• Title/Summary/Keyword: Biomedical technology

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Preparation of hybrid Fe3O4 nanoparticles for biomedical applications (생의학적 응용을 위한 Fe3O4 복합 나노입자의 제조)

  • Bae, Sung-Su;Nguyen, The Dung;Kim, Kyo-Seon
    • Journal of Industrial Technology
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    • v.36
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    • pp.77-81
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    • 2016
  • Superparamagnetic $Fe_3O_4$ nanoparticles with particle size from 10 to 20 nm were synthesized by coprecipitation method. Subsequently, the $Fe_3O_4$ nanoparticles were used to fabricate $Fe_3O_4/SiO_2$ core-shell nanoparticles by sol-gel method. The $Fe_3O_4/SiO_2$ nanoparticles synthesized by sol-gel method exhibit the high uniformities of particle size and shape. We also investigated the heating characteristics of $Fe_3O_4$ and $Fe_3O_4/SiO_2$ nanoparticles for biomedical applications. The $Fe_3O_4$ nanoparticles show the faster temperature increase and the higher specific loss power(SLP) value than the $Fe_3O_4/SiO_2$ nanoparticles.

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Physiological functions of the TRPM4 channels via protein interactions

  • Cho, Chang-Hoon;Lee, Young-Sun;Kim, Eunju;Hwang, Eun Mi;Park, Jae-Yong
    • BMB Reports
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    • v.48 no.1
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    • pp.1-5
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    • 2015
  • Transient Receptor Potential, Melastatin-related, member 4 (TRPM4) channels are $Ca^{2+}$-activated $Ca^{2+}$-impermeable cation channels. These channels are expressed in various types of mammalian tissues including the brain and are implicated in many diverse physiological and pathophysiological conditions. In the past several years, the trafficking processes and regulatory mechanism of these channels and their interacting proteins have been uncovered. Here in this minireview, we summarize the current understanding of the trafficking mechanism of TRPM4 channels on the plasma membrane as well as heteromeric complex formation via protein interactions. We also describe physiological implications of protein-TRPM4 interactions and suggest TRPM4 channels as therapeutic targets in many related diseases.

Nondestructive Estimation of Mechanical Orthogonality of Human Trabecular Bone by Computed Tomography and Spherical Indentation Test

  • Bae Tae Soo;Lee Tae Soo;Choi Kuiwon
    • Journal of Biomedical Engineering Research
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    • v.26 no.2
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    • pp.117-122
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    • 2005
  • The elastic modulus and the apparent density of the trabecular bone were evaluated from spherical indentation tests and Computed Tomography (CT) and their relationship was quantified. The femurs were prepared for trabecular bone analysis. Embedded with respect to their anatomical orientation, the transverse planes of the trabecular bone specimens were scanned at 1㎜ intervals using a CT scanner. The metaphyseal regions of femurs were sectioned with a diamond-blade saw, producing 8㎜ cubes. Using a specially made spherical indentation tester, the cubes were mechanically tested in the anterior-posterior (AP), medial-lateral (ML), and inferior-superior (IS) directions. After determination of modulus from the mechanical testing, the apparent densities of the specimens were measured. The results showed that the IS modulus was significantly greater than both the AP and ML moduli with the AP modulus greater than the ML modulus. This demonstrated that orthogonality was a structural characteristic of the trabecular bone. The power relationship between the modulus and the apparent density was also found to be statistically significant.

The Study of Design and Implementation of RFID Emergency Medical Information System(REMIS) (RFID와 HL7을 이용한 응급 의료 정보 시스템 설계 및 구현에 관한 연구)

  • Hong, Kyu-Seog;Hwang, Sung-Oh;Lee, Hyun-Sook;Yoon, Young-Ro
    • Journal of Biomedical Engineering Research
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    • v.28 no.5
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    • pp.703-712
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    • 2007
  • In this paper, we designed the RFID(Radio Frequency Identification) Emergency Medical Information System(REMIS). This REMIS offers the emergency patient's medical information using RFID and HL7(Health Level 7) to an emergency medical technician. In emergency situation as like coma, if the communication, from the patient's current location to the hospital, is possible, REMIS offer the medical information of the patient through REMIS server to an emergency medical technician. In the state of communication blocked, REMIS can offer the patient identification and the emergency information through RFID tag, which the patient wear, to an emergency medical technician. When this system was designed, the protection of the patient's medical information and their privacy was considered, and the HL7 was used to be compatible with another medical systems. Therefore, in this paper, REMIS was designed that it is always possible to offer the emergency patient's information to an emergency medical technician regardless of any communication status and to improve the emergency rescue process, effectively.

Rule Weight-Based Fuzzy Classification Model for Analyzing Admission-Discharge of Dyspnea Patients (호흡곤란환자의 입-퇴원 분석을 위한 규칙가중치 기반 퍼지 분류모델)

  • Son, Chang-Sik;Shin, A-Mi;Lee, Young-Dong;Park, Hyoung-Seob;Park, Hee-Joon;Kim, Yoon-Nyun
    • Journal of Biomedical Engineering Research
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    • v.31 no.1
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    • pp.40-49
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    • 2010
  • A rule weight -based fuzzy classification model is proposed to analyze the patterns of admission-discharge of patients as a previous research for differential diagnosis of dyspnea. The proposed model is automatically generated from a labeled data set, supervised learning strategy, using three procedure methodology: i) select fuzzy partition regions from spatial distribution of data; ii) generate fuzzy membership functions from the selected partition regions; and iii) extract a set of candidate rules and resolve a conflict problem among the candidate rules. The effectiveness of the proposed fuzzy classification model was demonstrated by comparing the experimental results for the dyspnea patients' data set with 11 features selected from 55 features by clinicians with those obtained using the conventional classification methods, such as standard fuzzy classifier without rule weights, C4.5, QDA, kNN, and SVMs.

A Generalized Calorie Estimation Algorithm Using 3-Axis Accelerometer

  • Choi, Jee-Hyun;Lee, Jeong-Whan;Shin, Kun-Soo
    • Journal of Biomedical Engineering Research
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    • v.27 no.6
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    • pp.301-309
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    • 2006
  • The main purpose of this study is to derive a regression equation that predicts the individual differences in activity energy expenditure (AEE) using accelerometer during different types of activity. Two subject groups were recruited separately in time: One is a homogeneous group of 94 healthy young adults with age ranged from $20\sim35$ yrs. The other subject group has a broad spectrum of physical characteristics in terms of age and fat ratio. 226 adolescents and adults of age ranged from $12\sim57$ yrs and fat ratio from $4.1\sim39.7%$ were in the second group. The wireless 3-axis accelerometers were developed and carefully fixed at the waist belt level. Simultaneously the total calorie expenditure was measured by gas analyzer. Each subject performed walking and running at speeds of 1.5, 3.0, 4.5, 6.0, 6.5, 7.5, and 8.5 km/hr. A generalized sensor-independent regression equation for AEE was derived. The regression equation was developed fur walking and running. The regression coefficients were predicted as functions of physical factors-age, gender, height, and weight with multivariable regression analysis. The generalized calorie estimation equation predicts AEE with correlation coefficient of 0.96 and the average accuracy of the accumulated calorie was $89.6{\pm}7.9%$.

Copper Phthalocyanine Field-effect Transistor Analysis using an Maxwell-wagner Model

  • Lee, Ho-Shik;Yang, Seung-Ho;Park, Yong-Pil;Lim, Eun-Ju;Iwamoto, Mitsumasa
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.3
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    • pp.139-142
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    • 2007
  • Organic field-effect transistor (FET) based on a copper Phthalocyanine (CuPc) material as an active layer and a $SiO_2$ as a gate insulator were fabricated and analyzed. We measured the typical FET characteristics of CuPc in air. The electrical characteristics of the CuPc FET device were analyzed by a Maxwell-Wagner model. The Maxwell-Wagner model employed in analyzing double-layer dielectric system was helpful to explain the C-V and I-V characteristics of the FET device. In order to further clarity the channel formation of the CuPc FET, optical second harmonic generation (SHG) measurement was also employed. Interestingly, SHG modulation was not observed for the CuPc FET. This result indicates that the accumulation of charge from bulk CuPc makes a significant contribution.

Recognition of Falls and Activities of Daily Living using Tri-axial Accelerometer and Bi-axial Gyroscope

  • Park, Geun-chul;Kim, Soo-Hong;Kim, Jae-hyung;Shin, Beum-joo;Jeon, Gye-rok
    • Journal of Sensor Science and Technology
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    • v.25 no.2
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    • pp.79-85
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    • 2016
  • This paper proposes a threshold-based fall recognition algorithm to discriminate between falls and activities of daily living (ADL) using a tri-axial accelerometer and a bi-axial gyroscope sensor mounted on the upper sternum. The experiment was executed ten times according to the proposed experimental protocol. The output signals of the tri-axial accelerometer and the bi-axial gyroscope were measured during eight falls and eleven ADL action sequences. The threshold values of the signal vector magnitude (SVM_Acc), angular velocity (${\omega}_{res}$), and angular variation (${\theta}_{res}$) parameter were calculated using MATLAB. From the preliminary study, three thresholds (TH1, TH2, and TH3) were set so that the falls could be distinguished from ADL. When the parameter SVM_Acc is greater than 2.5 g (TH1), ${\omega}_{res}$ is greater than 1.75 rad/s (TH2), and ${\theta}_{res}$ is greater than 0.385 rad (TH3), these action sequences are recognized as falls. If at least one or more of these conditions is not satisfied, the sequence is classified as ADL.

Finite Element Analysis on Stress Distribution in Base Metal-Ceramic Crown Margin Designs (유한요소법을 이용한 비귀금속-도재관 변연부 형태에 따른 응력 분포 분석)

  • Lee, Myung-Kon;Shin, Jung-Woog;Kim, Myung-Duk
    • Journal of Technologic Dentistry
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    • v.22 no.1
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    • pp.79-88
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    • 2000
  • The objective of this finite element method study was to analyze the stress distribution induced in a maxillary central incisor Ni-Cr base metal coping ceramic crowns with various margin design. Margin designs of crown in this experiment were knife-edge metal margin on chamfer finishing line of tooth preparation(M1), butt metal margin on shoulder finishing line(M2), reinforced butt metal margin on shoulder finishing line(M3), beveled metal margin on bevelde shoulder finishing line(M4). Two- dimensional finite element models of crown designs were subjected to a simulated biting force of 100N which was forced over porcelain near the lingual incisal edge. Base on plane stress analysis, the maxium von Miss stresses(Mpa) in porcelain venner was 0.432, in metal coping was 0.579, in dentin abutment was 0.324 for M1 model, and M2 model revealed in porcelain was 0.556, in metal coping was 0.511, in dentin was 0.339, and M3 model revealed in porcelain was 0.556, in metal coping was 0.794, in dentin was 0.383 for M4 model. All values of each material in metal-ceramic crown were much below the critical failure values.

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