• Journal of the Korean Society of Physical Medicine
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• v.10 no.1
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• pp.91-97
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• 2015

PURPOSE: In this study investigated the thermal effect in tissue mimicking phantom by the material of the ultrasonic transducer in low intensity sonication. METHODS: The material of the ultrasonic transducer was made of ceramic, stainless steel, aluminum. Korea Testing Laboratory was measured of the three kinds of materials the total output of the ultrasonic transducer. Each material was measured core temperature and the actual output depending on the type of transducer. Agarose tissue mimicking phantom and silicone tissue mimicking phantom was made. Transducers made of three kinds of materials were emitted in the phantom. It is shown as a graph about time and temperature and the surface temperature rising speed and deep temperature rise rate was investigated. RESULTS: Ceramic transducers were highest output. Higher than the stainless steel transducer, aluminum had the lowest total output. Deep temperature was the highest in the ceramic transducer, and the surface temperature was the highest in the stainless steel transducer. Thermal images of ceramic transducer showed that a valid output is formed deeper wider than the metal. CONCLUSION: Ceramic transducer is confirmed the excellence than the metal transducer in deep thermal effect and the actual output of the ultrasound.

• The Journal of the Acoustical Society of Korea
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• v.24 no.4E
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• pp.132-138
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• 2005

The purpose of this study is to measure the acoustic properties of Tofu and Acorn Curd (Dotori Muk), which are possibly used as tissue mimicking materials (TMMs). Due to its availability and low cost, Tofu was suggested as a TMM by several researchers who measured only sound speed and attenuation. The acoustic properties of Tofu and Muk including the backscattering coefficient were measured in this paper. Sound speed was measured by the time shift in a pulse echo setup. Attenuation coefficients and backscattering coefficients were measured by a broadband method using both 5 MHz and 10 MHz transducers in the frequency domain. The measured acoustic properties of both Tofu and Muk are observed to be similar to those of biological tissues such as beef liver or beef heart.

• Journal of radiological science and technology
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• v.26 no.1
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• pp.51-62
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• 2003

We carried out studies on develop of the ultrasound tissue mimicking materials(TMM) by synthesis of polymer urethane(C, CCR, $TiO_2$, tungsten, graphite, silver type). The major finding were as follows; (1) C type TMM was shown good homogeneity, penetration, gray scale like as liver tissue and propagated speed 1,540 m/s, attenuation $0.5{\sim}0.7\;dB/cm/MHz$. (2) $TiO_2$ type TMM was shown heterogeneous dot echo pattern. (3) Silver type TMM was appear good homogeneous echo pattern like as echo texture of thyroid gland. Therefor, C type TMM will be useful for ultrasound Q/A phantom materials and previous phantom materials.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.245-252
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• 2010

This study analyzed speed of sound, impedance, attenuation coefficient in accordance with acoustic characteristic standard of body soft tissue corresponding with Annex DD of IEC standard 60601-2-37(2007) which is about tissue mimicking materials (TMM) synthesized by polyurethane as a main material and new type of n-type scatter materials. This study reached the following conclusion after analyzing and evaluating image characteristic with SONOACE 9900 c PRIME (MEDESON Co.) and brightness, maximum penetration with convex probe (2.5~5.0 MHz). When n-type scatter materials are increasingly synthesised 0~8% with prepolymer as a main material and polyol mixture as a catalyst, 1. The more scatter materials are increased, the more sound speed of TMM becomes closely similar to soft tissue. 2. The more scatter materials are decreased, the more acoustic impedance becomes closely similar to soft tissue. 3. The more scatter materials are increased, the more attenuation coefficient is increased. 4. The more scatter materials are increased, the more average brightness of images is increased, but there is threshold. 5. The maximum penetration becomes closely similar to soft tissue at the 6% TMM as a scatter material.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.1
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• pp.28-34
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• 2014

Recently, ultrasound therapy has become a new and effective treatment for many brain diseases. Therefore, skull-mimicking phantoms have been developed to simulate the skull and brain tissue of a human and allow further research into ultrasound therapy. In this study, the suitability of various skull-mimicking materials(HDPE, POM C, Acrylic) for studies of brain-tumor treatments was evaluated using focused ultrasound. The acoustic properties of three synthetic resins were measured. The skull-mimicking materials were then combined with an egg white phantom to observe the differences in the ultrasound beam distortion according to the type of material. High-intensity polyethylene was found to be suitable as a skull-mimicking phantom because it had acoustic properties and a denatured-area shape that was close to those of the skull,. In this study, a skull-mimicking phantom with a multi-layer structure was produced after evaluating several skull-mimicking materials. This made it possible to predict the denaturation in a skull in relation to focused ultrasound. The development of a therapeutic protocol for a range of brain diseases will be useful in the future.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.2.2-2.2
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• 2011

The central strategy in tissue engineering involves a biomaterial scaffold as a delivery carrier of cells and a depot to deliver bioactive molecules. The ability of scaffolds to control cellular response to direct particular repair and regeneration processes is essential to obtain functional tissue engineering constructs. Therefore, many efforts have been made to understand local interactions of cells with their extracellular matrix (ECM) microenvironment and exploit these interactions for designing an ideal scaffold mimicking the chemical, physiological, and structural features of native ECM. ECM is composed of a number of biomacromolecules including proteins, glycosaminoglycans, and proteoglycans, which are assembled together to form complex 3-dimensional network. Electrospinning is a process to generate highly porous 3-dimensional fibrous structure with nano to micro scaled-diameter, which can closely mimic the structure of ECM. In this presentation, our approaches to develop biomimetic electrospun fibers for modulation of cell function will be discussed.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.368-373
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• 2009

A human tissue mimicking phantom is constructed to assess the performance of a medical ultrasound elasticity imaging system. In a human body, the tumor or cancer is stiffer than its surrounding normal tissue. A technique fur imaging the elasticity of such a tissue is referred to as elastography. Homogeneous elasticity phantoms with differing Young's moduli are constructed using a plastic hardener and softener to simulate the mechanical characteristics of a diseased human tissue. The Young's modulus of the fabricated homogeneous phantom materials were measured from 11.1 to 79.6 kPa depending on the mixing ratio of the amount of the hardener to that of the softener. An ultrasound lesion mimicking phantom was made of these materials, and ultrasound elasticity imaging was performed on it. It is confirmed in this paper that the fabricated plastic-based elasticity phantom is useful in representing the elastic characteristics of a human tissue.

• Tissue Engineering and Regenerative Medicine
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• v.15 no.6
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• pp.673-697
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• 2018

BACKGROUND: Cartilage tissue engineering (CTE) aims to obtain a structure mimicking native cartilage tissue through the combination of relevant cells, three-dimensional scaffolds, and extraneous signals. Implantation of 'matured' constructs is thus expected to provide solution for treating large injury of articular cartilage. Type I collagen is widely used as scaffolds for CTE products undergoing clinical trial, owing to its ubiquitous biocompatibility and vast clinical approval. However, the long-term performance of pure type I collagen scaffolds would suffer from its limited chondrogenic capacity and inferior mechanical properties. This paper aims to provide insights necessary for advancing type I collagen scaffolds in the CTE applications. METHODS: Initially, the interactions of type I/II collagen with CTE-relevant cells [i.e., articular chondrocytes (ACs) and mesenchymal stem cells (MSCs)] are discussed. Next, the physical features and chemical composition of the scaffolds crucial to support chondrogenic activities of AC and MSC are highlighted. Attempts to optimize the collagen scaffolds by blending with natural/synthetic polymers are described. Hybrid strategy in which collagen and structural polymers are combined in non-blending manner is detailed. RESULTS: Type I collagen is sufficient to support cellular activities of ACs and MSCs; however it shows limited chondrogenic performance than type II collagen. Nonetheless, type I collagen is the clinically feasible option since type II collagen shows arthritogenic potency. Physical features of scaffolds such as internal structure, pore size, stiffness, etc. are shown to be crucial in influencing the differentiation fate and secreting extracellular matrixes from ACs and MSCs. Collagen can be blended with native or synthetic polymer to improve the mechanical and bioactivities of final composites. However, the versatility of blending strategy is limited due to denaturation of type I collagen at harsh processing condition. Hybrid strategy is successful in maximizing bioactivity of collagen scaffolds and mechanical robustness of structural polymer. CONCLUSION: Considering the previous improvements of physical and compositional properties of collagen scaffolds and recent manufacturing developments of structural polymer, it is concluded that hybrid strategy is a promising approach to advance further collagen-based scaffolds in CTE.

• Journal of radiological science and technology
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• v.26 no.2
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• pp.49-56
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• 2003

The purposes of this study are to improve the ultrasound resolution of various nylon and metallic mono-filament wires, therefore, it was tested that it analyze on nylon mono-filament wire of 0.1 mm in A Co.'s ultrasonic phantom and synthesis of C15 g tissue mimicking materials(TMM), analyze resolution of nylon and metallic mono-filament wires in water and TMM. The results obtained were summarized as follows: 1. Metallic mono-filament wire of 0.1 mm and nylon mono-filament wire of 0.12 mm, 180 denier showed that it cleared dot echo pattern. 2. Metallic and nylon mono-filament wire of 0.2 mm showed that it cleared comet tail echo by reverberation artifact. 3. Nylon and metallic mono-filament wire of 0.1 mm showed that it can used for dead zone and axial resolution test. 4. Nylon mono-filament wire compared with metallic mono-filament wire showed that it satisfy elasticity and construction. 5. Degree of hardness of na not changed mono-filament's echo textures.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.19-24
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• 2003

We carried out studies on development and characteristic of ultrasound brast training biopsy phantom. the major finding were of follow ; (1) C type TMM was shown good homogeneity, brightness and attenuation as like human soft tissue. (2) $TiO_2$ 4.10%w/v TMM was shown good homogeneous echo texture and propagated speed as like the human Tissue. (3) $TiO_2$ type TMM was appeared lower brightness and higher penetration rate than C type TMM. Therefor, Breast TM phantom and target material TMM will be useful $TiO_2$ 4.10 %w/v TMM and C 2.09 %w/v TMM.