• Journal of KIISE
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• v.42 no.7
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• pp.910-918
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• 2015

This paper presents a parameter visualization technique to overcome the limitation of the naked eye in contrast-enhanced ultrasonography. A method is also proposed to compensate for the distortion and noise in ultrasound image sequences. Meaningful parameters for diagnosing liver disease can be extracted from the dynamic patterns of the contrast enhancement in ultrasound images. The visualization technique can provide more accurate information by generating a parametric image from the dynamic data. Respiratory motions and noise from micro-bubble in ultrasound data may cause a degradation of the reliability of the diagnostic parameters. A multi-stage algorithm for respiratory motion tracking and an image enhancement technique based on the Markov Random Field are proposed. The usefulness of the proposed methods is empirically discussed through experiments by using a set of clinical data.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.1
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• pp.28-41
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• 2024

The carbon balance serves as a valuable indicator of a plant's physiological status under diverse environmental conditions. We investigated the photosynthetic and respiratory responses of the Asian surfgrass Phyllospadix iwatensis along the northeast coast of the Korean peninsula in response to changing water temperature (ranging from 5℃ to 30℃) to estimate the seasonal whole-plant carbon balance through a series of incubation experiments. The maximum gross photosynthetic rate (P_max) showed a significant difference among the temperature treatments, while there was no significant difference in photosynthetic efficiency (α). The maximum gross photosynthetic rate of P. iwatensis reached its peaks at 20℃ treatment (101.65 μmol O₂ g^-1 DW h^-1) but decreased rapidly at 30℃. The saturation irradiance (I_k), compensation irradiance (I_c), and respiration rate (R) of P. iwatensis exhibited significant differences among the temperature treatments. The saturation irradiance increased up to 20-25℃ (121.59-124.50 μmol photons m^-2 s^-1) and sharply decreased at 30℃. The compensation irradiance and respiration rate increased steadily with rising water temperature. The ratio of P_max to R (P_max:R ratio) was the highest at 5℃ but dramatically decreased at 30℃. The whole-plant carbon balance, calculated based on photosynthetic parameters, respiration rates, and biomass, exhibited distinct seasonal variation, increasing during winter and spring and decreasing during summer and fall, which is consistent with the highest in situ growth in spring and severely limited growth at the highest water temperature conditions. Phyllospadix iwatensis displayed a negative carbon balance during late summer, fall, and winter, but demonstrated a positive carbon balance during spring and early summer. Our findings suggest that the rising seawater temperatures associated with climate change may lead to significant alterations in the seagrass ecosystem functioning along the rocky shores of the Korean east coast.

• Journal of Society of Preventive Korean Medicine
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• v.14 no.2
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• pp.105-120
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• 2010

Objectives : This study aims to evaluate the effects of expiration-to-inspiration time ratio (E/I-ratio) on heart rate, which represents cardiac autonomic function, and cold-heat in the healthy people. Methods : 49 healthy young volunteers(male : female = 32 : 17) were recruited in the study. The participants completed the questionnaire for yin-yang pattern identification and then we measured the chest plethysmogram for respiration signal and the electrocardiogram for NN intervals during different E/I-ratio from 1 to 2. We compared heart rate variability including RMS-SD, VLF, LF and HF, and the trend-cycle factors decomposed from NN interval data by time series analysis among the respective E/I-ratio. We also confirmed the difference on the trend-cycle factors according to the score of the questionnaire for cold and heat pattern identification. Results : There were differences on the trend-cycle factors from NN interval data, but no significant difference on heart rate variability, among the respective E/I-ratio. We also found significant relationship between the trend-cycle factors and the heat pattern identification scores. Conclusions : The results indicate that cardiac autonomic function can be modulated by the E/I-ratio and the modulation will be slower and more tendencious than respiratory sinus arrhythmia.

• Fire Science and Engineering
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• v.22 no.2
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• pp.121-128
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• 2008

Adverse health effects of inhaled smokes are associated with the amount of the particles deposited in human lung. Lung model is needed to simulate smoke deposition because of the hardness of the in vivo deposition experiment. However, it is hard to realize the successively decreasing bifurcations in the model. In this work, an experimental lung model was developed to simulate the smoke deposition in the lung. Instead of bifurcating airways, the lung model was made of packed beds of which size decreased downwards. The experimental results using this model showed good agreements with existing results for real lung in the deposition characteristics. The model could be applied to the studies of health risk assessment of the inhaled smoke particles generated by fire.

• PNF and Movement
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• v.19 no.2
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• pp.173-182
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• 2021

Purpose: The purpose of this study was to compare the effects of underwater and ground-based diagonal pattern exercises on the balance confidence and respiratory functions of chronic stroke patients. Methods: Thirty chronic stroke patients were assigned randomly to an experimental (n = 15) or control (n = 15) group. The experimental group performed an underwater diagonal pattern exercise. The control group performed a ground-based diagonal pattern exercise. Training was conducted once a day for 30 minutes, five days per week for six weeks. Balance confidence was measured using the Activities-Specific Balance Confidence Scale-Korea version. Respiratory function was measured using a spirometer. Results: In a comparison within groups, the experimental and control groups showed significant differences in balance confidence after the experiment (p < 0.05). In a comparison between the two groups, the experimental group showed a more significant difference in balance confidence than the control group (p < 0.05). In a comparison within groups, the experimental group showed a significant difference in respiratory functions after the experiment (p < 0.05). In a comparison between the two groups, the experimental group showed a more significant difference in respiratory functions than the control group (p < 0.05). Conclusion: Based on these results, underwater diagonal pattern exercises effectively improved the balance confidence and respiratory functions of chronic stroke patients.

• Journal of the Korean Society of Radiology
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• v.83 no.2
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• pp.378-386
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• 2022

With the ongoing coronavirus disease 2019 (COVID-19) pandemic, there is an increasing interest in the sequelae and care in recovered patients. Although the long-term sequelae of COVID-19 are still unknown, recently published reports suggest that some of the patients have persistent symptoms and show radiologic abnormalities after discharge. Herein, we present cases of four patients with previous COVID-19 infection manifesting pulmonary sequelae, including pulmonary fibrosis or organizing pneumonia pattern with persistent dyspnea after recovery.

• Tuberculosis and Respiratory Diseases
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• v.63 no.5
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• pp.423-429
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• 2007

Background: Alveolar recruitment (RM) is one of the primary goals of respiratory care for an acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The purposes of alveolar recruitment are an improvement in pulmonary gas exchange and the protection of atelectrauma. This study examined the effect and safety of the alveolar RM using pressure control ventilation (PCV) in early ALI and ARDS patients. Methods: Sixteen patients with early ALI and ARDS who underwent alveolar RM using PCV were enrolled in this study. The patients data were recorded at the baseline, and 20 minutes, and 60 minutes after alveolar RM, and on the next day after the maneuver. Alveolar RM was performed with an inspiratory pressure of $30cmH_2O$ and a PEEP of $20cmH_2O$ in a 2-minute PCV mode. The venous $O_2$ saturation, central venous pressure, blood pressure, pulse rate, $PaO_2/FiO_2$ ratio, PEEP, and chest X-ray findings were obtained before and after alveolar RM. Results: Of the 16 patients, 3 had extra-pulmonary ALI/ARDS and the remaining 13 had pulmonary ALI/ARDS. The mean PEEP was 11.3 mmHg, and the mean $PaO_2/FiO_2$ ratio was 130.3 before RM. The $PaO_2/FiO_2$ ratio increased by 45% after alveolar RM. The $PaO_2/FiO_2$ ratio reached a peak 60 minutes after alveolar RM. The Pa$CO_2$ increased by 51.9 mmHg after alveolar RM. The mean blood pressure was not affected by alveolar RM. There were no complications due to pressure injuries such as a pneumothorax, pneumomediastinum, and subcutaneous emphysema. Conclusion: In this study, alveolar RM using PCV improved the level of oxygenation in patients with an acute lung injury and acute respiratory distress syndrome. Moreover, there were no significant complications due to hemodynamic changes and pressure injuries. Therefore, alveolar RM using PCV can be applied easily and safely in clinical practice with lung protective strategy in early ALI and ARDS patients.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.267-273
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• 1993

Background: Panting method for airway resistance measurement has the disadvantages of departing from the normal breathing pattern and of difficult for some patients to perform. We can measure airway resistance during quiet breathing under more physiologic conditions. Airway resistance is often measured during panting but attempts have been made to facilitate resistance measurements during quiet breathing. This study was designed to compare airway resistance measurements during panting with those during quiet breathing. Method: The 24 normal persons and 29 pulmonary disease patients were included in this study. Spirometry was performed and airway resistance measurement was also done during panting and quiet breathing concomittently. Results: The results were as follows; 1) High correlations were found between airway resistance measurements during panting and quiet breathing. 2) Resistance fell during panting, 21.2% in Raw tot, and 22.1% in Raw 0.5. 3) In normal persons, airway resistance fell more during panting when comparing to those in pulmonary disease patients. 4) This was largely independent of thoracic gas volume differences, because the specific airway conductance rose significantly during panting 5) The patients in whom resistance didn't fell during panting was supposed to the patients who couldn't perform panting successively because of high resistance. Conclusions: Although airway resistance can be measured during panting or quiet breathing according to the patient's performance, we must consider resistance fell during panting, by a mean 20%. It may be concluded that quiet breathing is more likely than panting to provide a relevant measurement of airway resistance.

• The Journal of Korean Society for Radiation Therapy
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• v.35
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• pp.41-51
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• 2023

Purpose: This study compares and analyzes the image quality of 3D-CBCT(Cone Beam Computed-Tomography) and Gated CBCT according to baseline changes during SBRT(Stereotactic Body RadioTherapy) in lung cancer patients to find a useful CBCT method for correcting movement due to breathing Materials and methods : Insert a solid tumor material with a diameter of 3 cm into the QUASAR^TM phantom. 4-Dimentional Computed-Tomography(4DCT) images were taken with a speed of the phantom at period 3 sec and a maximum amplitude of 20 mm. Using the contouring menu of the computerized treatment planning system Eclipse^TM Gross Tumor Volume was outlined on solid tumor material. Set-up the same as when acquiring a 4DCT image using Truebeam STx^TM, breathing patterns with baseline changes of 1 mm, 3 mm, and 5 mm were input into the phantom to obtain 3D-CBCT (Spotlight, Full) and Gated-CBCT (Spotlight, Full) images five times repeatedly. The acquired images were compared with the Signal-to-Noise Ratio(SNR), Contrast-to-Noise Ratio(CNR), Tumor Volume Length, and Motion Blurring Ratio(MBR) based on the 4DCT image. Results: The average Signal-to-Noise Ratio, Contrast-to-Noise Ratio, Tumor Volume Length and Motion Blurring Ratio of Spotlight Gated CBCT images were 13.30±0.10%, 7.78±0.16%, 3.55±0.17%, 1.18±0.06%. As a result, Spotlight Gated-CBCT images according to baseline change showed better values than Spotligtht 3D-CBCT images. Also, the average Signal-to-Noise Ratio, Contrast-to-Noise Ratio, Tumor Volume Length and Motion Blurring Ratio of Full Gated CBCT images were 12.80±0.11%, 7.60±0.11%, 3.54±0.16%, 1.18±0.05%. As a result Full GatedCBCT images according to baseline change showed better values than Full 3D-CBCT images. Conclusion : Compared to 3D-CBCT images, Gated-CBCT images had better image quality according to the baseline change, and the effect of Motion Blurring Artifacts caused by breathing was small. Therefore, it is considered useful to image guided using Gated-CBCT when a baseline change occurs due to difficulty in regular breathing during SBRT that exposes high doses in a short period of time

• Food Science and Preservation
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• v.16 no.6
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• pp.817-823
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• 2009

We investigated the effects of storage temperature and packaging treatment on the freshness of high-quality 'Fuji' apples to improve consumer confidence in the maintenance of high fruit quality during distribution. A 0.35 mm-deep PET tray form-sealed with a 0.05 mm LDPE film lid was developed and tested with the aim of optimizing gas composition within the package headspace to utilize potential modified atmosphere (MA) storage to maintain the freshness of apples. Weight loss, color difference, firmness, respiration rate, gas concentrations in packages, acidity, solid soluble content, and fruit decay rate were measured during storage at $5^{\circ}C$ and $25^{\circ}C$. The results showed that respiration rate, weight loss, color difference, and firmness were lower and overall quality better during storage at $5^{\circ}C$ compared with $25^{\circ}C$. Also, the fruits packed in the functional tray form showed a low level of quality changes compared with the control (no packaging). The accumulated gasconcentrations in the headspace of the packages decreased from 21% to 12% $O_2$ and increased from 0% to 5% $CO_2$ (v/v) on day 7, and after remained at those levels thereafter. Soluble solid contents and total acidities of the packaged fruits were in the range of $11\;-\;14^{\circ}Brix$ and 0.2 0.3% during storage. Decay rates in the control and packaged fruits were more than 20% and less than 10% at 3 weeks, respectively. Based on the standard acceptable level (less than 10%) of total weight loss, it could be estimated that the shelf life of top-quality fruits packed in functional trays was 3 weeks at $5^{\circ}C$ and 16 weeks at $25^{\circ}C$, whereas the shelf life of the control fruit was 1 week and 12 weeks, respectively. For the top-quality fruit "Fuji" apples, the best results were obtained with a functional tray form for packaging treatment and a storage temperature of $5^{\circ}C$.