• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.511-517
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• 2004

The existing rehabilitation systems were developed to exercise specific joints only. Therefore rehabilitating the various joints of human, various kinds of devices are need. To overcome these defects, this paper proposed the CMRS, an integrated system that performs various rehabilitation exercises. The characteristics of motion and the positions between human body and the system were investigated with the kinematics analysis of upper and lower limb of human body. We presented a proper mechanism to develop a rehabilitation device on the base of the study and studied the relative positions between head part and human joints. Through the simulations, the possibility of rehabilitation system was verified. And the base frame was also developed for convenient and stable position control. Finally, the CMRS was developed as an 8 degree of freedom mechanism. It is expected that the CMRS will be applied to the rehabilitations of various joints.

• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.531-538
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• 1998

This paper represents the design of 3D endoscopic image processing system in order to Improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery. The proposed 3D systems have four features of stereo endoscopic image processing The multiplexer give field seauential stereo for recording and for aligning cameras and viewing stereo with 3D monitor. Demultiplexing of the field sequential image which separates out the R and L images for dual TFT-LCD 3D monitor viewed with passive polarized glasses. separable processing of the left and right eye images, and design of TFT-LCD 3D monitor. The viewing angle, zone, and image quality of the Polarization-type Stereoscopic Display (SM500TFT-3D) system which we have developed using 15 Samsung TFT-1.CD with a screen resolution of 1024×768 pixels were measured and compared with those of Electric Shutter-type Stereoscopic Display system. The result of experiments shows that the Polarization-type Stereoscopic Display System using TFT-LCD has a wade viewing angle and zone which Is necessary fort multi-view and it has better image quality and stability of the optical performances than the Electric Shutter-type does.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.53-58
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• 1999

Eddy current in MRI systems degrades gradient field linearity and distorts gradient waveform. When the waveform distortion is spatially variant, it is very difficult to perform special imaging techniques such as the echo planar imaging technique or the fast spin echo imaging technique. In this study, we have developed a new technique to estimate the distorted gradient waveforms at any points inside the imaging region using the finite element method. After obtaining the eddy-current-effect transfer function, which represents magnitude and phase characteristics of the gradient field at a particular point, we have used the transfer function to estimate the actual gradient waveforms at the point. To verify the proposed technique, we have compared the estimated gradient waveforms with the measured ones.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.233-241
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• 1997

The research on chromosomes is very significant in cytogenetics since genes of the chromosomes control revelation of the inheritance plasma. The human chromosome analysis is widely used to study leukemia, malignancy, radiation hazard, and mutagen dosimetry as well as various congenital anomalies such as Down's, Klinefelter's, Edward's, and Patau's syndrome. The framing and analysis of the chromosome karyogram, which requires specific cytogenetic knowledge is most important in this field. Many researches on automated chromosome karyotype analysis methods have been carried out, some of which produced commercial systems. However, there still remains much room to improve the accuracy of chromosome classification and to reduce the processing time in real clinic environments. In this paper, we proposed a hierarchical artificial neural network(HANN) to classify the chromosome karyotype. We extracted three or four chromosome morphological feature parameters such as centromeric index, relative length ratio, relative area ratio, and chromosome length by preprocessing from ten human chromosome images. The feature parameters of five human chromosome images were used to learn HANN and the rest of them were used to classify the chromosome images. The experiment results show that the chromosome classification error is reduced much more than that of the other researchers using less feature parameters.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.280-286
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• 2007

We evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (PGPR) strains Bacillus subtilis GB03 and B. amyloliquefaciens IN937a formulated with the carrier chitosan (Bio Yield) for its capacity to elicit growth promotion and induced systemic resistance against infection by Cucumber Mosaic Virus (CMV) and Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana. The biopreparation promoted plant growth of Arabidopsis hormonal mutants, which included auxin, gibberellic acid, ethylene, jasmonate, salicylic acid, and brassinosteroid insensitive lines as well as each wild-type. The biopreparation protected plants against CMV based on disease severity in wild-type plants. However, virus titre was not lower in control plants and those treated with biopreparation, suggesting that the biopreparation induced tolerance rather than resistance against CMV. Interestingly, the biopreparation induced resistance against CMV in NahG plants, as evidenced by both reduced disease severity and virus titer. The biopreparation also elicited induced resistance against P. syringae pv. tomato in the wild-type but not in NahG transgenic plants, which degrade endogenous salicylic acid, indicating the involvement of salicylic acid signaling. Our results indicate that some PGPR strains can elicit plant growth promotion by mechanisms that are different from known hormonal signaling pathways. In addition, the mechanism for elicitation of induced resistance by PGPR may be pathogen-dependent. Collectively, the two-Bacilli strain mixture can be utilized as a biological inoculant for both protection of plant against bacterial and viral pathogens and enhancement of plant growth.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.114-119
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• 2009

Field test was conducted to investigate primary factors reducing rapeseed harvesting using a reciprocating cutter-bar of combine. The results showed that the correlation between crop moisture content and yield loss had a U-type, which indicated that the yield reduction increased at too high and too low crop moisture contents. The proper ranges of crop moisture contents were 27${\sim}$35%, 21${\sim}$56%, and 62${\sim}$73% in case of grain, pod and stem, respectively. Crop moisture content was negatively correlated with header loss, but positively correlated with threshing loss. In contrary, stem moisture content showed positive correlations with total loss, threshing loss and separation loss. Working speed was positively correlated with header loss. Total flow rate, pod flow rate and stem flow rate were highly correlated with threshing loss and separation loss. However, grain flow rate did not show any correlation with total loss. According to the principal component analysis, two principal components were derived as components with eigenvalues greater than 1.0. The contribution rates of the first and the second components were 52.7% and 38.9%, which accounted for 91.6% of total variance. As a contributive factor influencing total loss of rapeseed mechanical harvesting, a crop moisture content factor was greater than a crop flow rate factor. The stepwise multiple regression analysis for total loss was conducted using crop moisture content factor, crop flow rate factor and coefficient. However, the model did not show any correlation among independent and dependent factors ($R^2$=0.060).

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.106-113
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• 2009

This study was carried out to test feasibility of a granule fertilizer applicator for rapeseed seeding in paddy fields. The metering plate of a conventional applicator was modified for rapeseed seeding. The modified plate had new three seeding openings with total area of $342mm^2$. Average target discharging rates ranged from 6.3 to 21.0 g/s and correlated with opening areas. Application patterns of the rapeseed seeding showed M-shape. The coefficients of variation of the application showed 70.5% at 0.99 m/s of forwarding speed and 14.3 g/s of a discharge rate, and 77.7% at 1.72 m/s of a forwarding speed and 8.23 g/s of a discharge rate. The coefficients of variation in the direction of transverse of the tractor ranged from 7.3 to 47.7%. In rapeseed seeding tests using the applicator, seed damages rates were less than 15% due to the agitator, the seed hopper and the seeding plate break. Therefore, improvements of the applicator blow heads and seeding equipments were required in order to apply rapeseed efficiently.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.349-354
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• 2006

The aromatic hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the biological and toxicological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related chemicals. The application of recombinant reporter plasmid such as the firefly luciferase gene has proven to be a very effective method to detect these chemicals. The bioassay system, CALUX, is sensitive in directly detecting AhR-agonists from a variety of environmental and biologic materials. However, responses of the AhR-dependent bioassays are dependent on the cell types used. Thus, we developed a sensitive bioassay using the recombinant mouse hepatoma cell (Hepa1c1c7) for the determination of dioxins. The recombinant cell line was stably transfected with firefly luciferase reporter gene (pGudLuc1.1). The transfected cells showed the highest induction of luciferase activity at 4.5 hr and a decrease beyond this time point. The system showed the highest sensitivity of detection ever reported. Upon TCDD exposure cells showed 2 fold increase at 10 pM and 7 fold increase at 100 pM, respectively. The passage number after the transfection played an important role in the sensitivity. The increase of passage number tended to increase the sensitivity of the cells up to 15. The media without phenol red showed a higher induction rate than with phenol red, suggesting the preferable use of phenol red-free media for the bioassay. Since each of the assays has unique characteristics that make them suitable for some screening applications and not others, development of sensitive bioanalytical methods based on a variety of cellular systems in a key to the successful determination of dioxins. The bioassay system developed in this study will contribute to further development of successful screening the AhR agonists among the environmental mixture. In addition, the rapid and sensitive nature of this cellular system can be applied as a valuable tool to screen the dioxin-like moieties among the prodrugs at the initial stage, thereby expediting the new drug discovery.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.40-43
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• 1993

Electronic fetal monitoring system is an easier ar d usual method in various prenatal and labor period fetal surveilence methods currently in use. But there haven't been enough cases of using the central monitoring system despite the fact that the bedside fetal monitoring system have already been widely in use in Korea as an essential medical equipment item. We have developed more efficient central fetal monitoring system based on the personal computer with the visual maternal monotoring device using infrared camera which processes the signals from existing bedside fetal monitoring systems such as H/P's 8040 series. And we have performed the clinical application on 41 pregnant women and the results were satisfactory. In conclusion, more efficient and familial fetal monitoring is possible with our PC based central fetal monitoring system which provides the medical personnel with the view of a selected pregnant woman on the same screen where the electronic waveforms and data are displayed.

• Journal of Biomedical Engineering Research
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• v.32 no.2
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• pp.158-164
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• 2011

Breast cancer is the most frequently appearing cancer in women, these days. To reduce mortality of breast cancer, periodic check-up is strongly recommended. X-ray mammography is one of powerful diagnostic imaging systems to detect 50~100 um micro-calcification which is the early sign of breast cancer. Although x-ray mammography has very high spatial resolution, it is not easy yet to distinguish cancerous tissue from normal tissues in mammograms and new tissue characterizing methods are required. Recently ultrasound elastography technique has been developed, which uses the phenomenon that cancerous tissue is harder than normal tissues. However its spatial resolution is not enough to detect breast cancer. In order to develop a new elastography system with high resolution we are developing x-ray elasticity imaging technique. It uses the small differences of tissue positions with and without external breast compression and requires an algorithm to detect tissue displacement. In this paper, computer simulation is done for preliminary study of x-ray elasticity imaging. First, 3D x-ray breast phantom for modeling woman's breast is created and its elastic model for FEM (finite element method) is generated. After then, FEM experiment is performed under the compression of the breast phantom. Using the obtained displacement data, 3D x-ray phantom is deformed and the final mammogram under the compression is generated. The simulation result shows the feasibility of x-ray elasticity imaging. We think that this preliminary study is helpful for developing and verifying a new algorithm of x-ray elasticity imaging.