• 한국가시화정보학회:학술대회논문집
• /
• 2005.12a
• /
• pp.93-98
• /
• 2005

The mean and RMS velocity field of the respiratory gas flow in tile human airway was studied experimentally by particle image velocimetry(PIV). Some researchers investigated the airflow for the mouth breathing case both experimentally and numerically. But it is very rare to investigate the airflow of nose breathing in a whole airway due to its geometric complexity. We established the procedure to create a transparent rectangular box containing a model of the human airway for PIV measurement by combination of the RP and the curing of clear silicone. We extend this to make a whole airway including nasal cavities, larynx, trachea, and 2 generations of bronchi. The CBC algorithm with window offset (64*64 to 32*32) is used for vector searching in PIV analysis. The phase averaged mean and RMS velocity distributions in Sagittal and coronal planes are obtained for 7 phases in a respiratory period. Some physiologic conjectures are obtained. The main stream went through the backside of larynx and trachea in inspiration and the frontal side in expiration. There exist vortical motions in inspiration, but no prominent one in expiration.

• KIPS Transactions on Software and Data Engineering
• /
• v.7 no.3
• /
• pp.91-98
• /
• 2018

Automatic detection of pig wasting diseases is an important issue in the management of group-housed pigs. In particular, porcine respiratory diseases are one of the main causes of mortality among pigs and loss of productivity in intensive pig farming. In this paper, we propose a noise-robust system for the early detection and recognition of pig wasting diseases using sound data. In this method, first we convert one-dimensional sound signals to two-dimensional gray-level images by normalization, and extract texture images by means of dominant neighborhood structure technique. Lastly, the texture features are then used as inputs of convolutional neural networks as an early anomaly detector and a respiratory disease classifier. Our experimental results show that this new method can be used to detect pig wasting diseases both economically (low-cost sound sensor) and accurately (over 96% accuracy) even under noise-environmental conditions, either as a standalone solution or to complement known methods to obtain a more accurate solution.

• Journal of Veterinary Clinics
• /
• v.9 no.2
• /
• pp.401-406
• /
• 1992

For the purpose of effective treatment and prevention of porcine respiratory diseases, Enrofloxacin(Baytril premix) was administered in the feed to trial herd occurred sporadically the respiratory diseases and then a serious investigation was carried out on the therapeutic effect, weight gain, feed conversion rate and lung lesion scoring. The results obtained were as follows, 1. The grower pigs which were administered with Baytril premix for 10 days gained the average body weight of 31kg for 33 days compared to 20.5kg of control group(p<0.05). Also drastical improvement of feed conversion rate(p<0.05) and disappearance of clinical signs were approved. 2. Average scorings of lung lesions were 7.92% in the medication group and 15.8% in the control group respectively. 3. Respiratory diseases outbreaked in the trial farm were pleuropneumonia caused by Actinobacillus (Haemophilus)pleuropneumoniae, Mycoplasmal pneumonia and Pasteurellosis.

• Clinical and Experimental Pediatrics
• /
• v.48 no.4
• /
• pp.401-405
• /
• 2005

Purpose : The use of mechanically-assisted ventilators at home reduces morbidity and improves the quality of life in children with chronic respiratory failure. But in Korea there is no clinical data of children with home mechanical ventilation. We investigated ventilator types, duration, the causes of failure or death, and the cost needed for care. Methods : We retrospectively analyzed the medical records of 21 children who were admitted and who applied for home mechanical ventilation at the Pediatric Intensive Care Unit in Asan Medical Center. Phone interviews took place after discharge. and interviewed by phone after discharge. Results : The median age was 31 months; the median duration with ventilator was 25 months. Underlying diseases were 16 neuromuscular diseases, one metabolic disease and four chronic respiratory diseases. The types of ventilator were pressure and volume type(16 and five patients, respectively). The frequency of ventilation failure was once per 19 months. Weaning could be performed in three cases. Frequencies of admission after receiving ventilators were 1.7 times per year; the most common cause was pneumonia. Nine patients(43%) died; four of them died because of endotracheal tube obstruction. The costs for medical care were about 1,110,000 won per month. Conclusion : There is an increment in the numbers of individuals who need mechanical ventilation support. The most common cause of death was endotracheal tube obstruction. The most important problem for the patients was medical cost. There needs to be more interest in patients with ventilator and social welfare systems to support their families need to be prepared.

• Clinical and Experimental Pediatrics
• /
• v.52 no.11
• /
• pp.1241-1248
• /
• 2009

Purpose:The etiology of Kawasaki disease (KD) is still unknown. Recently, an association between human coronavirus NL63 (HCoV-NL63) and KD was implicated. Hence, we attempted to determine the association between KD and acute respiratory viral infections. Methods:Nasopharyngeal aspirate samples were obtained from 54 patients diagnosed with KD at the Seoul National University (SNU) Children's Hospital and SNU-Bundang Hospital between October 2003 and September 2006. Viral diagnoses of 11 respiratory viruses were made using multiplex reverse transcriptase-polymerase chain reaction (RT-PCR): respiratory syncytial virus (RSV), adenovirus, rhinovirus (RV), parainfluenza viruses (PIVs) 1 and 3, influenza viruses (IFVs) A and B, human metapneumovirus (HMPV), human bocavirus (HBoV), HCoV OC43/229E, and HCoV-NL63. Clinical data were reviewed retrospectively. Results:The median age was 32 months (6 months-10.4 years). Respiratory symptoms were observed in 37 patients (69%). The following respiratory viruses were identified in 12 patients (22%): RV (n=4), PIV-3 (n=2), HBoV (n=2), and adenovirus, RSV, PIV-1, IFV-A, and HCoV-NL63 (n=1). Co-infection with PIV-3 and RV was observed in one patient. Respiratory symptoms were observed in 7 (58.3%) and 30 (71.4%) patients of the virus-positive and virus-negative groups (P>0.05). Response rate to intravenous immunoglobulin administration was 67% (n=8) and 86% (n=36) in the virus- positive and virus-negative groups (P>0.05). Conclusion:Respiratory symptoms were commonly observed in KD patients but the association between respiratory viruses and KD were not found. Large multicenter-based investigations are required to confirm the association between acute respiratory viral infections and KD.

• Pediatric Infection and Vaccine
• /
• v.21 no.3
• /
• pp.207-213
• /
• 2014

Purpose: This study aimed to investigate the association between respiratory virus infection and pneumococcal colonization in children. Methods: From May 2009 to June 2010, nasopharyngeal (NP) aspirates were obtained from patients under 18 years old who visited Seoul National University Children's Hospital for respiratory symptoms. NP samples were used to detect respiratory viruses (influenza virus A and B, parainfluenza virus 1, 2 and 3, respiratory syncytial virus A and B, adenovirus, rhinovirus A/B, human metapneumovirus, human coronavirus 229E/NL63 and OC43/HKU1) by RT-PCR and pneumococcus by culture. Results: Median age of the patients was 27 months old. A total of 1,367 NP aspirates were tested for respiratory viruses and pneumococcus. Pneumococcus was isolated from 228 (16.7%) of samples and respiratory viruses were detected from 731 (53.5%). Common viruses were rhinovirus (18.4%), respiratory syncytial virus (RSV) A (10.6%), adenovirus (6.9%), influenza virus A (6.8%). Pneumococcal isolation rate was significantly higher in the cases of positive virus detection than negative detection [21.3% (156/731) vs. 11.3% (72/636), P <0.001]. For individual viruses, pneumococcal isolation rate was positively associated with detection of influenza virus A [24.7% (23/93) vs 16.1% (205/1274), P=0.001], RSV A [28.3% (41/145) vs 15.3% (187/1222), P=0.001], RSV B [31.3% (10/32) vs 16.3% (218/1335), P=0.042], rhinovirus A/B [22.6% (57/252) vs 15.3% (171/1115), P=0.010]. Conclusion: The study revealed that pneumococcal isolation from NP aspirates is related with respiratory virus detection. The result of this study could be used to investigate how respiratory viruses and pneumococcus cause clinical diseases.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.6 no.1
• /
• pp.17-23
• /
• 2003

Purpose: The aim of this study was to determine clinical significance of dual-probe esophageal pH monitoring and to compare four pH monitoring parameters between proximal and distal esophagus in pathological gastroesophageal reflux disease with recurrent respiratory symptoms. Methods: Among the thirty-four patients who were performed 24 hr pH monitoring, seventeen patients with pathological distal reflux were classified into two groups: Group I (n:12) had recurrent respiratory symptoms and Group II (n:5) hadn't recurrent respiratory symptoms. The ambulatory dual-probe esophageal pH monitoring was performed for 18~24 hr. A pathologic GER was defined when reflux index (percent of the investigation time a pH<4) exceeded the 95th percentile of normal value. Results: Among the sixteen patients with recurrent respiratory symptoms, twelve patients (75%) have pathological distal reflux. Whereas among the eighteen patients without recurrent respiratory symptom, five patients (28%) have pathological distal reflux. In the Group I, the significant differences between proximal and distal esophageal pH recordings persisted for all parameters, but didn't persist in group II except for longest episode. Comparing esophageal pH four parameters between group I and group II at the proximal esophageal site, all parameters didn't show statistically significant differences. Conclusion: Regardless of respiratory symptoms, patients with pathological distal reflux didn't show statistically significant differences in the all parameters at the proximal esophageal site. Therefore we may reconsider usefulness of dual probe pH meter in patients with recurrent respiratory symptoms.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.3
• /
• pp.329-335
• /
• 2019

Annually, millions of children die from respiratory virus infections. Human rhinovirus (HRV) is a causative agent of severe respiratory infections in young, elderly, and asthmatic patients with weak immunity. In this study, 9,010 respiratory virus specimens were collected from January 2012 to December 2018 at Dankook University Hospital, Cheonan and examined by real-time reverse transcription polymerase chain reaction. Twelve respiratory viruses were detected. The mean detection rate was 21.3% (N=1,920/9,010), and the mean age of HRV-positive patients was 6.5 years (median age: 1.6 years, range: 0.0~96.0). The detection rate was the highest in July (32.4%) and the lowest in February (8.3%). When the detection rate was analyzed by age group, the detection rate was the second highest in patients aged 10~19 years. The co-infection rate of HRV was 35.3%, and the most common combination was with Adenovirus. Respiratory virus infections are known to occur in children and elderly people with weak immunity. However, in this study, the detection rate was second highest in patients aged 10~19 years. Indeed, the detection rate in this age group was more than 15%, except in January and February. These results suggested that steady-state studies on the infection patterns of HRV are required.

• Clinical and Experimental Pediatrics
• /
• v.52 no.6
• /
• pp.661-666
• /
• 2009

Purpose : To determine the prevalence and clinical features of codetected respiratory etiological agents for acute respiratory infection in hospitalized children. Methods : Nasopharyngeal aspirates were obtained from hospitalized children with acute respiratory infection at Dankook University Hospital from September 2003 through June 2005. Immunofluorescent staining and culture were used for the detection of respiratory viruses (influenza virus [IFV] types A, B; parainfluenza virus [PIV] types 1, 2, 3; respiratory syncytial virus [RSV]; adenovirus [AdV]). Polymerase chain reaction (PCR) assays were used for Mycoplasma pneumoniae (MP) and Chlamydia trachomatis (CT) detection, and PCR and culture were performed for enterovirus detection. Acid-fast staining and culture were performed for tuberculosis detection. The demographic and clinical characteristics were reviewed retrospectively from the patients medical records. Results : Evidence of two or more microbes was found in 28 children: RSV was detected in 14, PIV 3 in 10, AdV in 10, MP in 8, PIV 2 in 8, CT in 4, and PIV 1 in 3. Codetected agents were found as follows: RSV＋PIV 2, 6 patients; AdV＋MP, 4 patients; AdV＋PIV, 3 patients; RSV＋MP, 3 patients; PIV 1＋PIV 3, 3 patients. Distinct peaks of codetected agents were found in epidemics of MP and each respiratory virus. Conclusion : The codetected infectious agents were RSV, PIV, AdV, and MP, with distinct peaks found in epidemics of MP and each respiratory virus. Although advances in diagnostic methods have increased the prevalence of codetection, its clinical significance should be interpreted cautiously.

• Clinical and Experimental Pediatrics
• /
• v.52 no.8
• /
• pp.893-897
• /
• 2009

Purpose : Advances in neonatal intensive care have improved the survival rate of low-birth-weight infants, but mild bronchopulmonary dysplasia (BPD) with the accompanying need for prolonged oxygen supplement remains problematic. Maternal chorioamnionitis and neonatal ventilator care affect the development of BPD. This study aimed to examine whether maternal chorioamnionitis or neonatal ventilator care affect the development of BPD dependently or independently. Methods : We performed a retrospective study of 158 newborn infants below 36 weeks of gestational age and 1,500 gm birth weight admitted to the neonatal intensive care unit of Daegu Fatima Hospital between January 2000 and December 2006. We analyzed the incidence of BPD according to maternal chorioamnionitis and neonatal ventilator care. Result : Histologic chorioamnionitis was observed in 50 of 158 infants (31.6%). There were no significant differences in the development of BPD (P=0.735) between the chorioamnionitis (+) and chorioamnionitis (-) groups. In the multiple regression analysis, ventilator care (OR=7.409, 95% CI=2.532-21.681) and neonatal sepsis (OR=4.897, 95% CI=1.227-19.539) affected the development of BPD rather than maternal chorioamnionitis (OR=0.461, 95% CI=0.201-1.059). Conclusion : Ventilator care or neonatal sepsis may play a role in the development of BPD rather than maternal chorioamnionitis.