• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.232-235
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• 1997

Apnea refers to episode of apnea (or not breathing) lasting more than 10 seconds that occur while sleeping. These episodes, whitch can occur hundreds of times per night, may transiently awaken resulting in fragmentation of sleep. Although the precise cause of Sudden Infant Death Syndrome(SIDS) are still unclear, there is evidence to suggest that hypoxaemia may be a contributory actor. Transcutaneous oxygen monitor can be used, but it is very difficult to use or baby stayed at home. In this reason, monitors whitch is easy or deal with are reqiured. In 1972, Steinschieder reported that two of the five infants noted to have apnea lasting or more than 20 seconds later died of SIDS episode, he also suggested that home monitoring or neonates should be used or managing apnea at home. Transthoracic electrical impedance technique is used or acquiring respiration waveform and detecting episode of apnea state. Transthoracic electrical impedance measurements have been made from the human trunk over the frequency range 9.6KHz to 614KHz. We conclude that application of impedance technique or detecting apnea state is proper or neonates.

• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.44-49
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• 2022

The number of single-person households is increasing worldwide, and among them, the proportion of elderly single-person households is increasing. In the case of elderly single-person households, a significant portion of their leisure time is devoted to watching TV. However, if they fall asleep while watching TV without turning it off, it may be difficult to sleep well due to lights and sounds of TV, which can cause health problems such as depression and reduced immunity. Therefore, in this paper, we propose a system that automatically turns off the TV when a person watching TV falls asleep. Images are collected using the camera installed in front of the TV. Since the posture of a person watching TV varies from a sitting posture to a lying posture, the system is designed to determine whether or not to fall asleep regardless of the posture. In addition, since it becomes difficult to judge eye movements as a person moves away from the TV, a method for extending the judgmentable distance is proposed. The system model was implemented and tested using a Raspberry Pi, a monitor, an infrared sensor, and a camera. Eye movements were judged regardless of sitting or lying position, and the distance between a user and a TV was extended by about 200 cm.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.24-33
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• 2002

Objectives: Nasal continuous positive airway pressure (CPAP) corrected elevated blood pressure (BP) in some studies of obstructive sleep apnea syndrome (OSAS) but not in others. Such inconsistent results in previous studies might be due to differences in factors influencing the effects of CPAP on BP. The factors referred to include BP monitoring techniques, the characteristics of subjects, and method of CPAP application. Therefore, we evaluated the effects of one night CPAP application on BP and heart rate (HR) reactivity using non-invasive beat-to-beat BP measurement in normotensive and hypertensive subjects with OSAS. Methods: Finger arterial BP and oxygen saturation monitoring with nocturnal polysomnography were performed on 10 OSAS patients (mean age $52.2{\pm}12.4\;years$; 9 males, 1 female; respiratory disturbance index (RDI)>5) for one baseline night and another CPAP night. Beat-to-beat measurement of BP and HR was done with finger arterial BP monitor ($Finapres^{(R)}$) and mean arterial oxygen saturation ($SaO_2$) was also measured at 2-second intervals for both nights. We compared the mean values of cardiovascular and respiratory variables between baseline and CPAP nights using Wilcoxon signed ranks test. Delta ($\Delta$) BP, defined as the subtracted value of CPAP night BP from baseline night BP, was correlated with age, body mass index (BMI), baseline night values of BP, BP variability, HR, HR variability, mean $SaO_2$ and respiratory disturbance index (RDI), and CPAP night values of TWT% (total wake time%) and CPAP pressure, using Spearman's correlation. Results: 1) Although increase of mean $SaO_2$ (p<.01) and decrease of RDI (p<.01) were observed on the CPAP night, there were no significant differences in other variables between two nights. 2) However, delta BP tended to increase or decease depending on BP values of the baseline night and age. Delta systolic BP and baseline systolic BP showed a significant positive correlation (p<.01), but delta diastolic BP and baseline diastolic BP did not show a significant correlation except for a positive correlation in wake stage (p<.01). Delta diastolic BP and age showed a significant negative correlation (p<.05) during all stages except for REM stage, but delta systolic BP and age did not. 3) Delta systolic and diastolic BPs did not significantly correlate with other factors, such as BMI, baseline night values of BP variability, HR, HR variability, mean SaO2 and RDI, and CPAP night values of TWT% and CPAP pressure, except for a positive correlation of delta diastolic pressure and TWT% of CPAP night (p<.01). Conclusions: We observed that systolic BP and diastolic BP tended to decrease, increase or remain still in accordance with the systolic BP level of baseline night and aging. We suggest that BP reactivity by CPAP be dealt with as a complex phenomenon rather than a simple undifferentiated BP decrease.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.283-291
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• 2000

The purpose of this study was to compare the sedative effect of three routes of administration - intramuscular, intranasal drop-in, intranasal spray - with midazolam. The twenty two uncooperative children from 23 months to 76 months who required at least three dental appointment. Each patient was assigned randomly to receive intramuscular(Group I, 0.15mg/kg), intranasal drop-in(Group II, 0.20mg/kg), intranasal spray(Group III, 0.20mg/kg) administration at each visit. Sleep, crying, movement, and overall behavior response were evaluated, and the sedative effects were evaluated by Houpt's rating scale In order to monitor the sedated patients, pulse rate and peripheral oxygen saturation were measured by pulse oximeter during treatment procedures. The results were as follows 1. Pulse rate and peripheral oxygen saturation were stable through all the treatment procedures, and there were no statistically significant differences among three routes of administration(P>0.05). 2. The effect on sleep was, III, II, I, in order, III group was the most effective through all the treatment procedures, except rubber-dam placement and filling phase (P<0.0001). 3. The effects on crying, movement, overall behavior were II, III, I, in order, II group was the most effective through all treatment procedures(P<0.0001).

• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.11-18
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• 2010

In this paper, it introduced the device that was fabricated for monitoring sleeping positions of infants with 3-axis accelerometer. Sleep monitoring studies has been usually conducted two ways. To monitor sleeping posture by installing a camera and then recording of sleep in the sleeping room continuously is the first one. The other one is monitoring pressure sensor's results data for sleeping. Those two ways' benefits are that are able to get relatively accurate sleeping posture data but, there are many disadvantages like constraints of spaces and places, the installation of sensors or cameras, and high cost. In addition, it has a lot of problems that difficult to solve. For babies, it's not easy to apply, as well as uncomfortable. The proposed method uses a 3-axis accelerometer's X axis, Y axis, Z axis position output values in order to recognize the bad ground sleeping position that use of the buzzer alarm. This method uses a 3-axis acceleration sensor to measure the data and transmit sleeping posture using Bluetooth wireless in real time monitoring. The data is helpful for prevention safety hazard such as choked themselves when they slept back side on.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.207-214
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• 2008

Under future internet environment, wireless sensor networks will be used in a wide range of applications. A major problem for designing sensor protocol is developing the most energy efficient technique to monitor an area of interest for a long time since sensors have some constraints such as small and a limited energy level. In addition, data latency is often a critical issue since sensory data is transmitted via multi hop fashion and need to be delivered timely for taking an appropriate action. Our motivation for designing a data forwarding protocol is to minimize energy consumption while keeping data latency bound in wireless sensor networks. In this paper, we propose a data forwarding protocol that consists of wakeup scheduling and MAC protocols, the latter of which is designed to achieve load balancing. Simulation results show that the proposed framework provides more energy-efficient delivery than other protocol.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.3
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• pp.671-677
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• 2012

A black-box program was implemented in order to monitor abnormal symptoms of human body irregularly occurring during sleep. The system consists of sensor probing body signals, auxiliary devices such as the alarm, lamp, network camera, and signal monitoring computer. Various types of sensors, PPG, ECG, EEG, temperature, respiration sensor, G-sensor, and microphone were used to more exactly identify the causes of abnormal symptoms. If a symptom occurs, the system records the patient's condition to provide information being utilized in the treatment. The sensors are attached on some locations of body being proper to check a specific type of abnormal reaction. Based on the normal range and type of measurement data, criteria of signal levels were set to distinguish abnormal reaction. An abnormal signal being probed, the program starts to operate the lamp, alarm, and network camera at the same time and stores the signal and video data.

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.1-7
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• 2013

Train accidents can be directly connected to fatal accidents-collision, derailment, Fire, railway crossing accidents-resulting in tremendous human casualties. First of all, the railway derailment is not only related to most of railway accidents but also it can lead to much more catastrophic accompanying train overtured than other factors. Therefore, it is most important factor to ensure railway safety. some foreign countries have applied to the detector machines(e.g., ultrasonic detector car, sleep mode, current detector, optical sensing, optical fiber). Since it was developed in order to prevent train from being derailed. In korea, the existing track method has been used to monitor rail condition using track circuit. However, we found out it impossible for Communication Based Train Control system(CBTC), recent technology to detect rail condition using balise(data transmission devices) without no track circuit. For this reason, it is needed instantly to develop real-time monitoring system used to detect broken rails. Firstly, this paper presents domestic and international statues analysis of rail breaks technology. Secondly, the composition and the characteristics of the real-time monitoring system. Finally, the evidence that this system could assumed the location and type of broken rails was proved by the experiment of prototype and operation line tests. We concluded that this system can detect rail break section in which error span exist within${\pm}1m$.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.645-653
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• 2014

A Bridge Navigational Watch Alarm System (hereafter 'BNWAS') is to monitor and detect if an officer of watch(hereafter 'OOW') keeps a sharp lookout on the bridge. The careless lookout of an OOW could lead to marine accidents. For this reason on June 5th, 2009, IMO decided that a ship is equipped with a BNWAS. However, an existing BNWAS gives the OOW a lot of inconvenience and stress in its operation. It requires that the OOW should press reset buttons to confirm their alert watch on the bridge at every three to twelve minute. Many OOWs have complained that at some circumstances they cannot focus on their bridge activities including watch-keeping due to a lots of resetting inputs of BNWAS. Accordingly, IMO has allowed the use of a motion sensor as a resetting device. The motion sensor detects the movements of human body on the bridge and subsequently sends reset signals directly to BNWAS automatically. As a result, OOWs can work uninterrupted. However, some of classification societies and flag authorities have a slightly different stance on the use of motion sensor as a resetting method for BNWAS. The reason is that the motion sensor may trigger false reset signals caused by the motion of objects on the bridge, especially a slight movement such as toss and turn of human body which can extend the period of careless watch. As a basic study to minimize the false reset signals, this paper proposes a simple configuration of BNWAS, which consists of only three motion sensors associated with 'AND' and 'OR' logic gates. Additionally, several considerations are also proposed for the implementation of motion sensors. This study found that the proposed configuration which consists of three motion sensors is better than an existing one by reducing false reset signals caused by a slight movement of human body in one's sleep. The proposed configuration in this paper filters false reset signals and is simple to be implemented on existing vessels. In addition, it can be easily installed just by a basic electrical knowledge.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.45-51
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• 2001

Objectives: The experience of traffic accident is a kind of the psychosocial stressors to person. The traffic accident-related patients may show the psychophysiologic hyperarousal. So we examined the differences of psychophysiologic response between patients with and without the memory of experienceing a traffic accident. Methods: Twenty-four traffic accident-related patients were divided into two groups according to ther memory of a traffic accident. In psychological assessment, levels of anxiety and depression were evaluated by State-Trait Anxiety Inventory, Beck's Depression Inventory, and Hamilton Rating Scales For Anxiety and Depression. Heart rate, electrodermal response (EDR), and electromyographic activity (EMG) were measured by biofeedback system, and systolic and diastolic blood pressure by automated vital sign monitor during baseline, task, and rest periods. We utilized script-driven imagery technique as a stressful task. The patients listened to the script describing their own traffic accident experience and were instructed to imagine the event during the task period. Statistically analytic data were obtained from the differences of psychological and psychophysiologic data between two groups. Results: The memory group did not show significantly higher EDR than the none memory group, but showed higher tendency during baseline, imagery, and rest periods. The memory group showed significantly lower EMG than the none memory group during rest period. However, there were no differences in other psychophysiologic reponses between the two groups. Conclusion: Our results showed that the memory group had higher tendency in autonomic arousal level such as electrodermal response than the none memory group. We suggest that physicians need to minimize repetitive imagery of traffic accident (reexperience), and decrease the autonomic hyperarousal in the treatment of traffic accident-related patients.