symptomatic cardiac disease. Moreover, the vasoconstriction caused by the cold and hyperoxaemia should incite great caution in both coronary and hypertensive patients. The contraindication related to betablocker therapy is controversial and the debate has not been settled in France. The danger of drowning makes underwater diving hazardous in all pathologies carrying a risk of syncope. Pacemaker patients should be carefully assessed and the depth of diving limited. Finally, the presence of right-to-left intracardiac shunts increases the risk of complications during decompressionand contraindicates underwater diving. Patent foramen ovale is a special case but no special investigation is required for its detection. The cardiologist examining candidates for underwater diving should take all these factors into consideration because, although underwater diving is a sport associated with an increased risk, each year there are more and more people, with differing degrees of aptitude, who wish to practice it.

Decompression Sickness↗