• Journal of Biomedical Engineering Research
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• v.7 no.2
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• pp.159-168
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• 1986

As a fundamental study of Near IR tomography system, transmission parameters of the mongolian breast tissue at 904 nm wavelengh were measured. A analytical model to determin the light intensity in the breast was developed and the measurement, and gheoretical calculations were obtained.

• Journal of Biomedical Engineering Research
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• v.7 no.1
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• pp.41-44
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• 1986

The objective of tissue characterization is to provide quantitative information about the physical state of tissue interrogated by an ultrasound beam. In the computer simulation, it was found that the echoes were composed of the interferences of the ultrasonic waves reflected from both sides of the thin object, and could be separated by the spectral correlation method. Also, the phantom study demonstrates that thickness of the thin acryl layer beyond the resolution of common ultrasonic imaging systems can be measured- using this method.

• Journal of Biomedical Engineering Research
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• v.5 no.1
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• pp.39-46
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• 1984

In order to improve the performance of ultrasonic diagnostic equipment, it is important to development the signal processing considering the ultrasonic properties of biological medium and propagation mechanism in tissue. Attenuation coefficient is not only important factor to analyze propagation properties, but also it is significant to estimate it in view of tissue characterization, so we show one of the method to estimate attenuation coefficient of biological tissue and the results of estimation.

• Journal of Biomedical Engineering Research
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• v.6 no.2
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• pp.43-52
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• 1985

In this paper, the depth and attenuation coefficient are estimated from the mutilayered liver tissue which contained a inhomogeneous one using reflected ultrasonic signals and the abnormal one is detected quantitatively. Regarding a liver tissue as several reflectors, we analyzed each one by the frequency spectral difference method and discussed its attenuation characteristics. For the verification of this method, the liver pantom and acryle are used. And also we proved the usefulness through the experiment.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1149-1152
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• 2005

This thesis estimates relationships between area and volume of visceral adipose tissue about health risk. Visceral adipose tissue quantity showed the quantitative relationship, where degree of area was similar to the volume.Threrfore, it is more useful to use the area which is simpler,than the volume when using visceral adipose tissue quantity for estimating the degree of danger factors related with fatness.

• Polymer(Korea)
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• v.36 no.5
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• pp.651-655
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• 2012

Considerable effort has been directed toward the use of silk fibroin as a biotechnological material in biomedical applications on account of its excellent biodegradability, biocompatibility, and unique mechanical properties. For use in tissue engineering, it is very important to design and control the pore architecture of polymeric scaffolds, which provide the vital framework for seeded cells to organize into functioning tissue. In the present study, a silk fibroin scaffold with controlled interconnectivity and pore size was prepared using an electrospinning method with poly(ethylene oxide).

• Journal of Biomedical Engineering Research
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• v.27 no.3
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• pp.117-124
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• 2006

Recently, active research has been going on to measure the elastic modulus of human soft tissue with medical ultrasound imaging systems for the purpose of diagnosing cancers or tumors which have been difficult to detect with conventional B-mode imaging techniques. In this paper, a real-time ultrasonic elasticity imaging system is implemented in software on a Pentium processor-based ultrasonic diagnostic imaging system. Soft tissue is subjected to external vibration, and the resulting tissue displacements change the phase of received echoes, which is in turn used to estimate tissue elasticity. It was confirmed from experiment with a phantom that the implemented elasticity imaging system could differentiate between soft and hard regions, where the latter is twice harder than the former, while operating at an adequate frame rate of 20 frames/s.

• Macromolecular Research
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• v.15 no.4
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• pp.370-378
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• 2007

Mechanical stimulation is known to activate several cellular signal transduction pathways, leading to the induction of signaling molecules and extracellular matrix (ECM) proteins, thereby modulating cellular activities, such as proliferation and survival. In this study, primary human dermal fibroblasts (HDFs) were seeded onto chitosan-based scaffolds, and then cultured for 3 weeks in a bioreactor under a cyclic strain of 1 Hz frequency. Compared to control samples cultured under static conditions, the application of a cyclic strain stimulated the proliferation of HDFs in I week, and by week 3 the thickness of the cell/scaffold composites increased 1.56 fold. Moreover, immunohistochemical staining of the culture media obtained from the cell/scaffold samples subjected to the cyclic strain, revealed increases in the expression and secretion of ECM proteins, such as fibronectin and collagen. These results suggest that the preconditioning of cell/scaffold composites with a cyclic strain may enhance the proliferation of HDFs, and even facilitate integration of the engineered artificial dermal tissue into the host graft site.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8351-8358
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• 2016

Electronic cleansing is an image post processing technique in which the tagged colonic content is subtracted from colon using CTC images. There are post processing artefacts, like: 1) soft tissue degradation; 2) incomplete cleansing; 3) misclassification of polyp due to pseudo enhanced voxels; and 4) pseudo soft tissue structures. The objective of the study was to subtract the tagged colonic content without losing the soft tissue structures. This paper proposes a novel adaptive method to solve the first three problems using a multi-step algorithm. It uses a new edge model-based method which involves colon segmentation, priori information of Hounsfield units (HU) of different colonic contents at specific tube voltages, subtracting the tagging materials, restoring the soft tissue structures based on selective HU, removing boundary between air-contrast, and applying a filter to clean minute particles due to improperly tagged endoluminal fluids which appear as noise. The main finding of the study was submerged soft tissue structures were absolutely preserved and the pseudo enhanced intensities were corrected without any artifact. The method was implemented with multithreading for parallel processing in a high performance computer. The technique was applied on a fecal tagged dataset (30 patients) where the tagging agent was not completely removed from colon. The results were then qualitatively validated by radiologists for any image processing artifacts.

• Proceedings of the KSLP Conference
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• 2003.11a
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• pp.183-183
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• 2003

Background and Objectives : Cartilage reconstruction is one of medical issue in otolaryngology. Tissue engineering is presently being utilized in part of cartilage repair. Sources of cells for tissue engineering are chondrocyte from mature cartilage and bone marrow mesenchymal stem cells that are able to differentiate into chondrocyte. Recent studies have shown that adipose tissue have mesenchymal stem cells which can differentiate into adipogenic, chondrogenic myogenic osteogenic cells and neural cell in vitro. In this study, we have examined chondrogenic potential of the canine adipose tissue-derived mesenchymal stem cell(ATSC). Materials and Methods : We harvested canine adipose tissue from inguinal area. ATSCs were enzymatically released from canine adipose tissue. Under appropriate culture conditions, ATSCs were induced to differentiate into the chondrocyte lineages using micromass culture technique. We used immunostain to type II collagen and toluidine blue stain to confirm chondrogenic differentiation of ATSCs. Results : We could isolate ATSCs from canine adipose tissue. ATSCs expressed CD29 and CD44 which are specific surface markers of mesenchymal stem cell. ATSCs differentiated into micromass that has positive response to immunostain of type II collagen and toluidine blue stain. Conclusion : In vitro, ATSCs differentiated into cells that have characteristic cartilage matrix molecules in the presence of lineage-specific induction factors. Adipose tissue may represent an alternative source to bone marrow-derived MSCs.