The aim of this work is to determine the dynamics of nitrogen saturation in small laboratory animals. Nitrogen was chosen as a model gas in this study because of its availability and characteristics, as it is not metabolised and is subject to passive diffusion. By subjecting different species of animals to hyperbaric exposures of increasing time and pressure, the study aimed to identify how rapid a decompression was possible to achieve an outcome that saw 50% of the animals surviving the ensuing acute decompression sickness.
The basic parameters of hyperbaric exposure - pressure and time - made it possible to describe the saturation phenomena on the basis of partial saturation periods and to show whether a small animal organism can be considered as a single compartment model.
Zbigniew Dąbrowiecki, Małgorzata Dąbrowiecka, Romuald Olszański and Piotr Siermontowski
In the event of an epidemic of Legionnaires’ disease, prompt and unambiguous identification of the source of infection and immediate undertaking of repair actions is a necessary condition to limit and minimise the effects of the developing epidemic. In the classical method for determining the level of Legionella bacteria in water samples, the effectiveness of the reparative action (increase of the water temperature in the water supply system to 600C, additional chlorination) can only be confirmed after 14 days!!! Only by using the IMMS&FCM method can Legionella’s determination time be reduced to 2-4 hours, which is the most important factor in limiting the development of an epidemic.
The material proposes a generalised model for the development of underwater technology, understood as a technical means of penetrating and exploring the depths of the oceans. The model was developed on the basis of the previously proposed bifurcation model. The basis and starting point for the development of the model was the analysis of literature. The proposed model indicates that regardless of which technical solution for underwater penetration was developed in the past, it will belong to one of the three defined developmental ‘streams’ of this technique. Since the proposed model has the characteristic of a flowing stream and is more general than the bifurcation model, its name has been proposed as a generalised amnistic developmental model of the underwater technique.
There were evaluated responses of the respiratory system to changes in the variables of the external environment under increased pressure. To the model of professional underwater human activity underwater served the conditions of full saturation in compressed air or nitrogen-oxygen gas mixtures. Technical devices were presented by a number of underwater laboratories, mounted at the bottom (Ikhtiander-66, 67 and 68), hyperbaric chambers, submersible drilling rigs (Bur-1 and 2), and an autonomous diving Ikhtiander-2 for a long stay in the water.
Studies of respiratory gases mass transport conditions in man showed than within the pressure range of 0.25-1.1 MPa at density of moderate hyperoxic and nitrogen-helio-oxygen environment up to 14 kg/m3 oxygen and carbon dioxide regimes of the organism come to a new functional level which provides the adaptation to the extremal conditions. It is determined that an increase of physiological dead breathing space, a decrease of the rate of the O2 diffusion through the alveole-capillary barrier, intensification of unevenness of ventilator-perfusional relations in lungs and an increase of blood shunting in lungs are the main respiratory mechanisms which regulate mass transfer of O2 and CO2 in man under hyperbaria. The leading hemodynamic mechanism is the retention of volume blood circulation and cardiac output. It is studied how the compression rate, high partial pressures of oxygen and nitrogen, microclimate parameters in inhabited hypebaric chambers influence changes of functional breathing system. Absence of hypoxic state is proved in man (full saturation of man with nitrogen) under normoxia in nitrogen-oxygen environment with the density 6.34 kg/m3. These are also the data about accelerated rehabilitation of divers using the method of active adaptation o high altitudes. Basic directions in physiological studies of functional breathing system under increased pressure of gas and water environment are described.
This article is a continuation of the article published in issue No. 3 (64) 2018 of Polish Hyperbaric Research, which demonstrated the scope of changes which a typical car lift should be subjected to in order to extend its functionality to that of a hoist, that lifts the lid of the decompression chamber, in a breathing simulator used at the Department of Underwater Works Technology of the Naval Academy in Gdynia.
Jerzy K. Garbacz, Mariusz Kozakiewicz and Barbara Rymian
This article is related thematically to two of our earlier publications, which demonstrated full equivalence of statistical and phenomenological methods in the description of physical gas adsorption on the surface of a solid body, and the fundamental possibility of analytical solution of adsorbate-adsorbate association problems in the entire multi-layer adsorption phase. The quasi-chemical scheme of secondary interactions leading to the formation of horizontal multimolecular adsorption complexes has been elaborated. A new adsorption equation was formulated taking into account the dimerisation of adsorbed molecules in the whole adsorption phase, as well as the influence of topography of the binding sites of adsorbent surfaces on the form of this solution.
In the article the author presents the specificity of deep diving decompression in relation to the revolution in diving which was triggered by the introduction of a personal computer in recreational diving. Continuous development of these computers, especially in the last decades of our century, concerned deep-sea technical and recreational dives. Deep-sea dives are difficult and risky in terms of underwater physiology and decompression. In characterizing the decompression of a diver, realized with the use of a computer for deep-sea dives, the author compares the realization of decompression in professional deep-sea dives. He also points out the formal and technical obstacles to the implementation of personal dive computers. In summary, the article evaluates the possibility of using the diving computer in the implementation of underwater works.
The previous article described a new approach methodology1 for work on the development of technology for the use of the SCR CRABE SCUBA2 type diving apparatus. However, after its publication numerous questions emerged regarding the genesis of the research undertaken, also from foreign partners using the same rebreather. The work on changing the technology of use was preceded by analyses, which were available only to people involved in the decision-making process. Demonstrating all the details of the decision-making process may be tedious, but failing to present them at all might raise justified doubts about the advisability of conducting a long-term research cycle.
This article only presents preliminary analyses. The necessity to perform them resulted from the specific requirements for military technologies3 which, as broadly as possible, should be knowledge-based. The knowledge-based approach by its very nature allows continuous improvement of the adequacy of the predictions made, the estimation of the level of risk when diagnosing deviations from the repeatability or precision of the model, and the possibility of adapting the technology to the changing requirements of the user resulting from tactical considerations of its use.
In the article the author describes the Polish specificity of deep dives used in underwater deep-sea works. The article briefly discusses the methods of deep diving used in the world to proceed to underwater works in the Polish offshore zone of 50-90m depth (according to the Act; deep water works are works below a depth of 50m). When discussing these methods, the author describes the technical-organisational and formal conditions and the type of conducted works. It then presents the methodology for evaluating the effectiveness of the main element of deep-sea works, i.e. diving. It provides information on deepsea underwater works on the Baltic Sea carried out by the Department of Underwater Works Technology of the Naval Academy in cooperation with the Polish Navy until 2001 and civil companies to date. On the basis of his own data from underwater deep-sea works, the author presents the methodology of evaluation of their effectiveness from the point of view of deep dives. In his conclusions, he puts forward recommendations for improving the efficiency of such works.
Patent foramen ovale (PFO) is a condition present in 25% of the adult population. It is a remnant of fetal foramen ovale which allows blood to pass from the right to the left atrium, bypassing the fetal lungs. In majority adults it does not have any clinical significance, but in some people it may allow shunting of venous blood into the left atrium (right – left – shunt or RLS), circumventing the lung filter, especially during sneezing, cough, lifting heavy equipment. Is such case, PFO may be a route for venous emboli or gas bubbles from veins to the arterial system. It is known as a paradoxical embolism and may be cause of ischaemic stroke or neurologic decompression sickness (DCI), inner-ear DCI and cutis marmorata. Transesophageal echocardiography is considered as a reference standard in detection of intracardial shunts. Its sensitivity and specificity ranges between 94%-100%. However, TEE is an invasive examination with potentially serious side effects. An alternative examination in RLS detection is contrast enhanced Transcranial Doppler (the bubble study or c-TCD). In comparison to TEE, Transcranial Doppler is not invasive, relatively not expensive and save technique. With its high sensitivity and specificity in detection of PFO, 97% and 93% respectively, it may improve detection of RLS and allow to conduct screening examination for PFO in divers.