• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2391-2398
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• 2009

Premature ventricular contractions are the most common of all arrhythmias and may cause more serious situation in some patients. Therefore, the detection of this arrhythmia becomes crucial in the early diagnosis and prevention of possible life threatening cardiac diseases. Most of the algorithms detecting PVC reported in literature is not always feasible due to the presence of noise and P wave making the detection difficult, and the process being time consuming and ineffective for real time analysis. To solve this problem, a new approach for the detection of PVC is presented based rhythm analysis and beat matching in this paper. For this purpose, the ECG signals are first processed by the usual preprocessing method and R wave was detected. The algorithm that decides beat type using the rhythm analysis of RR interval and beat matching of QRS width is developed. The performance of R wave and PVC detection is evaluated by using MIT-BIH arrhythmia database. The achieved scores indicate sensitivity of 99.74%, positive predictivity of 99.81% and sensitivity of 93.91%, positive predictivity of 96.48% accuracy respectively for R wave and PVC detection.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.47-53
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• 2023

PURPOSE: A visual feedback method was proposed to induce brain stimulation in a stroke patient, and among them, there was a treatment using a mirror. On the other hand, mirror therapy focuses only on the functional changes in body movements, and analysis of neurophysiological mechanisms of brain activity is lacking. In addition, studies on evaluating the activity and response generated in specific brain regions during visual feedback training using mirrors are insufficient. METHODS: Fifteen healthy adults (male: 10, female: 5, Years: 23.33 ± 1.23), who were right-handed were recruited. By attaching the C3, Cz, and C4 channels in the sensorimotor cortex using an electroencephalogram, training was performed under the conditions without mirror-based visual feedback (No-condition) and with visual feedback (Tasks-condition). At this time, the immediate activity of the mu-rhythm in response to training was separated and evaluated. RESULTS: The tasks-condition of C3, Cz, and C4 channels activated the relative mu-rhythm rather than the no-condition, and all showed significant differences (p < .05). In addition, in all channels at the start time, the tasks-condition was more active than the no-condition (p < .05). The activity of the cortical response was higher in the tasks-condition than in the no-condition (p < .05). CONCLUSION: The mu-rhythm activity can be evaluated objectively when visual feedback using a mirror is applied to healthy subjects, and a basic analysis protocol is proposed.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.177-183
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• 2014

The ussur brown katydid, Paratlanticus ussuriensis (Orthoptera: Tettigoniidae), causes substantial damage in orchard areas in South Korea. Daily rhythm and mating behaviors were investigated in last instar nymphs, immature adults and mature adults of P. ussuriensis. The daily rhythm was repeated upon resting, moving, and feeding. The daily rhythm of the movement behavior similar in both last instar nymphs and immature adults. Last instar nymphs becoming active at 10:06 and ceasing activity at 21:12 in average. Immature adults becoming active at 11:30 and ceasing activity at 20:08 in average of totally 10 individuals. However, mature adults showed a different active time of 15:30. Generally, behavior was affected by the conditions of their environment, especially temperature. Mature adults activated later than nymphs and immature adults. Mature adults display mating behavior at a particular time of day (approximately 20:00). P. ussuriensis showed a mating behavioral sequence which was similar to related species in completely retaining the spermatophylax. Females took 270 min to 360 min to completely retain the spermatophylax. The daily rhythm of P. ussuriensis, indicating its occurrence and ecology, could be useful as basic data for managing field populations of P. ussuriensis.

• 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 architectural history
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• v.15 no.2
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• pp.115-136
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• 2006

Colin Rowe's 'Transparency' is one of core ideas applied to 20th Modern Architecture. It implies not only an optical characteristic, the perfectly clear, but also a broader spacial order, a simultaneous perception of different spacial locations. The former connected with physical attribute itself, and the latter deeply with the metaphorical idea of time, 'Simultaneity', embodying a new spacial quality. However, If we analyze the meaning of "Simultaneity" implicated in "Transparency" with the perspective of Henry Bergson's "Duration", there would be only little possibility as a solution to the problem of embodying a new spacial quality in architecture. As such a question emerging, this paper attempts to point out the problem of Colin Rowe's idea, "Simultaneity", and suggest a new architectural design method to overcome its inconsistency by interpretation and application of Bergson's "Image and Rhythm".

• The Journal of Korean Physical Therapy
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• v.25 no.6
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• pp.374-378
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• 2013

Purpose: Human body have biological rhythmic pattern in a day, which is affected by internal and external environmental factors. We investigated whether respiratory function was fluctuated according to the influence of time-of-day (around at 9 am, 1 pm, and 6 pm) in health subjects, using pulmonary function test (PFT). Methods: Eighteen healthy volunteers (8 men, mean ages; $22.4{\pm}1.6$, mean heights; $166.61{\pm}9.60$, mean weight; $59.3{\pm}10.3$) were recruited. Pulmonary function test (PFT) was measured at three time points in day, around 9 am, 1 pm, and 6 pm in calm research room with condition of under 55dB noise level, using a spirometer (Vmax 229, SensorMecis, USA). Forced vital capacity (FVC), forced expiratory volume at one second (FEV1), FVC/FEV1, and peak expiratory flow (PEF) were acquired. Results: In comparison of raw value of PFT among three time points, subjects showed generally better respiratory function at 9 am, than at other points, although no significance was found. In comparison of distribution of ranking for respiratory function in each individual, only PEF showed significant difference. In general, distributional ratio of subjects who showed best performance of respiratory function in a day was high. Conclusion: These findings showed that circadian rhythm by diurnal pattern was not detected on respiratory function throughout all day. But, best performance on respiratory function was observed mostly in the morning, although statistical significance did not exist.

• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.79-85
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• 2018

Objective: This study aimed to create a strategic training method to enhance optimal athletic ability using information from 1H to 10H rhythmic units. Method: Top three world class athletes and three national winners of 110-m hurdle finals from the 2010 Daegu International Athletics Competition and 2017 National Athletics Championship, respectively, were selected. To analyze the kinematic variables, Dartfish 9.0 was used for two-dimensional analysis. Results: Regarding the interval time from the start to the finish line, the national athletes took less time during the pure acceleration phase (start to 1H) than the foreign athletes. The horizontal velocity increase was slower after 1H; the national athletes showed a lack of ability to accelerate at the interval phases. Moreover, the hurdle clearance time between phases was longer in the national athletes than in the foreign athletes and lacked consistency. Conclusion: The national athletes lacked the ability to accelerate at the transition, maximum rhythm, rhythm maintenance, and re-acceleration phases and showed a longer hurdle clearance time. If technical improvements and strategic training methods using rhythmic units are applied for hurdling motions, the national athlete's hurdling abilities, performance, and consistency could improve.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.347-352
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• 1999

Background: The atrial fibrillation in patients with mitral valvular heart disease is frequently converted to sinus rhythm after the mitral valve surgery. This sinus restoration implies an important meaning in that it not only helps postoperative convalescence in patients with unstable hemodynamics but also reduces the rate of postoperative thromboembolism. Material and Method: We retrospectively analyzed 184 patients who received mitral valve surgery from June 1986 to December 1996 to investigate the trend of rhythm change following mitral valve surgery and thus to clarify the predisposing factors of postoperative sinus rhythm conversion and its maintenance. Result: The sinus rhythm was restored after the operation in 54 out of 139 patients with atrial fibrillation preoperatively(38.8%). However, the atrial fibrillation recurred in 41 patients at the time of discharge showing a recurrence rate of 75.9 percent. The mean duration of sinus rhythm in patients with eventual atrial fibrillation recurrence was 8.2${\pm}$5.9 days. Only 15 patients were in sinus rhythm at the time of late follow-up with the mean follow-up period of 84.4${\pm}$34.7 months. While the age, duration of symptoms, duration of atrial fibrillation, left atral size, and pulmonary artery pressure were thought to be the predisposing factors for sinus conversion after the operation, only the duration of atrial fibrillation and ejection fraction were considered risk factors for the recurrence of the atrial fibrillation following sinus conversion. Conclusion: This study suggests that the early operation is mandatory for the satisfactory result regarding postoperative rhythm. Moreover, additional operative measure in adjunct to the intervention of mitral valve should be considered for the maintenance of restored sinus rhythm as reflected by high postoperative recurrence rate of atrial fibrillation.

• Korean Journal of Biological Psychiatry
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• v.24 no.1
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• pp.26-31
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• 2017

Objectives A normal circadian rhythm of autonomic nervous system function stands for the daily change of sympathetic and parasympathetic modulation, which can be measured by heart rate variability (HRV). Generally, patients in the intensive care unit (ICU) are prone to sleep-wake cycle dysregulation, therefore, it may have an influence on the circadian rhythm of autonomic nervous system. This study was designed to interpret possible dysregulation of autonomic nervous system in ICU patients by using HRV. Methods HRV was assessed every 3 hours in 21 ICU patients during a 7-minute period. The statistical differences of HRV features between the morning (AM 6 : 00-PM 12 : 00), and the afternoon (PM 12 : 00-PM 18 : 00) periods were evaluated in time domain and frequency domain. Results Patients showed significantly increased normalized power of low frequencey (nLF), absolute power of low frequencey (LF)/absolute power of high frequencey (HF) in the afternoon period as compared to the morning period. However, normalized power of high frequency (nHF) was significantly decreased in the afternoon period. There was no statistically significant difference between the morning period and the afternoon period in the time domain analysis. Conclusions The increased sympathetic tone in the afternoon period supports possible dysregulation in the circadian rhythm of autonomic nervous system in ICU patients. Future studies can help to interpret the association between autonomic dysregulation and negative outcomes of ICU patients.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.375-382
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• 2021

Adolescents with disabilities have unnatural behavior and language, which makes it difficult to use soft and flexible language and behavior, and lack of learning experience has limitations in not being free in mature behavioral communication. Eurhythmics musical rhythm elements were divided into time and space, power and weight, and balance and fluidity and reflected in teaching and learning so that adolescents with disabilities could have comfortable, creative, and original thoughts that bring about changes in thawing. In order to increase the effectiveness of education in the direction of observing the effect of improving self-esteem, communication, and creativity of adolescents with disabilities, the study guide applying the Eurhythmics rhythm element was fused with music education, art education, and physical education, and interviewed by selecting research participants. Based on the questionnaire, an observation method suitable for the study of adolescents with disabilities was conducted. As a result of the study, it was observed that the educational effect of the disabled youth was improved as a result of conducting the class by applying the Eurhythmics rhythm elements time and space, force and weight, balance and fluidity by integrating music, art, and physical education(line dance, playtime). Therefore, to supplement the limitations in this learning process, various educational methods applicable to the education of youth with disabilities, a support system that can reflect Eurhythmics education through physical play, and a method to properly compose various learning tools do.