• 제목/요약/키워드: Medical Engineering

검색결과 8,959건 처리시간 0.035초

경추용 자립형 케이지의 실험적 평가 (Testing Evaluation for Stand-Alone Cervical Cage)

  • 백명현;이문환
    • 한국정밀공학회지
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    • 제33권11호
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    • pp.937-941
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    • 2016
  • Stand-alone cervical cage consists of a PEEK body, Ti plate, and screw, which are configured as a single-piece. Through a single operation, this implantable medical device is capable of completely fixing the cervical vertebral body. For example, instead of a plate, which is normally used, the intervertebral disc is removed and replaced with a cervical cage. It should be noted that in Korea, KFDA guidelines for a stand-alone cervical cage have not yet been suggested. Therefore, the aim of this study is to present the systematic study of the static compression test, static torsion test, dynamic compression test, and expulsion test. Further, the test method is designed to refer to the ASTM standard and relative literature.

SIFT 특징을 이용한 의료 영상의 회전 영역 보정 (Correction of Rotated Region in Medical Images Using SIFT Features)

  • 김지홍;장익훈
    • 한국멀티미디어학회논문지
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    • 제18권1호
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    • pp.17-24
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    • 2015
  • In this paper, a novel scheme for correcting rotated region in medical images using SIFT(Scale Invariant Feature Transform) algorithm is presented. Using the feature extraction function of SIFT, the rotation angle of rotated object in medical images is calculated as follows. First, keypoints of both reference and rotated medical images are extracted by SIFT. Second, the matching process is performed to the keypoints located at the predetermined ROI(Region Of Interest) at which objects are not cropped or added by rotating the image. Finally, degrees of matched keypoints are calculated and the rotation angle of the rotated object is determined by averaging the difference of the degrees. The simulation results show that the proposed scheme has excellent performance for correcting the rotated region in medical images.

Development of a knowledge-based medical expert system to infer supportive treatment suggestions for pediatric patients

  • Ertugrul, Duygu Celik;Ulusoy, Ali Hakan
    • ETRI Journal
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    • 제41권4호
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    • pp.515-527
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    • 2019
  • This paper discusses the design, implementation, and potential use of an ontology-based mobile pediatric consultation and monitoring system, which is a smart healthcare expert system for pediatric patients. The proposed system provides remote consultation and monitoring of pediatric patients during their illness at places distant from medical service areas. The system not only shares instant medical data with a pediatrician but also examines the data as a smart medical assistant to detect any emergency situation. In addition, it uses an inference engine to infer instant suggestions for performing certain initial medical treatment steps when necessary. The applied methodologies and main technical contributions have three aspects: (a) pediatric consultation and monitoring ontology, (b) semantic Web rule knowledge base, and (c) inference engine. Two case studies with real pediatric patients are provided and discussed. The reported results of the applied case studies are promising, and they demonstrate the applicability, effectiveness, and efficiency of the proposed approach.

골이식재의 표면 특성 연구 동향과 유효성 분석 ( Research trends and Efficacy Analysis of Surface Characteristics of Bone Grafts)

  • 정용훈;이계욱;정태곤
    • 한국표면공학회지
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    • 제57권4호
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    • pp.234-253
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    • 2024
  • As the population ages, the importance of effective bone disease treatments is increasing, highlighting the role of bone grafts. Bone grafts are categorized into natural (autografts, allografts, xenografts) and synthetic (ceramics, polymers). Natural grafts have excellent regenerative abilities but pose biological risks, while synthetic grafts are biocompatible but less effective in regeneration. Various studies aim to enhance the safety and efficacy of bone grafts, significantly altering their surface properties. This review examines these studies and the resulting surface changes, aiming to guide future research and clinical applications.

자화침 시스템의 자율신경계 활성화 효과 검증을 위한 동공크기변이 분석 (Analysis of Pupil Size Variability for Effectiveness Verification of Activation Level of Autonomic Nerve System by Electromagnetic Acupuncture System)

  • 류문학;이나라;최우혁;김수병;이용흠;신태민
    • Korean Journal of Acupuncture
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    • 제29권4호
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    • pp.554-562
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    • 2012
  • Objectives : The purpose of this research is to verify the effects of the Electromagnetic acupuncture(EMA) on BL15 by Pupil size variability(PSV) which is directly related to the activation of the Autonomic Nervous System. Methods : Thirty male subjects participated in this study and were divided into three groups(non-stimulated, manual acupuncture and EMA group). The size of pupil was measured in the cube place of $60{\times}60{\times}60$ cm in order to avoid the effect of the surrounding circumstances. All subjects were measured the size of left pupil about 200sec in the constant illumination. Results : We observed the decrease in PSV of manual acupuncture group compared to non-stimulation group, but it was not significant statistically(p>0.05). The decrease in PSV of EMA group was observed in comparison to two groups, and we confirmed the result of significant difference statistically(p<0.05). Conclusions : We concluded that EMA treatment method is enough to activate in the parasympathetic nerve system by inducing the biotransformation.

Effect of Codonopsis lanceolata with Steamed and Fermented Process on Scopolamine-Induced Memory Impairment in Mice

  • Weon, Jin Bae;Yun, Bo-Ra;Lee, Jiwoo;Eom, Min Rye;Ko, Hyun-Jeong;Kim, Ji Seon;Lee, Hyeon Yong;Park, Dong-Sik;Chung, Hee-Chul;Chung, Jae Youn;Ma, Choong Je
    • Biomolecules & Therapeutics
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    • 제21권5호
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    • pp.405-410
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    • 2013
  • Codonopsis lanceolata (Campanulaceae) traditionally have been used as a tonic and to treat patients with lung abscesses. Recently, it was proposed that the extract and some compounds isolated from C. lanceolata reversed scopolamine-induced memory and learning deficits. The purpose of this study was to evaluate the improvement of cognitive enhancing effect of C. lanceolata by steam and fermentation process in scopolamine-induced memory impairment mice models by passive avoidance test and Morris water maze test. The extract of C. lanceolata or the extract of steamed and fermented C. lanceolata (SFCE) was orally administered to male mice at the doses of 100 and 300 mg/kg body weight. As a result, mice treated with steamed and fermented C. lanceolata extract (SFCE) (300 mg/kg body weight, p.o.) showed shorter escape latencies than those with C. lanceolata extract or the scopolamine-administered group in Morris water maze test. Also, it exerted longer step-through latency time than scopolamine treated group in passive avoidance test. Furthermore, neuroprotective effect of SFCE on glutamate-induced cytotoxicity was assessed in HT22 cells. Only SFCE-treated cells showed significant protection at 500 ${\mu}g/ml$. Interestingly, steamed C. lanceolata with fermentation contained more phenolic acid including gallic acid and vanillic acid than original C. lanceolata. Collectively, these results suggest that steam and fermentation process of C. lanceolata increased cognitive enhancing activity related to the memory processes and neuroprotective effect than original C. lanceolata.

Expression of HERC4 in Lung Cancer and its Correlation with Clinicopathological Parameters

  • Zeng, Wen-Li;Chen, Yao-Wu;Zhou, Hui;Zhou, Jue-Yu;Wei, Min;Shi, Rong
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권2호
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    • pp.513-517
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    • 2015
  • Background: Growing evidence suggests that the members of the ubiquitin-proteasome system (UPS) are important for tumorigenesis. HERC4, one component, is a recently identified ubiqutin ligase. However, the expression level and function role of HERC4 in lung cancer remain unknown. Our objective was to investigate any correlation between HERC4 and development of lung cancer and its clinical significance. Materials and Methods: To determine HERC4 expression in lung cancer, an immunohistochemistry analysis of a tissue microarray containing samples of 10 lung normal tissues, 15 pulmonary neuroendocrine carcinomas, 45 squamous epithelial cancers and 50 adenocarcinomas was conducted. Receiver operating characteristic (ROC) curve analysis was applied to obtain a cut-off point of 52.5%, above which the expression of HERC4 was regarded as "positive". Results: On the basis of ROC curve analysis, positive expression of HERC4 was detected in 0/10 (0.0%) of lung normal tissues, in 4/15 (26.7%) of pulmonary neuroendocrine carcinomas, in 13/45 (28.9%) of squamous epithelial cancers and in 19/50 (38.0%) of adenocarcinomas. It showed that lung tumors expressed more HERC4 protein than adjacent normal tissues (${\chi}^2$=4.675, p=0.031). Furthermore, HERC4 positive expression had positive correlation with pT status (${\chi}^2$=44.894, p=0.000), pN status (${\chi}^2$=43.628, p=0.000), histological grade (${\chi}^2$=7.083, p=0.029) and clinical stage (${\chi}^2$=72.484, p=0.000), but not age (${\chi}^2$=0.910, p=0.340). Conclusions: Our analysis suggested that HERC4 is likely to be a diagnostic biomarker for lung cancer.

Identification of Atherosclerosis Related Gene Expression Profiles by Treatment of Benzo(a)pyrene in Human Umbilical Vein Endothelial Cells

  • Lee, Sun-Hee;Lee, Seung-Eun;Ahn, Hyun-Jong;Park, Cheung-Seog;Cho, Jeong-Je;Park, Yong-Seek
    • Molecular & Cellular Toxicology
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    • 제5권2호
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    • pp.113-119
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    • 2009
  • Benzo(a)pyrene (BaP) is a persistent environmental contaminant and is present in tobacco smoke. BaP is considered a major contributor of cardiovascular disease. While the activation of endothelial cells by stimuli including tobacco smoke and air pollution contributes importantly to cardiovascular disease, the nature of BaP's mechanism is unclear. In this study, gene expression profiles were investigated in BaPtreated human umbilical vein endothelial cells (HUVECs). Various atherosclerosis related genes could be up- and down-regulated more than 2-fold by BaP, and mRNA levels of atherosclerosis related genes encoding apolipoproteinC III, TLR 2, ICAM 1 and exportin 4 were significantly increased by BaP. Our data suggest that BaP-mediated changes in gene expression contribute to the progression of cardiovascular disease.

Induction of Apoptosis in Human Leukemic Cell Lines by Diallyl Disulfide via Modulation of EGFR/ERK/PKM2 Signaling Pathways

  • Luo, Nian;Zhao, Lv-Cui;Shi, Qing-Qiang;Feng, Zi-Qiang;Chen, Di-Long;Li, Jing
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3509-3515
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    • 2015
  • Background: Diallyl disulfide (DADS) may exert potent anticancer action both in vitro and in vivo. Although its effects on cancer are significant, the underlying mechanisms remain unknown. In this study, we sought to elucidate possible links between DADS and pyruvate kinase (PKM2). Materials and Methods: $KG1{\alpha}$, a leukemia cell line highly expressing PKM2 was used with a cell counting kit (CCK)-8 and flow cytometry (FCM) to investigate the effects of DADS. Relationships between PKM2 and DADS associated with phosphorylation of EGFR, ERK1/2 and MEK, were assessed by western blot analysis. Results: In $KG1{\alpha}$ cells highly expressing PKM2, we found that DADS could affect proliferation, apoptosis and EGFR/ERK/PKM2 signaling pathways, abrogating EGF-induced nuclear accumulation of PKM2. Conclusions: These results suggested that DADS suppressed the proliferation of $KG1{\alpha}$ cells, providing evidence that its proapoptotic effects are mediated through the inhibition of EGFR/ERK/PKM2 signaling pathways.

Effect of Bone Cement Volume and Stiffness on Occurrences of Adjacent Vertebral Fractures after Vertebroplasty

  • Kim, Jin-Myung;Shin, Dong Ah;Byun, Dong-Hak;Kim, Hyung-Sun;Kim, Sohee;Kim, Hyoung-Ihl
    • Journal of Korean Neurosurgical Society
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    • 제52권5호
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    • pp.435-440
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    • 2012
  • Objective : The purpose of this study is to find the optimal stiffness and volume of bone cement and their biomechanical effects on the adjacent vertebrae to determine a better strategy for conducting vertebroplasty. Methods : A three-dimensional finite-element model of a functional spinal unit was developed using computed tomography scans of a normal motion segment, comprising the T11, T12 and L1 vertebrae. Volumes of bone cement, with appropriate mechanical properties, were inserted into the trabecular core of the T12 vertebra. Parametric studies were done by varying the volume and stiffness of the bone cement. Results : When the bone cement filling volume reached 30% of the volume of a vertebral body, the level of stiffness was restored to that of normal bone, and when higher bone cement exceeded 30% of the volume, the result was stiffness in excess of that of normal bone. When the bone cement volume was varied, local stress in the bony structures (cortical shell, trabecular bone and endplate) of each vertebra monotonically increased. Low-modulus bone cement has the effect of reducing strain in the augmented body, but only in cases of relatively high volumes of bone cement (>50%). Furthermore, varying the stiffness of bone cement has a negligible effect on the stress distribution of vertebral bodies. Conclusion : The volume of cement was considered to be the most important determinant in endplate fracture. Changing the stiffness of bone cement has a negligible effect on the stress distribution of vertebral bodies.