• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.169-176
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• 2015

Implantable closed-loop epilepsy controllers require ideally both accurate epileptic seizure detection and low power consumption. On-chip oscillators can be used in implantable devices because they consume less power than other oscillators such as crystal oscillators. In this study, we investigated the tolerable error range of a lower power on-chip oscillator without losing the accuracy of seizure detection. We used 24 ictal and 14 interictal intracranial electroencephalographic segments recorded from epilepsy surgery patients. The performance variations with respect to oscillator frequency errors were estimated in terms of specificity, modified sensitivity, and detection timing difference of seizure onset using Generic Osorio Frei Algorithm. The frequency errors of on-chip oscillators were set at ${\pm}10%$ as the worst case. Our results showed that an oscillator error of ${\pm}10%$ affected both specificity and modified sensitivity by less than 3%. In addition, seizure onsets were detected with errors earlier or later than without errors and the average detection timing difference varied within less than 0.5 s range. The results suggest that on-chip oscillators could be useful for low-power implantable devices without error compensation circuitry requiring significant additional power. These findings could help the design of closed-loop systems with a seizure detector and automated stimulators for intractable epilepsy patients.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.747-750
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• 2004

The researching content of this article is to implement the image grabber system for use the dental hospital image examination. It receives the NTSC analog image through CCD optical camera, which is using the close photographing. we made the image grabber board, which gathers and obtains the analog image, by PCI format. We developed the C++ application and device drive to operate this board so that we totally could implement and confirm this Image grabber system.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.29-33
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• 1992

We examine the compression performance of two irreversible (lossy) compression techniques, ADCT-VQ (Adaptive Discrete Cosine Trandform - Vector Quantization) and JPEG (Joint Photographic Experts group) which are basis of medical image information systems. Under the same compression ratio, MSE(Mean Square Error) is 0.578 lower in JPEG than in ADCT-VQ while SNR(Signal to Noise Ratio) is 1.236 dB higher in JPEG than in ADCT-VQ.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.43-48
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• 2007

The medical imaging processing area with the development of high-speed Internet and the portable embedded system under prevailed ubiquitous environment is quick in research and development for the system that can search and decipher the patient's information in anytime and anywhere. Especially, the new applications demand utilizing scout images besides diagnostic purposes. With the development of ubiquitous system, medical image viewers are utilizing to the hospitals combined with PACS system and Web browser. This paper implements the mobile terminal based medical image viewing system that shows the potential in wireless environment.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.05
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• pp.9-12
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• 1991

The correlation search method yields velocity information by tracking scatter patterns between medical image frames. The displacement vector between a target region and the best correlated search region indicates the magnitude and direction of the inter-frame motion of that particular region. However, if the noise sources in the target region and the search region are correlated Gaussian, then the cross-correlation technique fails to work well because it estimates the cross-correlation of both signals and noises. In this paper we develop a new correlation search method which seeks the best correlated third-order statistics between a target and the search region to suppress the effect of correlated Gaussian noise sources. Our new method yields better estimations of velocity than the conventional cross-correlation method.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.293-296
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• 1996

In this paper, we studied two image characteristics, similarity and smoothness, which give rise to local and global redundancy in image representation. The similarty means that any patterns in the image repeat itself anywhere in the rest of image. The smoothness means that the gray level values within a given block vary gradually rather than abruptly. In this sense, we propose a lossless medical image compression scheme which exploits both types of redundancy. This method segments the image into variable size blocks and encodes them depending on characteristics of the block. The proposed compression schemes works better than other compression schemes such as the huffman, the arithmetic, the Lempel-Ziv and the lossless scheme of JPEG.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1250-1252
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• 2009

Cellular 망에서의 무선통신은 일반적으로 하나의 송수신안테나를 사용하거나 둘 이상의 송수신 안테나를 사용한다. MRRC(Maximum Ratio Receiver Combining)기법의 경우 여러 안테나를 사용하여 신호룰 수신하는 시스템이며, 이 경우 각 안테나의 채널에 따른 이득과 손실을 고려한 수신기가 제안되었다. Cellular model에서의 SINR 값에 따른 추정을 통해 최적 결합 기법을 적용한 MRRC 수신기를 사용하는 경우, 이에 따른 Cellular modeling을 이용하여 시스템 레벨에서의 MRRC 기법과 Optimum-MRRC 기법을 도입으로 인한 성능의 개선을 알 수 있다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.6
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• pp.251-260
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• 2010

Through the convergence of medical services and the IT technique, the patient's personal health information computerization has been rapidly spread with propagation of electronic medical record(EHR). In addition, by entering u-health, the demand of the secondary use for public health, medical research, and medical service using electronic patient health care records are increasing. The personal health information secondary uses for the development of academic medical area and service, are very good thing. But, carelessly to use personal health information, the patient privacy would be damaged. However, there are not yet systematic studies about secondary use of personal health information. Therefore, in this paper, we analyze the difference of the internal and external bill for personal medical data secondary use and propose the direction of the medical service development and preservation of the individual's privacy.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.294-298
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• 1997

In the magnetic resonance imaging, the fast spin echo imaging technique is a widely used clinical imaging method, since its scanning time is much shorter than the conventional spin echo imaging and it gives the almost same image quality. However, the fast spin echo technique has two times longer imaging time or the dual echo acquisition which can obtain a spin density image and a $T_2$-weighted image simultaneously. To overcome such a drawback, this paper proposes a new fast dual echo imaging technique which can give the same quality images at the single echo imaging time. The proposed technique reduces the imaging time by overlapping most of echo train data for each image reconstruction. In order to verify its validity and usability the human head experimental results which were obtained at the 0.3T permanent MRI system are presented.

• Electronics and Telecommunications Trends
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• v.32 no.6
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• pp.27-39
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• 2017

A variety of medical devices are utilized to repair or help injured body functions after accidental injury(such as a traffic accident), population aging, or disease. Such medical devices are being actively researched and developed in portable form, skin patchable type, and further, implantable form. In the future, active implantable medical devices for neuro and brain sciences are expected to be developed. Active implantable medical devices that detect brain signals and control neurology for a wider understanding of human cognition and nerve functions, and for an understanding and treatment of various diseases, are being actively pursued for future use. In this paper, the core elements of implantable devices that can be applied to neuro and brain sciences are classified into electrode technologies for bio-signal acquisition and stimulation, analog/digital circuit technologies for signal processing, human body communication technologies, wireless power transmission technologies for continuous device use, and device integration technologies to integrate them. In each chapter, the latest technology development trends for each detailed technology field are reviewed.