• Title/Summary/Keyword: Biomedical technology

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Feedback control for stable PPG measurement (안정된 광전용적맥파(PPG) 측정을 위한 피드백 제어 연구)

  • Lee, Hyun-Ki;Jho, Jung-Hyun;Sin, Woo-Sik;Yoo, Gil-Won
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.891-892
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    • 2006
  • Photoplethsymogram (PPG) drifts due to the changes in respiration and blood perfusion as well as external light. This hinders a proper PPG measurement. We controlled DC drifts by controlling the signal ground of PPG signals. A microprocessor-based system successfully controlled DC drifts of PPG signals.

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8 bit digital signal processing for a portable biosignal monitoring device (휴대용 생체신호 측정시스템의 8비트 디지털신호처리)

  • Shin, Woo-Sik;Ji, Yong-Hwan;Cho, Jung-Hyun;Yoon, Gil-Won
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.893-894
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    • 2006
  • DSP based on a 8 bit microprocessor was studied for ECG and PPG signals. Digital filtering has an advantage of reducing hardware components in system-on-chip design. However, low resolution such as in 8 bit data has much difficulties in DSP. We demonstrated a comparable performance of DSP filtering compared with analog filters.

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Small GTPases and formins in mammalian oocyte maturation: cytoskeletal organizers

  • Kwon, So-Jung;Lim, Hyun-Jung J.
    • Clinical and Experimental Reproductive Medicine
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    • v.38 no.1
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    • pp.1-5
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    • 2011
  • The maturation process of mammalian oocytes accompanies an extensive rearrangement of the cytoskeleton and associated proteins. As this process requires a delicate interplay between the cytoskeleton and its regulators, it is often targeted by various external and internal adversaries that affect the congression and/or segregation of chromosomes. Asymmetric cell division in oocytes also requires specific regulators of the cytoskeleton, including formin-2 and small GTPases. Recent literature providing clues regarding how actin filaments and microtubules interact during spindle migration in mouse oocytes are highlighted in this review.

Development of Indocyanine Green and 5-Aminolevulinic Acid Detection System for Surgical Microscope (수술현미경용 다중형광 관측 시스템 연구)

  • Kim, Hong Rae;Lee, Hyun Min;Yoon, Woong Bae;Kim, Young Jae;Kim, Seok Ki;Yoo, Heon;Joo, Jae Young;Kim, Kwang Gi;Lee, Seung-Hoon
    • Journal of Biomedical Engineering Research
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    • v.36 no.1
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    • pp.16-21
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    • 2015
  • Indocyanine green(ICG) and 5-aminolevulinic acid(5-ALA) have been widely used to mark blood vessels or tumors. However, fluorescent dye detection systems were designed to use one type of dyes only. In this study, we proposed a detection system capable of detecting Indocyanine green and 5-aminolevulinic acid. Multiple filters and light sources are integrated into a single system. In this study, we performed analysis of fluorescent dyes and configured a detection system. During the analysis, it was found that Indocyanine green and 5-aminolevulinic acid have the maximum intensity at $40{\mu}M$. We designed light source for fluorescent dyes and conducted compatibility test using a commercial surgical microscope. The fluorescent dye detection system was configured based on the experimental results. The developed system successfully detects Indocyanine green and 5-aminolevulinic acid. Therefore, more efficient surgical operations can be achieved using both fluorescent dyes at the same time. We expect that the developed system can increase the survival rate of patients.

An Open Medical Platform to Share Source Code and Various Pre-Trained Weights for Models to Use in Deep Learning Research

  • Sungchul Kim;Sungman Cho;Kyungjin Cho;Jiyeon Seo;Yujin Nam;Jooyoung Park;Kyuri Kim;Daeun Kim;Jeongeun Hwang;Jihye Yun;Miso Jang;Hyunna Lee;Namkug Kim
    • Korean Journal of Radiology
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    • v.22 no.12
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    • pp.2073-2081
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    • 2021
  • Deep learning-based applications have great potential to enhance the quality of medical services. The power of deep learning depends on open databases and innovation. Radiologists can act as important mediators between deep learning and medicine by simultaneously playing pioneering and gatekeeping roles. The application of deep learning technology in medicine is sometimes restricted by ethical or legal issues, including patient privacy and confidentiality, data ownership, and limitations in patient agreement. In this paper, we present an open platform, MI2RLNet, for sharing source code and various pre-trained weights for models to use in downstream tasks, including education, application, and transfer learning, to encourage deep learning research in radiology. In addition, we describe how to use this open platform in the GitHub environment. Our source code and models may contribute to further deep learning research in radiology, which may facilitate applications in medicine and healthcare, especially in medical imaging, in the near future. All code is available at https://github.com/mi2rl/MI2RLNet.

Measurement and removal of a cerenkov light in a plastic optical fiber to detect a scintillating light (섬광검출을 위한 플라스틱광섬유에서의 체렌코프 빛 측정 및 제거)

  • Cho, Dong-Hyun;Jang, Kyoung-Won;Yoo, Wook-Jae;Shin, Sang-Hun;Lee, Bong-So;Park, Byung-Gi;Cho, Hyo-Sung;Kim, Sin
    • Journal of Sensor Science and Technology
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    • v.17 no.2
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    • pp.100-105
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    • 2008
  • The objectives of this study are to measure and to remove Cerenkov lights generated in a fiber-optic radiation sensor by a charge-coupled device. we have fabricated a fiber-optic radiation sensor which comprises an organic scintillator, a plastic optical fiber and a charge-coupled device. Charge-coupled device as a light measuring tool has many advantages which are easy in multi-dimensional measurements, high spatial resolution and relatively low cost.

Feasibility study on the development of noncontact temperature sensor using infrared optical fiber (적외선 투과 광섬유를 이용한 비접촉식 온도 센서 개발을 위한 기초 연구)

  • Yoo, Wook-Jae;Cho, Dong-Hyun;Chung, Soon-Cheol;Tack, Gye-Rae;Jun, Jae-Hoon;Lee, Bong-Soo;Son, Sang-Hee;Cho, Seung-Hyun
    • Journal of Sensor Science and Technology
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    • v.15 no.3
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    • pp.179-185
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    • 2006
  • We have developed a noncontact temperature sensor using a silver halides infrared optical fiber. An infrared radiation from a heat source is transferred by a silver halides infrared optical fiber and measured by infrared sensors such as a thermopile and a thermal optical power-meter. The relationships between the temperature of a heat source and the output voltage of the thermopile and the optical power of a thermal optical power-meter are determined. The measurable temperature range using a thermopile and a thermal optical power-meter are from 100 to $750^{\circ}C$ and from 30 to $750^{\circ}C$ respectively. It is expected that a noncontact temperature sensor using infrared optical fiber can be developed for medical and industrial usages based on the results of this study.

Egr-1 regulates the transcription of the BRCA1 gene by etoposide

  • Shin, Soon Young;Kim, Chang Gun;Lee, Young Han
    • BMB Reports
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    • v.46 no.2
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    • pp.92-96
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    • 2013
  • The breast cancer susceptibility gene BRCA1 encodes a nuclear protein, which functions as a tumor suppressor and is involved in gene transcription and DNA repair processes. Many families with inherited breast and ovarian cancers have mutations in the BRCA1 gene. However, only a few studies have reported on the mechanism underlying the regulation of BRCA1 expression in humans. In this study, we investigated the transcriptional regulation of BRCA1 in HeLa cells treated with etoposide. We found that three Egr-1-binding sequences (EBSs) were located at -1031, -1005, and -385 within the enhancer region of the BRCA1 gene. Forced expression of Egr-1 stimulated the BRCA1 promoter activity. EMSA data showed that Egr-1 bound directly to the EBS within the BRCA1 gene. Knockdown of Egr-1 through the expression of a small hairpin RNA (shRNA) attenuated etoposide-induced BRCA1 promoter activity. We conclude that Egr-1 targets the BRCA1 gene in HeLa cells exposed to etoposide.