• 한국정보전자통신기술학회논문지
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• 제2권3호
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• pp.23-29
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• 2009

심박수는 심장이 혈액을 전신에 보낼 때에 고동치는 속도, 즉 매 분당 박동수를 말하 며 성인남자의 경우 보통 1분동안 60~80회가 정상적이다. 심박수가 정상보다 적으면 서맥, 많으면 빈맥이라 하며 이 경우 여러 가지 질병에 걸릴 수 있으며 상황에 따라 사망에 이르기까지도 한다. 따라서 심박수는 건강한 생활에 매우 중요한 역할을 하고 있다. 본 연구에서는 ECG를 통하여 심박수를 자동 추출하는 방법에 관하여 연구하였다. 육안으로 측정한 심박수를 기준으로 첫째 ECG를 2차 미분을 이용하여 심박수를 추출하는 방법과 자기상관함수를 이용하여 심박수를 추출한 방법으로 구한 심박수를 비교하여 고찰 하였다. 실험 데이터는 MIT/BIH Database를 이용하였다.

• 전기학회논문지
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• 제67권6호
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• pp.794-798
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• 2018

There is a growing need for a care system that can continuously monitor, manage and effectively relieve stress for modern people. In recent years, mobile healthcare devices capable of measuring heart rate have become popular, and many stress monitoring techniques using heart rate variability analysis have been actively proposed and commercialized. In addition, respiratory biofeedback methods are used to provide stress relieving services in environments using mobile healthcare devices. In this case, breathing information should be measured well to assess whether the user is doing well in biofeedback training. In this study, we extracted the heart beat interval signal from the PPG and used the oscillator based notch filter based on the IIR band pass filter to track the strongest frequency in the heart beat interval signal. The respiration signal was then estimated by filtering the heart beat interval signal with this frequency as the center frequency. Experimental results showed that the number of breathing could be measured accurately when the subject was guided to take a deep breath. Also, in the timeing measurement of inspiration and expiration, a time delay of about 1 second occurred. It is expected that this will provide a respiratory biofeedback service that can assess whether or not breathing exercise are performed well.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.27.1-27.7
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• 2015

The aim of this study was to evaluate the clinical relevance of autogenous fresh demineralized tooth (Auto-FDT) prepared at chairside immediately after extraction for socket preservation. Teeth were processed to graft materials in block, chip, or powder types immediately after extraction. Extraction sockets were filled with these materials and dental implants were installed immediately or after a delay. A panoramic radiograph and a conebeam CT were taken. In two cases, tissue samples were taken for histologic examination. Vertical and horizontal maintenance of alveolar sockets showed some variance depending on the Auto-FDT and barrier membrane types used. Radiographs showed good bony healing. Histologic sections showed that it guided good new bone formation and resorption pattern of the Auto-FDT. This case series shows that Auto-FDT prepared at chairside could be a good material for the preservation of extraction sockets. This study will suggest the possibility of recycling autogenous tooth after immediate extraction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권2호
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• pp.142-150
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• 2006

PURPOSE : The 3rd molar extraction of mandible is common in out-patient office of oral and maxillofacial surgery. And it is dynamic minor operation with changes of vital signs. most of patients are already sensitive about their dental treatment. The changes of emotion are reached to the highest level when patients is laid down to be treated on unit chair. It can be induced to undesirable accidents as to this fear. The undesirable complications are nausea, vomiting, hyperventilation, dyspnea, syncope, shock and so on. The severe changes of vital signs may influence their behavior and make serious medical malpractice or suit such as fracture of dental instruments and injury of proximal area. METHOD AND PATIENTS : A total of 99 selected normal patients were reviewed. Among this, 70 patients(43 men, 27 women with statistical significance) were included in this study. Each steps(pre-anesthesis, 5 minutes after anesthesis, just after mucogingival incision, just after tooth section, just after suture and gauze biting) were investigated for a change of a vital signs. It is analyzed to 2 categories,"Means" and "Tendency". The "Means" is the amount of vital signs changed in comparison with pre-step during operation. That means is the amount of vital changes by each step operation. Next, " Tendency" is changes of vital signs in comparison with step1 during operation. RESULT : This is the changing tendency of vital signs with time. That is active effect of fear and pain. Thus this "Means" and "Tendency" will present a sudden changes of vital signs and it can lead to more safe treatment. CONCLUSION : Thus, the purpose of this study is, through careful operation in each step, to less on patients' complication and increase trust between patient and OMFS. This study is a first article shown with the amount of "Means" and "Tendency" in vital signs, when a third molar of mandible is extracted. This study will be base study of patients with general diseases, because it selected only patients without general diseases.

• 전자공학회논문지B
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• 제31B권2호
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• pp.80-87
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• 1994

Fetal monitoring is a routine procedure to obtain a record of physiologic functions during pregnancy and labor. It is required to determine fetal heart frequency accurately. There are various types of fetal heart rate(FHR) determination and the most frequently applied method is transabdominal Doppler ultrasound. However, in the case of weak or noise corrupted Doppler ultrasound signals, conventional peak detections and the autocorrelation function method have many difficulties to determine FHR precisely. Also the autocorrelation function is effected by threshold level and window size. To solve these problems, the high resolution pitch determination algorinthm is introduced to detect FHR from Doppler ultrasound signals. This scheme digitally processes Doppler ultrasound signal for digital rectification, envelope detection, decimation and correlation calculation of two interconnected segments and then FHR is determined by its maximal value. Even in the case of a greatly smeared noise signal, this algorithm is able to search FHR more accurately than autocorrelation function by means of compensating FHR with a constant correlation threshold. This algorithm is simulated by 386-MATLAB on PC 486/DX and verified that it is superior to the autocorrelation function method.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권9호
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• pp.547-553
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• 2003

In this paper, we designed the PC-based analyzer of the power spectral density that could estimate the heart rate variability from time series data of R-R interval. The power spectral density estimated that it applied the autoregressive model to the measured electrocardiogram during a short period. Also, the characteristics of the designed analyzer are that it could process of the signal filtering, the generation and recomposition of time series and the feature extraction at the same time. Especially the analyzer reconstructed which applied the lowpass filter of the time series composed by the linear interpolation so as to enhance the signal-to-noise feature. We could estimate the power spectral density that confirmed a variety of power peak with low frequency range and high frequency rang of autonomic nerve by the heart rate variability.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.231-236
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• 1999

This study was performed to examine 1) Whether hypothermic cardiac arrest produces myocardial HSP72 expression; 2) And if, whether it serves to protect the heart against the subsequent hypothermic arrest. In the present study, neonatal rats were placed in an icebath to induce hypothermia. To determine whether hypothermic cardiac arrest produces myocardial HSP72, experimental animals were subjected to 10-min hypothermic insult before the extraction of the heart. The intervals between the insult and extraction were 1 (1 HR), 4 (4 HR), 8 (8 HR), 24 (24 HR) or 72 (72HR) hours. A minimal amount of HSP72 was detected in control, 1 HR and 72 HR groups. In contrast, 8 HR and 24 HR groups showed a significant level of HSP72 expressions. To assess the cardioprotective effect of HSP72 against hypothermic cardiac arrest, we compared the proportion of recovery from the arrest between control and preconditioned (PREC) animals. Control animals were subjected to 20-min hypothermic insult, while PREC group was preconditioned by 10-min hypothermic insult 8 hours before the 20-min test hypothermic insult. Resuscitation rate from cardiac arrest induced by the 20-min hypothermic insult in PREC group was significantly higher than that in controls. These results suggest that the cardioprotective effect of hypothermic preconditioning is associated with an increase in HSP72 expression.

• 한국음향학회지
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• 제29권2호
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• pp.133-140
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• 2010

연속 심음신호로부터 추출한 새로운 시간영역에서의 특징들을 추가하여 심장질환 분류의 성능을 개선한다. 기존에 사용되고 있는 켑스트럼 영역 특징인 멜주파수 켑스트럼 계수 (MFCC)에 심음 포락선, 심잡음 확률벡터, 심잡음 진폭값 변동으로 구성된 새로운 3종류의 시간영역 특징을 추가한다. 심장 질환 분류 및 검출 실험에서, 시간영역 특징의 분류 정확도에 대한 기여도를 평가하고 순차적 특징선택 방식을 이용하여 시간영역 특징을 선택한다. 선택된 특징들은 다층 퍼셉트론(MLP), support rector machine (SVM), extreme learning machine (ELM)와 같은 신경회로망 패턴 분류기에 대하여 의미있고 일관되게 분류 정확도를 개선함을 보여준다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권6호
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• pp.348-355
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• 2022

Objectives: To compare the vital sign stability and cost of two commonly used sedatives, midazolam (MDZ) and dexmedetomidine (DEX). Patients and Methods: This retrospective study targeted patients who underwent mandibular third molar extractions under intravenous sedation using MDZ or DEX. The predictor variable was the type of sedative used. The primary outcome variables were vital signs (heart rate and blood pressure), vital sign outliers, and cost of the sedatives. A vital sign outlier was defined as a 30% or more change in vital signs during sedation; the fewer changes, the higher the vital sign stability. The secondary outcome variables included the observer's assessment of alertness/sedation scale, level of amnesia, patient satisfaction, and bispectral index score. Covariates were sex, age, body mass index, sleeping time, dental anxiety score, and Pederson scale. Descriptive statistics were computed including propensity score matching (PSM). The P-value was set at 0.05. Results: The study enrolled 185 patients, 103 in the MDZ group and 82 in the DEX group. Based on the data after PSM, the two samples had similar baseline covariates. The sedative effect of both agents was satisfactory. Heart rate outliers were more common with MDZ than with DEX (49.3% vs 22.7%, P=0.001). Heart rate was higher with MDZ (P=0.000). The cost was higher for DEX than for MDZ (29.27±0.00 USD vs 0.37±0.04 USD, P=0.000). Conclusion: DEX showed more vital sign stability, while MDZ was more economical. These results could be used as a reference to guide clinicians during sedative selection.

• 대한치과의사협회지
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• 제45권12호통권463호
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• pp.753-760
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• 2007

노화가 진행되고 있는 중, 장년층의 교정치료시에 통상적인 교정치료의 방법과 함께 다음과 같은 사항을 고려하여야 한다. 1. 치주질환 존재시 교정치료전 치주치료를 선행하여야 한다. 2. 발치 치료가 필요할 경우 치주 상태 및 치아 상태를 고려하여 발치할 치아를 선정하여야 한다. 3. 기존 보철물 존재시 보철물의 상태, 고정원으로 사용여부, 크기 조절 필요 여부, 환자의 경제적 상황 등을 고려햐여 처치한다. 4. 치료 종료 후 가철식 유지장치보다는 고정식 보정장치를 이용하여 치아의 유지력을 보강하는 것이 권장된다.