• The Korean Journal of Emergency Medical Services
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• v.17 no.3
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• pp.21-28
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• 2013

Purpose: The purpose of this study is to get basic user guidelines of safe and efficient bag-valve-mask application on patients having abnormal pathophysiological pulmonary conditions. Methods: This study was performed by pre-qualified 35 EMS junior and senior students. Participants were instructed to compress ambulatory bag randomly about half, one-third, one-fourth within different airway resistance and pulmonary compliance. Resultant tidal volume and pulmonary wedge pressures on RespiTranier monitor were analysed in relation to pulmonary physiologic index. Results: At least over half compression of bag guaranteed minimal tidal volume regardless of pulmonary conditions. There was no increase of pulmonary wedge pressure above the level of barotrauma on half compression at any pulmonary conditions. Conclusion: Assisted ventilation with ambulatory bag on patients with pathological pulmonary conditions should be over half compressed regardless of respiratory disease entity.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.723-730
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• 1995

Background: Noninvasive ventilation has been used extensively for the treatment of patients with neuromuscular weakness or restrictive chest wall disorders complicated by hypoventilatory respiratory failure. Recently, noninvasive positive pressure ventilation has been used in patients with alveolar hypoventilation, chronic obstructive pulmonary disease(COPD), and adult respiratory distress syndrome. Sanders and Kern reported treatment of obstructive sleep apnea with a modification of the standard nasal CPAP device to deliver seperate inspiratory positive airway pressure(IPAP) and expiratory positive airway pressure(EPAP). Bi-level positive airway pressure(BiPAP) unlike nasal CPAP, the unit delivers a different pressure during inspiration from that during expiration. The device is similar to the positive pressure ventilator or pressure support ventilation. Method and purpose: Bi-level positive airway pressure(BiPAP) system(Respironics, USA) was applied to seven patients with acute respiratory failure and three patients on conventional mechanical ventilation. Results: 1) Two of three patients after extubation were successfully achieved weaning from conventional mechanical ventilation by the use of BiPAP ventilation with nasal mask. Five of seven patients with acute respiratory failure successfully recovered without use of conventional mechanical ventilation. 2) $PaO_2$ 1hour after BiPAP ventilation in acute respiratory failure patients significantly improved more than baseline values(p<0.01). $PaCO_2$ 1hour after BiPAP ventilation in acute respiratory failure patients did not change significantly more than baseline values. Conclusion: Nasal mask BiPAP ventilation can be one of the possible alternatives of conventional mechanical ventilation in acute respiratory failure and supportive method for weaning from mechanical ventilation.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.3
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• pp.113-125
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• 2023

The COVID-19 pandemic has led to the normalization of mask-wearing worldwide, and young children are particularly vulnerable to respiratory diseases. Children's masks come in various sizes and shapes, causing confusion among consumers who struggle to find products that can accommodate their child's unique physical conditions. This research aims to analyze the shape and dimensions of health masks designed for young children. A total of 67 mask varieties were collected, and 58 were subjected to analysis. The masks were found to have two primary shapes: foldable and beak-like, with sizes categorized as small and extra-small. The majority of masks were manufactured in Korea, and the size labeling systems varied among manufacturers. The mask materials were non-woven fabric or polypropylene, and there was diversity in terms of the adjustable earbands and the use of additional accessories. The dimensions of the masks varied depending on their shape, with significant differences in the weight and the length of the wire holes. Subsequent research should focus on conducting wearability evaluations to verify the dimensional suitability of commercially available children's health masks based on shape and size. Additionally, this study aims to provide foundational data that can assist in the development of children's masks with size ranges that differentiate them from adult masks and cater to specific age groups.

• Medical Lasers
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• v.8 no.2
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• pp.43-49
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• 2019

The plume produced by vaporizing tissue with a laser contains a variety of contaminants called laser-generated air pollutants (LGACs). LGACs consist of a mixture of toxic gas components, biomicroparticles, dead and living cells, and viruses. Toxic odors and thick smoke from surgical incisions and the coagulation of tissues can irritate eyes and airways, as well as cause bronchial and pulmonary congestion. Because of the potential risk of the smoke, it is advisable to appropriately remove it from the surgical site. We recommend using a smoke evacuator to remove the smoke. Suction nozzles should be placed as close as possible to the surgical site in a range of 2 cm or less. In-line filters should be used between the inlet and outlet of the surgical site. All air filtration devices should be capable of removing particles below 0.1 microns in size. The filter pack should be handled according to infection control procedures in the operating room. The laser mask can be an auxiliary protective device if it is properly worn. Some smoke inhaled under the nose wrap or over the side of the mask will not be filtered. As in electrosurgical operations, a suitable mask should be worn while smoke is present.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.477-485
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• 2020

This study is a random allocation similar experimental study to compare and analyze the difference in BVM (Bag-Valve-Mask) ventilation volume according to the characteristics of the rescuer's hand and the type of mask using a standardized mannequin. To this end, the Basic Life Resuscitation Education Center of D University in gwangju. Recruiting 39 students who have completed the basic resuscitation course for emergency medical personnel and the Korean-style specialized cardiac rescue course, In addition to measuring the physical characteristics of the hand, the average amount of ventilation per minute using a bag-mask was measured and analyzed. As a result, the type of mask that was not most affected by the characteristics of the hand and provided adequate Minute Ventilation was the soft type (tube, silicone) mask. On the other hard (tube, silicone) masks were found to be unsuitable for general use as they were greatly affected by the characteristics of workers' hands. COVID-19 is currently increasing the risk of transmission to paramedics and patients. Considering this situation, the universal use of a semi-permanent hard-type mask, which is disadvantageous not only for preventing infection but also for proper ventilation, should be avoided. In addition to the ease of use, it should be actively utilized in the field by supplying a soft type mask that can provide stable ventilation even with 'predominance recognition' and proper ventilation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.124-133
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• 2020

Objectives: Mask fit is a crucial factor in preventing respiratory infections among healthcare workers. The current coronavirus(COVID-19) pandemic calls for the replacement of imported N95 medical masks with domestic N95 versions. In this study, we aimed to determine whether these masks provide proper protection. Methods: Thirty-five participants from three healthcare institutions donned four types of masks and Quantitative Fit Tests(Portacount, USA) were performed. The order of fit test for the four types of masks was randomized, and a three-minute washout period was applied between test times(2 min 29 sec) to reduce potential error stemming from physical exhaustion. Results: There were no significant differences in the Fit Factor for the four types of masks, and there were no gender differences. However, the Fit Factor significantly differed across the three healthcare institutions (p=0.007). With eight of the 35 participants passing, the pass rate with the criteria of 100 or higher was 21%. Conclusions: The mask used in this study was a new domestic N95 medical mask, and the participants were unfamiliar with how to wear it. They reported difficulties with mask fitting. In light of a previous finding that mask fit improved with frequently used masks, wearer preferred masks, or when masks that are regularly worn are used during fit training, the fact that participants were unfamiliar with the mask used in this study is a limitation that should not be overlooked.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.282-288
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• 2022

Facial masks have become indispensable in daily life to prevent infection and spread through respiratory droplets in the era of the corona pandemic. To understand how effective two different types of masks (i.e., KF-94 mask and dental mask) are in blocking respiratory droplets, i) we preferentially analyze wettability characteristics (e.g., contact angle and contact angle hysteresis) of filters consisting of each mask, and ii) subsequently observe the dynamic behaviors of microdroplets impacting at high velocities on the filter surfaces. Different wetting properties (i.e., hydrophobicity and hydrophilicity) are found to exhibit depending on the constituent materials and pore sizes of each filter. In addition, the pneumatic conditions for stably and uniformly dispensing microdroplets with a certain volume and impacting behaviors associated with the impacting velocity and filter type change are systematically explored. Three distinctive dynamics (i.e., no penetration, capture, and penetration) after droplet impacting are observed depending on the type of filter constituting the masks and droplet impact velocity. The present experimental results not only provide very useful information in designing of face masks for prevention of transmission of infectious respiratory diseases, but also are helpful for academic researches on droplet impacts on various porous surfaces.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.295-303
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• 2021

Objective: Paint manufacturing industry workers are exposed to various lung cancer carcinogenic substances including hexavalent chromium and crystalline silica. Studies have been conducted on lung cancer in Paint manufacturing industry workers and the concentration of hexavalent chromium in paint industry; however, the concentration of crystalline silica and hexavalent chromium and cases of lung cancer in a single Paint factory has never been reported in Korea. Methods: To determine whether the cancer was related to his work environment, we assessed the level of exposure to carcinogens during pouring and mixing talc and pigment. In addition, a mask fit test was performed for the worker. Results: Analysis of talc and silica bulk powder materials showed that crystalline silica (quartz) was 5% in talc and 100% in silica. The green and yellow pigments contained 87% and 92% of lead chromate, respectively. Our quantitative analysis of pigment powder samples showed that the hexavalent chromium contents quantified in the green and yellow pigment samples were 87% and 92%, respectively. In order to estimate his exposure level of hexavalent chromium, we measured a personal exposure level of hexavalent chromium for a worker in accordance with the National Institute for Occupational Safety and Health #7605 method. The results showed that the worker was exposed to the high level of hexavalent chromium (0.033 mg m-3). In addition, the talc powder also contained 5% quartz, and the worker's exposure level to respirable quartz exceeded OEL. As a result of the respiratory protection fit test for workers, the overall Fit Factor was '15' when wearing a second-grade mask and '25' when wearing a first-grade mask, significantly lower than the US Occupational Safety and Health Agency (OSHA) pass value of "100". Conclusion: Workers who pouring and mixing powder materials such as talc or colored pigments in paint manufacturing company may be exposed to high concentrations of carcinogenic substances. These findings indicate that it is necessary to local ventilation system inspection, safety and health education for employers and workers, and periodically monitoring and manage the working environment.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.378-385
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• 2023

The importance of wearing respiratory protective equipment has been highlighted even more during the COVID-19 pandemic. Even if the suitability of respiratory protection has been confirmed through testing in a laboratory environment, there remains the potential for leakage points in the respirators due to improper application by the wearer, damage to the equipment, or sudden movements in real working conditions. In this paper, we propose a method to detect the occurrence of leak holes by measuring the pressure changes inside the mask according to the wearer's breathing activity by attaching an IoT sensor to a full-face respirator. We designed 9 experimental scenarios by adjusting the degree of leak holes of the respirator and the breathing cycle time, and acquired respiratory data for the wearer of the respirator accordingly. Additionally, we analyzed the respiratory data to identify the duration and pressure change range for each breath, utilizing this data to train a neural network model for detecting leak holes in the respirator. The experimental results applying the developed neural network model showed a sensitivity of 100%, specificity of 94.29%, and accuracy of 97.53%. We conclude that the effective detection of leak holes can be achieved by incorporating affordable, small-sized IoT sensors into respiratory protective equipment.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.250-255
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• 2015

Purpose: To compare audio-only biofeedback to conventional audiovisual biofeedback for regulating patients' respiration during four-dimensional radiotherapy, limiting damage to healthy surrounding tissues caused by organ movement. Materials and Methods: Six healthy volunteers were assisted by audiovisual or audio-only biofeedback systems to regulate their respirations. Volunteers breathed through a mask developed for this study by following computer-generated guiding curves displayed on a screen, combined with instructional sounds. They then performed breathing following instructional sounds only. The guiding signals and the volunteers' respiratory signals were logged at 20 samples per second. Results: The standard deviations between the guiding and respiratory curves for the audiovisual and audio-only biofeedback systems were 21.55% and 23.19%, respectively; the average correlation coefficients were 0.9778 and 0.9756, respectively. The regularities between audiovisual and audio-only biofeedback for six volunteers' respirations were same statistically from the paired t-test. Conclusion: The difference between the audiovisual and audio-only biofeedback methods was not significant. Audio-only biofeedback has many advantages, as patients do not require a mask and can quickly adapt to this method in the clinic.