• Title/Summary/Keyword: Biomedical Engineering

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The Feasibility of the DKUH-75 Left Ventricular Assist Device for Acute Cardiogenic Shock in Pigs (돼지의 급성 심인성 쇼크 모델에서 DKUH-75 좌심실보조키의 유용성에 관한 연구)

  • Park, Seong-Sik
    • Journal of Chest Surgery
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    • v.40 no.3 s.272
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    • pp.168-179
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    • 2007
  • Background: The recent trend of an increasing number of patients with acute cardiogenic shock or chronic congestive heart failure following myocardial infarction, as well as the considerable number who can not be weaned from cardiopulmonary bypass after open heart surgery, call for immediate efforts to develop affordable ventricular assist devices that are suitable for the Korean physique. Recently, a pneumatic pulsatile ventricular assist device (VAD), named DKUH-75, has been developed by the Department of Biomedical Engineering, in collaboration with the Department of Thoracic and Cardiovascular Surgery of Dankook University College of Medicine. The feasibility of the DKUH-75 VAD was evaluated on the bases of common hemodynamic variables and echocardiographic measurements in pigs, which are subjected to an acute cardiogenic shock state following myocardial infarction, using a novel coronary artery ligation method employing the ischemic preconditioning concept. Material and Method: Acute cardiogenic shock was induced in 10 Yorkshire Landrace Duroc strain pigs by ligating the left anterior descending coronary artery via an ischemic preconditioning process. The hemodynamic variables were monitored, with epicardial echocardiographic measurements performed before and one hour after the ligation. The DKUH-75 VAD was implanted into 5 pigs one hour after the onset of the shock. The hemodynamic variables and echocardiographic measurements were taken one hour after installation of the VAD. Result: The systolic, diastolic and mean systemic arterial pressures were significantly decreased in all the experimental animals one hour after the ligation. The systolic, diastolic and mean pulmonary arterial pressures were increased (Eds note: this completely contradicts the preceding statement? However, if you mean the non-experimental animals this should be stated?). The left ventricular end diastolic pressure (LVEDP) was increased, but the cardiac index decreased, An increase in the left ventricular end systolic dimension and decreases in the fractional shortening and ejection fraction were observed all animals one hour after the coronary artery ligation. In all 5 of the VAD implanted pigs, the systolic and mean systemic arterial pressures were increased, and the pulmonary arterial pressures decreased one hour after the implantation; the LVEDP decreased, but the cardiac index was significantly increased, In the echocardiographic measurements, the left ventricular end systolic dimension decreased after the implantation of the VAD, but the fractional shortening and ejection fraction significantly increased. Conclusion: Significant improvements in the hemodynamic variables and echocardiographic measurements were observed in the 5 VAD implanted animals one hour after installation, which had been subjected to an acute cardiogenic shock state by ligation of the coronary artery, indicating that the DKUH-75 VAD could help in the recovery of the myocardial function. This suggests that the DKUH-75 VAD is feasible in the short term in relation to an acute cardiogenic shock state due to myocardial infarction.

A comparative study on the spiritual needs between nursing students and nurses in Busan and Gyeongnam province (부산 경남 지역 간호 대학생과 간호사의 영적 요구도 비교)

  • Cho, Hyun;Sim, Eun-Kyung;Kwon, Young-Chae;Bae, Young-Hee;Woo, Young-Ok;Ji, Jae-Hoon;Jung, Ja-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.5
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    • pp.2178-2188
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    • 2012
  • This study is based upon 200 final responses from a survey conducted for 153 nurses and 147 nursing students in Busan and Gyeongnam province from september to october 2011. It is carried out to compare and understand the spiritual needs of nurses and nursing students that are inclined to be more exposed unhealthy people rather than healthy people. In this study, the level of spiritual care needs was divided into five fields such as 'love and fellowship', 'hope and peace', 'meaning and purpose of life', 'acceptance of death' and 'relationship with God' and was investigated. As a result, the love and fellowship was the highest level in group of nurses (r = 3.82) and the relationship with God was the lowest one (r = 2.73). In contrast, a group of nursing students showed that love and fellowship was the highest level (r = 3.92) and relationship with God was the lowest (r = 2.99) among five fields. There were statistical significances between nurses and nursing students in 'acceptance of death' and 'relationship with God' (p < 0.05). When looking at correlation between fields of spiritual needs of nurses, the correlation between 'meaning and purpose of life' and 'hope and peace' was the highest (r = .699) and the correlation between 'relationship with God' and 'hope and peace' was the lowest (r = .247). As the result of analysis on correlation between fields of spiritual needs of nursing students, the correlation between 'meaning and purpose of life' and 'hope and peace' was the highest (r = .660) and the correlation between 'acceptance of death' and 'relationship with God' was the lowest (r = .277). Therefore, it would be imperative to develop a more efficient and systemized education program for the spiritual care of nursing patients, on the basis of understanding the spiritual needs of nurses and nursing students.

The Composition of the Root of Ixeris dentata var. albiflora Nakai. and Cell Viability and DPPH Radical Scavenging Activities of its Extract (흰씀바귀 (고채(苦菜), Ixeris dentata var. albiflora Nakai)뿌리의 성분 분석과 추출물의 세포 생존율 및 DPPH 라디칼 소거 활성)

  • Hong, Seul-Gi;Jeong, Dong-Myong;Kim, Ki-Young;Hwang, Eun-Hee
    • Journal of Nutrition and Health
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    • v.43 no.2
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    • pp.105-113
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    • 2010
  • Ixeris dentata var. albiflora Nakai, a herbal plant, is often used to make a strong stomach as an antiphlogistic used when dyspepsia and to improve appetite in Korea and China. And also it is used for adult diseases such as diabetes and liver diseases as Korean traditional medicine. In this study, the composition and DPPH radical scavenging activities of the root of Ixeris dentata var. albiflora Nakai and its effects on cell viability on vero and chang cells were investigated. Moisture, crude ash, crude protein and crude lipid were 79.14, 2.49, 8.28 and 2.56 g/100 g respectively. The highest mineral content was K. The major free sugars were glucose, fructose and sucrose. Major fatty acid are linoleic acid, palmic acid and linolenic acid. Major amino acids were glutamic acid, arginine and aspartic acid and the total contents of amino acids were 28.12 mg/g. The methanol extracts were further fractionated with n-hexane, chloroform, ethylacetate, butanol and water to get an active fraction. In addition, cell viabilities in each fraction were determined. Methanol extract, butanol, and aqueous fraction showed strong survival rates in vero cell and chang cell viability test, and hexane, chloroform, and ethylacetate fraction were examined for toxin in a cell. The root of Ixeris dentata var. albiflora Nakai had scavenging activities against DPPH radicals in a dose-dependent assay. Ethylacetate fraction's SC50 was $6.8\{\mu}g/mL$, very strong DPPH radical scavenging activities, but water fraction did not show any activity.

Fertilizing Effects of Swine Compost Fermented with Sawdust on Mixed Pastures (혼파초지에 대한 톱밥발효돈분의 시용효과)

  • Shin, J. Soon;Cho, Young-Mu;Lee, Hyo-Ho;Yoon, Sea-Hung;Park, Geun-Je;Choi, Ki-Chun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.24 no.3
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    • pp.245-252
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    • 2004
  • Experiment was carried out to find the fertilizing effects of 8 different application rates of swine compost fermented with sawdust(SCS) including Chemical fertilizer(CF) on forage yield and soil chemical characteristics of mixed pastures sown in Sep. 1993 at National Livestock Research Institute, RDA., in Suwon during low years. It was arranged in a randomized complete block design with three replicates. Dry matter yield were shown at similar among treatments except Control and $50\%$ SCS of standard amount plot. In botanical composition, the legume and weeds percentages of each treatment were increased as advancing year. The final year's legume percentage were high in line with SCS fertilizing plots($39\%{\sim}43\%$), SCS + CF plots($30\%{\sim}41\%$) and CF plot($32\%$). In productions of TDN, NE and crude protein yield, SCS or SCS($75\%$) + CF($25\%$) were nearly same comparing those of CF, respectively. Phosphate, potassium, magnesium contents and K/(Ca + Mg) except calcium contents of those SCS fertilizing plots in plant were generally high with comparing CF. Those contents were proportional according to the fertilizing amount These result indicate the possibility to substitute chemical fertilizer for SCS($75\%$, 25ton/ha) + CF, $25\%$) as manure-N 210 kg/ha, but might be considered accumulation phosphate in the soil.

Functional Magnetic Resonance Imaging of Brain Reactivity to Insomnia-Related vs. General Anxiety-Inducing Stimuli in Insomnia Patients with Subjective-Objective Discrepancy of Sleep (주관적-객관적 수면시간 차이를 보이는 불면증 환자에서 일반적 불안에 비해 불면증 관련 자극으로 인한 뇌활성에 관한 기능적 자기공명영상 연구)

  • Kim, Nambeom;Lee, Jae Jun;Cho, Seo-Eun;Kang, Seung-Gul
    • Sleep Medicine and Psychophysiology
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    • v.27 no.1
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    • pp.24-31
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    • 2020
  • Objectives: Subjective-objective discrepancy of sleep (SODS) is a common symptom and one of the major phenotypes of insomnia. A distorted perception of sleep deficit might be related to abnormal brain reactivity to insomnia-related stimuli. We aimed to investigate differences in brain activation to insomnia-related stimuli vs. general anxiety-inducing stimuli among insomnia patients with SODS, insomnia patients without SODS, and healthy controls (HCs). Methods: All participants were evaluated for subjective sleep status using a sleep diary and questionnaires; occult sleep disorders and objective sleep status were assessed using polysomnography and actigraphy. Task functional magnetic resonance imaging was performed during insomnia-related stimuli (Ins) and general anxiety-inducing stimuli (Gen). Brain reactivity to Ins versus Gen was compared among insomnia with SODS, insomnia without SODS, and HC groups, and a combined insomnia disorder group (ID, insomnia with and without SODS) was also compared with HCs. Results: In the insomnia with SODS group compared to the insomnia without SODS group, the right precuneus and right supplementary motor areas showed significantly increased BOLD signals in response to Ins versus Gen. In the ID group compared to the HC group, the left anterior cingulate cortex showed significantly increased BOLD signals in response to Ins versus Gen. Conclusion: The insomnia with SODS and ID groups showed higher brain activity in response to Ins versus Gen, while this was not observed in the insomnia without SODS and HC groups, respectively. These results suggest that insomnia patients with sleep misperception are more sensitive to sleep-related threats than general anxiety-inducing threats.

The Anti-angiogenic Potential of a Phellodendron amurense Hot Water Extract in Vitro and ex Vivo (in Vitro와 ex vivo에서 황백 온수추출물의 신생혈관 억제효과)

  • Kim, Eok-Cheon;Kim, Seo Ho;Bae, Kiho;Kim, Han Sung;Gelinsky, Michael;Kim, Tack-Joong
    • Journal of Life Science
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    • v.25 no.6
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    • pp.693-702
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    • 2015
  • Blocking new blood-vessel formation (angiogenesis) is now recognized as a useful approach to the therapeutic treatment of many solid tumors. The best validated approach to date is to target the vascular endothelial growth-factor (VEGF) pathway, a key regulator of angiogenesis. Many natural products and extracts that contain a variety of chemopreventive compounds have been shown to suppress the development of malignancies through their anti-angiogenic properties. Phellodendron amurense, which is widely used in Korean traditional medicine, has been shown to possess antitumor, antimicrobial, and anti-inflammatory properties, among others. The present study investigated the effects of P. amurense hot-water extract (PAHWE) on angiogenesis, a key process in tumor growth, invasion, and metastasis. To investigate PAHWE’s anti-angiogenic properties, this study’s authors performed an analysis of angiogenesis and endothelial-cell proliferation, migration, invasion, and tube formation, as well as zymogram assays and the rat aortic ring-sprouting assay. PAHWE inhibited cell growth, mobility, and vessel formation in response to VEGF in vitro and ex vivo. Furthermore, it reduced VEGF-induced intracellular signaling events, such as the activation of matrix metalloproteinases (MMPs) -2 and -9. These results indicate that PAHWE’s anti-angiogenic properties might lead to the development of potential drugs for treating angiogenesis-associated diseases such as cancer.

Design of 1× Optical Path Relay Adapter for Beam Splitting Prism used in Day & Night Scope (주야 관측경용 빔 분리프리즘을 위한 1× Optical Path Relay Adapter 설계)

  • Lee, Dong-Hee;Choi, Gyu-Jung;Jung, In;Park, Seung-Hwan
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.4
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    • pp.441-447
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    • 2012
  • Purpose: This paper is about development and design of the 1x optical path relay adapter for the beam splitting prism by us the day & night scope. Methods: To product the day & night scope by using the beam splitting prism and the commercial zoom optical system with the C-mount lens barrel structure, the optical path relay adapter, which doesn't change the image size of the zoom optical system and can stretch the position of the image-forming surface, is needed. We could design the 1x optical path relay adapter by using the CodeV program in which the Lens Module mode is offered. Results: We could design the optical path relay adapter used in the day&night scope with the beam splitting prism, of which characteristics have the EFL of -56.0 mm, the magnification of +1.0x, the distance from the 1st lens surface to the last lens surface of about 20.4 mm. The resolution of this system is characterized by 30 lp/mm at 40% MTF. This is enough to accommodate the designed optical path relay adapter can overcome the resolution of the 3rd generation of image intesifier tubes. Conclusions: By designing and applying the optical path relay adapter of which optical characteristics have the EFL of -56.0 mm, the magnification of +1.0x, the distance from the 1st lens surface to the last lens surface of about 20.4 mm, and the resolution of 30 lp/mm at 40% MTF, we could develop the new type day&night scope consisting of the beam splitting, the commercial zoom optical system with the C-mount lens barrel structure, and the 3rd generation of image intesifier tubes.

Development of Prism Dot-sight Combined with Thermal Imaging Camera (열영상 카메라가 결합된 프리즘 도트사이트 개발)

  • Park, Seung-Hwan;Jung, Bo-Seon;Lee, Dong-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.4
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    • pp.479-485
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    • 2014
  • Purpose: This study relates to the development of the prism dot-sight combined with the thermal imaging camera. Methods: We have placed a reflector designed to the doublet type in the front of a BS (beam splitting) prism, have placed an OLED panel and a dot reticle generator to the top and bottom of the reflecting surface of the BS prism, and have placed a detachable magnifier between the BS prism and the observer by which the observer can see the magnified image of the OLED panel. By doing this, we were able to configure the new type prism dot-sight combined with the thermal imaging camera. Results: By placing the removable magnifier designed with a new type between the BS prism and the observer, we could design the new type prism dot-sight which performs the role of the dot sight by removing the magnifier during the day-time, and performs the role of the night scope during the night-time by which we can observe the enlarged image of the thermal imaging camera through the BS prism by attaching the removable magnifier. Conclusions: In this study, we have developed the prism dot-sight combined with the thermal imaging camera which is able to play the role of the day or night scope selectively, by disposing the designed magnifier characterized by the focal length of 44 mm, the viewing angle of ${\pm}7.0^{\circ}$, and the MTF value of 0.5 or more at the criterion of 50 lp/mm and the 0.7 field between the BS prism and the observer. By doing so, we could design and fabricate the new type prism dot-sight combined with the thermal imaging camera which can further increase the rapidity of firing and provide more convenience in the mounting of a firearm than the detachable combination of an existing dot sight and an existing night scope.

Comparison of Actigraphic Performance between $ActiWatch^{(R)}$ and $SleepWatch^{(R)}$:Focused on Sleep Parameters Utilizing Nocturnal Polysomnography as the Standard (활동기록기($ActiWatch^{(R)}$$SleepWatch^{(R)}$) 성능 비교 연구:야간수면다원기록을 표준으로 한 수면변인을 중심으로)

  • Shin, Hong-Beom;Lee, Ju-Young;Lee, Yu-Jin;Kim, Kwang-Jin;Lee, Eun-Young;Han, Jong-Hee;Im, Mee-Hyang;Jeong, Do-Un
    • Sleep Medicine and Psychophysiology
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    • v.12 no.1
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    • pp.27-31
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    • 2005
  • Objectives: We attempted to compare the performance of 2 commercially available actigraphies with focus on sleep parameters, using polysomnography as standard comparison tool. Methods: Fourteen normal volunteers (5 males and 9 females, mean age of $28{\pm}4.6\;years$) participated in this study. All the participants went through one night of polysomnography, simultaneously wearing 2 different kinds of actigraphies on each wrist. Polysomnographic and actigraphic data were stored, downloaded, and processed according to standard protocols and then statistically compared. Results: Both $ActiWatch^{(R)}$ and $SleepWatch^{(R)}$ tended to overestimate the total sleep time, compared to the polysomnography. $SleepWatch^{(R)}$ tended to underestimate the sleep latency. The two actigraphs and the polysomnograph did not show significant difference of sleep efficiency, when compared with one another. In addition, all of the sleep parameters from the instruments showed linear correlations except in $SleepWatch^{(R)}'s$ sleep latency. The sleep parameters from the two actigraphs did not show much noteworthy difference, and linear relationships were found between the sleep parameters from the two actigraphs. There was no significant distinction in the results of the two different actigraphs. Conclusion: The results of two actigraphies can be used interchangeably since the sleep parameters of the two different actigraphies do not show significant differences statistically. Overall, it is not legitimate to use actigraphy as a substitute for polysomnography. However, since sleep parameters except sleep latency show linear correlations, actigraphy might possibly be used to follow up patients after polysomnography.

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Computer Assisted EPID Analysis of Breast Intrafractional and Interfractional Positioning Error (유방암 방사선치료에 있어 치료도중 및 분할치료 간 위치오차에 대한 전자포탈영상의 컴퓨터를 이용한 자동 분석)

  • Sohn Jason W.;Mansur David B.;Monroe James I.;Drzymala Robert E.;Jin Ho-Sang;Suh Tae-Suk;Dempsey James F.;Klein Eric E.
    • Progress in Medical Physics
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    • v.17 no.1
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    • pp.24-31
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    • 2006
  • Automated analysis software was developed to measure the magnitude of the intrafractional and interfractional errors during breast radiation treatments. Error analysis results are important for determining suitable planning target volumes (PTV) prior to Implementing breast-conserving 3-D conformal radiation treatment (CRT). The electrical portal imaging device (EPID) used for this study was a Portal Vision LC250 liquid-filled ionization detector (fast frame-averaging mode, 1.4 frames per second, 256X256 pixels). Twelve patients were imaged for a minimum of 7 treatment days. During each treatment day, an average of 8 to 9 images per field were acquired (dose rate of 400 MU/minute). We developed automated image analysis software to quantitatively analyze 2,931 images (encompassing 720 measurements). Standard deviations ($\sigma$) of intrafractional (breathing motion) and intefractional (setup uncertainty) errors were calculated. The PTV margin to include the clinical target volume (CTV) with 95% confidence level was calculated as $2\;(1.96\;{\sigma})$. To compensate for intra-fractional error (mainly due to breathing motion) the required PTV margin ranged from 2 mm to 4 mm. However, PTV margins compensating for intefractional error ranged from 7 mm to 31 mm. The total average error observed for 12 patients was 17 mm. The intefractional setup error ranged from 2 to 15 times larger than intrafractional errors associated with breathing motion. Prior to 3-D conformal radiation treatment or IMRT breast treatment, the magnitude of setup errors must be measured and properly incorporated into the PTV. To reduce large PTVs for breast IMRT or 3-D CRT, an image-guided system would be extremely valuable, if not required. EPID systems should incorporate automated analysis software as described in this report to process and take advantage of the large numbers of EPID images available for error analysis which will help Individual clinics arrive at an appropriate PTV for their practice. Such systems can also provide valuable patient monitoring information with minimal effort.

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