• 핵의학기술
• /
• 제17권2호
• /
• pp.84-89
• /
• 2013

PET-CT (Positron Emission Tomography-Computed Tomography)의 융합영상(Fusion image)에서 긴 영상 획득 시간에 의한 환자의 움직임은 융합영상에서 부적합한 결과로 나타나 영상의 질과 진단에 큰 영향을 준다. 의료장비 회사에서 제공하는 팔 지지대는 환자 자세에서의 편의성과 안전성을 고려하지 않아 PET/CT를 검사하는 동안 팔과 머리의 움직임 때문에 뇌기저부의 영상 결손이 생기고 머리의 좌우, 상하 움직임으로 인하여 재촬영이 빈번하다. 이에 우리는 두경부와 팔의 움직임을 최소화할 수 있는 환자보정기구를 개발하여 PET/CT 촬영 시 환자에게 편의성과 안전성을 제공하고 환자의 움직임으로 인한 재촬영을 줄이고자 한다. 2012년 6월부터 7월까지 PET Torso 검사를 위해 핵의학과에 내원하는 환자들 중 움직임에 불편함이 전혀 없는 환자 20명과 어깨 통증으로 팔을 올리기가 불편한 환자 20명을 대상으로 Patient Holding System (PHS)와 팔의 경사도($25^{\circ}$, $27^{\circ}$, $29^{\circ}$, $31^{\circ}$, $33^{\circ}$, $35^{\circ}$)를 변화시켜 가장 편안한 자세와 경사도를 선정 하였다. 또한 지지대 재질의 투과성에 대하여 유관업체의 검증을 하였고, 환자의 머리와 팔을 밴드(벨크로 형태)로 고정하여 이에 대한 편의성을 질의하였다. 그리고 움직임에 의한 재촬영 빈도를 알아보기 위해 2012년 1월부터 12월까지 PET Torso를 시행한 환자들 중 환자보정기구 사용 전/후 재촬영 여부를 분석하였다. 움직임에 불편이 전혀 없는 환자에서는 18명이 PHS와 팔의 각도가 $29^{\circ}$에서 가장 편안함을 느낀다고 답하였으며, 2명은 각각 $27^{\circ}$, $31^{\circ}$이라고 답하였다. 어깨 통증을 느끼는 환자에서는 15명이 $31^{\circ}$에서 가장 편안함을 느낀다고 답하였고, $33^{\circ}$에서 2명, $35^{\circ}$에서 3명이었다. 이를 위해 손잡이 부분이 상, 하 움직임이 가능하도록 제작하였다. 환자보정기구 재질의 투과성은 검증된 상태이며, 환자보정기구 자체의 움직임을 방지하기 위하여 PHS와 보정기구를 밴드(벨크로 형태)로 고정시켰다. 두경부의 움직임을 최소화할 수 있는 홈을 만들고 머리를 고정할 수 있게 고정밴드를 부착 하였고, 손목 및 전완과 상완의 움직임을 제한할 수 있는 고정밴드를 부착하여 팔의 흔들림으로 인한 움직임을 최소화 하였다. PET Torso 촬영 시 움직임에 의한 재촬영 빈도는 환자고정기구 사용 전 10.56% (191건/1,808명), 사용 후 2.77% (48 건/1,732명)로 7.79%의 발생 빈도를 줄일 수 있었다. 최근 의료 환경의 변화와 혁신으로 고가의 영상검사가 늘어남에 따라 고객이 요구하는 차별화된 서비스 제공은 필수적이다. 따라서 PET/CT를 검사하는 동안 환자의 편안함과 안전성을 확보하기 위해 인체공학적인 환자보정기구를 제공하여야 한다. 따라서 본 연구를 통해 PET Torso 검사 시 환자의 체형과 상황에 따라 인체공학적 경사도를 상, 하 조절할 수 있는 환자보정기구를 제작하였으며, 팔의 움직임에 의한 뇌기저부의 영상결손을 줄이고 머리의 움직임으로 인한 재촬영을 줄일 수 있었다.

• 디지털융복합연구
• /
• 제12권2호
• /
• pp.335-341
• /
• 2014

사용자 스마트폰에서 네트워크 비디오를 실시간으로 재생하려면, 서버가 비디오 콘텐츠를 스트리밍 방식으로 전송해야 한다. 일반적으로 상거래 서버는 유료 가입자 인증과 콘텐츠 분배를 담당한다. 단점은 사용자들의 서비스 요구가 급증하면 서버의 과부하, 전송 대역폭의 제한으로 고객에게 돌아가는 서비스 품질이 저하된다는 것이다. P2P 프로토콜은 콘텐츠를 보유한 사용자가 서버 역할을 분담하기 때문에 수요가 집중될 수록 서비스 품질이 좋아진다. 하지만 P2P 프로토콜은 분산된 서버를 제어할 수 없기 때문에 불법 콘텐츠 분배가 가능하여 상거래 용도로 적합하지 않다. 본 논문에서는 P2P 기반의 모바일 상거래에 적합한 동적 그룹 인증 기법을 제안한다. 제안한 기법은 공통키 생성, 공통키 업데이트, 그룹 서명 및 검증 프로토콜로 구성된다. 그룹을 구성하는 시더의 가입과 탈퇴를 반영할 수 있고, 하이브리드 P2P 기반의 상거래 모델에 적용되어 상거래 서비스는 중앙 서버가 담당하고 콘텐츠는 P2P 기반으로 분배할 수 있다.

• 한국근적외분광분석학회:학술대회논문집
• /
• 한국근적외분광분석학회 2001년도 NIR-2001
• /
• pp.3104-3104
• /
• 2001

The research described here was undertaken with the aim of monitoring, optimizing and ultimately controlling the production of heterofermentative microbes used as starters in the salami industry. The use of starter cultures in the fermented meats industry is a well-established technique used to shorten and standardize the ripening process, and to improve and control the organoleptic quality of the final product. Starter cultures are obtained by the submerged cultivation of suitable microorganisms in stirred, and sometimes aerated, fermenters where monitoring of key physiological parameters such as the concentration of biomass, substrates and metabolites suffers from the general lack of real-time measurement techniques applicable to aseptic processes. In this respect, the results of the present work are relevant to all submerged fermentation processes. Previous work on the application of on-line NIR spectroscopy to the lactic acid fermentation (Dosi et al. - Monreal NIR1995) had successfully used a system based on a measuring cell included in a circulation loop external to the fermenter. The fluid handling and sterility problems inherent in an external circulation system prompted us to explore the use of an in-line system where the NIR probe is immersed in the culture and is thus exposed to the hydrodynamic conditions of the stirred and aerated fluid. Aeration was expected to be a potential source of problems in view of the possible interference of air bubbles with the measurement device. The experimental set-up was based on an in-situ sterilizable NIR probe connected to the instrument by means of an optical fiber bundle. Preliminary work was carried out to identify and control potential interferences with the measurement, in particular the varying hydrodynamic conditions prevailing at the probe tip. We were successful in defining the operating conditions of the fermenter and the geometrical parameters of the probe (flow path, positioning, etc.) were the NIR readings were reliable and reproducible. The system thus defined was then used to construct and validate calibration curves for tile concentration of biomass, carbon source and major metabolites of two different microorganisms used as salami starters. Real-time measurement of such parameters coupled with the direct interfacing of the NIR instrument with the PC-based measurement and control system of the fermenter enabled the development of automated strategies for the interactive optimization of the starter production process.

• 대한의용생체공학회:의공학회지
• /
• 제38권4호
• /
• pp.143-152
• /
• 2017

The main purpose of this research was to examine the EMG characteristics of driver's upper limb and driving performance for operating accelerator and brake pedal by using four types of left hand control devices(Push/Pull, Push/Right angle, Push/Rock, Push/Twist) during simulated driving. The persons with disabilities in the lower extremity have problems in operation of the vehicle because of functional impairments for controlling accelerator and brake pedal. Therefore, if hand control device is used for adaptive driving controls in persons with lower extremity loss, the disabled people could improve their quality of mobility life by driving a car. Twenty subjects were involved in this research to assess driving performance and EMG activities for operating accelerator and brake pedal by using four types of left hand controls in driving simulator. We measured EMG responses of six muscles(posterior deltoid, middle deltoid, biceps, triceps, extensor carpi radialis, and flexor carpi radialis) during pulling and pushing movement with four types of left hand controls for acceleration and braking. STISim Drive 3 program was used for evaluation test of four types of left hand control devices in straight lane course for time to reach target speed and brake reaction time. While operating the four types of left hand controls for acceleration, EMG activities of posterior deltoid in normal subjects were significantly increased(p < 0.05) compared to the disabled subjects. It was also found that EMG responses of triceps and posterior deltoid were significantly increased(p < 0.05) when using the Push/Right angle type than Push/Pull type. While operating the four types of left hand controls for braking, EMG activities of flexor carpi radialis and triceps in subjects with disability were significantly increased(p < 0.05) compared to the normal subjects. It was shown that muscle responses of posterior deltoid, middle deltoid and triceps were significantly increased when using the Push/Right angle type than Push/Rock type. Time to reach target speed and brake reaction time in subjects with disability was increased by 2.5% and 4.6% on average compared to normal subjects. The person with disabilities showed a tendency to relatively slow performance in acceleration at the straight lane course.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.288-289
• /
• 2011

Indium Tin Oxide (ITO) is a typical highly Transparent Conductive Oxide (TCO) currently used as a transparent electrode material. Most widely used deposition method is the sputtering process for ITO film deposition because it has a high deposition rate, allows accurate control of the film thickness and easy deposition process and high electrical/optical properties. However, to apply high quality ITO thin film in a flexible microelectronic device using a plastic substrate, conventional DC magnetron sputtering (DMS) processed ITO thin film is not suitable because it needs a high temperature thermal annealing process to obtain high optical transmittance and low resistivity, while the generally plastic substrates has low glass transition temperatures. In the room temperature sputtering process, the electrical property degradation of ITO thin film is caused by negative oxygen ions effect. This high energy negative oxygen ions(about over 100eV) can be critical physical bombardment damages against the formation of the ITO thin film, and this damage does not recover in the room temperature process that does not offer thermal annealing. Hence new ITO deposition process that can provide the high electrical/optical properties of the ITO film at room temperature is needed. To solve these limitations we develop the Magnetic Field Shielded Sputtering (MFSS) system. The MFSS is based on DMS and it has the plasma limiter, which compose the permanent magnet array (Fig.1). During the ITO thin film deposition in the MFSS process, the electrons in the plasma are trapped by the magnetic field at the plasma limiters. The plasma limiter, which has a negative potential in the MFSS process, prevents to the damage by negative oxygen ions bombardment, and increases the heat(-) up effect by the Ar ions in the bulk plasma. Fig. 2. shows the electrical properties of the MFSS ITO thin film and DMS ITO thin film at room temperature. With the increase of the sputtering pressure, the resistivity of DMS ITO increases. On the other hand, the resistivity of the MFSS ITO slightly increases and becomes lower than that of the DMS ITO at all sputtering pressures. The lowest resistivity of the DMS ITO is $1.0{\times}10-3{\Omega}{\cdot}cm$ and that of the MFSS ITO is $4.5{\times}10-4{\Omega}{\cdot}cm$. This resistivity difference is caused by the carrier mobility. The carrier mobility of the MFSS ITO is 40 $cm^2/V{\cdot}s$, which is significantly higher than that of the DMS ITO (10 $cm^2/V{\cdot}s$). The low resistivity and high carrier mobility of the MFSS ITO are due to the magnetic field shielded effect. In addition, although not shown in this paper, the roughness of the MFSS ITO thin film is lower than that of the DMS ITO thin film, and TEM, XRD and XPS analysis of the MFSS ITO show the nano-crystalline structure. As a result, the MFSS process can effectively prevent to the high energy negative oxygen ions bombardment and supply activation energies by accelerating Ar ions in the plasma; therefore, high quality ITO can be deposited at room temperature.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제27권5호
• /
• pp.403-414
• /
• 2005

The purpose of this study was to identify the effectiveness of the modified distraction osteogenesis (DO) method with the concept of overdistraction and compression stimulation which have been previously suggested by the authors in 2002 and to explore the optimal distraction-compression ratio and appropriate latency period for the compression force application during consolidation. The experimental specimens were assessed with radiography, histologic findings, and dual energy x-ray absorptiometry (DEXA) after the conventional DO method and the modified DO technique had been applied on rat mandibles. Total 60 rats were used for the study. In experimental group of 54 adult rats, mandibular osteotomies between the first and second molar areas were performed and customized external distractors were applied. The surgeries on 6 rats of control group also were done with same osteotomy technique and DO device application. Final amount of distraction was set-up as 2 mm on both groups. But, in a experimental group of 54 rats, distraction osteogenesis with a compression force were performed with the different distraction-compression ratio and variant latency periods for compression. The three ratio-subgroups were made as distraction 4 mm group with compression 2 mm, distraction 3 mm group with compression 1 mm, and distraction 2.5 mm group with compression 0.5 mm. In addition, The three subgroups with 3, 7, 11 days latency period prior compression were allocated on each ratio-subgroups. Total 9 subgroups consisted of 6 rats on each subgroup. In control group of 6 rats, conventional distraction technique were routinely performed. The rats of control groups were sacrificed on postoperative 3, 6 weeks after 2 mm distraction. The rats in the experimental groups also were sacrificed on the same euthanasia days of control groups to compare the wound healing. Final available specimens were 55 rats except 5 due to osteomyelitis, device dislodgement. Distraction-compression combined group on 6 weeks generally had showed increased bone mineral density than the same period group of conventional distraction technique on the DEXA study. More matured lamellar bone state and extended trabecular pattern in the combined group than those of control group were also observed in the histologic findings on 6 weeks. In the distraction-compression combined groups, the bone density of 2.5 mm distraction subgroups with 0.5 mm compression showed the highest value on the DEXA study among various force ratio groups. In the distraction-compression combined groups, the bone density of 3 day latency period subgroups showed the highest value on the DEXA study among various latency period groups for the compression application. From this study, we could deduce that 1/5 force ratio for the compression versus distraction, 3 day latency period prior compression application would be the most effective condition if modified distraction osteogenesis technique might be applicable. The modified DO method with a compression force may improve the quality of bone regenerate and shorten total treatment period in comparison with conventional DO technique clinically.

• 한국의학물리학회지:의학물리
• /
• 제18권2호
• /
• pp.98-106
• /
• 2007

2005년 6월 연세의료원 세브란스병원에서는 진단목적으로 20대의 5 mesa 화소 Totoku ME511L 평판 LCD 표시장치를 추가하여 PACS를 확장하였다. 20대의 Totoku ME511L 표시장치를 대상으로 반사, 휘도 반응, 휘도 공간 의존, 분해능, 잡음, 베일링 그레어, 그리고 색도 항목에 대하여 AAPM TG 18보고서에 기준하여 정량적인(또는 시각적인) 인수검사를 실시하였다. 측정에 사용된 장치는 색도를 측정할 수 있는 만원경식 휘도계, 조도계, 반사 측정에 필요한 빛 선원, 빛 차단 장치, 그리고 TG18 테스트 패턴들이었다. 선택된 8대의 표시장치에 대한 평균 확산 반사계수($R_d$)는 $0.019{\pm}0.02sr^{-1}$이었다. 휘도 반응 검사에서, 휘도비(LR), 최대 휘도 변이($L_{max}$), 그리고 최대 대조도 반응 변이는 각각 $550{\pm}100,\;2.0{\pm}1.9%$, 그리고 $5.8{\pm}1.8%$이었다. 휘도 균일도 검사에서, 최대 휘도 변이는 TG18-UNL10 테스트 패턴의 10% 휘도에 대하여 $14.3{\pm}5.5%$이었다. 분해능 측정은 휘도 측정법으로 수행하였으며 중심에서 퍼센트 휘도(${\Dalta}L$)는 $0.94{\pm}0.64%$이었다. 시각적인 방법의 잡음측정의 모든 경우에서, 중앙 및 주위 4사분면에서 가장 작은 것을 제외하고 15개의 모든 정사각형의 표적을 인식할 수 있었다. 글레어 비(GR)은 $12,346{\pm}1,995$이었다. 최대 색도 균일도 지표(D)는 $0.0025{\pm}0.0008$이었다. 또한 국내 실정에 적합한 진단용 표시장치의 정도관리 가이드라인 연구 결과를 제시하였다. 모든 인수검사 결과는 AAPM TG18 보고서 기준에 포함되어 진단 목적으로 사용하기에 적합하였다. 결론으로 인수검사는 표시장치가 진단에 사용하기에 적합한 성능임을 알려줄 뿐만 아니라 정도관리의 가이드라인, 최적 판독 환경, 그리고 표시장치의 교체시기를 결정하여주는 중요한 역할을 할 수 있다.

• Journal of Acupuncture Research
• /
• 제26권6호
• /
• pp.101-110
• /
• 2009

Objectives : We developed and proposed a guideline for safety and performance assessment of electric cupping apparatus(Class 2 medical device). Methods : We drafted the guideline for safety and performance assessment of electric cupping apparatus by referring the existing standards and guideline, based on online questionnaire for Korean medical doctors and measurement data from commercially available products. Physical dimension of cups and inner vacuum pressure were acquired for the measurement in order to achieve the purposes. Results : This guideline only can be applied to electric cupping apparatus for enhancing blood circulation by employing negative pressure generated by electricity. Seven items of appearance and label, operation test of pump, variation test of input electricity, vacuum level test, vacuum sustain test, cup-size dependent test, noise level test are suggested for evaluation subjects and methods required for electric cupping devices. Requirements for the design and development of electric cupping devices are suggested: vacuum level indicator, vacuum generation rate, pressure control, valve detachment stability, cup comparability, safety measure, surge protection, user friendliness, instruction for use (IFU). Conclusions : We proposed a guideline for safety and performance assessment of electric cupping apparatus to improve the quality of relating products and aid the commercialization of them, by aiming higher industrial competitiveness of the medical device sectors in Korea. Discussion with related institutes such as industry, academy and government is further required. Public hearings also need to be held prior to the establishment of a final guideline and standard.

• 분석과학
• /
• 제25권6호
• /
• pp.382-387
• /
• 2012

산화에틸렌($C_2H_4O$, Ethylene oxide, EtO)은 에탄올아민 같은 공업적으로 중요한 물질이나 에틸렌 글리콜의 생산 원료 또는 살균제로 이용되는 물질이다. 산화에틸렌은 불화탄화수소를 분사제 또는 바탕가스로 하여 액화혼합가스로 제조되어 열에 약한 의료기기나 저장시설의 소독에 널리 사용되고 있다. 액화혼합가스의 생산 및 사용 시 품질관리 및 안전관리를 위해 각 성분의 몰분율을 정확히 측정할 필요가 있다. 휘발성 액체시료 중 각 기체성분들은 증기압이나 끓는점 등과 같이 물리 화학적 성질이 다르므로 몰분율 측정 시 실린더 내부의 상층에 평형을 이루고 있는 기체시료 또는 하층의 기화되지 않은 액체시료를 직접 측정기기에 주입하는 방법에 따라 측정 결과가 다를 수 있다. 본 연구에서는 액화혼합가스를 액체 또는 기체 상태로 주입할 수 있는 새로운 온라인 시료도입장치를 고안하고 GC/AED (gas chromatograph-atomic emission detector)를 사용하여 산화에틸렌과 불화탄화수소 액화혼합가스를 측정하였으며 AED의 검출특성, 기기에 주입 시 시료의 상태, 측정파장에 따른 측정결과의 정확성 및 반복성을 조사하였다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권6호
• /
• pp.55-61
• /
• 2015

Based on the literature study for the determination of perchlorate in soil we chose the ion chromatography as a measurement method and decided to use 70 mM KOH as an eluent to avoid the interference derived from the co-elution of pyrophosphate (P₂O₇⁴⁻), tripolyphosphate (P₃O₁₀⁵⁻). Also we proposed to use air dried soil through 0.15 mm sieve and distilled water as an extractant. Under the these basic concepts, we carried out the experiments to set up the detail procedure like solid to liquid ratio (S/L ratio), extraction time, device for extraction and indicating factors for quality control (e.g. precision, accuracy, MDL, LOQ). In case of time and device for extraction, 5 hours of mechanical shaking or 1 hour of centrifugation showed better precision and accuracy than that of sonication for 1 hour According to these results, we proposed the extraction method combining 5 hours of mechanical shaking with 1 hour of centrifugation. From the aspect of S/L ratio, the ratio of 1/2 or 1/3 showed resonable precision and accuracy. In case of the ratio of 1/2, there would be some problems in the separation process when the proportion of fine particle is high. Therefore, we proposed the extraction ratio of solid to liquid as 1/3 instead of 1/2. With the consideration of cost effectiveness and soil salinity, we proposed the use of cartridge for removing the interfering anions like chloride, sulfate and carbonate in specific sample such as saline soil.