Breathing Apparatus Research Articles

Nghiên cứu chế tạo hộp tái sinh không khí trong thiết bị thở cá nhân, sử dụng trong trường hợp khẩn cấp trên tàu hải quân

This paper presents some results on manufacturing air regenerative tanks in personal breathing apparatus. The air regennerator tank consists of two main components: the starter part and the regeneration seeds. The starter part has a weight of 115g including the followinbg ingredients: KO2 40.0%; NaO2 14.0%; KHSO4 40.0%; Al 3.0%; CaSiO3 3.0%. They have a total working time to provide oxygen gas of 23 seconds, the instantaneous oxygen volume generated reaches 13.6 liters. Regenerating seedbed has a mass of 300g used OKCh-3M seeds with active oxygen content over 25.5%, main fraction 2.5-4.0 mm. The ability of PĐA-E.VN was confirmed on artificial lung equipment and testing on voluntary people. The working time and the surface temperature of the air regenerator tank are some indicators to evaluate devices. The generation and resistance of the air regenerator are quivalent to the comaprison sample as following in the design documents.

Моделирование дыхательного аппарата на химически связанном кислороде с кругомаятниковой схемой воздуховодной части

At present, the main prospects for improving the insulating means of respiratory protection are associated with the chemical method of oxygen reservation. The arguments in favor of this choice are the high packing density of oxygen and its self-regulating supply, depending on the physical activity of a person. The main schemes of the air duct part of breathing apparatus on chemically bound oxygen are circular and pendulum. The attempt is made in the article to combine the advantages of the circular (small harmful space) and pendulum (small volume of the dead layer) schemes of breathing apparatus on chemically bound oxygen. For these purposes, the formalism method was developed, which allows mathematically and with the help of a computer to simulate the dynamic sorption activity of the regenerative cartridge of a breathing apparatus with a hybrid (circular-pendulum) scheme of the air duct part. The increase in the protective action of the apparatus is determined due to the use of the resource of the dead sorbent layer in the result of the air flow reverse in the pendulum part of the regenerative cartridge. Feasibility of using a hybrid scheme in the self-rescuers with a short period of protective action is shown. The optimal length of the pendulum part is determined, at which the breathing resistance decreases, and the harmful space occupied by the air returning for inhalation without contact with the unreacted layers of the oxygen-containing product is not increased. Its weak dependence on the total length of the regenerative cartridge and the maximum permissible concentration of carbon dioxide in the air returning to inhalation is shown, which makes the circular pendulum scheme realizable in practice.

Tactical Combat Casualty Care Scenario: Management of a Gunshot Wound to the Chest in a Combat Swimmer.

Tactical Combat Casualty Care (TCCC) has always emphasized the need to consider the tactical setting in developing a plan to care for wounded unit members while still on the battlefield. The TCCC Guidelines provide an evidence-based trauma care approach to specific injuries that may occur in combat. However, they do not address what modifications might need to be made to the basic TCCC guidelines due to the specific tactical setting in which the scenario occurs. The scenario presented below depicts a combat swimmer operation in which a unit member is shot while in the water. The unit casualty response plan for a combat swimmer who sustains a gunshot wound to the chest while on a mission is complicated by the inability to perform indicated medical interventions for the casualty while he is in the water. It is also complicated by the potential for ballistic damage to his underwater breathing apparatus and the need to remain submerged after wounding for at least for a period of time to avoid further hostile fire. Additionally, there is a potential for a cerebral arterial gas embolism (CAGE) and/or a tension pneumothorax to develop while surfacing because of the decreasing ambient pressure on ascent. The tactical response may be complicated by limited communications between the mission personnel while submerged and by the vulnerability of the mission personnel to antiswimmer measures if their presence is compromised.

Reduced Oxygen Breathing Device（ROBD）を用いた常圧低酸素訓練プロファイルの検討

Reduced Oxygen Breathing Device（ROBD）を用いた常圧低酸素訓練プロファイルの検討

Hazardous Gas Analysis during Fire Investigation

Various types of hazardous substances are generated at fire scenes. Firefighters usually use the self-contained breathing apparatus (SCBA) during firefighting; however, SCBA is very inconvenient to use in other works (e.g., fire investigation and fire scene commands). Therefore, firefighters can be exposed to numerous chemicals. In this study, concentrations of hazardous gases were measured by utilizing gas analyzers with seven sensors during fire investigations. Six fire investigators measured the concentrations of hazardous gases directly as they worked. This included capturing the maximum concentrations of SO2 at seven places, HCHO at 29 places, NO2 at one place, HCN at 13 places, and CO at two places where the concentration exceeded the short-term exposure limit (STEL). When reconstruction experiments were performed, the maximum allowable concentrations for most hazardous chemicals fell below the STEL approximately 90 min after the fire occurrence. Therefore, we determined that fire investigators should wear proper respiratory protective equipment when working.

Respiratory kinematics and the regulation of subglottic pressure for phonation of pitch jumps - a dynamic MRI study.

The respiratory system is a central part of voice production as it contributes to the generation of subglottic pressure, which has an impact on voice parameters including fundamental frequency and sound pressure level. Both parameters need to be adjusted precisely during complex phonation tasks such as singing. In particular, the underlying functions of the diaphragm and rib cage in relation to the phonation of pitch jumps are not yet understood in detail. This study aims to analyse respiratory movements during phonation of pitch jumps using dynamic MRI of the lungs. Dynamic images of the breathing apparatus of 7 professional singers were acquired in the supine position during phonation of upwards and downwards pitch jumps in a high, medium, and low range of the singer's tessitura. Distances between characteristic anatomical landmarks in the lung were measured from the series of images obtained. During sustained phonation, the diaphragm elevates, and the rib cage is lowered in a monotonic manner. During downward pitch jumps the diaphragm suddenly changed its movement direction and presented with a short inspiratory activation which was predominant in the posterior part and was associated with a shift of the cupola in an anterior direction. The magnitude of this inspiratory movement was greater for jumps that started at higher compared to lower fundamental frequency. In contrast, expiratory movement of the rib cage and anterior diaphragm were simultaneous and continued constantly during the jump. The data underline the theory of a regulation of subglottic pressure via a sudden diaphragm contraction during phonation of pitch jumps downwards, while the rib cage is not involved in short term adaptations. This strengthens the idea of a differentiated control of rib cage and diaphragm as different functional units during singing phonation.

Search & rescue operations during interior firefighting: A study into crawling speeds

Firefighters perform search operations during fires in order to rescue people. Full-scale tests to evaluate the effectiveness of the techniques used to search a room have been organized in the absence of fire. 42 search crews completed 7 different set-ups. The crews consisted of Belgian and Dutch firefighters as trained to date. They searched four 12 m2 bedrooms and three 31 m2 office spaces. Searching an empty space was compared to searching a furnished space. The impact of using a hose line was evaluated. 4 min is a good order of magnitude for the search of a bedroom. The time needed increases with increasing surface, but not proportionally. Crews can search a larger area per unit of time in the 31 m2 office than in the 12 m2 bedroom. The average air consumption rate in the breathing apparatus is 68–70 lpm for both rooms. When using a hose, the search becomes longer in time and takes a higher air consumption rate (average: 84 lpm). The decision to take a hose line or not is therefore very important. Crews where the two firefighters are side by side are more effective than crews where they are behind the other.

Vestibular effects of diving

Over the last 45 years, recreational self-contained underwater breathing apparatus (SCUBA) diving as a leisure activity has increased in popularity. According to the Professional Association of Diving Instructors (PADI), more than 23 million diver certificates have been issued across the globe. Given the popularity of scuba diving, it is incumbent on every physician to know and understand the specific medical hazards and conditions associated with scuba diving. Although diving has become more accessible and the equipment is much safer now, diving still has its inherent dangers. Each year incidents occur, ranging from seasickness and sinus problems to heart conditions and mortality. More than 80% of all diving complications occur in the head and neck region. A number of studies have found that diving can lead to the development of vestibular disorders such as: Barotrauma, Decompression sickness, Otitis externa, Bilateral exostoses, Chronic sinusitis (barosinusitis), Serous tubotympanic catarrh, Tinnitus, Dizziness, Vertigo. The aim of this paper was to share our experience in the field of treating patients with different types of ENT disorders after or before a diving session. We briefly summarized the most important information for some of the disorders. We included in our study for a period of 12 years: a total of 24 patients (four females and 20 males), who dive. They were between 25 and 55 years of age. Some presented in clinics with an ENT disorder. 19 were professional, qualified divers, five (three males and two females) dove for the first time. On all 24 patients we performed: audiometry tests, Tympanometry tests, OAE, Static and dynamic vestibular tests, vHIT – in the last five years, otoscopy examination, dental check-ups. All divers – no matter professionalists or not – should follow these recommendations: a thorough prophylactic ENT check-up should be performed before an active diving session. Chronic ENT inflammations should be addressed in a timely manner. Divers should follow all instructions from the certified Diving Associations.

Background concentrations of Argon-39 in shallow soil gas

While radioisotopes of noble gases are known to be indicators of underground nuclear explosions (UNE), McIntyre et al. (2017) was the first to report the presence of 39Ar in shallow soil gas in association with a decades old UNE. While this finding hinted at the potential application of 39Ar to be used as an indicator of a UNE, doing so would also require an understanding of the natural concentrations of 39Ar present in soil gas. Without knowing the expected range and variability of naturally occurring concentrations of 39Ar, it is difficult to determine what measured concentrations would be indicative of an elevated concentration. This paper presents results from 16 soil gas samples and three atmospheric air samples collected from various locations across the western United States. Shallow soil gas samples were collected into self-contained underwater breathing apparatus (SCUBA) tanks using a custom-built soil gas sampling system and then processed and analyzed for 39Ar. The measured concentrations of 39Ar varied from atmospheric air concentrations to about 3.5 times atmospheric air concentrations (58 mBq/m3). The results presented here represent the first measurements of natural background 39Ar concentrations in shallow soil gas. This data will be necessary if 39Ar is to be used as an indicator of UNE.

Traditional folk aerophones in the context of training in art schools

The purpose of the article is to study considers the traditional pipe tools and methods of its introduction into the educational process of art schools, based on the historical experience of learning/imitation in terms of the authentic process in the tradition. Methodology. To achieve the goal of the research, historical-instrumental, ethnic-pedagogical, comparative, and ethnic-organophonic methods were used. The scientific novelty is that the article presents traditional folk wind aerophones (svystuntsi, okaryna, tylynka, pivtoradentsivka, dvodentsivka, frilka, floyara, rebro (flute Pana), Boyko`s pyshchavka, Polissya dudka-vykrutka and dudka-kolianka, truba, trembita) and the system of their step-by-step study in the pipe class. Conclusions. From the standpoint of our own many years of experience in pedagogical and concert-performance practice, conclusions are drawn about the tested approaches to implementation in the already established class of so-called. "Academic" pipes of a number of traditional wind instruments on the basis of an "additional instrument" using the well-known principles of ethnic-pedagogy and K. Orff's system. The introduction of this technique in the educational process of primary education will not only contribute to greater interest/motivation of young pipers who master the well-known system of so-called. D. Deminchuk's "academic" flute, but also serves as a solid methodological basis for the formation of the game and breathing apparatus for beginners of "academic" wind specializations. The training will be effective in a comprehensive approach to mastering traditional Ukrainian aerophones and creating conditions for learning/learning the game from the bearers of the pipe tradition and the opportunity to make at least introductory folklore expeditions to regions where the studied instruments and music still function.

Usage of and attitudes toward heat‐ and moisture‐exchanging breathing devices among adolescent skiers

Usage of and attitudes toward heat‐ and moisture‐exchanging breathing devices among adolescent skiers

Origins of disaster management: the British mine rescue system, c. 1900 to c. 1930

Disaster management is a neglected area of British business history. Industrial disasters led to significant loss of life and imposed considerable costs on firms involved. This article examines the emergence of a network of mine rescue stations across UK coalfields in the early twentieth century, making use of previously overlooked records of mine rescue station boards. Pioneering mine rescue stations were established in Yorkshire at coalowners’ initiative in 1901 and 1902, a few years before provision of rescue stations and breathing apparatus became mandatory. As well as rescue operations, these facilities were used to put out colliery fires and restore damaged mines. The involvement of coalowners in mine rescue also signalled that the industry was interested in miner safety at a time of growing unrest. The article concludes that there is scope for much more research into the early years of disaster management in the mines and in other industries.

DENSITY ZOOXANTHELLA BASED ON THE LIFE FORM OF CORAL ON MARAK ISLAND WEST SUMATERA PROVINCE

This study aims to determine differences in zooxanthella density based on the life forms of coral Acropora Branching, Submassive Acropora, Branching, Foliose, Heliopora and comparing zooxanthella densities between the forms of coral form. This study was conducted in January-February 2020 on Marak Island, Nagari Sungai Pinang, West Sumatera Province. Zooxanthella density was calculated at the Marine Biology Laboratory, Department of Marine Sciences, University of Riau. The survey methode was used in this study, where the data collected was primary data. Coral Sampling was done by free collection using the SCUBA (Self Contained Underwater Breathing Apparatus). The result of study in the waters of Marak Island, West Sumatera on Acropora Branching corals were in the range of 0.004-0.13×106 cells/cm2. Acropora Submassive range of 2.95- 3.56×106 cells/cm2. Branching range of 2.41-2.59×106 cells/cm2. Foliose range of 0.44-1.09×106 cell/cm2. Heliopora range of 1.30-1.59×106 cell/cm2. The highest zooxanthella density was in Submassive Acropora and the lowest in Acropora Branching corals due to different forms of growth and temperature influences. Different forms of coral growth affect the zooxanthella density on a coral and the success of coral growth depends on the zooxanthella density and the size of the corallite of each coral life form.

Evaluation of the Helicopter Emergency Breathing Apparatus on Egress Performance.

BACKGROUND: Emergency helicopter landing at sea is dangerous. Specialized training, known as helicopter underwater escape training (HUET), prepares occupants to quickly exit the helicopter, which often inverts and sinks. In most jurisdictions, helicopter occupants are equipped with a helicopter underwater egress breathing apparatus (HUEBA) to provide sufficient air for escape. HUET trainees report that the HUEBA is easy to use, but it is well known that learners are often overconfident in their judgement of learning. To better understand how the HUEBA affects HUET sequence performance, we investigated whether using the HUEBA influences the sequence movement time and number of errors.METHODS: Twelve participants (7 men and 5 women, mean age 25.33 9.57 SD) with no prior experience with HUET performed consecutive trials of the HUET sequence, 5 with the HUEBA and 5 without the HUEBA. Video of each trial recorded the total movement time and enabled movement time analyses of each component of the sequence: crossing arms, tucking the head, pushing the window, inserting the regulator, and releasing the seatbelt. These recordings were also used to score performance errors according to a checklist.RESULTS: Analyses revealed that using a HUEBA increased the total movement time and time to release the seatbelt by 0.36 and 0.39 s, respectively, in comparison to without the HUEBA.DISCUSSION: Our study illustrates that using the HUEBA during the HUET sequence increases total movement time and time to release the seatbelt. However, this difference is marginal and unlikely to have practical significance during underwater escape.King M, Sanli E, Mugford K, Martina S, Brown R, Carnahan H. Evaluation of the helicopter emergency breathing apparatus on egress performance. Aerosp Med Hum Perform. 2020; 91(12):962965.

A comparison of the breathing apparatus deadspace associated with a supraglottic airway and endotracheal tube using volumetric capnography in young children.

BackgroundSupraglottic airway (SGA) devices including the air-Q® are being used with increasing frequency for anesthesia in infants and younger pediatric patients. To date, there is minimal research documenting the potentially significant airway deadspace these devices may contribute to the ventilation circuit when compared to an endotracheal tube (ETT). The aim of this study was to evaluate the airway apparatus deadspace associated with an air-Q® versus an ETT in young children.MethodsIn a prospective cohort study, 59 patients between 3 months and 6 years of age, weighing between 5 and 20 kg, scheduled for outpatient urologic or general surgery procedures were recruited. An air-Q® or ETT was inserted at the discretion of the attending anesthesiologist, and tidal volume, positive end expiratory pressure, respiratory rate, and end-tidal CO2 were controlled according to protocol. Airway deadspace was recorded using volumetric capnography every 2 min for 10 min. ResultsGroups were similar in demographics. There was a significant difference in weight-adjusted deadspace volume between the air-Q® and ETT groups, 4.1 ± 0.8 ml/kg versus 3.0 ± 0.7 ml/kg, respectively (P < 0.001). Weight-adjusted deadspace volume (ml/kg) increased significantly with decreasing weight for both the air-Q® and ETT groups.ConclusionsIn healthy children undergoing positive pressure ventilation for elective surgery, the air-Q® SGA introduces significantly greater airway deadspace than an ETT. Additionally, airway deadspace, and minute ventilation required to maintain normocarbia, appear to increase with decreasing patient weight irrespective of whether a SGA or ETT is used.

Design and Implementation of Ventilator for Breathing Apparatus

This paper present the design and implementation of a ventilator for a breathing apparatus. The ventilators that developed are the positive pressure ventilation type, the cycled volume mode and the controlled mechanical ventilation method (CMV). The technology that used is the ambu bag. The design and manufacture includes an automatic ambu bag pressing mechanical system and a control system using the arduino microcontroller. The mechanical design that is compact, lightweight, energy saving, low cost, meets aesthetics and is friendly makes this tool attractive so it is not scary for patients. BPM (beep per minute), IER (inspiratory expiratory ratio) and TV (tidal volume) parameters can be controlled via a touch screen or remotely using a mobile phone via 4 buttons remotely to facilitate and avoid transmission of Covid-19 to medical personnel. BPM can be set from 5-20 BPM, IER from 1: 1 to 1: 4 and TV from 40-100%. The results of ventilator testing that have been done show a good response.

Characterising the exposure of Australian firefighters to polycyclic aromatic hydrocarbons generated in simulated compartment fires

Firefighters are exposed to a wide variety of chemicals including polycyclic aromatic hydrocarbons (PAHs) while attending fire scenes. The objective of this study was to understand the exposure of firefighters to PAHs when attending simulated compartment fires that consisted of either a diesel pan or particleboard fire. Firefighters remained in the compartment fires for 15min while using standard gear including self contained breathing apparatus (SCBA). Firefighters were able to remove firefighting clothing and shower within 10min of leaving the burn. Air samples were collected from inside the compartment during the fire. Twenty-six (26) firefighters participated in the study providing urine and skin wipe samples collected from the wrist and neck before and after either one of the burn types. The concentrations of PAHs were measured in skin wipes and air samples, while concentrations of monohydroxy metabolites of PAHs (OH-PAHs) were measured in urine. The concentrations of all PAHs were significantly higher (p<0.05) in the smoke layer of particleboard fires than in diesel pan fires. Correspondingly, the level of PAHs deposited on the wrists and necks of participants attending the particleboard fires was higher than those attending diesel pan fires. Urine samples from participants who attended diesel pan fires showed no significant difference (p>0.05) in the concentration of all OH-PAHs between pre-burn and post-burn. Samples from participants who attended particleboard fires, showed no significant difference (p>0.05) between 1-hydroxypyrene (1-OH-PYR) concentrations in urine pre- and post-burn. However, median concentrations of hydroxynaphthalenes (OH-NAPs), hydroxyfluorenes (OH-FLUs) and hydroxyphenanthrenes (OH-PHEs) increased significantly from 5.2, 0.44 and 0.88μgg-1 creatinine pre-burn to 12, 1.4 and 1.2μgg-1 creatinine post-burn, respectively. This suggests that in compartment burns with high concentrations of PAHs in the smoke layer, such as those created by the particleboard fires, exposure to PAHs can be observed though urinary OH-PAH metabolites. Overall, concentrations of urinary OH-PAHs were relatively low considering the potential exposure in these burns. This suggests protective equipment in combination with rapid removal of firefighting ensembles and showering are relatively effective in controlling exposure.

Теоретико-вероятностный подход к моделированию респиратора на химически связанном кислороде

At present, the main prospects for improving the insulating means of respiratory protection are related to the chemical method of oxygen reservation. The arguments in favor of this choice are the high density of oxygen packaging and its self-regulating supply, depending on the physical activity of the person. Usually, the working process in devices on chemically bound oxygen is modeled using mathematical physics methods that solve the so-called sorption dynamics problem. As a result, under given boundary and initial conditions, the concentration of CO2 molecules in the regenerative cartridge turns out to be a deterministic function of time and coordinates. However, the coordinate of the elementary act of sorption is essentially a random variable. The law of its distribution evolves as the absorbing resource of the regenerative cartridge is consumed. Taking into account the above, a probability-theoretic approach to modeling the working process of an insulating breathing apparatus based on chemically bound oxygen was developed. The approach is based on the description by probability theory methods of the random coordinate of the elementary act of chemosorption of a CO2 molecule by potassium peroxide granules and the random lifetime of this molecule in the regenerative cartridge of the respiratory apparatus. The evolution of the initial and central statistical moments of these values is established. The symmetry of their probability density with respect to the permutation of dimensionless arguments is shown, which are the time and distance from the entrance to the regenerative cartridge to the considered layer of chemisorbent. The presence of symmetry increases the speed of numerical experiments by one or two orders of magnitude. Gaussian asymptotics of the process at long times and corrections to it by inverse degrees of dispersion due to asymmetries and excesses of different orders are revealed. This further increases the speed of numerical experiments in computer simulation of the working process of an insulating respirator on chemically bound oxygen.

Guillain Barre Syndrome pada Kehamilan

Guillain-Barre Syndrome (GBS) is a clinical syndrome characterized by the presence of the complete flaksid that occurs in acute. GBS associated with autoimmune reaction that affect peripheral nerve, radix, and cranial nerve. The incidence of GBS is 1 – 2 per 100,000 people/year. The incident was followed by increased age and the increasing population of obstetrics. GBS in pregnancy ranged from 13% in the first trimester, 47% in the second trimester, and 40% in the third trimester. In this case report reported Mrs. M 27 years old with a diagnosis of G2P1A0 h. 39-40 weeks + insimanation + living single fetal Presentation Head + Inpartu kala II + GBS + Failed + Vacuum Severily Underweight (BMI = 17) + TBJ 3000 Gr. Diagnosis of GBS are enforced based on anamnesis, physical examination and complementary examinations. From a previous illness history found anamnesis the weakness of limbs beginning in 2016. A history of the use of breathing apparatus and admitted tot the ICU in the first pregnancy. Mrs. M had a history of infections before being diagnosed with GBS. On this second pregnancy patients cannot move lower extremity but upper extermity is still functioning. Physical examination result of mothers and babies in the normal range even though found in conditions of severily BMI underweight. The patient finally decided to SC (section caesaria) and applied the IUD intracaesarean GBS in pregnancy is a coincidental. GBS is rarely aggravate pregnancy, but if not quickly identified and handled can enhance the high morbidity in both mother and fetus. In acute attacks (AIDP) in pregnant women with GBS increase stress on the mother or the fetus. The stress that occurs can also stimulate the immune system to produce prostaglandins, resulting in premature birth. Patients can give birth when the gestational age is still 7 months. It was different in the second pregnancy in this case where the patient was diagnosed with chronic inflammatory demyelinating polyradiculopathy (CIDP) so that GBS did not affect the mother and the fetus.

Thermal Load of Mine Rescuer in the Underwear and Protective Clothing with Phase Change Materials in Simulated Utility Conditions.

A new set of underwear and protective clothing with phase change materials (PCM) for mine rescuers has been developed in order to increase their safety of work. It includes PCM pouches absorbing excess heat from the body. In order to evaluate thermal load of mine rescuers, physiological tests were carried out for three variants of possible use of the developed set of clothing: for mine rescuers wearing only the underwear with PCM; for a set of underwear and protective clothing; and for a complete set of clothing with closed-circuit compressed oxygen breathing apparatus. Tests were performed in difficult microclimate conditions, reflecting the typical working conditions of rescuers that cause a significant thermal load. The use of outer clothing shortened safe time of exposure to such conditions by about 36%, while the addition of respiratory protective device to this set further shortened this time to a lesser extent (by another 13%).