• 핵의학기술
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• 제15권1호
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• pp.34-38
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• 2011

표준섭취계수(Standard Uptake Value, SUV)는 PET 검사에 있어서 매우 중요한 지표이다. 그러나 이는 장비에 따라서 다르게 나타난다. 그러므로 실제의 SUV와 장비에 따른 SUV의 차이를 알아보고자 한다. 실험을 위해 사용된 PET scanner는 본원과 보라매 병원에서 사용하고 있는 Biograph True Point True V 40 (Siemens, USA), Gemini Dual (Philips, USA), Gemini TF 64 (Philips, USA) 총 3대로 이루어져 있다. SUV를 평가하기 위한 phantom은 NEMA PET phantom (Data Spectrum co., USA)이고 내부에 3개의 hot insert를 포함하고 있으며 총 중량은 6.8kg으로 phantom과 물의 중량을 합친 무게이다. 방사성동위원소는 $^{18}F$-FDG 25.9 MBq (0.7 mCi)와 29.6 MBq (0.8 mCi)을 사용하였고 스캔은 두 번으로 나누어 이루어졌다. 25.9 MBq (0.7 mCi)은 background에 3.7 MBq (0.1 mCi), insert 1에 3.7 MBq (0.1 mCi), insert 2에 7.4 MBq (0.2 mCi), insert 3에 11.1 MBq (0.3 mCi)이 주입되었고 29.6 MBq (0.8 mCi)은 background에 1.85 MBq (0.05 mCi), insert 1에 7.4 MBq (0.2 mCi), insert 2에 9.25 MBq (0.25 mCi), insert 3에 11.1 MBq (0.3 mCi)이 주입되었다. Uptake time은 20분이고 2 bed scan을 하였으며 bed 당 3분의 영상획득이 이루어졌다. 두 번의 실험 모두 실제의 SUV와 유사하게 나타났다. 방사능량이 소량일 경우에는 그 차이가 미미했으나 방사능량이 증가할수록 그 차이는 점점 벌어졌다. 하지만 그 차이 또한 크지는 않았다. 장비 별 차이를 백분율로 환산하면 Biograph의 경우 87.2%, Gemini Dual은 91.2%, Gemini TF 64는 85.9%로 나타났으며 이는 실제의 값에 유의하다. 장비 별로 분류해보면 Biograph와 Gemini Dual은 비슷한 결과를 보여주었고 다만 Gemini TF 64에서만 두 장비보다 낮게 나타났다. 실험 결과 장비 별로 SUV의 차이는 있으나 그 차이가 실제의 값에 유의하였다. SUV가 차이가 나는 이유는 장비 별 재원의 차이와 재구성 방법, 제조사 별 SUV 함수식에서 기원이 되는 것으로 파악되며 소량의 방사능량에서는 차이가 없으나 방사능량이 증가할수록 차이가 커지는 것으로 보아 이 점에서의 추후 고찰은 필요할 것으로 사료된다.

• 수면정신생리
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• 제20권2호
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• pp.75-81
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• 2013

목 적 : 혐오 자극에 대한 뇌의 기능적 영상 연구에 있어서 기능적 자기공명영상, 양전자방출단층촬영 등의 연구는 많이 진행되어 있으나 저해상 전자기 단층촬영(low resolution brain electromagnetic tomography) 분석을 이용한 연구는 거의 없다. 본 연구의 목적은 피험자들에게 시각적 혐오자극을 준 후 나타나는 대뇌 피질의 활성변화를 저해상 전자기 단층촬영을 이용하여 파악하고자 하는 것이다. 방 법 : 총 45명($27.1{\pm}2.6$세)의 건강한 젊은 성인남녀가 연구에 참여하였다. 국제정서사진체계를 사용하여 중립자극에서 4장, 신체훼손과 관련된 혐오자극에서 4장의 사진을 뽑아 피험자들에게 각 30초간 보여주면서 뇌파를 측정하였다. 저해상 전자기 단층촬영분석을 시행하여 중립자극에 대비해 혐오자극에서의 변화된 전류밀도를 비교 분석하였다. 결 과 : 혐오시각 자극을 받는 동안 피험자 모두 불쾌감, 놀람, 스트레스를 받았다고 보고하였다. 저해상 전자기 단층촬영 분석상 세타파에서 좌측 전두엽의 위이마이랑(BA10)과 중간이마이랑(BA10, 11) 영역에서 유의미한 전류밀도의 감소를 보이는 복셀 클러스터가 관찰되었다. 이 복셀 클러스터는 총 11개의 복셀로 구성되어 있으며 유의미한 전류밀도(p<0.05)의 감소를 나타내는 t값의 임계값은 -1.984이었다. 남녀 간의 혐오 반응 정도에 유의미한 차이는 없었다. 결 론 : 이 연구의 결과인 시각 혐오자극에 의한 배외측 전전두엽의 활성은 혐오 정서의 조절과 관여되어 있을 것으로 생각된다.

• 대한의용생체공학회:의공학회지
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• 제6권2호
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• pp.1-8
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• 1985

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70$\pm$1.32mmHg/min)compared to CF dialyzers(4.32$\pm$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500, 550, 570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500, 550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3, 000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.SpO2 with Plethysmograph.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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• pp.17-17
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• 1993

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

• 대한방사선기술학회지:방사선기술과학
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• 제37권1호
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• pp.49-56
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• 2014

최근 PET/CT는 CT의 발전과 함께, 피폭선량의 저감화를 위한 다양한 연구가 진행되고 있다. 이러한 연구 중 비스무스(bismuth) 차폐체에 관한 연구가 활발하게 진행 중이지만 현재 PET/CT 검사에서의 적용은 활성화 되지 않았다. 그러므로 본 연구를 통하여 PET/CT 검사에서의 비스무스 차폐체의 적용에 따라 영상의 질과, 표준화섭취계수(SUV)에 미치는 영향을 확인하는데 목적을 두었다. 유방차폐의 적용을 위해 0.06 mm Pb 성분을 포함하고 있는 비스무스 차폐체(AttenuRad_F&L Medical Product Co, USA)를 사용하여 PET/CT 장비 GEMINI TF 64(Philips Healthcare, Cleveland, USA)에 적용하였다. 실험은 NEMA IEC Body Phantom을 사용하여 비스무스 차폐체 적용 유무에 따른 영상을 획득하였다. 또한 적용 시에는 0cm, 1cm, 2cm의 간격 변화를 주어 영상을 획득하였고, 각각의 영상을 EBW(Extended Brilliance Workstation)NM ver.1.0을 이용 팬텀의 Depth에 다른 관심영역을 설정하고 표준섭취계수를 각각 10회씩 측정, 분석하였다. 또한 SPSS ver.18을 통해 통계 분석하였다. PET의 방출(Emission)영상 획득 시 비스무스 차폐체의 적용으로 발생한 방사선 경화현상에 기인하여 표준섭취계수가 증가한 것을 확인하였으며(P<0.005), 깊이에 따른 차이는 팬텀의 심부에서 표면으로 갈수록 표준섭취계수가 증가하였다(P<0.005). 또한 차폐체 사용 시 간격이 줄어들수록 표준섭취계수가 증가하는 것을 확인하였다(P<0.005). 본 연구를 통해 피폭저감을 목적으로 사용하는 비스무스 차폐체의 PET/CT에서의 검사에 적용을 고려할 수 있다. 차폐체 적용에 따른 표준섭취계수의 차이가 존재하며 그 차이는 차폐체와 표면의 간격이 넓을수록 줄어든다. 그러므로 차폐체의 충분한 간격 설정이 고려되어야 할 것이며, 영상의 질과 표준섭취계수 편차의 감소를 고려한다면, 질환에 따라 표재성 질환보다는 심부나 타 장기의 적용이 우선시 되어야 할 것이다. 또 한 비스무스차폐체 사용에 따른 표준섭취계수를 감안한 임상 검사 적용 시, 불필요한 피폭감소 효과를 기대할 수 있을 것으로 사료된다.

• 핵의학기술
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• 제17권1호
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• pp.36-42
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• 2013

최근 PET/CT는 CT의 발전과 함께, 피폭선량의 저감화를 위한 다양한 연구가 진행되고 있다. 이러한 연구 중 비스무스(bismuth) 차폐체에 관한 연구가 활발하게 진행 중이지만 현재 PET/CT 검사에서의 적용은 활성화 되지 않았다. 그러므로 본 연구를 통하여 PET/CT 검사에서의 비스무스 차폐체의 적용에 따라 영상의 질과, 표준화섭취계수(SUV)에 미치는 영향을 확인하는데 목적을 두었다. 유방차폐의 적용을 위해 0.06 mmPb 성분을 포함하고 있는 비스무스 차폐체 (AttenuRad__F&L Medical Product Co, USA)를 사용하여 PET/CT 장비 GEMINI TF 64 (Philips Healthcare, Cleveland, USA)에 적용하였다. 실험은 NEMA IEC Body Phantom을 사용하여 비스무스 차폐체 적용 유무에 따른 영상을 획득하였다. 또한 적용 시에는 0cm, 1cm, 2cm의 간격 변화를 주어 영상을 획득하였고, 각각의 영상을 EBW (Extended Brilliance Workstation)NM ver.1.0을 이용 팬텀의 Depth에 다른 관심영역을 설정하고 표준섭취계수를 각각 10회씩 측정, 분석하였다. 또한 SPSS ver.18을 통해 통계 분석하였다. PET의 방출(Emission)영상 획득 시 비스무스 차폐체의 사용에 따라 표준섭취계수가 증가한 것을 확인하였으며 (P<0.005), 깊이에 따른 차이는 팬텀의 심부에서 표면으로 갈수록 표준섭취계수가 증가하였다(P<0.005). 또한 차폐체 사용 시 간격이 줄어들수록 표준섭취계수가 증가하는 것을 확인하였다(P<0.005). 본 연구를 통해 피폭저감을 목적으로 사용하는 비스무스차폐체의 PET/CT에서의 검사에 적용을 고려할 수 있다. 차폐체 적용에 따른 표준섭취계수의 차이가 존재하며 그 차이는 차폐체와 표면의 간격이 넓을수록 줄어든다. 그러므로 차폐체의 충분한 간격 설정이 고려되어야 할 것이며, 영상의 질과 표준섭취계수 편차의 감소를 고려한다면, 질환에 따라 표재성 질환보다는 심부나 타 장기의 적용이 우선시 되어야 할 것이다. 또한 비스무스차폐체 사용에 따른 표준섭취계수를 감안한 임상 검사 적용 시, 불필요한 피폭 감소 효과를 기대할 수 있을 것으로 사료된다.

• 한국의학물리학회지:의학물리
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• 제17권1호
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• pp.24-31
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• 2006

유방암 환자의 방사선치료에 있어 치료도중(intrafractional) 및 분할 치료 간(intefractional)에 발생되는 오차를 측정하는 자동분석소프트웨어를 개발하였다. 오차 분석 결과는 3차원 입체조형 방사선치료를 임상에 적용하기에 앞서 적절한 치료계획용적(Planning Target Volume, PTV)을 설정하는 데 있어 매우 중요하다. 본 연구에서는 전자포탈영상장치(Electrical Portal imaging Device, EPID)로써 Portal Vision LC250 액체 충전형 이온화 검출기를 사용하였다(fast frame-averaging 모드, 초당 1.4 프레임, 256X256 픽셀). 12명의 환자에 대해 최소 7일 이상씩 영상을 획득하였다. 매 치료마다 평균 8 내지 9개의 영상을 각 빔에 대해 얻었다(분당 400 MU 선량률). 총 2,931 (720 측정을 포함하는)개의 영상을 정량적으로 분석할 수 있는 자동화 영상 분석 소프트웨어를 개발하였다. 이를 통해 호흡으로 인해 발생하는 치료도중 오차와 분할 치료간 발생하는 분할치료오차의 표준편차($\sigma$)들을 계산하였다. 신뢰 구간 95%로 임상표적체적(Clinical Target Volume, CTV)을 포함할 수 있는 PTV 마진은 $2\;(1.96\;{\sigma})$으로 계산되었다. 주로 호흡으로 인해 유발되는 치료도중오차를 보상하기 위해 필요한 PTV 마진은 2 mm에서 4 mm이었다. 반면에 분할 치료간 오차를 보상하기위해 필요한 PTV 마진은 7 mm에서 31 mm이었다. 12명의 환자에 대한 전체 평균오차는 17 mm이었다. 분할치료 간 오차는 호흡에 의해 유발되는 치료도중 오차에 비해 2배에서 15배까지 더 크게 나타났다. 유방암 치료에 있어 3차원 입체정형조사나 세기조절방사선치료(Intensity Modulated Radiation Therapy, IMRT)를 적용하기에 앞서 반드시 셋업 오차의 크기를 측정하여 PTV에 적절히 반영되어야 한다. 유방에 대한 3차원 입체정형조사나 세기조절방사선치료를 위해 반드시 필요한 것은 아니지만, 큰 PTV 마진을 줄여주기 위해서는 영상유도방사선치료(Image Guided Radiation Therapy, IGRT)가 매우 유용하게 이용될 수 있다. 전자포탈영상장치 들은 본 보고서에서 기술한 바와 같은 자동분석소프트웨어를 반드시 포함하여야 한다. 이를 통해 수많은 EPID 영상들을 자동화 처리하고 오차분석을 시행함으로써 각 병원의 임상적용 방법 및 환경에 따라 상이하게 나타날 수 있는 오차의 크기를 감안한 적절한 PTV마진을 구하는데 도움을 얻을 수 있다. 이러한 장치들은 또한 최소의 노력으로 환자 치료를 관찰할 수 있는 귀중한 정보를 제공해 준다.

• 핵의학기술
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• 제23권2호
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• pp.51-58
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• 2019

핵의학 체외 검사실 에서는 시약 Lot가 변경될 때, Lot 간의 결과가 신뢰성이 있는지를 판단하기 위해 Lot 간 동등성 검사(comparability test between reagent lots) 또는 시약 병행 검사(reagent parallel test)를 시행하는데, 다수의 국내 검사실에서는 두 lot 간 결과 차이로부터 %difference를 구하여 저농도에서는 20% 이내, 중 고농도에서는 10% 이내로 설정하고 있으며 범위를 벗어 날 경우 재검사 시행으로 범위를 맞추는 실정이다. 따라서 본원의 핵의학 체외 검사실에서 시행되는 몇 가지 검사를 선정하여 parallel test의 결과를 분석해보았고, 검사별 맞춤 %difference 값 선정에 도움 될 만한 참고 자료를 마련해 보고자 하였다. Thyroid-stimulating hormone(TSH), Free thyroxine(FT4), Carcinoembryonic antigen(CEA), CA-125, Prostate-specific antigen(PSA) 그리고 HBs-Ab, insulin, 7종목에 대해 2018 1월부터 2018년 11월까지의 기간 동안의 시약 lot 변화에 따른 정도 관리 물질의 결과를 분석하였다. TSH, F-T4, CEA, CA-125, PSA의 측정에는 IRMA의 원리를 이용한 RIA-MAT 280 system이 사용되었고, Insulin의 측정에는 TECAN 자동화 분주 장비와 GAMMA-10 측정 장비가 사용되었다. HBs-Ab의 측정에는 HAMILTON 자동화 분주 장비와 GAMMA-10 측정 장비가 사용되었다. 각각 전용 시약과 전용 칼리브레이터, 전용 정도 관리 물질이 사용되었다. 1. TSH [%diffrence Max / Mean / Median] (P-value by t-test > 0.05) C-1(저농도) [14.8 / 4.4 / 3.7 / 0.0 ] C-2(중농도) [10.1 / 4.2 / 3.7 / 0.0] 2. FT4 [%diffrence Max / Mean / Median] (P-value by t-test > 0.05) C-1(저농도) [10.0 / 4.2 / 3.9 / 0.0] C-2(고농도) [9.6 / 3.3 / 3.1 / 0.0 ] 3. CA-125 [%diffrence Max / Mean / median] (P-value by t-test > 0.05) C-1(중농도) [9.6 / 4.3 / 4.3 / 0.3] C-2(고농도) [6.5 / 3.5 / 4.3 / 0.4] 4. CEA [%diffrence Max / Mean / median] (P-value by t-test > 0.05) C-1(저농도) [9.8 / 4.2 / 3.0 / 0.0] C-2(중농도) [8.7 / 3.7 / 2.3 / 0.3] 5. PSA [%diffrence Max / Mean / Median] (P-value by t-test > 0.05) C-1(저농도) [15.4 / 7.6 / 8.2 / 0.0] C-2(중농도) [8.8 / 4.5 / 4.8 / 0.9] 6. HBs-Ab [%diffrence Max / Mean / Median] (P-value by t-test > 0.05) C-1(중농도) [9.6 / 3.7 / 2.7 / 0.2] C-2(고농도) [8.9 / 4.1 / 3.6 / 0.3] 7. insulin [%diffrence Max / Mean / Median] (P-value by t-test > 0.05) C-1(중농도) [8.7 / 3.1 / 2.4 / 0.9] C-2(고농도) [8.3 / 3.2 / 1.5 / 0.1] 모두 정도 관리 물질의 lot 변경 시에도 유의미한 차이가 없었으며 표본 수가 늘어남에 따라 검사실과 검사 종목 별 맞춤 허용 기준을 설정할 수 있을 것이라 기대할 수 있었다. 면역 방사 계수 측정법에서 비교적 검출률이 높은 종목들을 선정해서 일 것이라 판단되며 여러 번 재 측정된 결과 값이기 때문일 수도 있겠다. 대부분의 검사 결과에서 허용 기준인 10%에 크게 못 미치는 차이를 보였으며 저농도 target 값을 가진 경우에도 허용 기준인 20%에 가까운 수치를 보이진 않았다. 더 오랜 기간 동안의 관찰과 연구를 통해 평균의 균질화가 이루어진다면 종목 별 검사실 맞춤 허용 기준을 얻을 수 있을 것으로 판단되며 더 다양한 변수를 고려한 관찰과 연구도 필요할 것이다.

• 한국치위생학회지
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• 제7권1호
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• pp.73-89
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• 2007

The purpose of this study was to examine the reality of inservice education provided to members of Korean Dental Hygienists Association, the state of relevant academic conferences, and the perception of the members about inservice education and academic conference. It's basically meant to help boost their participation in inservice education and their satisfaction with it, and to show some of the right directions for that. The subjects in this study were dental hygienists who attended a symposium on July 1, 2006. After a survey was conducted, the answer sheets from 489 participants were analyzed, and the findings of the study were as follows: 1. General hospitals and university hospitals made up the largest group(91.4%) that gave a monthly leave of absence, and the second largest group was dental hospitals(75.4%), followed by dental clinics(58.3%) and public dental clinics(48.0%). The most common closing time in dental clinics and dental hospitals was 5 p.m., and that was 12 p.m. in general hospitals and university hospitals. The dental hygienists in public dental clinics didn't work on Saturdays. By type of workplace, treatment was the most common duty for the dental hygienists in dental clinics and dental hospitals to perform, and those who worked at general hospitals, university hospitals and public health clinics were in charge of extensive range of jobs. 2. The rates of the dental hygienists who took that education stood at 94.9% in public dental clinics, 78.7% in dental hospitals and 75.3% in dental clinics, general hospitals and university hospitals. Regarding how many marks they got on an yearly basis, those who got eight marks or more made up the largest group(55.6%), followed by four marks or more(11.8%), six marks or more(3.4%), and two marks or more(1.5%). As for the usefulness of inservice education for their job performance, the largest number of the dental hygienists(40.8%) found it to be helpful, and the second greatest group(37.5%) considered its effectiveness to be so-so. The third largest group(8.4%) found it to be of great use, and the fourth biggest group(4.2%) considered it to be of no service. The fifth biggest group(l.3%) thought it was absolutely useless. By type of workplace, the workers in dental clinics, dental hospitals, general hospitals and university hospitals wanted the most to learn how to take care of clinical work(acquisition of up-to-date technology), and those in public health clinics hoped the most to learn about public dental health. By type of workplace, the workers in dental clinics had their sight set on self-development the most, and the dental hygienists in dental hospitals, general hospitals, university hospitals and public health clinics were most in pursuit of acquiring new knowledge. By type of workplace, the specific given conditions at work were most singled out by the dental clinic workers as the reason, and the dental hospital employees pointed out time constraints the most. The dental hygienists in general hospitals and university hospitals cited time constraints and financial burden the most, and the public health clinic personnels mentioned inaccessibility of a place for inservice education as the reason. 3. The public health clinic workers participated in academic conferences the most(90.8%), followed by the general and university hospital personnels(68.8%), dental hospital employees(65.6%) and dental clinic workers(65.5%). By type of workplace, the public health clinic workers(73.5%) expressed the most satisfaction, followed by the general and university hospital employees(67.7%), dental clinic workers(62.3%) and dental hospital personnels(54.1%). By type of workplace, the employees of dental clinics, dental hospitals, general hospitals and university hospitals preferred Saturdays, and the public health clinic workers had a liking for weekdays. As for a favored place, hotels were most preferred, followed by university hospitals, general hospitals, college lecture rooms, district halls and local public institutions. Hotels were most favored regardless of the type of workplace. 4. Regarding outlook on inservice education, they had the highest opinion on the facilities and given conditions of lecture rooms($3.41{\pm}0.83$), followed by the professionalism of lecturers($3.34{\pm}0.83$), procedures of receipt and attendance confirmation($3.34{\pm}0.83$) and class size($3.13{\pm}0.89$). On the contrary, they took the most dismal view of the inaccessibility of a place of inservice education($2.08{\pm}0.92$), followed by limited opportunity and limited date for that education($2.51{\pm}0.99$), extra financial burden($2.53{\pm}1.18$) and high tuition fee($2.57{\pm}0.96$).

• 한국환경생태학회지
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• 제25권3호
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• pp.327-357
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• 2011

본 연구는 한국과 일본에 분포하는 산림군락의 분포와 종조성에 관한 비교연구이다. 식생조사 자료 1844를 이용하여 79개 산림군락을 식별하였으며, 54개 종군으로 구분되어 조사지역 간의 종조성의 유사성과 이질성을 나타냈다. 또한, 산림군락의 상관을 나타내는 구성종의 특징에 따라 14개 산림형으로 구분하였으며, 조사지역의 수직적 식생대는 유사한 특징을 나타내고 있지만 지역 간 서로 다른 우점종과 종조성 차이를 나타냈다. 저지대에 구실잣밤나무 또는 메밀잣밤 나무를 우점종으로 하는 모밀잣밤나무속-산림형(Castanopsis-Type)은 한반도 북부와 울릉도를 제외한 조사지역에 분포하고 있으며, 후박나무-산림형(Persea thunbergii-Type)은 조사지역의 전역에 넓게 분포하고 있다. 구릉대에 분포하는 일본젓나무-산림형(Abies firma-Type)의 상록수림은 큐슈북부와 쓰시마섬에 분포하고 있다. 산지대에 참나무속(활)-산림형(Quercus(D)-Type)과 너도밤나무속-산림형(Fagus-Type)으로 구성된 낙엽활엽수림은 조사지역에 넓게 분포하고 있지만, 신갈나무와 너도밤나무가 우점하는 산림군락은 한국에 분포하며, 물참나무, Fagus crenata(일명: 부나), Fagus japonica(일명: 이누부나)가 우점하는 산림군락은 일본에 분포하고 있다. 아고산대에서는 전나무속-참나무속(활)-산림형(Abies-Quercus(D)-Type), 구상나무-산림형(Abies koreana-Type), 눈잣나무-산림형(Pinus pumila-Type)이 한반도와 제주도에 분포하고, 주목-산림형(Taxus cuspidata var. nana-Type), Abies mariesii-Type(일명: 아오모리토도마츠-산림형), 눈잣나무-산림형(Pinus pumila-Type)은 일본 중부지역에 분포하고 있다. DCA 분석결과, 제1축에 대하여 낮은 수치에서부터 상록활엽수림, 낙엽활엽수림, 상록침엽수림이 배치되었다. 또한, 지역적으로는 제1축의 낮은 수치에서 부터 일본 산림형, 제주도 산림형, 한반도 산림형이 순차적으로 배치되었다. 기후요인 중 온량지수와 연교차는 제1축에 대하여 높은 상관관계를 나타내며, 해양성 기후에서 대륙성 기후를 반영하고 있음을 시사하고 있다. 지리적으로 가깝고 온난한 저해발, 저위도 지역에 분포하는 산림형일수록 산림군락간의 종조성적 유사성이 크며, 이에 반하여 지리적으로 격리되어 있으며, 고위도, 고해발지역에 분포하는 산림형일수록 산림군락간의 종조성의 차이가 뚜렷하고 산림군락의 종조성적 독립성이 강하였다. 이러한 형성요인은 오랫동안의 각 지역의 지사적(地史的)인 식물상의 구성적 특성을 반영하고 있다.