Scientific papers 1976 - 1979
In association with Hennessy, Hempleman developed a
complex formula taking into account the diffusion, the
surface tension around the bubble, the elasticity of tissues,
the perfusion, the voltage of the gas in the liquid to
describe the magnification of bubbles and their circulation
in the body.
In contrast to the Haldane model, it is considered that the
gas diffuses through the alveolar walls to dissolve in the
blood and broadcasts also in cartilage (only organic fabrics
retained in the model). This model is said “by diffusion”
David E. Yount (US navy at Hawaii) is a developer of the
Variable Permeability Model (VPM) that believes that
“nuclei” of gas need to be present to trigger the formation
of bubbles during or after decompression. The “nuclei” or
gas pockets occur in the natural state and may develop
from the gas nucleus trapped in small hydrophobic
crevices or be generated by tribonucleation. It is thought
that the surface tension at the external of the bubble
creates a sort of “skin”, which is the interface between the
free gases inside the bubble and the liquids/dissolved
gases in the tissue compartments. The skin of the bubble
can be compared to an elastic membrane with
microscopic holes which are closing gradually when the
size of the bubble decreases and opening gradually when
the size of the bubble increases: The permeability of the
bubble varies, that is why this model is called “Variable
Permeability Model”.
In this article, a model is investigated in which stability is
maintained by surface-actiive skins of varying gas
permeability.
This document is the final report of a workshop performed
on the 13 and 14 of November 1979 under the direction
of doctors Lambertsen and Bornmann.
This article was written to support the famous book
“Decompression Sickness: The Biophysical Basis of
Prevention and Treatment” (published by John Wiley in
New York and London), where the Thermodynamic
approach was explained in detail.
It describes the problems arising with decompression and
their approach by Brian Hills.
In this article, Brian Hills described the implication of
supersaturation and counterdiffusion for bubble
formation. He said that it could explain the occurrence of
decompression sickness when decompression is normally
not called for.
This document, published in 1978, describes
experimentations made during the seventies in support of
US Navy and the NASA activities with the particiaton of
the University of Pennsylvania, the U.S. Naval Medical
Research Institute, the U.S. Naval Submarine Medical
Center, the NASA Manned Spacecraft Center, the
University of Florida at Gainesville, and the Virginia Mason
Hospital at Seattle.
This study discusses the occurrence of incapacitating
vestibular dysfunction in men breathing mixes such as
nitrogen-helium-oxygen or neon-helium-oxygen mixtures
while surrounded by helium.
These symptoms were identified along with dermal gas
lesions and continuous venous gas embolization as part of
the isobaric counterdiffusion phenomenon, which is a
significant hazard in manned undersea activities.
Author: Edvard A. Hemmingsen.
Various solutions of surfactants and electrolytes were
equilibrated with argon at gas pressures up to 202 atm
and then decompressed to atmospheric pressure while
observed visually or cinematographically for the
occurrence of bubbles.
Using the Doppler detector implanted on the pulmonary
artery or posterior vena cava in sheep and goats, the team
demonstrated the presence of gaseous emboli in all
Haldane model.
Decompression limits for compressed air determined by
ultrasonically detected blood bubbles.
The direct decompression limits for a group of divers over
a range of pressure-time air exposures was determined
using ultrasonic detection of venous gas emboli (VGE). In
addition to dry chamber exposures, ranging from 233 ft
for 7 min to 25 ft for 720 min, the authors exposed six
divers to open ocean dives at 165 ft for 10 min. Findings
demonstrated a strong individual propensity to form
VGE, correlating with susceptibility to bends.
Authors: John B Hartley, George m Santangelo, Howard
Rasmussen, Howard Goldfine
This study examined membrane-related oxygen poisoning
in Escherichia coli K1060 and its parent strain, K-12 Ymel. It
concluded that the kinetics of oxygen toxicity in E. coli are
dependent upon the particular unsaturated fatty acyl
chain composition of the membrane, that the membrane
composition influences the rate-limiting step in hyperbaric
oxygen toxicity, but that a direct structural effect of
hyperbaric oxygen on the membrane lipid, such as
oxidation of the unsaturated acyl chain moiety, is unlikely
in these cells.
Authors: T.E Berghage, J.Voromasti, E.E.P Barnard
This article reviews the US Navy and other recompression
procedures used throughout the world in 1978.
Author: Thomas E. Berghage
This document from the Undersea Medical Society
reports discussions logged during a Workshop held in
September 1978 and supported by the US Office of Naval
Research.
The participants were the most advanced US scientists in
decompression theory at this time.
Authors: H. Le Messurier, T. N. Smith, and W. r. Wood
The authors developed a model for behavior of specimens
in gel, and conformity with the results of an
experimentation program was demonstrated. With the
insight provided by this model, a substantial analogy
between important aspects of the behavior of gel and
tissue was claimed, and application of this model to the
refinement and development of diving and
decompression procedures was proposed.
Authors: Wayne A. Gerth & Edward A. Hemmingsen
Spontaneous cavitation is considered as a potential cause
of decompression accidents. Water with high gas
supersaturation can be stable without cavitation, but
increased supersaturation can lead to system failure and
bubble formation. The concentration of a gas in a solution,
which is influenced by its solubility, plays a significant role
in determining the stability of gas supersaturation in
liquids.
Authors: B. Gardette, A. Ternisien
This key document, written in French, summarizes
experimentations made by Comex on the use of Dopplers
during the years 1976 & 1977.
These operations led to the improvement of devices and
their corresponding procedures for use.
Authors: Louis D Homer, R. Clifton Bailey
Doctors Homer and Bailey conducted extensive research
on statistics for the US Navy.
This paper presents an approach to maximum likelihood
estimation (MLE) using analogies. The resulting algorithm
offers a direct and general approach to Maximum
Likelihood Estimation, simplifying the estimation process,
especially when dealing with complex likelihood functions.
Authors: William L. Hunter, Gene B. Pope, Danny A. Arsu
This document, published in 1978, aimed to improve US
Navy diving procedures. Although the incidence rate of
decompression sickness was below 0.1%, which was
considered low, it was acknowledged that accidents still
occurred and needed to be prevented.
Authors:
W.H. Spaur, E.D. Thalmann, E.T. Flynn, J.L. Zunirick, T.W.
Reedy, and J. M. Ringelberg
This document discusses experiments performed during
helium-oxygen saturation dives ranging from 150 to 1000
fsw to study the limits of multiple and extended-duration
excursions, both deeper and shallower than the storage
depth.
It was found that the distance a diver can safely ascend
without decompression is a function of depth, increasing
from 75 feet at a saturation depth of 225 feet to 180 feet
at I000 feet. Also, initiating saturation decompression
immediately after an excursion was considered safe.
Publisher:
The Undersea and Hyperbaric Medical Society (UHMS)
This workshop, held in Bethesda, Maryland, from
September 6 to 7, 1978, explored the complexities of
decompression theory and provided a platform for
collaboration and knowledge exchange. The Office of
Naval Research supported it.
Although the official proceedings remain a valuable
resource, the spirit of inquiry and exploration still shapes
our understanding of underwater medicine and safety.
Authors: K.E. Kidman, G. Masurel, R. Guillerm
This document explains how to establish a databank
containing Doppler ultrasonic bubble flow data obtained
during and after the decompression of divers.
This databank can serve as a foundation for future
computer correlation studies.
Author: Thomas D. Kunkle
This document pertains to experiments on the formation
of bubbles when gas dissolves in liquid and becomes
supersaturated.
The findings are that:
•
Viscosity significantly influences bubble growth.
•
Pressure and diffusion also affect the bubbles' behavior
and the gas transfer rate.
•
The solubility of the gas also plays a crucial role in the
dynamics of bubbles.
Authors: Murray Epstein
This study examines the physiological changes that occur
in the cardiovascular and renal systems when the human
body is immersed in water up to the neck, also known as
head-out water immersion. It was found that head-out
water immersion increases central blood volume, cardiac
output, peripheral vascular resistance, glomerular filtration
rate, and urine output. That demonstrates that head-out
water immersion can be used as a model to assess the
body's ability to maintain a stable fluid balance.
Authors: Banks Anderson, Joseph C. Farmer
Patients at the Duke hyperbaric facility reported vision
blurring after repeated hyperoxic exposures, unlike
attendants who breathed air and noted no visual
disturbances. Investigations revealed that this blurring was
due to myopia, which increased during hyperoxic
exposure and gradually returned to normal after
treatment ended.
Authors: T. Balazs & V. J. Ferrans
Chemically induced cardiomyopathies often result from a
cardiac metabolic imbalance due to exaggerated
functional effects, such as those caused by adrenergic
beta-receptor stimulants and vasodilating
antihypertensives. Another type of toxic cardiomyopathy
arises from direct cardiotoxic mechanisms unrelated to
cardiovascular functional effects, exemplified by
cardiomyopathy caused by anthracycline antineoplastic
agents. The text discusses these cardiomyopathies'
pathogenesis, morphological changes, and toxicologic
features, focusing on their detection in preclinical toxicity
studies.
Authors: M.G. Hayward, W.R. Keatinge
This study describes an instance of progressive
symptomless hypothermia that developed during a fully
monitored laboratory experiment aimed at assessing
individual responses to mild surface cooling in water.
Authors: Britton Chance, Helmut Sies, & Alberto Boveris.
This study established a quantitative framework for redox
systems biology, which examines the roles of reduction-
oxidation (redox) reactions in biological systems. It made
seminal discoveries about hydrogen peroxide metabolism
and its role in redox biology
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Authors:
James W. Miller, George M Adams, Peter B. Bennett,
Richard E. Clarke, Robert W. Hamilton, David J. Kenyon,
Robert I Wicklund
This 1976 paper offers a thorough overview and
documentation of the prevailing practices and research
concerning hyperbaric saturation exposures utilizing air or
nitrogen-oxygen mixtures. It aims to emphasize the
application of vertical excursions in these exposures,
delineate pertinent laboratory and field projects, and
discuss notable results and applications. Furthermore, it
endeavors to evaluate current capabilities and pinpoint
areas requiring further investigation.
Janus 4 is notable for achieving an open-sea dive to a
depth of 460 metres (1510feet) in 1977, which was a
remarkable feat at the time. This document outlines the
successful completion of the first phase, which involved
testing the physiological suitability of candidates, and the
goals of the second phase, which include simulating
actual sea conditions, living in confined spaces at great
depths, and training the divers involved in the program.
Authors: W. H. Spaur, E. D. Thalmann, E. T. Flynn, J. L.
Zunirick, T. W. Reedy, J. M. Ringelberg.
This paper reports on the findings of a study conducted
on helium-oxygen saturation dives, which aimed to
determine the limits of safe excursion ascents for divers,
both deeper and shallower than the saturation depth,
without requiring decompression. The study results have
been used to update the U.S. Navy's procedures and
tables for saturation diving, specifically regarding unlimited
duration excursions.
Authors: Brian A, hills
The purpose of this paper is to discuss and analyze the
mechanisms of decompression sickness, focusing on the
underlying physiology and physics to improve prevention
and treatment methods. It emphasizes a detailed
examination of what occurs within the body during
decompression sickness, rather than solely relying on the
occurrence of symptoms to evaluate procedures. It also
mentions specific categories of decompression sickness,
such as limb bends and air embolism, and considers
factors that might enhance neurological symptoms. In
addition, it explores calculations to prevent Type II
decompression sickness and methods for predicting and
detecting pulmonary oxygen toxicity.
