• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2126-2134
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• 2015

The present study suggests a localization method for the first (S₁) and the second (S₂) feature of heart sounds, based on an algorithm involving frequency filtering, energy detection, and interval regulation. Localization accuracy was evaluated by comparing the algorithm with the traditional Hilbert transform-based localization method. Results show that the sensitivity and the positive predictivity value of proposed method, respectively, were 97.27 % and 99.94 % in S₁ detection and 94.99 % and 100 % in S₂ detection.

• 전기학회논문지
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• 제62권10호
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• pp.1444-1450
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• 2013

Esophageal stethoscope is used for monitoring the heart sounds and breath sounds of patients during surgery under a general anesthesia. Recently, an electronic esophageal stethoscope (EES)[1] has been developed for the purpose of real-time monitoring these information visually. This system uses only a microphone as the sound sensor. A drawback of the EES system is that it may be difficult to distinguish the first sound ($S_1$) and the second sound ($S_2$) of heart, because their periods are irregular depending on patients. In this paper, we propose an improved EES system in which the infrasound is measured by adding a pressure sensor as well as a sound sensor. We investigate some correlations between the infrasound and characteristics of the heart sound. The proposed system has been tested on 15 patients. The results show that the new system is capable of detecting the first sound more reliably and easily determining the heart rate and breathing period.

• 대한한의학원전학회지
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• 제19권2호통권33호
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• pp.97-107
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• 2006

From the study on the relation of voice and O-jang(五臟廳), the conclusion is as follows. The function of breathing out in larynx is involved with lung and kidney. Lung press out the air, at the same time, kidney supports that to maintenance the density of air constantly. So the person who has short breathing can not make strong voice, and also if having a weak kidney in upper Cho[下蕉], their voice will be changed so very softly to cannot make hard type of voice and lingering sounds. Opening and Closing of vocal cords are controled by liver and spleen. when vocal cords are contracted, liver makes tension, whereas spleen does in slackness. So liver is likely to make high-piched sounds in tension of vocal cords, and spleen is the same to do smoothy and husky sounds through relaxing the vocal cords. In the rising condition of liver function, the temp of speech become fast, and more the pronunciation is clearer, it means that the function of thinking by spleen is operated well. Otherwise, indistinct pronunciation means that in the body seup-sa(濕邪) spreads. Also depression of emotion in speech often makes Gi(氣) of heart weaker, whereas it means regular condition of heart including Simpo(心包) that expression of emotion looks happy.

• The Journal of the Acoustical Society of Korea
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• 제28권2E호
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• pp.72-78
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• 2009

Heart sound segmentation into its components, S1, systole, S2 and diastole is the first step of analysis and the most important part in the automatic diagnosis of heart sounds. Conventionally, the Shannon energy envelope peak detection method has been popularly used due to its superior performance in locating S1 and S2. Recently, the HMM has been shown to be quite suitable in modeling the heart sound signal and its use in segmenting the heart sound signal has been suggested with some success. In this paper, we compared the two methods for heart sound segmentation using a common database. Experimental tests carried out on the 4 different types of heart sound signals showed that the segmentation accuracy relative to the manual segmentation was 97.4% in the HMM based method which was larger than 91.5% in the peak detection method.

• 감성과학
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• 제18권3호
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• pp.63-70
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• 2015

본 연구는 1/f fluctuation의 ${\alpha}$기울기 따라 구성된 사운드를 들었을 때 감정 스트레스 업무에 종사하고 있는 피험자들의 심박 변화를 확인하고자 하였다. 기존의 연구에서는 주로 사용자의 심리상태 안정시키는 효과 또는 생리적 안정성에 1/f fluctuation의 ${\alpha}$기울기가 관계가 있는 것으로 보고되었다. 본 연구에서는 1/f fluctuation 수준을 총 3가지 나누어 제작한 사운드를 독립변수로 사용하였다. 독립변수는 감정노동 종사자에게 제시하여 그에 따른 심장반응을 측정하였다. 종속변수는 네 가지로 BPM(Beat Per Minute), VLF(Very Low Frequency), SDNN(Standard Deviation of NN intervals), 그리고 HF(High Frequency) 파워(Power)값을 확인하였다. 분석결과 기울기가 3인 1/fluctuation 사운드는 각성효과를 보였다. 기울기 1, 2인 사운드는 이완효과가 있는 것을 통계적으로 검증하였다. 이러한 1/f fluctuation 사운드의 특성을 활용해 감정 노동자들의 스트레스를 완화시키기 위한 서비스에 응용될 수 있을 것으로 사료된다.

• Fibers and Polymers
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• 제7권4호
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• pp.450-456
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• 2006

The objectives of this study were to investigate physiological and psychological responses to the rustling sound of Korean traditional silk fabrics and to figure out objective measurements such as sound parameters and mechanical properties determining the human responses. Five different traditional silk fabrics were selected by cluster analysis and their sound characteristics were observed in terms of FFT spectra and some calculated sound parameters including level pressure of total sound (LPT), Zwicker's psychoacoustic parameters - loudness(Z), sharpness(Z), roughness(Z), and fluctuation strength(Z), and sound color factors such as ${\Delta}L\;and\;{\Delta}f$. As physiological signals, the ratio of low frequency to high frequency (LF/HF) from the power spectrum of heart rate variability, pulse volume (PV), heart rate (HR), and skin conductance level (SCL) evoked by the fabric sounds were measured from thirty participants. Also, seven aspects of psychological state including softness, loudness, sharpness, roughness, clearness, highness, and pleasantness were evaluated when each sound was presented. The traditional silk fabric sounds were likely to be felt as soft and pleasant rather than clear and high, which seemed to evoke less change of both LF/HF and SCL indicating a negative sensation than other fabrics previously reported. As fluctuation strength(Z) were higher and bending rigidity (B) values lower, the fabrics tended to be perceived as sounding softer, which resulted in increase of PV changes. The higher LPT was concerned with higher rating for subjective loudness so that HR was more increased. Also, compression linearity (LC) affected subjective pleasantness positively, which caused less changes of HR. Therefore, we concluded that such objective measurements as LPT, fluctuation strength(Z), bending rigidity (B), and compression linearity (LC) were significant factors affecting physiological and psychological responses to the sounds of Korean traditional silk fabrics.

• 전자공학회논문지SC
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• 제47권1호
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• pp.47-55
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• 2010

심음은 심질환을 진단하는 1차적인 수단이지만 비정상 심음인 S2에서 A2와 P2의 분열 신호와 S2에 S3의 분마음 간섭 신호는 전문 의사들조차 청각적으로 구분하기 쉽지 않아 초기 진단에 어려움이 있다. 본 논문에서는 청각적으로 구분이 어려운 심음들을 분류하기 위해 PCG 신호의 주파수 특성에 적합한 분석 및 합성 방법을 제안한다. 제안한 방법은 심음을 매칭 퍼슈잇으로 분해한 후 주파수 특성에 맞게 대역별로 합성하여 분석함으로써 청진으로 구분이 어려운 신호를 다른 상태의 심음과 구별한다. 실험 결과 분석을 통해 초기 진단 시 불명확한 S2의 분열 유무, S2의 분열 상태, 그리고 S3의 분마음 간섭 신호를 구별할 수 있었으며 분열의 정확한 시간 간격을 확인할 수 있었다.

• 한국멀티미디어학회논문지
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• 제19권3호
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• pp.557-566
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• 2016

Heart sounds generated by the beating heart and blood flow reflect the turbulence created when the heart valves snap shut. Cardiac diagnosis is typically started by an auscultation using a stethoscope, from which a medical doctor, depending on his hearing capabilities and training, listens and interprets the acoustic signal. This method of diagnostic is uncertain, mostly due to the fact that human ear loses the acoustic frequency sensitivity through the years. Even though an auscultation has some weaknesses like uncertainty, it is considered as a primary tool due to its simplicity. In this paper, heart murmur detection algorithm is proposed using time and frequency characteristics of heart sound. The propose heart murmur detection method adapted conventional primary heart sound detection method in time domain and modified spectral flatness method in frequency domain for detecting heart murmurs. From experimental results, it is confirmed that the proposed algorithm detect the heart murmurs efficiently.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권4호
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• pp.367-374
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• 2007

Purpose: The diagnostic relevancies and characteristics and of clinical methods in the diagnosis of internal derangement(ID) were tested by comparing the results of them with those of magnetic resonance imaging(MRI). Methods: 75 patients(150 temporomandibular joints; TMJs), who were suspected to have ID by clinical diagnoses, were included. Clinical diagnoses including mouth opening pathway and TMJ sound were conducted and MRI takings were done. Accuracies, sensitivities, specificities, positive predictive values, and negative predictive values of clinical diagnosis, mouth opening pathway, and TMJ sound were calculated by comparing with diagnoses with MRIs. Results: Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of clinical diagnosis were 59.3%, 83%, 49%, 81%, and 51%. They were 59%, 82%, 25%, 73%, and 35% for mouth opening pathways. Although deviation was somewhat accurate for representing disc displacement with reduction(ADDWR), other discrepancies on opening pathways were not clinically relevant. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of clicking sounds were 85%, 49%, 78%, 85%, and 37%. TMJs with crepitus were only three. But all TMJs with crepitus were diagnosed to have disc displacement without reduction(ADDWOR). Conclusion: When compared with diagnoses with MRIs, clinical diagnoses for ID were not so accurate. But they were suitable for screening tests for ID. Opening pathways and TMJ sounds were not so relevant in the diagnoses of IDs and so it was concluded that considerations for other factors must be included in the diagnoses of IDs.

• 한국임상수의학회지
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• 제16권2호
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• pp.478-481
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• 1999

A 8 years old male Pomeranian weighing 4 kg was referred because of coughing of 4 months' duration. Heart sounds and cardiac apex beat were showed more intense on the right side. On radiographic views, loss of normal line of the diaphragm, gas-containing intestines and stomach in thoracic cavity, and right displacement of heart were observed. Ultrasonography revealed that liver located adjacent to the heart. Although the dog died due to severe respiratory disorder in surgical procedure, in thoracic and abdominal surgery, a large defect was found in the left and right ventral muscular portion and left central tendon of the diaphragm, extending from the esophageal hiatus to rib. Left and right cranial lobe of liver, small intestines, stomach and spleen were herniated in the thoracic cavity. Because of the size and chronicity of the defect in the diaphragm, closure was impossible with an abdominal muscle graft.