• Archives of Craniofacial Surgery
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• v.23 no.2
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• pp.64-70
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• 2022

Background: Anterolateral thigh (ALT) flaps are versatile soft tissue flaps that have become the standard soft-tissue flaps used for head and neck reconstruction. They provide a long vascular pedicle, constant vessel diameter, abundant soft tissue coverage, and minimal donor site morbidity. The ALT flap was initially designed on the basis of a septocutaneous (SC) perforator. However, more recent research has shown that a substantial number of ALT flaps are now based on musculocutaneous (MC) perforators, and the ratio between MC and SC perforators varies among studies. In this study, we analyzed the perforating pattern of ALT flaps along with their clinical outcomes during head and neck reconstruction in the Korean population. Methods: From October 2016 to July 2020, 68 patients who had undergone an ALT flap procedure for head and neck reconstruction were enrolled retrospectively. The perforating pattern of the cutaneous perforator vessel (MC perforator/SC perforator/oblique branch), pedicle length, and flap size were analyzed intraoperatively. Patient demographics and flap necrosis rates were also calculated. Results: The highest number of cutaneous perforator vessels supplying the ALT flap were the MC perforators (87%). The proportion of MC perforators was significantly higher than that of the SC perforators and oblique branches. Flap necrosis occurred in seven cases (11.86%); sex, hypertension, diabetes mellitus, coronary artery disease, perforator course, and history of radiotherapy did not significantly affect flap necrosis. Conclusion: The ALT free flap procedure remains popular for reconstruction of the head and neck. In this study, we observed that the majority of cutaneous vessels supplying the flaps were MC perforators (87%). When using the MC perforator during flap elevation, careful dissection of the perforator is required to achieve successful ALT flaps because intramuscular dissection is difficult. Perforator pattern and history of radiotherapy did not affect flap necrosis.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.834-850
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• 2011

In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1415-1418
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• 2008

Scaffold fabrication for regenerating functional human tissues has an important role in tissue engineering, and there has been much progress in research on scaffold fabrication. However, current methods are limited by the mechanical properties of existing biodegradable materials and the irregular structures that they produce. Recently, Solid freeform fabrication (SFF) technology was remarked by fabricating 3D free-form micro-structures. Among SFF technologies, we tried to fabricate scaffolds using micro-stereolithography which contain the highest resolution of all SFF technologies and precision deposition system which can use various biomaterials. And we developed the CAD/CAM system to automate the process of scaffold fabrication and fabricate the patient customized scaffolds. These results showed the unlimited possibilities of our SFF technologies in tissue engineering.

• Journal of Biomedical Engineering Research
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• v.24 no.3
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• pp.141-149
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• 2003

This paper proposes a method of measuring and imaging the stiffness of human soft tissue to diagnose cancers or tumors which have been difficult to detect in ultrasound B-mode imaging systems. To measure the soft tissue stiffness, sinusoidal vibrations are applied to it, and the magnitude of its mechanical vibration is determined by estimating the temporal variation of speckle pattern brightness in ultrasound B-mode images. It is verified by simulation and experiment that the proposed method can estimate the relative tissue stiffness from B-mode images with a relatively small amount of computation.

• Journal of Chest Surgery
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• v.25 no.11
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• pp.1240-1244
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• 1992

Human sparganosis caused by Sparganum mansoni, the larval plerocercoid worm of the genus Spirometra, is not uncommon in Korea and is mostly found in subcutaneous or adipose tissue of the abdominal, thoracic wall and inguinal region, but is rarely found in the orbital cavity, brain and breast. It, at present, is a surgical disease because its diagnosis depends almost on the demonstration of the larva[e] from lesion or finding the worm section in surgical pathology specimens. We experienced a case of human sparganosis from a 48 years old woman who had a history of eating a raw frog. We report the case and review the related literatures.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.160.1-160.1
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• 2003

Persistent organic pollutants (POPs) have spread throughout the global environment to threaten human health and damage ecosystems. with evidence of POPs contamination in wildlife, human blood. and breast milk documented worldwide. Breast milk is an ideal medium for assessing exposures to POPs. POPs enter humans largely as contaminants of dietary animal products, where they sequester in adipose tissue, serum, and breast milk and equilibrate at similar levels on a fat weight basis. (omitted)

• Journal of Life Science
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• v.19 no.12
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• pp.1777-1786
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• 2009

Thymosin ${\beta}4$, a small protein containing 43 amino acids, has multi-functional roles in cell physiology. It was first identified as a thymic maturation factor and recently has been shown to accelerate wound healing, hair growth, angiogenesis, tumor growth, and metastasis. It was also reported to play a key role in developing organs, including the nervous system and heart. Thymosin ${\beta}4$ induces the expression of vascular endothelial cell growth factor (VEGF), laminin-5, and other important biologically active genes. Using tissue microarray analysis, we investigated the expression patterns of thymosin ${\beta}4$ and VEGF in various normal human adult tissues. Thymosin ${\beta}4$ was highly expressed in the liver, pancreas, ductal epithelium of the salivary gland, and heart, and moderately expressed in the skin, lung, spleen, lymph node, thymus, ureter, and blood endothelial cells in both the lung and adrenal gland. The expression of VEGF generally co-localized with thymosin ${\beta}4$ and VEGF was highly expressed in the pancreas, ureter, mammary gland, liver, esophagus, and blood endothelial cells in both the lung and adrenal gland. These results suggest that thymosin ${\beta}4$ plays an important role in the function of various organs and since the expression pattern of thymosin ${\beta}4$ co-localized with VEGF, part of that function may be to induce or maintain angiogenesis.

• Journal of Sensor Science and Technology
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• v.29 no.4
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• pp.237-242
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• 2020

This paper deals with relative position estimation using a Kalman filter (KF) based on inertial sensors that have been widely used in various biomechanics-related outdoor applications. In previous studies, the relative position is determined using relative orientation and predetermined segment-to-joint (S2J) vectors, which are assumed to be constant. However, because body segments are influenced by soft tissue artifacts (STAs), including the deformation and sliding of the skin over the underlying bone structures, they are not constant, resulting in significant errors during relative position estimation. In this study, relative position estimation was performed using a KF, where the S2J vectors were adopted as time-varying states. The joint constraint and the variations of the S2J vectors were used to develop a measurement model of the proposed KF. Accordingly, the covariance matrix corresponding to the variations of the S2J vectors continuously changed within the ranges of the STA-causing flexion angles. The experimental results of the knee flexion tests showed that the proposed KF decreased the estimation errors in the longitudinal and lateral directions by 8.86 and 17.89 mm, respectively, compared with a conventional approach based on the application of constant S2J vectors.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.3
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• pp.245-253
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• 1992

To evaluate the tissue response of demineralized and undimineralized xenogeneic bone-martrix graft in extraskeletal site, we prepared human bone as a implant matrix, and outbred mouse as a recipient. Before clinical application of bank bone of human in Wonkwang university, we should confirm the allogeneic bone grafts us a biologically useful bone graft substitutes, obtanined from the patients receiving oral and maxillofacial surgery. The clinical evaluation and histologic studies showed that both (demineralized and undemineralized) xenogeneic bone matrix grafts were not rejected and that they seemed to stimulate new bone formation at the transplanation site. Undemineralized xenogeneic bone marb6 grafts showed minimal bone induction and gradual demineralization with slow resorption and showed that the differentiation of cells showing fibroblastic activity adjacent to the sop tissue were slowly and less frequently than demineralized bone. Characteristical differences between the demineralized and undemineralized matrix were the appearance of foreign body giant cells (multinucleated giant cells) and the evidence of sloe resorption in undemineralized bone matrix.

• Journal of the Optical Society of Korea
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• v.19 no.2
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• pp.123-129
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• 2015

A pulse is generated when the heart pumps blood into the arterial system. The heart pumps blood only when it contracts, not when it relaxes; therefore, blood enters the arterial system in a cyclical form. Artery beating is visible in some parts of the body surface, such as the radial artery of the wrist. This paper mainly uses the feature in which near-infrared spectroscopy penetrates skin to construct a non-invasive measurement system that can measure small vibration in the subcutaneous tissue of the human body, and then uses it for the pulse measurement. This measurement system uses the optical moir$\acute{e}$ principle, together with the fringe displacement made by small vibration in the subcutaneous tissue, and an image analysis program to calculate the height variation from small vibrations in the subcutaneous tissue. It completes a measurement system that records height variation with time, and that together with a fast Fourier transform (FFT) program, they can convert the pulse waveform generated by vibration (time-amplitude) to heartbeat frequency (frequency-amplitude). This is a new and non-invasive medical assistance system for measuring the pulse of the human body, with the advantages of being simple, fast, safe and objective.