A study for development and evaluation of non-invasive system for stimulator of subcutaneous tissue using finite element

의공학과/석사[한글] 본 논문은 보완대체의학 중 뜸 요법의 효과를 대체할 수 있는 비침습적 심부 자극을 위해 사용될 고주파 자극 입력 파형 구성에 관한 연구이다. 침구 의학의 세계시장은 그 수요와 사용 지역이 20세기 말부터 지속적으로 증가되고 있다. 하지만, 침구 의학의 높은 사용량과 달리 아직까지 침 요법에 비교하여 뜸 요법에 대한 연구는 아직 미비한 실정이다. 뜸 요법은 치료를 위해 발생시키는 열 자극의 조절을 재료의 종류와 양에 의존하기 때문에 자극의 강도를 조절하기 쉽지 않았다. 이로 인해 자극 강도의 조절이 부적절했을 경우, 치료의 효과가 미미하거나, 반대로 피부 화상에 대한 위험성 또한 지니고 있다. 따라서 피부 심부에 위치한 경혈 혹은 경락의 집중적 자극을 목적으로 하는 뜸의 열에너지 전달 효율성을 증대시키고, 부작용을 개선시킨 새로운 자극 방법이 요구되고 있다. 본 연구에서는 뜸 효과를 대체할 수 있는 비침습적 심부 자극 시스템 개발을 위한 자극패턴을 구성하려고 한다. 이를 위해 현재 상용화된 애권 뜸과 구관 뜸을 이용하여 돼지의 생체 시편을 이용한 실험을 수행하였다. 이 생체외 실험은 일정한 두께로 제작된 생체 시편을 적층하였고, 시편 위에 뜸이 위치한 곳을 중심으로 시편의 층과 층 사이에 일정한 간격을 두고 위치한 온도 센서를 이용하여 온도 변화를 측정하였다. 뜸을 이용한 생체외 실험에서는 온열 자극의 전달이 생체 조직의 특정 부위에서 집중되지 못하며 자극의 강도를 조절하기 어렵다는 것을 확인할 수 있었다. 이를 보완하고자 유한요소해석법을 이용하여 생체 조직 표면에서 각각의 고주파 자극 입력 파형들의 영향을 분석하였다. 이를 통해 애권 뜸과 구관 뜸에 의한 시편의 표면 온도에 나타내는 변화와 유사하지만, 심부에서 열 자극이 집중되는 특성을 갖는 두 종류의 입력 파형을 구성하였다. 또한, 새롭게 개발된 고주파 자극 입력기를 이용하여 뜸을 이용한 생체외 실험과 동일한 조건하에 실험을 수행하여, 고주파 자극 구성 1과 2가 생체 조직에 인가되어 심부에서 자극이 집중되는 것을 확인할 수 있었다. 본 연구를 통해 기존의 뜸 요법이 가지고 있던 온열 요법에 의한 피부 표면의 화상을 예방하고 뜸을 통해서는 수행할 수 없었던, 자극 강도의 조절이 용이하고 특정 부위에 집중하여 자극할 수 있는 최적화된 고주파 전류 자극 조건을 제시하였다. 향후 인체 피부 층들의 열전달 특성을 좀 더 자세히 반영하여, 개선된 유한요소모델을 이용한 추가연구를 통해 비침습적 심부 자극을 위해 제시한 고주파 입력 파형 구성 1과 2의 정량적인 효과 분석이 필요할 것으로 사료된다. [영문]Therapies applied to therapies not commonly included in main current medicine typically are promoted research on various procedures for healing and health care for used instead of main current treatment. Terms of the therapies have repeatedly changed over time. The shifting language is exemplified by the creation about a couple of decades ago of the National Institutes of Health(NIH) Office of Alternative Medicine, which, in 1999, was renamed the National Center for Complementary and Alternative Medicine(NCCAM). Current, terminology favors Complementary and Alternative Medicine(CAM). Moxibustion therapy is considered to be important field in CAM. Moxibustion has been a part of acupuncture practice for thousands of years. Moxibustion is conducted via 2 main methods of stimulation: indirect and direct. Indirect moxibustion produces mild heat stimulation through conduction or radiation of heat. Conversely, direct moxibustion is one of the traditional ways, in which moxa sticks are burned at acupuncture points on the skin. However, it often caused burns at the moxibustion site. Hence it was demanded increasing efficiency of heat transfer of moxibustion with eradication or improvement of side effects for focused stimulation on acupuncture in deep skin. Currently, with development of medical science, the treatments by using radio-frequency energy has begun to receive increased attention as an effective minimally invasive approach for treatment of patients. To date, these techniques have been used to treat tumor located inside the human body with high frequency(200-1200kHz) alternating current voltage source. Current passing through tissue from the active electrode leads to ion agitation, which is converted by means of friction into heat. In this study, evaluation of non-invasive focused depth skin stimulation system for possibility decision was performed which was using heat energy by the ion agitation. Results of an in vitro experiment obtained with application of moxibustion for quantitative analysis were investigated difficulties which heat energy hardly focused on deep tissue, and intensity adjustment of the heat energy. A complement of these issue, input pulse generated from high frequency stimulator was analyzed by using finite element analysis. Results of effect analysis were also obtained on the outer surface of the tissue model to present like as effect of moxibustion thus pulse combination 1 and 2 was developed. The combinations induced thermal changes on the surface of the tissue like as the effect of moxibustion as well as focused on deep inside of tissue. This study suggested high frequency pulse combinations for non-invasive depth skin stimulation for alternative method of moxibustion and attempted as a pilot study for a development of this system.ope

인체의 움직임과 관련된 근력, 관절 토크 및 전단력의 기계적 반응의 분석 검증

Dept. of Biomedical Engineering/박사In this study, the interactions between humans and the environment are measured and analyzed by several methods either directly or indirectly. Quantitative and objective measurements are obtained using a three-dimensional motion analysis system, a shear force sensor, and an anthropomorphic dummy. To evaluate the loads imposed on skin, muscles and joints during work-related human body movements. A motion analysis system is one of the most effective systems for capturing movement of the human body in three-dimensional space. The motion analysis results were used to generate virtual human body models to evaluate various human movements, such as working with a vacuum cleaner or a washing machine.Previous studies of human movements have applied well-known musculoskeletal models and analysis tools to introduce modeling systems that are easier to implement than adding new, complex methodology or overabundant tools to new models. This approach may be useful for evaluating complex human movements that are not much different from the expected results without the use of massive tools. A shear force sensor designed with a strain gauge could measure the change of strain induced by external forces on an object of interest, which could be transfer into a shear force component isolated from the external forces containing both tangential and shear forces. Moreover, the development of a shear force sensor and anthropomorphic dummy may be useful for evaluating the loads, pressure, and joint torque imposed on soft tissue and joints in the seated position.ope

15Cr-15Mn-4Ni 오스테나이트계 스테인리스강의 고온변형거동에 대한 탄소와 질소의 효과

MasterSingle hit compression tests were carried out at the temperature range of 800~1100 °C and the strain rate range of 0.01~1 s-1 for 15Cr-15Mn-4Ni based austenitic stainless steels containing either 0.1~0.3 wt.% of C or N. The high temperature strength, i.e. mean flow stress, increased as the concentration of either C or N increased. The mean flow stress, activation energy, and degree of lattice distortion of N-added steels were larger than those of C-added steels, while the dynamically recrystallized (DRXed) grain size and grain growth rate were smaller and slower in N-added steels. The effects of N on the high temperature strength were stronger due mainly to a stronger solid solution hardening effect which was attributed to the larger effective size of the N atoms compared to the C atoms. The dynamic recrystallization (DRX) was more suppressed in the N-added steels since N atoms strongly interact with moving dislocations, grain boundaries, or subgrain boundaries, which was evidenced by larger activation energy and peak stress

Marine Debris Detection and Mapping with Underwater Image Enhancement

This paper introduces the system of reconstructing underwater trash map. First, our systems improve performance of underwater object detection by using deep learning-based image enhancement. Also, we prove that using enhanced image, it needs a little labeled data compare to underwater images. Finally, we reconstruct underwater 2D trash map by stitching images and detecting trash coordinates.2

ENCODER FRAME DEVICE AND VEHICLE ODOMETRY MEASUREMENT SYSTEM USING THE SAME

엔코더 프레임 장치 및 이를 이용한 차량 위치 측정 시스템이 제시된다. 일 실시예에 따른 차량 위치 측정을 위한 엔코더 프레임 장치는 일측에 엔코더와 소정 간격 이격되어 결합되어 상기 엔코더의 위치를 고정시키는 제1 프레임; 상기 제1 프레임의 타측에 소정 간격 이격되어 배치되며, 캘리퍼와 결합되는 제2 프레임; 및 상기 제1 프레임과 상기 제2 프레임을 연결하는 연결부를 포함하여 이루어질 수 있다

나노자성입자를 이용한 자기영동기술 기반의 미세유체방울 분리

학위논문(석사) - 한국과학기술원 : 바이오및뇌공학과, 2011.8, [ viii, 40 p ]We report a novel droplet-based platform using magnetophoresis for sorting single-cell encapsulated droplets. In conventional method for encapsulating target sample in droplet, the entire volume of the aqueous phase is made into droplets in a sequential manner. This method results in high percentages of empty droplets compared to target sample encapsulating droplet. The number of target sample encapsulated in droplet follows Poisson statistics. Although the portion of single sample changes with initial sample concentration in aqueous phase, it is less than 40%. Therefore, a sorting technology of specific droplets among other droplets is highly needed to enhance the encapsulation efficiency. The conventional method for sorting specific droplets requires feedback process such as image sensor, photodetector and impedance detector. Also, complex device structure is needed and channel dimension should be changed depending on the size of the target sample. In this thesis, new approach based on magnetophoretic droplet sorting is introduced by incorporating magnetic nanoparticles into the droplets which can separate droplets depending on the number of cells inside without complex feedback process and fabrication steps. We first exploited the difference in the number of nanoparticle encapsulated droplets with or without a single cell inside. The droplets encapsulating a single cell have reducing numbers of magnetic nanoparticles as much as volume of the single cell. Since magnetic force on droplets is in proportion to the number of magnetic nanoparticles, the magnetic force on single-cell encapsulated droplets is reduced. Single-cell encapsulated droplets can be separated continuously from empty cells by difference in the lateral positions because they are subjected to different magnitude of magnetic force. We successfully demonstrated the possibility of single-cell droplet sorting method with preliminary experiments using microbeads instead of real cells. This platfor...한국과학기술원 : 바이오및뇌공학과

FATIGUE MEASUREMENT SYSTEM

장시간 운전에 따른 운전자의 허리 피로도를 평가하는 피로도 측정 시스템이 개시된다. 본 발명의 실시 예에 따른 피로 측정 시스템은, 차량 내 시트에 설치되어 운전자 허리 부위의 광학적 센싱 신호를 계측하는 광학 센서부; 상기 센싱 신호를 분석하여 시간에 따른 상기 허리 부위의 산소화 농도 변화량을 계산하고, 계산된 값을 토대로 허리 부위 피로도의 상대적 지표인 산소화 농도 변화량 곡선을 생성하여 피로도에 대한 시점을 검출하는 제어부; 및 상기 제어부의 제어에 따라 장시간 운전에 따른 운전자의 피로도를 경고하는 표시부를 포함한다

Parashewanella tropica sp. nov., a Novel Bacterium Isolated from a Marine Sponge from Chuuk lagoon, Federated States of Micronesia

A mesophilic, straight rod-shaped, non-flagellated bacterium, designated MEBiC05444T, was isolated from a marine sponge collected from Chuuk lagoon, Federated States of Micronesia. The strain was Gram-negative, catalase- and oxidase-positive and facultative anaerobe. The isolate aerobically grew at 8-38°C (optimum range 24-32°C), pH 4.01