• Journal of Korean Physical Therapy Science
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• v.29 no.2
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• pp.57-65
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• 2022

Background: This study was to determine whether the diaphragmatic breathing exercise using a DiP Belt(Diaphragmatic Pressure Belt) is effective in increasing the diaphragmatic motion and forced vital capacity. Design: Pretest-Posttest design. Methods: A total of 44 subjects(15 male, 29 female) participated in this study. All subjects were measured the diaphragmatic motion with a sonography and the Forced Vital Capacity(FVC) was measured with a digital spirometer. After 4 weeks, the subjects were intervened the diaphragmatic breathing exercise using a DiP belt and were remeasured for diaphragm motion and FVC. Results: After exercise intervention, quiet breathing significantly increased with the change in diaphragmatic motion and showed a moderate effect size (p<.01, Cohen's d = -0.53). In addition, it was significantly increased in deep breathing and showed a high effect size (p<.001, Cohen's d = -1.32). The mean diaphragmatic contraction pressure increased, but there was no significant difference and the peak diaphragmatic contraction pressure increased significantly (p<.05). Both diaphragmatic contraction pressure showed small effect sizes (respectively Cohen's d = -0.28, -0.33). In spirometry, FVC, Forced Expiratory Volume in 1 second (FEV₁), and FEV₁/FVC% all increased, but there was no significant difference. Only peak expiratory flow increased significantly and showed a small effect size (p<.05, Cohen's d = -0.41). Conclusion: The DiP belt diaphragmatic breathing exercise that the principle of visual feedback can correct diaphragm breathing in a short time, so it is a useful breathing exercise device that can help the diaphragm breathing exercise in the right way in clinical practice.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.140-143
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• 2004

To appropriately control or compensate breathing motion of targets in thorax or abdomen during radiotherapy is still demanding. Our idea is that a visual signal may help regulate patient's breathing pattern, by controlling its amplitude and cycle. The system involving breathing control with a visual signal for aperture maneuver with controlled breath (AMC) has been developed. A thermocouple is used to detect the temperature change due to patient's breathing. The system also consists of a mask, in which the thermocouple is installed, an operational amplifier, a converter, etc. Patients were instructed to control their respiration by breathing following the visuals signal, as watching a display that shows both patients' current breathing pattern and the signal. The patterns of patients' controlled breathing and the signals coincided well. Therefore, when AMC technique is applied, a target moves in the range that is 60 % less than the range of free breathing motion with the help of the system and so target margins can be reduced significantly. This study reveals that a visual signal is not only useful to control patient's breathing but also clinically effective.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.527-533
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• 2000

It is investigated that the characteristics of rotating cantilevered composite beam with a breathing crack. In the present study, the crack is modeled as a breathing crack which opens and closes with the motion of the unidirectional graphite-fiber reinforced polyimide beam. For the finite element analysis, the cracked element is modelled by the local flexibility matrix calculated on the basis of fracture mechanics using Castiligano theorem. Rotating beam is considered only transverse bending motion so that the element includes two degrees of freedom per node such as the transverse deflection and slope. The time history and frequency response function of the beam with a breathing crack are studied by Newmark direct time integration method and FFT(Fast Fourier Transform)simulation. Effects of various parameters such as the crack depths, crack locations, ply angles, volume fraction ratios, and rotating speeds of the beam are also studied. Numerical results indicate that it is more reliable to be modelled as a breathing crack than an open crack.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.1-5
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• 2021

Sleep apnea refers to a condition in which a person does not breathe during sleep, and is a dangerous symptom that blocks oxygen supply in the body, causing various complications, and the elderly and infants can die if severe. In this paper, we present an algorithm that classifies sleep breathing by analyzing the intensity of breathing with images alone in preparation for the risk of sleep apnea. Only the chest of the person being measured is set to the Region of Interest (ROI) to determine the breathing strength by the differential image within the corresponding ROI area. The adult was selected as the target of the measurement and the breathing strength was measured accurately, and the difference in breathing intensity was also distinguished using depth information. Two videos of sleeping babies also show that even microscopic breathing motions smaller than adults can be detected, which is also expected to help prevent infant death syndrome (SIDS).

• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.71-77
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• 2018

Purpose: To develop a two-dimensional (2D) image-based respiratory motion correction technique for free-breathing coronary magnetic resonance angiography (MRA). Materials and Methods: The proposed respiratory navigator obtained aliased a 2D sagittal image from under-sampled k-space data and utilized motion correlation between the aliased images. The proposed navigator was incorporated into the conventional coronary MRA sequence including the diaphragm navigator and tested in three healthy subjects. Results: The delineation of major coronary arteries was significantly improved using the proposed 2D motion correction (S/I and A/P) compared to one-dimensional (S/I) correction using the conventional diaphragm navigator. Conclusion: The 2D image-based respiratory navigator was proposed for free-breathing coronary angiography and showed the potential for improving respiratory motion correction compared to the conventional 1D correction.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.85-93
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• 2012

Purpose: It is essential to minimize the respiratory-induced motion of involved organs in the Tomotherapy for tumor located in the chest and abdominal region. However, the application of breathing control system to Tomotherapy is limited. This study was aimed to investigate the possible application of the ABCHES system and its efficacy as a means of breathing control in the tomotherapy treatment. Materials and Methods: Five subjects who were treated with a Hi-Art Tomotherapy system for lung, liver, gallbladder and pancreatic tumors. All patients undertook trained on two breathing methodes using an ABCHES, free breathing methode and shallow breathing methode. When the patients could carry out the breathing control, 4D-CT scan was a total of 10 4D tomographic images were acquired. A radiologist resident manually drew the tumor region, including surrounding nomal organs, on each of CT images at the inhalation phase, the exhalation phase and the 40% phase (mid-inhalation) and average CT image. Those CT images were then exported to the Tomotherapy planning station. Data exported from the Tomotherapy planning station was analyzed to quantify characteristics of dose-volume histograms and motion of tumors. Organ motions under free breathing and shallow breathing were examined six directions, respectively. Radiation exposure to the surrounding organs were also measured and compared. Results: Organ motion is in the six directions with more than a 5 mm displacement. A total of 12 Organ motions occurred during free breathing while organ motions decreased to 2 times during shallow breathing under the use of Abches. Based on the quantitative analysis of the dose-volume histograms shallow breathing showed lower resulting values, compared to free breathing, in every measure. That is, treatment volume, the dose of radiation to the tumor and two surrounding normal organs (mean doses), the volume of healthy tissue exposed to radiation were lower at the shallow breathing state. Conclusion: This study proposes that the use of ABCHES is effective for the Tomotherapy treatment as it makes shortness of breathing easy for patients. Respiratory-induced tumor motion is minimized, and radiation exposure to surrounding normal tissues is also reduced as a result.

• Journal of Biomedical Engineering Research
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• v.29 no.4
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• pp.323-328
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• 2008

A patient with respiratory disorders such as a sleep apnea is increasing as the obese patient increase on the modern society. Positive Airway Pressure (PAP) devices are used in curing patient with respiratory disorders and turn out to be efficacious for patients of 75%. However, these devices are required for evaluating their performance to improve their performance by the mechanical breathing simulator. Recently, the mechanical breathing simulator was studied by the real time feedback control. However, the mechanical breathing simulator by an open loop control was specially required in order to analyze the effect of flow rate and pressure after operating the breathing auxiliary devices. Therefore the aims of this study were to make the mechanical breathing simulator by a piston motion and a valve function from the characteristic test of valve and motor, and to duplicate the flow rate and pressure profiles of some breathing patterns: normal and three disorder patterns. The mechanical simulator is composed cylinder, valve, ball screw and the motor. Also, the characteristic test of the motor and the valve were accomplished in order to define the relationship between the characteristics of simulator and the breathing profiles. Then, the flow rate and pressure profile of human breathing patterns were duplicated by the control of motor and valve. The result showed that the simulator reasonably duplicated the characteristics of human patterns: normal, obstructive sleep apnea (OSA), mild hypopnea with snore and mouth expiration patterns. However, we need to improve this simulator in detail and to validate this method for other patterns.

• Journal of Korea Multimedia Society
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• v.21 no.9
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• pp.1076-1089
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• 2018

Respiration is the process of moving air into and out of the lung. Respiration changes the temperature in the chamber while exchanging energy. Especially the temperature of the face. Respiration monitoring using an infrared camera measures the temperature change caused by breathing. The conventional method assumes that motion is not considered and measures respiration. These assumptions can not accurately measure the respiration rate when breathing moves. In addition, the respiration rate measurement is performed by counting the number of peaks of the breathing waveform by displaying the position of the peak in a specific window, and there is a disadvantage that the breathing rate can not be measured accurately. In this paper, we use KLT tracking and block matching to calibrate limited weak movements during breathing and extract respiration waveform. In order to increase the accuracy of the respiration rate, the position of the peak used in the breath calculation is calculated by converting from a single point to a high resolution. Through this process, the respiration signal could be extracted even in weak motion, and the respiration rate could be measured robustly even in various time windows.

• Progress in Medical Physics
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• v.25 no.2
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• pp.72-78
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• 2014

The aim of the study is to test a hypothesis that quasi-breath-hold (QBH) biofeedback improves the residual respiratory motion management in gated 3D thoracic MR imaging, reducing respiratory motion artifacts with insignificant acquisition time alteration. To test the hypothesis five healthy human subjects underwent two gated MR imaging studies based on a T2 weighted SPACE MR pulse sequence using a respiratory navigator of a 3T Siemens MRI: one under free breathing and the other under QBH biofeedback breathing. The QBH biofeedback system utilized the external marker position on the abdomen obtained with an RPM system (Real-time Position Management, Varian) to audio-visually guide a human subject for 2s breath-hold at 90% exhalation position in each respiratory cycle. The improvement in the upper liver breath-hold motion reproducibility within the gating window using the QBH biofeedback system has been assessed for a group of volunteers. We assessed the residual respiratory motion management within the gating window and respiratory motion artifacts in 3D thoracic MRI both with/without QBH biofeedback. In addition, the RMSE (root mean square error) of abdominal displacement has been investigated. The QBH biofeedback reduced the residual upper liver motion within the gating window during MR acquisitions (~6 minutes) compared to that for free breathing, resulting in the reduction of respiratory motion artifacts in lung and liver of gated 3D thoracic MR images. The abdominal motion reduction in the gated window was consistent with the residual motion reduction of the diaphragm with QBH biofeedback. Consequently, average RMSE (root mean square error) of abdominal displacement obtained from the RPM has been also reduced from 2.0 mm of free breathing to 0.7 mm of QBH biofeedback breathing over the entire cycle (67% reduction, p-value=0.02) and from 1.7 mm of free breathing to 0.7 mm of QBH biofeedback breathing in the gated window (58% reduction, p-value=0.14). The average baseline drift obtained using a linear fit was reduced from 5.5 mm/min with free breathing to 0.6 mm/min (89% reduction, p-value=0.017) with QBH biofeedback. The study demonstrated that the QBH biofeedback improved the upper liver breath-hold motion reproducibility during the gated 3D thoracic MR imaging. This system can provide clinically applicable motion management of the internal anatomy for gated medical imaging as well as gated radiotherapy.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1044-1053
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• 2021

Objective: Motion-corrected averaging with a single-shot technique was introduced for faster acquisition of late-gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging while free-breathing. We aimed to evaluate the image quality (IQ) of free-breathing motion-corrected single-shot LGE (moco-ss-LGE) in patients with hypertrophic cardiomyopathy (HCM). Materials and Methods: Between April and December 2019, 30 patients (23 men; median age, 48.5; interquartile range [IQR], 36.5-61.3) with HCM were prospectively enrolled. Breath-held single-shot LGE (bh-ss-LGE) and free-breathing moco-ss-LGE images were acquired in random order on a 3T MR system. Semi-quantitative IQ scores, contrast-to-noise ratios (CNRs), and quantitative size of myocardial scar were assessed on pairs of bh-ss-LGE and moco-ss-LGE. The mean ± standard deviation of the parameters was obtained. The results were compared using the Wilcoxon signed-rank test. Results: The moco-ss-LGE images had better IQ scores than the bh-ss-LGE images (4.55 ± 0.55 vs. 3.68 ± 0.45, p < 0.001). The CNR of the scar to the remote myocardium (34.46 ± 11.85 vs. 26.13 ± 10.04, p < 0.001), scar to left ventricle (LV) cavity (13.09 ± 7.95 vs. 9.84 ± 6.65, p = 0.030), and LV cavity to remote myocardium (33.12 ± 15.53 vs. 22.69 ± 11.27, p < 0.001) were consistently greater for moco-ss-LGE images than for bh-ss-LGE images. Measurements of scar size did not differ significantly between LGE pairs using the following three different quantification methods: 1) full width at half-maximum method; 23.84 ± 12.88% vs. 24.05 ± 12.81% (p = 0.820), 2) 6-standard deviation method, 15.14 ± 10.78% vs. 15.99 ± 10.99% (p = 0.186), and 3) 3-standard deviation method; 36.51 ± 17.60% vs. 37.50 ± 17.90% (p = 0.785). Conclusion: Motion-corrected averaging may allow for superior IQ and CNRs with free-breathing in single-shot LGE imaging, with a herald of free-breathing moco-ss-LGE as the scar imaging technique of choice for clinical practice.