Scientific papers 1999
Study of human organ oxygen tolerance, lung flow-
volume and spirometric measurements performed
repeatedly before, during, and after continuous
oxygen exposures at 1.5, 2.0, and 2.5 ATA for
average durations of 17.7, 9.0, and 5.7 hours,
respectively.
Authors: D. Carturan, A. Boussuges, F. Molenat, H. Burnet,
J. Fondarai, B. Gardette.
The aim of this study was to assess the effect of the ascent
rate on the production of venous circulating bubbles
during the decompression following a recreational dive.
Authors: D. Carturan, A Boussuges, H Burnet, J. Fondarai,
P. Vanuxem, B. Gardette.
The aim of this work was to study the effects of individual
variables which can be assessed non invasively, on the
grades of bubbles detected 60 min after diving by means
of doppler monitoring, in a sample of 40 male scuba
divers. The variables Investigated were: age,
weight. maximal oxygen uptake (VO2 Max) and
percentage of body fat. Bubble signals were graded
according to the code of spencer.
Authors: D Carturan, A Boussuges, P Vanuxem, A
Bar-hen, H Burnet, & B Gardette.
Decompression sickness in diving is recognized as a multi-
factorial phenomenon, depending on several factors, such
as decompression rate and individual susceptibility. The
Doppler ultrasonic detection of circulating venous bubbles
after diving is considered a useful index for decompression
safety because of the relationship between bubbles and
decompression sickness risk. This study aimed to assess the
effects of ascent rate, age, maximal oxygen uptake (VO2
max ), and percent body fat on the production of bubbles
after diving. Fifty male recreational divers performed two
dives at 35 m during 25 min and then ascended in one
case at 9 m/min and in the other case at 17 m/min.
Authors: J. F. Himm & L. D. Homer
Observations of bubble evolution in rats after
decompression from air dives suggest that bubbles may
resolve more safely when the breathing gas is a heliox
mixture than when it is pure O2.
This is due to a transient period of bubble growth seen
during witches to O2 breathing. In an attempt to
understand these experimental results, the authors
developed a multigas-multi-pressure mathematical model
of bubble evolution.
Authors: D.J. Temple, R. Ball, P.K. Weathersby, E.C. Parker,
and S.S. Survanshi
In this study, published in 1999, doctors Temple, Ball,
Weathersby, Parker, and Survanshi compiled descriptions
of DCS cases that occurred after prospective air or
nitrogen-oxygen research dives with the detailed dive
profiles associated with each case.
The aim of this collection of more than 8000 exposures
and more than 400 DCS cases was to allow the analysis of
the relationship between the dive profiles and
manifestations of DCS».
Authors: G. H. Wiest, G. Lehnert, W. M. Bruck, M.
Meyer, E. G. Hahn, & J. H. Ficker
The purpose of this document in our database is to
understand the phenomenon of lung dryness that may
be associated with too dry air and the procedures to fight
it.
Authors: Yoojin Seo, phd, Kazuya Matsumoto, Youngman
Park, Motohiko Mohri, & Shigeaki Matsumoka
The sleep patterns were examined through three
simulated 20-m nitrox saturation dives. The standard
polysomnography of 12 divers was recorded respectively
for a total of 204 nights, as were patterns of change or
consistency in sleep variables. For the 11 divers in their 20s
and 30s there was nothing unusual about their sleep
variables. However, a reduction of total sleep time in
accordance with the lengthening of sleep latency was
observed.
Publisher: Smithsonian institution
Proceedings of a workshop held in the Smithsonian
institution in Washington DC in October 1999.
It was sponsored by the Office of the Provost, Smithsonian
Institution, Washington, D.C.
Authors: E.D. Thalmann, P.C. Kelleher, S.S. Survanshi, E.C.
Parker, P.K. Weathersby
From 1991-92, the first test of a probabilistic
decompression algorithm took place, updating divers'
schedules in real-time to keep the risk of decompression
sickness low. The trial focused on long dives lasting over 6
hours, which included repetitive and multi-level dives with
different gas mixes.The trial confirmed the algorithm's
effectiveness and reliability for Navy use, with DCS rates
within expected limits and no significant changes needed
for the algorithm.
Authors: D.J. Temple, R. Ball, P.K. Weathersby, E.C. Parker,
S.S. Survanshi
Decompression sickness (DCS) has always been viewed as
a straightforward yes-or-no condition. However, despite
years of research and the development of models to
predict DCS risk, there has not been much emphasis on
how various diving profiles are linked to specific DCS
symptoms. The authors collected data from more than
8000 military dives, including 400 cases of DCS, to
conduct a thorough analysis of how dive details are
related to the symptoms of the disease.
Authors: Boussuges A, Lafay V, Carturan D, Fondarai JA,
Sainty JM, Gardette B
The authors compared two methods for detecting venous
circulating bubbles: pulsed Doppler with 2D-
echocardiography guidance and the traditional
continuous Doppler. They tested these methods during a
professional helium/hydrogen saturation dive with four
divers, and after recreational SCUBA dives with 26 divers.
The study concluded that while both methods are equally
effective in ideal conditions, the image-guided pulsed
Doppler is more effective in challenging scenarios with
limited ultrasound visibility.
Authors: David E. Yount, Eric B. Maiken, Erik C. Baker
Physics-based bubble models, such as the Varying
Permeability Model (VPM), are increasingly used to
develop decompression schedules. The VPM simplifies the
process by using just three nucleation parameters and one
decompression parameter instead of traditional M-values
to limit the ascent. For the deeper and intermediate
decompression stages, the supersaturation limits set by
VPM tend to be lower than those calculated by
conventional dissolved-gas algorithms. The advancement
of this model has been supported by the collaborative
efforts of the online community known as the
"Decompression List".
Authors: Robert L. Spitzer, Michael Terman, Janet B.W.
Williams, Jiuan Su Terman, Ulrik F. Malt, Forbes Singer, and
Alfred J. Lewy.
This study aimed to validate a new rating scale for
measuring jet lag severity and to compare the
effectiveness of different melatonin regimens in alleviating
jet lag. It was a randomized, double-blind trial involving
257 Norwegian physicians who traveled from New York
to Oslo. The study concluded that further research is
needed to determine the effectiveness of melatonin in
preventing jet lag.
Authors: Robert Ball, Charles E. Lehner, and Erich C. Parker
The study investigates the risk of decompression sickness
(DCS) in humans using sheep as an animal model due to
their comparable body mass. Using linear-exponential,
probabilistic modeling, researchers analyzed no-stop
decompression outcomes from dives in both species. They
found that scaling response parameters between species,
while estimating tissue-compartment kinetic parameters
from combined human and sheep data, predicted DCS
risk more accurately than other models..
Authors: Juan Jose Poderoso, Constanza Lisdero,
Francisco Schopfer, Natalia Riobo, Marıa Cecilia
Carreras, Enrique Cadenas, and Alberto Boveris
This study investigates how nitric oxide (NO) affects
mitochondrial cytochrome oxidase and oxygen (O2)
uptake, focusing on the pathways within mitochondria
that utilize NO. The research uses various experimental
models to explore these pathways, including intact
mitochondria and specific mitochondrial particles. The
findings suggest that independent pathways for NO
utilization in mitochondria compete with NO binding to
cytochrome oxidase, thus alleviating the inhibition and
restoring O2 uptake.
Authors: R.J. Aitken, D. Bukingham, D. Richarson, J.C.
Gardiner, and D.S. Irvine
Over a 33-day diving program, divers were exposed to a
maximum pressure of 4.6 Mega Pascals (Mpa) for 7 days
to study the effects of extreme hyperbaric conditions on
male fertility. Semen samples were collected and analyzed
at various intervals before, during, and after the dive. The
results showed a significant decline in semen quality, with
a marked reduction in potential fertility by day +82,
characterized by oligoasthenoteratozoospermic profiles
and poor fertilizing potential of the sperm.
Authors: Kerry Strong Russel, M. Page Haynes, Teresa
Caulin-Glaser, James Rosneck, William C. Sessa, &
Jeffrey R. Bender
In this document, the authors demonstrate that Estradiol
(E2) stimulates the association of Heat Shock Protein 90
(Hsp90) with Endothelial Nitric Oxide Synthase (eNOS) in
human vascular endothelial cells. This binding enhances
the calcium sensitivity of eNOS and increases Nitric Oxide
(NO) release. The effects of E2 on Hsp90 binding to eNOS
were blocked by the estrogen receptor antagonist ICI
182,780, indicating that the effects are mediated through
the estrogen receptor.
Authors: David Smart, Sean Rubidge, Peter McCartney,
and Corry Van Den Broek.
This document provides an overview of the development
and improvements in safety within Tasmania's marine
finfish aquaculture industry, particularly focusing on the
significant reduction in diver morbidity due to enhanced
diving training, operations, and procedures over a ten-year
period.
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This presentation explains hydrogen's benefits and
potential applications as a respiratory gas in diving,
particularly for medium and deep-sea diving. It highlights
the advantages of hydrogen over helium, such as
reducing neurological disorders caused by high pressure,
decreasing respiratory load, and lowering the risk of
decompression sickness. The presentation also discusses
the development of the "ludion" diving technique using
hydrogen, which allows for deeper excursions without
decompression stops, and suggests that hydrogen could
open new possibilities for diving beyond 60 meters by
significantly reducing decompression time.
Authors: S. A. Sipinen, J. Ahovuo, and J.-P. Halonen
This study examined the effects of decompression
incidents on the brain, specifically through EEG and MRI
analysis, in divers. Its purpose was to determine whether
diving incidents, with or without symptoms of
decompression sickness (DCS) or arterial gas emboli (AGE),
lead to pathological changes in the central nervous
system. The text outlines the study's methodology and
results, comparing divers who experienced DCS, divers
without symptoms, and non-diving healthy controls.
This document describes a series of trials conducted at the
National Hyperbaric Centre in Aberdeen in March 1999 to
assess the likelihood of decompression bubbles forming
during operational diving, which could result in Doppler
grades exceeding grade 2. The report details the
methodology, including the dive profile, the number of
participants, and the conditions under which the trials
were conducted. It presents the primary conclusion that a
significant percentage of divers experienced bubble
grades higher than grade 2 and discusses the variability of
results between divers.
02 - Arterial baroreflex control during mild-to-moderate nitrous oxide
narcosis
- Published by the Undersea & Hyperbaric Medical Society (Author-released)
Authors: A. Osellund, P. Sundblad, A. K. Demetriades, D.
Linnarsson
This study examined the effects of light-to-moderate
nitrous oxide inhalation on bradycardia in divers,
focusing on baroreflex sensitivity. Results indicated no
major alterations in heart rate responses to hypertensive
stimuli, but a potential reduction in responses to
hypotensive stimuli, challenging the theory of inert gas
narcosis as a primary cause.
