• 대한의용생체공학회:의공학회지
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• 제38권4호
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• pp.153-162
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• 2017

The present study proposes a system that can detect sleep-disordered breathing automatically using an air mattress and oxygen saturation. A thin air mattress was fabricated to reduce discomfort during sleep, and respiration signals were acquired. The system was configured to be synchronized with a polysomnography to receive signals simultaneously with other bio-signals. The present study has been conducted with nine adult male and female patients with sleep-disordered breathing, and sleep-disordered breathing events have been detected by applying the signals acquired from the subjects to the rule-based detection algorithm. The sensitivity and positive predictive values were found to evaluate the performance of the system, which are 91.4% and 89.7% for all events, respectively. The comparison of apnea hypopnea index(AHI) between the polysomnography and the proposed method showed squared R-value of 0.9. This study presents the possibility of detecting sleep-disordered breathing at hospitals or homes using the proposed system.

• 대한의용생체공학회:의공학회지
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• 제35권6호
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• pp.177-184
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• 2014

Continuous monitoring of heart rates and respiratory rates for newborns or infants is very important since the abnormal breathing and heart problems can threaten the life of newborns or infants. A noncontact baby monitoring system based on a Doppler radar and an air mattress was designed. The Doppler radar was used to acquire respiratory signals and the air mattress was employed to obtain heart rates. The performance of the designed system was evaluated using a commercialized infant simulator ($Simbaby^{TM}$) and a respiration belt transducer was used to measure respiration rates as a reference. Results for respiratory rates revealed that the correlation coefficients between I-and Q-channel and the respiration belt were 0.84 and 0.91 and the mean ${\pm}$ standard deviations of errors between them were $1.66{\pm}1.92$ (bpm) and $0.88{\pm}1.65$ (bpm). Heart rates showed that the correlation coefficient between air mattress and set value of the simulator was 0.73 and the mean ${\pm}$ standard deviation of errors between them was $1.09{\pm}3.45$ (bpm). These results indicate that the designed system holds the potential as an effective monitoring tool for continuous monitoring heart rates and respiratory rates of newborns or infants.

• 근관절건강학회지
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• 제29권1호
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• pp.18-27
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• 2022

Purpose: A network meta-analysis was conducted to assess the comparative effects and ranks of repositioning for pressure ulcer prevention in adults. Methods: A network meta-analysis was performed in a frequency method, using the "netmeta" package of R software version 4.1. The effects of repositioning intervention were confirmed by the odds ratio. The comparative ranking of the repositioning effects was confirmed using the cumulative probability (P-score). Results: Seven intervention studies were included in this study. Based on the P-score, the use of the repositioning system was ranked as the most effective among all interventions (P-score 78.7%). Next was 3~4-hour repositioning combined with memory foam mattress use (P-score 77.2%), use of wearable sensor (P-Score 61.4%), 2-hour repositioning combined with memory foam mattress use (P-score 59.1%), 2-hour repositioning combined with powered air pressure redistribution mattress use (P-score 18.0%), and 4-hour repositioning combined with powered air pressure redistribution mattress use (P-score 18.0%). Conclusion: This study provides information on the relative comparative value of various repositioning interventions to prevent pressure ulcers using network meta-analysis. This is expected to be useful for nurses' decision-making when applying repositioning interventions in clinical practice

• 한국의류학회지
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• 제15권2호
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• pp.77-87
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• 1991

The purpose of this study were to investigate the bed climate and the physiological responses in sleep on the traditional Korean floor heating system called Ondol. Ondol has been the most widely used heating system in Korea, yet there has been a no systematic studies examined its environmental effects on human body. Experimental room was constructed to match the typical thermal environment of Ondol. (floor surface temperature; $32\~33^{\circ}C$, air temperature; $22.5{\pm}1.0^{\circ}C$, relative humidity; $64.0{\pm}4.0\%$RH, air velocity; 0.25 m/sec.) Three different combinations of bedclothes were chosen for the experiment based on the study results showing that they were the most widely used types in Korea. Type 1 was the combination of a cotton-padded mattress with a cotton-padded Korean style blanket. Type 2 was a cotton-padded mattress with a cotton-guilted Korean style blanket. Type 3 was a cotton-padded matless with a polyacryl blanket. Thermal resistance of each of these combina-tions in the bedclothes was measured using thermal manikin. Two adult female was chosen for the seven hour sleeping experiment which was known to be the average sleeping hours of Korean adult female. The bed climate was measured with the temperature under the mattress, the surface temper-ature of the mattress, and the air temperature and the relative humidity of the space between the mattress and blanket. The skin temperature, rectal temperature of the subjects and the bed climate were measured eight times, one hour before the experiment and every hour during the experiment. The weight loss and the subjective sensation were measured for the each subjects before and after the experiment. The procedure was repeated twice with two subjects and three types of bedclothes, yielding twelve combinations of results. The results were as follows; 1. With the surface temperature of $32\~33^{\circ}C$ of Ondol, air temperature was $22.5{\pm}1.0^{\circ}C$ with $64.0{\pm}4.0\%$ RH. The bed climates were $39.2{\pm}40.8^{\circ}C$ under the mattress, $35.3\~36.2^{\circ}C$ on the mattress, and $26.9\~32.0^{\circ}C$ with $56.0\~71.3\%$ RH between the mattress and the blanket. 2. Mean skim temperature during sleep was 34.2"C with local skin temperature of $34.0\~35.5^{\circ}C$. The skin temperatures of abdomen, thigh, foot were higher than the other parts of the body. 3. The skin temperature of chest, thigh, leg and back varied significantly according to the combinations of bedclothes. With the cotton-padded blanket, the skin temperature was the highest, while with the cotton-guilted blanket showed lowest. 4. Examining the relationship between the mean skin temperature and the local skin temper-ature, the chest temperature showed the highest correlation with the former. Therefore, the chest temperature can be recommended to represent the skin temperature in measuring the bed climate. 5. The subjective bed climates were $39.0\~40.4^{\circ}C$ under the mattress, $35.2\~35.9^{\circ}C$ on the mattress, $29.8\~31.6^{\circ}C$ with $56.8\~68.4\%$ RH between the mattress and blanket. In sum, from this experiment we not only obtained the reliable value of bed climates on Ondol, but also showed that the bed climates and the physiological responses were affected differently according to the materials of bed clothes.

• 한국방사선학회논문지
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• 제16권7호
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• pp.889-896
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• 2022

본 연구는 전산화단층촬영의 테이블에 에어 매트리스의 적용으로 인한 환자의 주관적 편안함의 변화를 설문지를 통하여 분석하고, 환자의 임상 영상을 정량적 정성적 평가를 통하여 화질 변화를 분석하여 에어 매트리스의 유용성을 평가하고자 하였다. 연구에 참여한 피험자는 남성이 221명, 여성이 229명이었으며, 연령 범위는 만 18세에서 86세이다. 영상의 화질 변화를 평가하기 위해 연구 대상자 중 Chest CT & Enhancement를 촬영한 환자를 단순 무작위 표본 추출(Simple random sampling) 방법을 사용하여 정량적 평가를 위하여 각 군당 50명씩 총 150명의 환자를 선정하였으며, 정성적 평가를 위하여 각 군당 20명씩 총 60명의 환자를 선정하였다. 본 연구결과 에어 매트리스로 인하여 환자의 주관적 편안함이 증가하였으며, 임상영상의 정량적, 정성적 평가 결과 화질의 차이는 나타나지 않았다. 이상의 결과를 보았을 때 에어 매트리스는 진단 영상에 아무런 해가 없이 환자의 주관적인 편안함을 높일 수 있는 방법으로 유용하게 적용될 수 있을 것으로 사료된다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.79-80
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• 2003

In order to develop an indoor assistive mobility equipment, we paid attention to the mechanism of locomotion in a snail, or a terrestrial gastropod molluscs. It is known that the snail moves by propagation of a pedal wave generating on a pedal surface of the snail and a pedal locomotion has flexibility far ground condition. An air mattress with a function of a pedal-like locomotion mechanism was developed and the performance of the pedal locomotory air mattress as mobility equipment was discussed.

• Journal of Korean Neurosurgical Society
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• 제54권5호
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• pp.444-447
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• 2013

In most intracranial surgery cases, a drain catheter is inserted to prevent the collection of the wound hematoma or seroma. A drain catheter is also inserted to drain the hematoma or the cerebrospinal fluid. The drain catheter itself does not cause complications; but many complications occur during its removal, such as hematoma, seroma, air collection and pseudomeningocele formation. To prevent these complications, neurosurgeons perform a suture on the catheter to remove the site. In this study, an additional horizontal mattress suture and an anchoring suture to the drainage catheter are proposed. This method maintains negative pressure in the catheter insertion site during the catheter removal, compresses the catheter tunnel site and attaches the external wounds strongly. The technique is easy and safe to perform, and does not require an additional suture to remove the catheter.

• Journal of Dental Anesthesia and Pain Medicine
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• 제15권4호
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• pp.193-200
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• 2015

Background: During head and neck surgery including orthognathic surgery, mild intraoperative hypothermia occurs frequently. Hypothermia is associated with postanesthetic shivering, which may increase the risk of other postoperative complications. To improve intraoperative thermoregulation, devices such as forced-air warming blankets can be applied. This study aimed to evaluate the effect of supplemental forced-air warming blankets in preventing postanesthetic shivering. Methods: This retrospective study included 113 patients who underwent orthognathic surgery between March and September 2015. According to the active warming method utilized during surgery, patients were divided into two groups: Group W (n = 55), circulating-water mattress; and Group F (n = 58), circulating-water mattress and forced-air warming blanket. Surgical notes and anesthesia and recovery room records were evaluated. Results: Initial axillary temperatures did not significantly differ between groups (Group $W=35.9{\pm}0.7^{\circ}C$, Group $F=35.8{\pm}0.6^{\circ}C$). However, at the end of surgery, the temperatures in Group W were significantly lower than those in Group F ($35.2{\pm}0.5^{\circ}C$ and $36.2{\pm}0.5^{\circ}C$, respectively, P = 0.04). The average body temperatures in Groups W and F were, respectively, $35.9{\pm}0.5^{\circ}C$ and $36.2{\pm}0.5^{\circ}C$ (P = 0.0001). In Group W, 24 patients (43.6%) experienced postanesthetic shivering, while in Group F, only 12 (20.7%) patients required treatment for postanesthetic shivering (P = 0.009, odds ratio = 0.333, 95% confidence interval: 0.147-0.772). Conclusions: Additional use of forced-air warming blankets in orthognathic surgery was superior in maintaining normothermia and reduced the incidence of postanesthetic shivering.

• 한국화재소방학회논문지
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• 제10권4호
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• pp.19-27
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• 1996

상층부의 온도, 경계면 높이 및 흐름형태를 연구하기 위하여 쓰레기통, 의자, 카페트, 소파, 매트리스 및 장농화재 실험을 실제 건물에서 수행하였다. 상부층의 온도와 경계면의 높이는 사각 쓰레기통의 경우 개구부의 흐름계수가 0.65∼0.8, 원형 쓰레기통 및 의자의 경우는 0.65∼0.9, 카페트, 소파, 매트리스 및 장농의 경우는 0.7∼O.9일 때 실험치와 비교적 잘 일치하였다. 경계면의 높이는 가구화재시 1[m] 근처에서 정상상태를 유지하였다. 다만, 최대온도를 나타내는 시간에는 경계면 높이가 바닥에서 0.25[m]∼0.75[m]까지도 내려왔다. 개구부의 흐름형태는 분산화재의 경우는 filling과 buoyant흐름이 나타났고, 집중화재의 경우는 filling에서 바로 flow로 가고 또 flow기간도 길게 나타났다. 경계면 높이가 내려오는 속도는 가구의 가연성 및 공기와의 접촉면적에 비례하여 경계면 높이가 1[m] 근처까지 내려오는데 소요되는 시간은 1분∼3분 이내로 나타났다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.162-168
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• 2001

In the present study, flow visualizations, hot-wire velocity measurements and computational fluid dynamics were performed in order to determine complicated air flow characteristics in a neonate incubator. In this study, following conclusions can be made: (1) The flow visualization technique developed in the present study revealed an enough qualitative information for the flow field in the neonate incubator. Flow structures in a neonate incubator with a realistic three-dimensional shape was successfully visualized the present study. (2) Results from the flow visualization were relatively in good agreements with those obtained from the computational fluid dynamics. (3) Velocities very near the neonate measured by the hot-wire anemometer were relevant to those obtained from the computational fluid dynamics. (4) Temperatures were higher at the neck region and the medial aspect of both thighs, but lower in both extremities. (5) Small vortices between the neonate and the mattress might interfere with convective and evaporative heat transfers on the neonate's surface. In the fluid dynamic aspect, it is important to eliminate the formation of these small vortices for the design of incubator chamber.