• 전기전자학회논문지
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• 제11권1호통권20호
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• pp.24-29
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• 2007

본 연구에서 심리적으로 안정된 상태에서 맥율을 측정할 수 있는 장치를 개발하였다. 개발된 시스템은 뇌파, 호흡파, 맥동파를 검출하는 하드웨어장치와 이들 신호를 획득하고 처리하는 소프트웨어로 구성하였다. 뇌파는 전두부에서 쌍극형으로 유도하였고, 호흡은 서미스터 브리지를 이용하여 구성된 변환기를 사용하여 비강 전부에서 유도하였으며 맥동파는 귀볼에서 유도한 용적맥파를 사용하였다. 피검자의 심리적 안정된 상태의 판정은 뇌파의 스펙트럼을 이용하였다. 맥율의 결정은 원전에 따라 1호흡 당 맥동수를 사용하였다. 개발된 장치를 사용하여 맥율검출 실험을 한 결과, 뇌파의 주파수 대역별 구분, 안정된 호흡신호의 검출과 이득 조절이 되는 용적맥파의 검출이 실시간으로 가능하였다. 그리고 검출된 신호로부터 맥율을 검출할 수 있었다.

• Journal of Korean Biological Nursing Science
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• 제17권3호
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• pp.271-276
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• 2015

Purpose: This study was to evaluate the effects on the heart rate and respiration rate of preterm infants when providing auditory stimulation on them. Methods: The design of this study was a nonequivalent control group pretest-posttest design in a quasi experimental study. Forty preterm infants were assigned to experimental and control groups : 20 in the auditory and 20 in the control group. The data were collected from May 2014 to October. The auditory stimulation was created by using an audio music tape provided 20-minute per day for 7 consecutive days. In data analysis, SPSS WIN 21.0 program was utilized for descriptive statistics, repeated measurement anova and Mann-Whitney. Results: General characteristics of the two groups showed no significant differences, thus two groups were found to be homogenous. There were no significant differences in heart rate and respiration rate between the auditory and control groups. Conclusion: The effect of auditory stimulation for 7 days was not effective in decreasing heart rate or respiration rate in premature infants. Therefore, the type and length of music therapy must be developed for the improvement of vital signs in preterm infants who were hospitalized in a neonatal intensive care unit.

• Journal of Ecology and Environment
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• 제34권4호
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• pp.411-423
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• 2011

This study was conducted to quantify soil $CO_2$ efflux using the continuous measurement method and to examine the applicability of an automatic continuous measurement system in a Korean deciduous broad-leaved forest. Soil respiration rate (Rs) was assessed through continuous measurements during the 2004-2005 full growing seasons using an automatic opening/closing chamber system in sections of a Gwangneung temperate deciduous forest, Korea. The study site was an old-growth natural mixed deciduous forest approximately 80 years old. For each full growth season, the annual Rs, which had a gap that was filled with data using an exponential function derived from soil temperature (Ts) at 5-cm depth, and Rs values collected in each season were 2,738.1 g $CO_2$ $m^{-2}y^{-1}$ in 2004 and 3,355.1 g $CO_2$ $m^{-2}y^{-1}$ in 2005. However, the diurnal variation in Rs showed stronger correlations with Ts (r = 0.91, P < 0.001 in 2004, r = 0.87, P < 0.001 in 2005) and air temperature (Ta) (r = 0.84, P < 0.001 in 2004, r = 0.79, P < 0.001 in 2005) than with deep Ts during the spring season. However, the temperature functions derived from the Ts at various depths of 0, -2, -5, -10, and -20 cm revealed that the correlation coefficient decreased with increasing soil depth in the spring season, whereas it increased in the summer. Rs showed a weak correlation with precipitation (r = 0.25, P < 0.01) and soil water content (r = 0.28, P < 0.05). Additionally, the diurnal change in Rs revealed a higher correlation with Ta than that of Ts. The $Q_{10}$ values from spring to winter were calculated from each season's dataset and were 3.2, 1.5, 7.4, and 2.7 in 2004 and 6.0, 3.1, 3.0, and 2.6 in 2005; thus, showing high fluctuation within each season. The applicability of an automatic continuous system was demonstrated for collecting a high resolution soil $CO_2$ efflux dataset under various environmental conditions.

• Journal of Ecology and Environment
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• 제42권4호
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• pp.272-277
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• 2018

Background: Studying the ecosystem carbon cycle requires analysis of interrelationships between soil respiration (Rs) and the environment to evaluate the balance. Various methods and instruments have been used to measure Rs. The closed chamber method, which is currently widely used to determine Rs, creates a closed space on the soil surface, measures $CO_2$ concentration in the inner space, and calculates Rs from the increase. Accordingly, the method is divided into automatic or manual chamber methods (ACM and MCM, respectively). However, errors of these methods and differences in instruments are unclear. Therefore, we evaluated the characteristics and difference of Rs values calculated using both methods with actual data. Results: Both methods determined seasonal variation patterns of Rs, reflecting overall changes in soil temperature (Ts). ACM clearly showed detailed changes in Rs, but MCM did not, because such small changes are unknown as Rs values are collected monthly. Additionally, Rs measured using MCM was higher than that using ACM and differed depending on measured plots, but showed similar tendencies with all measurement times and plots. Contrastingly, MCM Rs values in August for plot 4 were very high compared with ACM Rs values because of soil disturbances that easily occur during MCM measurements. Comparing Rs values calculated using monthly means with those calculated using MCM, the ACM calculated values for monthly averages were higher or lower than those of similar measurement times using the MCM. The difference between the ACM and MCM was attributed to greater or lesser differences. These Rs values estimated the carbon released into the atmosphere during measurement periods to be approximately 57% higher with MCM than with ACM, at 5.1 and $7.9C\;ton\;ha^{-1}$, respectively. Conclusion: ACM calculated average values based on various Rs values as high and low for measurement periods, but the MCM produced only specific values for measurement times as representative values. Therefore, MCM may exhibit large errors in selection differences during Rs measurements. Therefore, to reduce this error using MCM, the time and frequency of measurement should be set to obtain Rs under various environmental conditions. Contrastingly, the MCM measurement is obtained during $CO_2$ evaluation in the soil owing to soil disturbance caused by measuring equipment, so close attention should be paid to measurements. This is because the measurement process is disturbed by high $CO_2$ soil concentration, and even small soil disturbances could release high levels into the chamber, causing large Rs errors. Therefore, the MCM should be adequately mastered before using the device to measure Rs.

• 센서학회지
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• 제16권5호
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• pp.331-336
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• 2007

In this study, we have fabricated an infrared optical fiber based sensor which can monitor the respiration of a patient. The design of a chalcogenide optical fiber based sensor is suitable for insertion into a high electro-magnetic field environment because the sensor consists of low cost and compact mid-infrared components such as an infrared light source, a chalcogenide optical fiber and a thermopile sensor. A fiber-optic respiration sensor is capable of detecting carbon dioxide ($CO_{2}$) in exhalation of a patient using the infrared absorption characteristics of carbon gases. The modulated infrared radiation due to the presence of carbon dioxide is guided to the thermopile sensor via a chalcogenide receiving fiber. It is expected that a mid-infrared fiber-optic respiration sensor which can be developed based on the results of this study would be highly suitable for respiration measurements of a patient during the procedure of an MRI.

• 한국컴퓨터정보학회논문지
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• 제19권11호
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• pp.33-41
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• 2014

본 논문에서는 일상생활에 편리한 무구속 센서를 활용하여 호흡을 측정하는 시스템을 제안한다. 제안된 시스템은 Piezoelectric 센서를 내장한 센서 패드, 센서 패드로부터 출력된 호흡 신호를 증폭 필터링한 후 디지털로 변환하는 호흡 측정 기기, 센서 데이터 시각화 및 호흡 측정 알고리즘을 구현한 뷰어로 구성된다. 제안된 알고리즘은 센서 데이터의 임계값을 통해 추출된 최고점을 기준으로 한 호흡 주기에 기반하고 있다. 3명의 피실험자에 대하여 이동 평균 개수와 임계값을 변경해 가면서 호흡 측정 실험이 수행되었으며, 실험 결과에 의하면, 제안 시스템은 이동 평균 개수 50~60을 중심으로 임계값 800~1300 범위에서 약 5% 이내의 오류율이라는 양호한 성능을 나타내었다. 향후 본 시스템은 영 유아나 독거노인의 수면 중 질식사를 예방하는데 기여할 수 있을 것으로 기대된다.

• 한국정보통신학회논문지
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• 제9권1호
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• pp.204-209
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• 2005

초음파 센서를 이용한 호흡측정방식은 관성 및 압력의 오차의 영향을 거의 받지 않고, 반영구적으로 사용이 가능한 호흡기기이다. 초음파의 특성을 이용한 것으로 송수신시 초음파의 매질인 공기의 흐름에 의한 반송형식인 초음파의 전달속도 차이를 이용하여 호흡량 및 흐름을 detecting하는 기술이다. 본 논문에서는 환자를 중심으로 측정이 이루어져야 하기 때문에 센서의 송수신시 일어나는 신호의 sensitivity를 향상시켜서 약한 호흡에도 dectection이 가능하도록 시스템의 성능을 향상시켰다.

• 대한의용생체공학회:의공학회지
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• 제33권1호
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• pp.39-46
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• 2012

Electrical impedance tomography(EIT) can produce functional images with conductivity distributions associated with physiological events such as cardiac and respiratory cycles. EIT has been proposed as a clinical imaging tool for the detection of stroke and breast cancer, pulmonary function monitoring, cardiac imaging and other clinical applications. However EIT still suffers from technical challenges such as the electrode interface, hardware limitations, lack of animal or human trials, and interpretation of conductivity variations in reconstructed images. We improved the KHU Mark2 EIT system by introducing an EIT electrode interface consisting of nano-web fabric electrodes and by adding a synchronized biosignal measurement system for gated conductivity imaging. ECG and respiration signals are collected to analyze the relationship between the changes in conductivity images and cardiac activity or respiration. The biosignal measurement system provides a trigger to the EIT system to commence imaging and the EIT system produces an output trigger. This EIT acquisition time trigger signal will also allow us to operate the EIT system synchronously with other clinical devices. This type of biosignal gated conductivity imaging enables capture of fast cardiac events and may also improve images and the signal-to-noise ratio (SNR) by using signal averaging methods at the same point in cardiac or respiration cycles. As an example we monitored the beat by beat cardiac-related change of conductivity in the EIT images obtained at a common state over multiple respiration cycles. We showed that the gated conductivity imaging method reveals cardiac perfusion changes in the heart region of the EIT images on a canine animal model. These changes appear to have the expected timing relationship to the ECG and ventilator settings that were used to control respiration. As EIT is radiation free and displays high timing resolution its ability to reveal perfusion changes may be of use in intensive care units for continuous monitoring of cardiopulmonary function.

• 감성과학
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• 제19권3호
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• pp.81-88
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• 2016

본 논문은 깊이 카메라(Creative Senz3D)를 이용하여 호흡률을 측정하는 것에 대한 정확도와 영향을 미치는 요인들을 분석하였다. 영향 요인 분석에서는 깊이 카메라가 가지는 깊이 값에 대한 오차와 노이즈 그리고 주위 조도의 영향에 대하여 실험 연구를 진행하였다. 그 결과 깊이 카메라와 측정 대상의 거리가 증가함에 따라 깊이 값의 오차가 증가하였고 깊이 영상의 오른쪽은 실제 거리보다 깊이 값이 크게 측정되고 왼쪽은 실제 거리보다 깊이 값이 작게 측정되었다. 이에 따라 깊이 값이 영상의 영역에 따라 비대칭성을 가지고 있음을 알 수 있었다. 깊이 카메라와 측정 대상의 각도가 틀어짐에 따라서도 깊이 값의 차의 오차가 증가하였으며 깊이 카메라의 노이즈는 측정 거리가 멀어짐에 따라 점점 증가하였고 노이즈를 측정하는 윈도우의 크기가 증가함에 따라 감소하였다. 주위 조도는 깊이 값에 영향을 주지 않았다. 또한 실제 상황에서 사람을 대상으로 20회 호흡을 하게 하여 깊이 카메라를 이용해 호흡률을 측정하였고 호흡률이 제대로 측정됨을 확인하였다.

• 대한한의진단학회지
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• 제12권1호
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• pp.103-130
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• 2008

Background: For standardizing of Han-Yeol [寒熱], which is a kind of diagnosis method in oriental medicine, it is necessary to investigate into relationship of symptoms and signs representative of Han-Yeol [寒熱] to the biofunctional medical signals; thermal temperature by Thermography, Pulse-Respiration Ratio and so on. By correlation analysis of these data items acquired from patients, it could be provides the fundamental data for standardizing of Han-Yeol [寒熱]. Objectives: We performed this study to check the characteristics of thermal temperature with Han-Yeol [寒熱] statue by pulse-respiration ratio. Methods: We selected nine regions around acupoints including Yin dang[印堂], Sugu[水溝, GV26], Ch'ondol[天突, CV22], Chonjung[CV17], Chung-wan[中脘, CV12], Chonchu[天樞 S25], No-gung[勞官, P8], and calculated based on the utility of R.O.I.(Region of Integer) by IR-2000 these points temperature from 68 subjects. In practicing pulse-respiration ratio over 4.0 means the statues of Yeol [熱], pulse-respiration ratio below 4.0 means the statues of Han [寒]. To optimum conditions thermal temperature, which are not effected by internal and external variables, we studied preceding research. The results shows that optimal time period is 20minutes after undressed and the optimal region is the region around acupoints including Sugu [水溝, GV26]. Based on a preceding research results, we analyzed these data by Paired T-test between GV26 Region and 8-Thermography Regions and two-way repeated ANOVA with thermography$({\Delta}T)$ and Han-Yeol [寒熱] statue by pulse-respiration ratio. Results: 1. In applying of two-way repeated ANOVA with thermography$({\Delta}T)$ and Han-Yeol [寒熱] statue by pulse-respiration ratio, Sugu [水溝穴, GV26] - [印堂穴, HN1], Sugu 水溝, GV26] - Chonjung[CV17], Sugu [水溝, GV26] -Chung-wan[中脘, CV12]had significant differences. 2. In applying of Paired T-test between Sugu [水溝穴, GV26] Region and 8- Thermography Regions, there were significant differences except of Sugu [水溝穴, GV26] -Chondolp[天突, CV22]. 3. In the difference of Sugu [水溝, GV26] -Chung-wan[中脘, CV12], thermal temperature increases a lot in the statues of Yeol [熱], thermal temperature decreases a lot in the statues of Han [寒]. Conclusions: On the analysis of Thermography, we obtain the measurement conditions were considered the individual variations. And it is different that the thermal temperature change on Thermography according to Han-Yeol [寒熱] statue by pulse-respiration ratio.