• International journal of advanced smart convergence
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• v.9 no.4
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• pp.132-138
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• 2020

Worldwide, the number of corona virus disease 2019 (COVID-19) confirmed cases is rapidly increasing. Although vaccines and treatments for COVID-19 are being developed, the disease is unlikely to disappear completely. By attaching a smart sensor to the respirator worn by medical staff, Internet of Things (IoT) technology and artificial intelligence (AI) technology can be used to automatically detect the medical staff's infection symptoms. In the case of medical staff showing symptoms of the disease, appropriate medical treatment can be provided to protect the staff from the greater risk. In this study, we design and develop a system that detects cough, a typical symptom of respiratory infectious diseases, by applying IoT technology and artificial technology to respiratory protection. Because the cough sound is distorted within the respirator, it is difficult to guarantee accuracy in the AI model learned from the general cough sound. Therefore, coughing and non-coughing sounds were recorded using a sensor attached to a respirator, and AI models were trained and performance evaluated with this data. Mel-spectrogram conversion method was used to efficiently classify sound data, and the developed cough recognition system had a sensitivity of 95.12% and a specificity of 100%, and an overall accuracy of 97.94%.

• 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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.92-101
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• 2001

This article reviewed previous studies on the 3D face recognition and anthropometric facial analysis to design suitable respirators for individuals. 3D facial anthropometric data have not been reported in Korea yet. With 3D facial data, it is possible to design and to manufacture respirators having more effective respirator-face seal and thus providing more comfortable wearing than donning of those respirators designed using 1 and 2-dimensional data. Also 3D data could be used for respirator fit-testing and selecting suitable respirator type and size by computer simulation without several steps of fit-test to each individual worker.

• Safety and Health at Work
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• v.11 no.1
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• pp.61-70
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• 2020

Background: This study aims to assess whether the TSI PortaCount (Model 8020) is a measuring instrument comparable with the flame photometer. This would provide an indication for the suitability of the PortaCount for determining the workplace protection factor for particulate filtering facepiece respirators. Methods: The PortaCount (with and without the N95-Companion^TM) was compared with a stationary flame photometer from Moores (Wallisdown) Ltd (Type 1100), which is a measuring instrument used in the procedure for determining the total inward leakage of the particulate filtering facepiece respirator in the European Standard. Penetration levels of sodium chloride aerosol through sample respirators of two brands (A and B) were determined by the two measuring systems under laboratory conditions. For each brand, thirty-six measurements were conducted. The samples were split into groups according to their protection level, conditioning before testing, and aerosol concentration. The relationship between the gauged data from two measuring systems was determined. In addition, the particle size distribution inside the respirator and outside the respirator was documented. Linear regression analysis was used to calculate the association between the PortaCount (with and without the N95-Companion^TM) and the flame photometer. Results: A linear relationship was found between the raw data scaled with the PortaCount (without N95-Companion^TM) and the data detected by the flame photometer (R² = 0.9704) under all test conditions. The distribution of particle size was found to be the same inside and outside the respirator in almost all cases. Conclusion: Based on the obtained data, the PortaCount may be applicable for the determination of workplace protection factor.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.8
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• pp.497-503
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• 2017

A theoretical study on oxygen flow is fundamental to comprehend the practical production of an oxygen respirator and its stability. In this study, an orifice-type pressure-reducing component was designed for the newly developed oxygen respirator, using the commercial CFD tool, COMSOL Multiphysics, which increases its operational time compared to the existing component. The orifice was optimized by changing the length by 3, 6, and 9 mm within the entire computational domain of the oxygen respirator. Based on an oxygen flow rate of 0.028 kg/s, the oxygen respirator equipped with the newly developed orifice satisfied the flow rate within 33% for a respirator inlet pressure of 300 bar, and within 32.7% for 50, 75, and 100 bar. In terms of component manufacturing, the orifice length was selected as 3 mm, which removes additional changes to the existing component.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.440-448
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• 1998

In many developed countries, for example, USA, respirator fit testing is required before entering specific work environment to ensure that the respirator worn satisfies a minimum of fit and that the user knows when the respirator fits properly. Unfortunately because we have not fit test regulation in Korea, a lot of workers wearing respirators may be potentially exposed to hazards. This study was conducted to evaluate the fitting performance for respirators and correlation fit factors with facial dimensions of wearers. 110 subjects (70 males, 40 females) were fit tested for three quarter masks, i.e., two domestic-made Mask 2, and Y and one foreign-made Mask T using PortaCount 8020. A facial dimension survey of the same subjects was conducted to develop a facial dimension grids fer correlation fit factors with facial dimension parameters. A facial dimension grid was developed on the basis of face length and lip length for quarter masks. The results obtained were as follows : 1 Fit factors of Mask T were much higher than those of Masks Z, and Y. 2. Males were fitted more properly than females. 3. Male in box 'f' of grid would be adequately fitted Mask Y and male in box 'b', 'e', 'f', 'h' of grid would be sufficiently fitted Mask T. Female in box 'h' of grid may have a good fitting performance for both Mask Y, and T. But subjects in all boxes of grid would be inadequately fitted Mask Z.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.158-164
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• 1987

The purpose of this study is to analyze occupational history of coal miners with pneumoconiosis. In this study, occupational characteristics of 49 coal miners with pneumoconiosis were compared with those of 45 coal miners without pneumoconiosis but in similar age category($43{\sim}52$ years of age) based on interview survey. Various indices on occupational characteristics were developed for the following areas: duration of employment, perception of working condition, working density, dust concentration, temperature, humidity, and experience of respirator wearings. Perception of working condition were measured in 5 points scales but experiences of respirator wearing was measured in 3 points scale. Each index was multiplied by duration of employment. From the analysis, only the experience of respirator wearing showed statistically significant difference between the two groups. Therefore, respirator wearing seemed to be effective in reducing occurrence of pneumoconiosis.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.170-178
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• 2000

Most of manufacturers try to produce the most efficient filter for respirators with the lowest breathing resistance. Filter performance depends on low penetration, i.e., high efficiency (%), and low pressure drop ($mmH_2O$). This study was performed to evaluate performance of respirator filters by quality factor ($q_F$) and suggest the direction for improvement of respirator filters of good quality in Korea. Two mechanical filters, S and K made in Korea, three filtering facepieces, S made in China, C made in Korea and M made in USA, which were widely used in the workplace, were selected and tested efficiency and pressure drop in accordance with flow rate, using with Automated Filter Tester Model 8110 (TSI, USA). The best quality factor within the same respirator filter categories was $0.0672cm^{-1}\;H_2O$ for mechanical filter S, $0.0698cm^{-1}\;H_2O$ for filtering facepiece M at flow rate of 32Lpm. Mechanical filter S would be the best suitable during heavy work since qulity factors decrease less sharply than any others as increased flow rates. It was necessary for mechanical filter S to lower pressure drop without increasing efficiency, but mechanical filter K should be increased efficiency and decreased pressure drop. While filtering facepiece M had the best quality performance of three ones, Sand C should get much higher efficiency and lower pressure for better performance.

• Tuberculosis and Respiratory Diseases
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• v.58 no.3
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• pp.213-229
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• 2005

The first and the longest criminal indictment case of Korean medico-legal battle, so called BORAMAE Hospital Incident, was finally on its end by Korean Supreme Court's decision on June 24, 2004, after 7 years long legal dispute via Seoul District Court and Seoul Superior Appeal Court's decision. Boramae Hospital case was the first Korean legal case of Withdrawing Life-sustaining treatment of mechanical respirator on 58 years old Extradural Hematoma victim who was on Respirator under Coma after multi-organ failure postoperatively(APACHE II score: 34-39). Two physicians who have involved patient's care and had helped to make discharge the Near-death patient to home after repeated demand of patient's wife, due to economic reason, were sentenced as homicidal crime. This review article will discuss the following items with the review of US cases, Quinlan(1976), Nancy Cruzan(1990), Barber (1983), Helen Wanglie(1990), Baby K (1994) and Baby L cases, along with Official Statement of ATS and other Academic dignitaries of US and World.: [1] Details of Boramae Hospital incident, medical facts description and legal language of homicidal crime sentence. [2] The medical dispute about the legal misinterpretation of patient's clinical status, regarding the severity of the victim with multi-organs failure on Respirator under coma with least chance of recovery, less than 10% probability. [3] Case study of US, of similar situation. [4] Introduction of ATS official Statement on Withdrawing/ Withholding Life sustaining treatment. [5] Patient Autonomy as basic principle. [6] The procedural formality in Medical practise for keeping the legitimacy. [7] The definition of Medical Futility and its dispute. [8] Dying in Dignity and PAS(Physician Assisted Suicide)/and/or Euthanasia [9] The Korean version of "Dying in Dignity", based on the Supreme Court's decision of Boramae Hospital incident (2004.6.24.) [10] Summary and Author's Note for future prospects.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.27-39
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• 2000

Objectives : The purpose of this study is to analyze the factors associated with respirator usage on the basis of reasoned action theory. Methods : The data were collected from August 1 to September 30 1999, and study subjects consisted of 303 workers who were employed in the manufacturing industries. A self-administered questionnaire was used to measure the attitude, subjective norm and related factors. Results : In bivariate analysis, the variables related to protector usage were prevention of occupational disease, protection of toxic material, disturbance during working, troublesome of usage, proper exchange of protector. Multivariate logit analysis was used to estimate factors associated with respirator usage. Significant predictors that are related to respirator usage were attitude toward the behavior, size of industry and proper exchange of protector. Conclusions : The results suggest that it is strongly required to focus on attitude toward the behavior in order to improve workers' usage of respirator.