• 대한수의학회지
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• 제39권1호
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• pp.27-33
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• 1999

In the mammalian ovary, follicular development and atresia continuously occur during the reproductive cycles. Follicular atresia occurs through granulosa cell apoptosis. Apoptosis is known as the physiological cell death, which is regulated by bcl-2 gene family. In the bcl-2 gene family, bcl-2 and bcl-xLong are known as inhibitors of apoptosis, whereas bax and bcl-xShort are known as inducer of apoptosis. We thought that bcl-2 protein is associated with follicular development and atresia. But it is not known that the distribution of cells containing bcl-2 protein during follicular development and atresia. Therefore, to examine the distribution of cells with bcl-2 protein during ovarian follicular development and atresia, the immunohistochemistry was used in the rat ovary. Bcl-2 immunoreactivity was localized in the interstitial cells, theca externa cells and granulosa cells around of antrum. All positive signals were observed in the cytoplasm of these cells. Positive signals were strongly observed in the interstitial and theca externa cells of growing antral follicles. While, positive signals were weakly observed in these cells from atretic antral follicles. Positive signals were very weakly observed in the granulosa cells of growing and atretic antral follicles. According to these data, we suggested that bcl-2 proteins which were strongly expressed in the interstitial cells and theca externa cells of growing antral follicles inhibit follicular atresia. And we purposed that bcl-2 proteins regulated follicular development and atresia through the action of bcl-2 gene family.

• 대한전자공학회논문지SP
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• 제46권5호
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• pp.101-110
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• 2009

사용자의 활동 신호 또는 생체 신호를 무의식적이고 무구속적으로 측정하는 방법은 유비쿼터스 환경에서 헬스케어 뿐만 아니라 관련된 사용자 인터페이스를 실현하기 위해서 중요하다. 특히 무구속적인 측정은 장시간 동안 사용자의 활동을 모니터링하기 위한 활동 상태 추정 시스템에 사용되어야 한다. 본 논문에서는 가속도센서를 탑재한 핸드헬드 단말기의 시계열 가속도 분석을 통한 사용자 활동 상태 추정 기법을 제안한다. 제안된 사용자 활동 추정 시스템은 사용자의 불편함을 최소화하기 위해서 가속도센서를 사용자가 일상 생활동안 항상 휴대하고 있는 핸드헬드 단말기에 부착되어 구성되고, 이것을 실생활에서 실용적으론 구현하기 위해서 핸드헬드 단말기가 사용자에 의해서 휴대될 수 있는 위치를 앞주머니, 뒷주머니, 윗주머니, 가방, 허리, 손으로 쥐기 등과 같이 고려하였다.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권11호
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• pp.502-510
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• 2006

In this paper, we describe implementation of a computer access device for the severly motor-disability. Many people with severe motor disabilities need an augmentative communication technology. Those who are totally paralyzed, or 'locked-in' cannot use conventional augmentative technologies, all of which require some measure of muscle control. The forehead is often the last site to suffer degradation in cases of severe disability and degenerative disease. For example, In ALS(Amyotrophic Lateral Sclerosis) and MD(Muscular dystrophy) the ocular motorneurons and ocular muscles are usually spared permitting at least gross eye movements, but not precise eye pointing. We use brain and body forehead bio-potentials in a novel way to generate multiple signals for computer control inputs. A bio-amplifier within this device separates the forehead signal into three frequency channels. The lowest channel is responsive to bio-potentials resulting from an eye motion, and second channel is the band pass derived between 0.5 and 45Hz, falling within the accepted Electroencephalographic(EEG) range. A digital processing station subdivides this region into eleven components frequency bands using FFT algorithm. The third channel is defined as an Electromyographic(EMG) signal. It responds to contractions of facial muscles and is well suited to discrete on/off switch closures, keyboard commands. These signals are transmitted to a PC that analyzes in a time series and a frequency region and discriminates user's intentions. That software graphically displays user's bio-potential signals in the real time, therefore user can see their own bio-potentials and control their physiological signals little by little after some training sessions. As a result, we confirmed the performance and availability of the developed system with experimental user's bio-potentials.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.505-508
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• 2008

Electrocardiogram (ECG) and blood pressure (BP) are main vital signs which are the standards in most medical settings in assessing the most basic body functions. Multi parameters are desired in providing more information for health professionals in order to detect or monitor medical problems of patients more precisely. This study urges us to develop a robust wireless healthcare monitoring system which has multiple physiological signs measurements on real time that applicable to various environments which integrates wireless sensor network technology and code division multiple access (CDMA) network with extended feature of locally standalone diagnosis algorithms that implemented in tell phone. ECG signal and BP parameter of the patients are routinely be monitored, processed and analyzed in details at cell phone locally to produce useful medical information to ease patients for tracking and future reference purposes. Any suspected or unknown patterns of signals will be immediately forwarded to hospital server using cell phone for doctors' evaluation. This feature enables the patients always recognize the importance of self-health checking so that the preventive actions can be taken earlier through this analytic information provided by this monitoring system because "Prevention is better than Cure".

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.967-979
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• 2013

Now a day, Wireless Sensor Networks (WSNs) are being widely used in different areas one of which is healthcare services. A wireless medical sensor network senses patient's vital physiological signs through medical sensor-nodes deployed on patient's body area; and transmits these signals to devices of registered medical professionals. These sensor-nodes have low computational power and limited storage capacity. Moreover, the wireless nature of technology attracts malicious minds. Thus, proper user authentication is a prime concern before granting access to patient's sensitive and private data. Recently, P. Kumar et al. claimed to propose a strong authentication protocol for healthcare using Wireless Medical Sensor Networks (WMSN). However, we find that P. Kumar et al.'s scheme is flawed with a number of security pitfalls. Information stored inside smart card, if extracted, is enough to deceive a valid user. Adversary can not only access patient's physiological data on behalf of a valid user without knowing actual password, can also send fake/irrelevant information about patient by playing role of medical sensor-node. Besides, adversary can guess a user's password and is able to compute the session key shared between user and medical sensor-nodes. Thus, the scheme looses message confidentiality. Additionally, the scheme fails to resist insider attack and lacks user anonymity.

• The Korean Journal of Physiology
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• 제4권2호
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• pp.19-24
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• 1970

Since the discovery of the muscle spindle by Hassall (1831), an intensive studies of its anatomical and physiological characteristics had been undertaken. Recent morphological studies of Boyd (1962) demonstrated that the muscle spindles have two different intrafusal muscle fibers, nuclear bag and nuclear chain fiber, and these intrafusal fibers are under independent motor innervation by ${\gamma}_1$ and ${\gamma}_2$ motor neurone. Neurophysiological studies of Hunt and Kuffler (1951) showed regulatory effect of ${\gamma}$ motor neurone upon the excitability of the spindle afferents. Harvey and Mathews (1961) observed the dynamic and static characteristics of the two different spindle afferents, the primary and secondary ending. Furthermore, Mathews (1962) postulated the functional existance of two kind of ${\gamma}$ motor neurones, namely, the dynamic and static fusimotor fiber. Recent report of Kim and Partridge(1969) pointed out that the descending vestibular signals had increased the slope of the length-tension relationship in stretch reflex; Kim (1967) demonstrated that the descending vestibular impulses act upon the stretch reflex loop through the ${\gamma}$ motor pathway. These experimental evidences from the morphological and neurophysiological studies on the muscle spindles support the concept that the stretch reflex action of the skeletal muscle operates as a negative feedback control system. The author had discussed the way by which the f system participates in the control of stretch relfex feed back system. that was taken for a prototype of posture and movement.

• 설비공학논문집
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• 제29권3호
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• pp.134-141
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• 2017

The purpose of this study was to analyze physiological changes via a cold air reaction experiment to generate basic data that are useful for the development of an automobile active air conditioning system to prevent drowsiness. The $CO_2$ concentration causing drowsiness in vehicle operation was kept below a certain level. Air was blown to the driver's face by using an indoor air cooling apparatus. Sleepiness and the arousal state of the driver in cold wind were measured by physiological signals. It was evident in the EEG that alpha waves decreased and beta waves increased, caused by cold air stimulation. The ${\alpha}/{\beta}$ ratio was reduced by about 52.9% and an alert state confirmed. In the electrocardiogram analysis, the efficiency of cold air stimulation was confirmed by the mean heart rate interval change. The R-R interval had a delay time of about one minute compared to the EEG response. The findings confirmed an arousal effect from sleepiness due to cold air stimulation.

• 한국통신학회논문지
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• 제37권4C호
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• pp.283-289
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• 2012

웹 기반의 생체신호 모니터링 시스템은 대량의 생체신호를 처리, 분석하여 의료센터에 전송함으로써 환자에게 신속하고 적절한 의료 서비스를 제공할 수 있다. 따라서 본 논문에서는 생체 신호를 기반으로 심장 이혈 효과를 분석하기 위한 시스템을 설계, 구성하였다. 심장 이혈 효과 분석 시스템은 생체영상 및 음성신호를 입력받고 심장 관련 생체정보 특징 추출 기법을 적용하여 입력된 생체신호 측정 및 분석을 수행하였다. 또한, 피실험자 20명을 대상으로 시스템의 성능 평가를 수행하여 실제 홈 헬스케어에 적용 가능한 시스템임을 통계 분석을 통해 입증하였다.

• 대한의용생체공학회:의공학회지
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• 제19권5호
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• pp.539-546
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• 1998

본 연구에서는 시각과 청각자극을 대표하는 색과 음악자극 하에서 인감의 감성을 정량적으로 평가하고 색감성과 음악감성 사이의 상관성을 조사하였다. 감성의 정량화를 위하여 7점 척도 20항목의 설문지를 통한 의미 미분법과 요인분석을 사용하여 피험자의 주관적 평가를 수행하였고, 뇌전도, 심전도, 피부 전도도, 호흡률 등의 생체신호를 측정, 분석하였다. 피험사의 주관적 평가로부터 각 자극에 대한 대표 감성어휘를 도출하였으며, 생체신호의 분석을 통하여 본 논문에서 제안한 정규화된 변수 값으로 색자극콰 음악자극에 대한 감성을 정량적으로 평가하여 지표화할 수 있었다. 또한 색자극과 음악자극 사이의 상관성을 Kendall의 상관계수로 분석한 결과 0.461에서 0.810의 상관성이 있음을 확인하였다. 본 연구에서 사용한 감성어휘 추출방법이나 감성지표 개발 방법은 감성제품 개발이나 색치료, 음악치료 등에 이용될 수 있다.

• 융합신호처리학회논문지
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• 제3권1호
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• pp.27-32
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• 2002

본 논문에서 제안한 텔레미트리 시스템은 생체신호를 중거리로 전송하기 위한 RF 송신기와 전자파 간섭의 영향이 없는 광을 매체로한 수신기이다. 텔레미트리 시스템은 of 65$\times$125$\times$45mm크기이며, RF 송신부, 광 수신부와 생체신호 처리를 위한 CMOS 칩으로 구성되어 있다. 제안된 텔레메트리 장점은 전자파에 노출을 최소화하면서 중거리(50m) 텔레메트리가 가능하여, 자유로운 상태에서의 모니터링이 가능하다. 관측 시스템은 실시간 처리를 위해 dual-processor구조로 설계했다. 본 연구에서는 1 채널 360Hz, 16 Bits의 심전도 데이터를 1.42초 간격으로 실시간 웨이브렛 변환할 수 있었다.