• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.1 s.119
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• pp.1-7
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• 2007

Internal fibrillation of pulp fiber is an important factor affecting paper properties. Internal fibrillation of pulp fiber is usually introduced with several kinds of modifications of fiber by the mechanical treatment such as refining, high shear and/or high consistency mixing, etc. Unfortunately there are no standardized methods that can characterize the extent of internal fibrillation and its contribution on the paper properties. The purpose of this study is to try and find the potential methods that can characterize the internal fibrillation of pulp fiber quantitatively. Softwood bleached kraft pulp was treated with Hobart mixer to introduce the internal fibrillation without the significant fiber damage and external fibrillation. The extent of internal fibrillation was increased with the increase of mechanical treatment consistency. Several fiber properties were measured to find the potential means that could characterize and quantity the internal fibrillation. Laminated area could not be used as a means for quantifying the internal fibrillation because of the effect of swelling and the different internal fibrillation behavior at different mechanical treatment consistency. Micro and macro internal fibrillation models were proposed for describing the different behavior for the mechanical treatment at low and high consistencies of pulp. The Internal fibrillation showed good correlation with swelling of fiber wall. This trend was confirmed through the measurement of wall thickness and/or cross section area of fiber. Therefore the internal fibrillation possibly can be described as the indices indicating the change of wall thickness and/or cross section area.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.4
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• pp.665-672
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• 2001

Fibrillation is caused by wet abrasion and occurs during scouring treatments, domestic laundering and wet finishing. So, for clean fabrics, fibrillation must either be prevented or removed after it has occurred. In this study, we researched the influence thickness of tencel on fibrillation occurrence. And the three methods of SEM photograph, reflectance values and gray level values were used in order to present proper evaluation method for fibrillation. The results are as follows. The thickness of tencel was high affected with occurrence of fibrillation, that is, as the thickness of fabrics thicker, the fibrillation occurer. And all method applicated as fibrillation evaluation method very effected without big difference, but they come into be a little question in the side of exactness.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.249-258
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• 2021

The aim of this study was to determine the level of knowledge related to disease in patients with atrial fibrillation. We used the Jessa Atrial fibrillation Knowledge Questionnaire (JAKQ) and Knowledge of Atrial Fibrillation and Stroke Prevention Questionnaire(KAFSP). A total of 222 AF patients completed the JAKQ and KAFSP. The mean score of the JAKQ and KAFSP 54.7 and 18.5 points, respectively. In general, patients with Atrial fibrillation were well aware that atrial fibrillation causes stroke and that anticoagulants should be taken to prevent blood clots. However, they were not well aware of the precautions for taking anticoagulants, symptoms of atrial fibrillation, and treatment of atrial fibrillation. There was no statistically significant difference in atrial fibrillation knowledge score according to anticoagulants but the degree of knowledge related to VKA was low in patients taking VKA. The both score of JAKQ and KAFSP had significant differences in atrial fibrillation knowledge depending on the level of education. Based on these finding, it is necessary to develop a customized education program in order to improve the knowledge of patients with atrial fibrillation.

• Journal of Chest Surgery
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• v.25 no.12
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• pp.1404-1415
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• 1992

To understand the factors influencing Atrial fibrillation and embolism in mitral valve surgery and prevent their risk, we have reviewed our 324 patients who underwent mitral valve surgery from Fev. 1982 to May 1992. Age, disease duration, lesion type, left ventricular function and left atrial dimension were chosen as preoperative factors influencing the incidence of atrial fibrillation and embolism and their postoperative course, The number and type of replaced valve, site of atriotmy, LA obliteration, ACT and use of Defibrillator were chaser. as operative factors influencing postoperative rhythm change and postop emb-olization. The results of analyses were as follows 1. The incidence of preoperative atrial fibrillation, systemic embolism and LA throbmus was 63. 6%, 10.56% and 19.8% relatively. 2. The preoperative factors of atrial fibrillation onset was old age, prolonged symptom duration, stenotic lesion, lager LAD and lower ejection fraction. In the preoperative systemic embolism preoperative factors were old age, female, stenotic lesion. The left atrial thrombus found more commonly in patients with atrial fibrillation, old age, prolonged symptom duration, stenotic lesion and low ejection fraction. 3. The preoperative atrial fibriation persisted postoperatively in 165[50.9%] and converted to normal sinus rhythm in 50[15.4%]. The preoperative normal sinus rhythm per-eisted in 100[31%] and atrial fibrillation was occured postoperatively in 9[2.7%]. The prolonged symptom duration was the preoperative factor of persist atrial fibrillation. 4. Among 95 long term follow-up patients, atiral fibrillation was continued in 59[60%]. Conversion to normal sinus rhythm was more common significantly in left atriotomy and bileaflet valve replacement. 5. There were 12 patients who had postoperative embolism. Female, persist atrial fibrillation, no LA olbiteration and tilting disc monocusp valve were considered as possible factors influencing postoperative embolism but was impossible to analyse their statistical significance due to small sample size. So we have concluded that the patients with above risk factors need anticoagulant and early surgical intervention. Left atriotomy with minimal atrial injury, left auricular obliteration and bileaflet valve replacement may be needed to reduce postoperative atrial fibrillation persist and embolism.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1230-1233
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• 1998

The Cox-Maze procedure was developed as a cure for atrial fibrillation. The recovery rate of both atrial contractility is reported low in the atrial fibrillation associated with mitral valvular heart disease than that of loan atrial fibrillation. We performed the Cox-Maze procedure (Maze III) in three cases who suffered from non-mitral heart diseases associated with atrial fibrillation: A ruptured sinus of Valsalva aneurysm, a ventricular septal defect, and an aortic stenoinsufficiency. The Cox-Maze procedure was performed concomitantly with correction of the underlying heart disease. Conversion to sinus rhythm was achieved in all three patients, and both right and left atrial mechanical activities could be identified echocardiographically after three postoperative months.

• Journal of Sasang Constitutional Medicine
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• v.16 no.3
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• pp.114-117
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• 2004

1. Objectives As we advance to senior society the incidence rate of heart disease such as atrial fibrillation grows higher. These heart disease can also be treated by Sasang constitutional medical diagnosis and treatment. 2. Methods There is one case-report of the patient who has severe atrial fibrillation and was treated with Sasang constitutional medicine and Westen medicine as well. 3. Results The patient had shown remarkable clinical effects, especially when Sasang Constitutional Medical treatment was practiced. 4. Conclusions Thus we report the healing process and result of this atrial fibrillation.

• Journal of Korean Neurosurgical Society
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• v.53 no.6
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• pp.368-370
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• 2013

Post-stroke atrial fibrillation has been frequently reported especially in the patients with right insular infarct as an evidence of cerebrogenic mechanism affecting on cardiac rhythm. However, conversion to normal sinus rhythm after stroke in patients who had atrial fibrillation has not been reported. A 88-year-old men who had untreated atrial fibrillation was admitted to hospital due to left middle cerebral artery territory infarction. During admission, second ischemic attack occurred in right middle cerebral artery territory. At that time, his atrial fibrillation converted spontaneously to normal sinus rhythm. Restored sinus rhythm sustained until he died due to sepsis. This case is evidence supporting a theory that brain is associated with control of cardiac rhythm. If no risk factor is revealed by intensive investigation in patients with acute cerebral infarctions that cardioembolism is strongly suspected as a cause, physicians should concern transformation of atrial fibrillation to normal sinus rhythm after stroke.

• Journal of Biomedical Engineering Research
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• v.38 no.3
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• pp.123-128
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• 2017

Background and aims: The KCNQ1 S140G mutation involved in $I_{ks}$ channel is a typical gene mutation affecting atrial fibrillation. However, despite the possibility that the S140G gene mutation may affect not only atrial but also ventricular action potential shape and ventricular responses, there is a lack of research on the relationship between this mutation and ventricular fibrillation. Therefore, in this study, we analyzed the correlation and the influence of the KCNQ1 S140G mutant gene on ventricular fibrillation through computer simulation studies. Method: This study simulated a 3-dimensional ventricular model of the wild type(WT) and the S140G mutant conditions. It was performed by dividing into normal sinus rhythm simulation and reentrant wave propagation simulation. For the sinus rhythm, a ventricular model with Purkinje fiber was used. For the reentrant propagation simulation, a ventricular model was used to confirm the occurrence of spiral wave using S1-S2 protocol. Results: The result showed that 41% shortening of action potential duration(APD) was observed due to augmented $I_{ks}$ current in S140G mutation group. The shortened APD contributed to reduce wavelength 39% in sinus rhythm simulation. The shortened wavelength in cardiac tissue allowed re-entrant circuits to form and increased the probability of sustaining ventricular fibrillation, while ventricular electrical propagation with normal wavelength(20.8 cm in wild type) are unlikely to initiate re-entry. Conclusion: In conclusion, KCNQ1 S140G mutation can reduce the threshold of the re-entrant wave substrate in ventricular cells, increasing the spatial vulnerability of tissue and the sensitivity of the fibrillation. That is, S140G mutation can induce ventricular fibrillation easily. It means that S140G mutant can increase the risk of arrhythmias such as cardiac arrest due to heart failure.

• Journal of Chest Surgery
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• v.31 no.1
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• pp.59-65
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• 1998

Atrial fibrillation is the most common of all cardiac arrhythmias. It is associated with significant morbidity and mortality and is frequently resistant to medical therapy. On the experimental and clinical study, the presence of macroreentrant circuits and the absence of either microreentrant circuits or evidence of atrial automaticity suggests that atrial fibrillation should be amenable to surgical ablation. The results of the maze III procedure are associated with a higher incidence of postoperative sinus rhythm, improved long-term sinus node function, fewer pacemaker requirements, less arrhythmia recurrence, and improved long-term atrial transport function. We had experienced 4 patients with chronic atrial fibrillation. For the first time, Hioki procedure had been performed in the first patient with ASD and atrial fibrillation, regular sinus rhythm showed on postoperative EKG, but junctional rhythm and bradycardia developed postoperative 3 years. The maze III procedure for the rest with mitral valvular disease and atrial fibrillation had been done, followed by regular sinus rhythm for 2 patients and atrial fibrillation for 1 patient, managed with amiodarone, on immediate postoperative state. Echocardiogram documented good contraction of right atrium and hardly contraction of left atrium for 2 patients with regular sinus rhythm postoperative 3 months.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.1047-1054
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• 2012

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice, and its risk increases with age. Conventionally, the way of detecting AF was the time·frequency domain analysis of RR variability. However, the detection of ECG signal is difficult because of the low amplitude of the P wave and the corruption by the noise. Also, the time·frequency domain analysis of RR variability has disadvantage to get the details of irregular RR interval rhythm. In this study, we describe an atrial fibrillation pattern analysis based on symbolization and information entropy. We transformed RR interval data into symbolic sequence through differential partition, analyzed RR interval pattern, quantified the complexity through Shannon entropy and detected atrial fibrillation. The detection algorithm was tested using the threshold between 10ms and 100ms on two databases, namely the MIT-BIH Atrial Fibrillation Database.