• Journal of Korean Physical Therapy Science
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• v.26 no.2
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• pp.51-60
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• 2019

Background: The purpose of this study was to investigate the effects of HBOT (hyperbaric oxygen therapy) on the pain, ROM (range of motion) and muscle fatigue recovery of DOMS (delayed onset muscle soreness). Design: Randomized Controlled Trial. Methods: Twenty-six subjects who are student in their 20s at a university participated in this study, these subjects were assigned into two groups, a control group (n=12) and an experiment group (n=14). The subjects in experimental group were intervened by HBOT (40 minutes, 1.3 ATA), while ones on control group weren't by any intervention after induced DOMS. Results: First, in the comparison of VAS (visual analog scale), there were significant variations with the period (p<0.001), interaction of period (p<0.05) and group (p<0.05). In the comparison of PPT (pressure pain threshold), there were significant variations with the period (p<0.001) and interaction of period (p<0.05). Second, in the comparison of ROM, there were significant variations with the period (p<0.001), interaction of period (p<0.001) and group (p<0.01). Third, in the comparison of CK (creatine kinase) and LDH (lactate dehydrogenase), there no signigicant variations with all measure variables. Conclusion: The above results indicated that HBOT were effective to decrease the pain and improve the ROM in DOMS. Also the statistical significant variations of blood factors of muscle fatigue were not found in this.

• Journal of Preventive Medicine and Public Health
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• v.20 no.2 s.22
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• pp.221-227
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• 1987

In vivo ethane production in rats was used as an index of oxygen toxicity. The rats were allocated to four exposure conditions; hyperbaric oxygenation (HBO=5 ATA, 100% $O_2$), normobaric oxygenation (NBO=1 ATA,100% $O_2$), hyperbaric aeration (HBA=5 ATA, 21% $O_2$) and normobaric aeration (NBA=1 ATA, 21% $O_2$). After 120 minutes of exposure, the rats exposed to high concentration and/or high pressure oxygen exhaled significantly larger amounts of ethane than those exposed to NBA, and the differences in ethane production between any two groups were statistically significant (p<.01). This finding supports the hypothesis that hyperoxia increases oxygen free-radicals and the radicals produce ethane as a result of lipid peroxidation. It is notable that the ethane exhalation level of the HBA group was significantly higher than that of the NBO group. This difference could not be accounted for by the alveolar oxygen partial presure difference between the two groups.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.2
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• pp.144-153
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• 2016

This paper aims to demonstrate the design, structure analysis, and hydrostatic pressure test of the cylinder used in 2000m water depth. The cylinder was designed in accordance with ASME pressure vessel design rule. The 1.5 times safety factor required by the general rule was applied to the design of the cylinder, because ASME rule is so excessive that it is not proper to apply to the hydrostatic pressure test. The finite element analysis was conducted for the cylinder. The cylinder was produced according to the design. The hydrostatic pressure test was conducted at the hyperbaric chamber in KRISO. The results of finite element analysis(FEM) and those of the hydrostatic pressure test were almost the same, which showed that the design was exact and reliable.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.3
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• pp.302-312
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• 2012

Underwater vehicles play a very important role in underwater engineering. Water-tight junction box (WJB) is one of the key components in underwater vehicle. This paper puts forward a pressure self-adaptive water-tight junction box (PSAWJB) which improves the reliability of the WJB significantly by solving the sealing and pressure problems in conventional WJB design. By redundancy design method, the pressure self-adaptive equalizer (PSAE) is designed in such a way that it consists of a piston pressure-adaptive compensator (PPAC) and a titanium film pressure-adaptive compensator (TFPAC). According to hydro-mechanical simulations, the operating volume of the PSAE is more than or equal to 11.6 % of the volume of WJB liquid system. Furthermore, the required operating volume of the PSAE also increases as the gas content of oil, hydrostatic pressure or temperature difference increases. The reliability of the PSAWJB is proved by hyperbaric chamber tests.

• Journal of The Korean Society of Clinical Toxicology
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• v.21 no.2
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• pp.117-127
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• 2023

Purpose: No consensus currently exists regarding the maximal pressure of hyperbaric oxygen (HBO₂) therapy performed within 24 hours of acute carbon monoxide (CO) poisoning. This study aimed to evaluate the difference in therapeutic effects according to the first HBO₂ pressure (3.0 atmospheres absolute [ATA] vs. 2.8 ATA). Methods: We used prospectively collected registry data on CO poisoning at a tertiary academic hospital in the Republic of Korea. Adult patients with acute CO poisoning treated with HBO₂ within 24 hours after arrival at the emergency department and without the use of additional HBO₂ after 24 hours between January 2007 and February 2022 were included. Data from 595 patients were analyzed using propensity score matching (PSM). Patients with mild (non-intubated) and severe (intubated) poisoning were also compared. Neurocognitive outcomes at 1 month after CO poisoning were evaluated using the Global Deterioration Scale combined with neurological impairment. Results: After PSM, the neurocognitive outcomes at 1-month post-CO exposure were not significantly different between the 2.8 ATA (110 patients) and 3.0 ATA (55 patients) groups (p=1.000). Similarly, there was also no significant difference in outcomes in a subgroup analysis according to poisoning severity in matched patients (165 patients) (mild [non-intubated]: p=0.053; severe [intubated]: p=1.000). Conclusion: Neurocognitive sequelae at 1 month were not significantly different between HBO₂ therapy pressures of 2.8 ATA and 3.0 ATA in patients with acute CO poisoning. In addition, the 1-month neurocognitive sequelae did not differ significantly between intubated and non-intubated patients.

• Journal of Preventive Medicine and Public Health
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• v.25 no.1 s.37
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• pp.34-43
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• 1992

To investigate the effect of hyperoxia on EKG findings and to evaluate the applicability of EKG as noninvasive monitoring index of oxygen toxicity, 38 rabbits were continuously exposed to 6 different conditions-3 hyperbaric oxygenations (HBO-2.5, 3.5 and 5ATA, 100% $O_2$), normobaric oxygenation (NBO,100% $O_2$), hyperbaric aeration (HBA-5ATA, 21% $O_2$) and normobaric aeration (NBA, 21% $O_2$)-for 120 minutes and their EKG and time to dyspnea and convulsion were recorded. Dyspnea and death were observed in exposure conditions of HBO-3.5 and HBO-5 (Positive rate of dyspnea 10%, 100%, death : 10%, 25%, respectively) only, and convulsion in 4 oxygenation groups (NBO;20%, HBO-2.5;20%, HBO-3.5;20%, HBO-5;88%). Abnormal EKG findings included arrhythmia and ST-T changes and the incidences was increasing with doses(partial pressure of oxygen). In addition to EKG change, findings observed during exposure were dyspnea and convulsion in the order of appearance and when non specific ST-T change was accepted as positive(abnormal) finding, the frequency of abnormal EKG was statistically significant(p<0.01), but when it was excluded from positive results, the frequency of EKG change was not significant(p>0.05). These results suggest that the effect of hyperoxia on heart is myocardial ischemia and arrhythmia, that oxygenation more than 3.5ATA causes myocardial damage in 120 minutes exposure, and that EKG is valuable as monitoring index of oxygen toxicity.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.121-130
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• 1990

Plain 0.5% bupivacaine and hyperbaric 0.5% tetracaine were compared for spinal anesthesia in 40 patients undergoing operation of lower extremities. Lumbar puncture was performed with a 22 gauge spinal needle with the patient in the lateral recumbent position. The third lumbar interspace was chosen for the puncture, when a free flow of clear CSF was obtained, the local anesthetic solution (2.5ml of 0.5% bupivacaine or 2.0ml of hyperbaric 0.5% tetracaine) was injected at a rate of 0.1ml/sec without barbotage. After injection of anesthetics, clinical features were observed and compared between the two groups. The results were as follows : 1. The two groups were well matched for age, sex, height and weight. 2. In both groups, sensory block to $T_{12}$ dermatome was obtained within 4 minutes, mean maximal level of analgesia was $T_{6-7}$, and the mean time for maximal level was around 20 minutes. 3. The onset times of motor block were similar in both groups and complete motor block was obtained in all cases within 20 minutes. 4. The duration of analgesia above the $T_{12}$ dermatome was 3 hours, postoperative analgesia was 7 hours. These values were significantly prolonged than those of the tetracaine group(p<0.05). 5. The changes in systolic pressure in the bupivacaine group were significantly less than those of the tetracaine group(p<0.05). 6. The complications after spinal anesthesia were headache, numbness, urinary retention and backpain, and were no significant difference in both groups. From the obtained results, we concluded that plain 0.5% bupivacaine was a relatively satisfactory agent for spinal anesthesia for operation of lower extremities. The time of onset, height of block and the complications of postoperative period were similar in both groups. The advantages of plain 0.5% bupivacaine were less hypotension and long duration of analgesia.

• Journal of Preventive Medicine and Public Health
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• v.27 no.1 s.45
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• pp.84-106
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• 1994

Hyperbaric oxygen (HBO) therapy for carbon monoxide (CO) poisoning eventually inducing the hypoxia-reoxygenation condition, may produce oxygen free radicals, which forms 8-hydroxydeoxyguanosine (8-OH-dG) by attacking C-8 position of deoxyguanosine (dG) in DNA. Effects of oxygen partial pressure or duration of HBO therapy with or without CO poisoning on the tissue 8-OH-dG formation were investigated. Male Sprague-Dawley rats were grouped and exposed to air (control group), 4000 ppm of CO for 10 to 30 minutes (CO only group), air for 30 minutes after 30 minute exposure to 4000 ppm of CO(CO-air exposure group), HBO after 30 minute exposure to 4000 ppm of CO(CO-HBO group), or HBO therapy fo. $10{\sim}120$ minutes(HBO only group). The 8-OH-4G concentrations in the brain and the lung tissues were measured with high performance liquid chromatography and electrochemical detector (ECD). Average concentrations of the 8-OH-dG of each group were statistically compared. In the brain tissues, 8-OH-dG concentrations of the CO only group, the CO-air exposure group, and the CO-HBO group did not significantly differ from those of the control group. Similar insignificance was also found between the CO-HBO group and the HBO only groups. No appreciable dose-response relationship was observed between the 8-OH-dG concentration and the oxygen partial pressure or the duration of HBO. However, the 8-OH-dG concentrations of the 30 minute CO only group were higher than those of the CO-air exposure group (p-value<0.05). In the lung tissues, there were no significant differences between the 8-OH-dG concentrations of the control group and those of the CO only group, the CO-air exposure group, and the CO-HBO group. However, mean 8-OH-dG concentration of the CO-air exposure group was significantly higher than that of the CO only group under the same CO exposure condition(p-value<0.05). With the duration of CO exposure, the 8-OH-dG concentrations of the lung tissues decreased significantly (p-value<0.05). The concentrations of 8-OH-dG in the lung tissues proportionally increased with the duration of HBO, but no such relation was observed with the oxygen partial pressure. These results suggest that the brain may be more resistant to oxygen free radicals as compared with the lungs, and that oxygen toxicity following HBO may be affected by factors other than oxygen free radicals.

• Ocean and Polar Research
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• v.37 no.1
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• pp.73-80
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• 2015

In order to determine the appropriate volume of the a pressure compensator of deep seabed mining robots, this paper reports on an experimental test for oil volume change in an oil-filled box. At the design stage of underwater robots, it is crucial to determine the capacity of the hydraulic compensator which is replenished as much as the contracted oil volume of the robots. A pilot mining robot, MienRo was designed to work under 6,000 m in the deep sea. The hydraulic actuating oil and pressure compensating oil of MineRo may be exposed at a hydrostatic pressure environment of 600 bar. Although the oil can be assumed to be incompressible, its volume is actually changed under high pressure conditions due to air contained in the oil and oil contraction. To determine the capacity of the pressure compensator, the oil contraction rate should be verified through an experimental test using a hyperbaric chamber.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.351-352
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• 2023

동물용 고압산소치료 시 산소를 통한 가압은 이미 있는 공기를 제거하고 산소로 대치시키는데 효율성이 떨어져서 100%에 가까운 산소분압을 구현하는데 어려움이 있고, 그 방법도 표준화되지 않았다. 따라서 어떠한 방식의 산소가압이 신속하고 효율적으로 100%에 가까운 산소분압을 구현할 수 있는지에 대한 방안을 개발하고 표준화할 필요가 있다. 동물용 고압산소치료를 활용한 동물실험이나 동물의 치료 중 가압 단계에서 간헐적 환기 방법이 더 신속하게 100%에 가까운 산소 분압을 보이므로 향후 표준 지침 개발을 위한 중요한 기반 연구와 제안으로 활용 가능하다. 이는 재난 기반으로의 고압산소챔버의 활용을 위한 기초 자료가 될 것이다.