• Journal of Sensor Science and Technology
• /
• v.24 no.4
• /
• pp.239-246
• /
• 2015

Blood pressure is possible to diagnose a disease associated with blood pressure and judgment the current health of patients. Automatic blood pressure monitor capable of measuring a blood pressure easily in hospital and at home have become spread. In this study, we developed the blood pressure simulator (BPS) that can test the arm-type automatic blood pressure monitor that is commonly used in hospital. BPS is to produce a pressure similar to the pressure wave generated in the human blood using a servo disk motor. Then, using the silicon tube, it implements the situations such as human blood vessels, and to output the generated pressure waveform. Simply the BPS's phantom put on the cuff and it is able to simulate blood pressure. So anyone can quickly test the blood pressure monitor within one minute and it is possible to shorten the test time required for the automatic blood pressure monitor. In Performance test, the trends and the standard deviation of the values measured in the BPS is similar to the value of the measured pressure from people with normal blood pressure. Thus, the development BPS showed a possibility of taking into account the actual blood pressure measurement environment simulator.

• Progress in Medical Physics
• /
• v.17 no.2
• /
• pp.123-129
• /
• 2006

A test code was written to apply the EGS5 Monte Carlo code recently published to radiotherapy. This test code was designed to calculate the depth dose in cylindrical phantom for point source model. The evaluation of the test code was peformed by calculating the depth dose curves for high energy electrons of 5, 9, 12, and 15 MeV photons of Co-60 and 10 MV in water and comparing the results with DOSRZ/EGS4 results. In depth dose results, the differences between test code and DOSRZ/EGS4 were estimated to be less then ${\pm}1.5%\;and\;{\pm}3.0%$ approximately for electron and photon beams respectively.

• Journal of radiological science and technology
• /
• v.4 no.1
• /
• pp.55-62
• /
• 1981

This study was conducted, during the period of 20-30th, July in 1981, to survey measurement methods in thyroid uptake rate test in Seoul city. The results were summarized as follows: 1. For the great part of nuclear medcine department, a mount of radioiodine($^{131}I$) administrated to the patients was $50-100{\mu}Ci$ in thyroid uptake rate test. 2. Distribution of scintillation, counter with crystal size of $1\frac{1}{2}inch$ was 43%, 3inch(22%), 2.5inch(14%) and $2\frac{1}{2}inch$ was 7% in RAI uptake rate test. 3. When RAI uptake rate test was performed, distribution of collimator in use was flat field type collimator(78%) in general and cylindrical type collimator was 22%. 4. High voltage applied to the P-M tube was $900{\sim}1000V$(50%) and most units provided $3{\sim}15%$ of the window range for the $^{131}I$ peak $\gamma-ray$ energy. 5. Distribution on the use of neck phantom for measurements standard solution was 57% and distribution of b filter in use for room background counts and extrathyroidal tissue was 43% and 50%. 6. The distance between the counter and the source was 25cm(58%) in measuring radioactivity of standard solution, thyroid tissue and background radioactivity count. 7. The early uptake measurements(2, 4, 6 hours) are done after administration of the radioiodine dose and also 24-hour and 48-hour uptake measurements are done in routine test.

• Journal of radiological science and technology
• /
• v.42 no.1
• /
• pp.19-24
• /
• 2019

For general radiological examinations, even in the same area and the same test, the test conditions must be set differently according to the patient. However, since it is impossible to consider the body shape and conditions of patients every time in medical institutions where various patients visit, the tests are conducted by setting the AEC which automatically sets the test conditions. AEC is most commonly used in chest radiography. Therefore, the purpose of this study is to propose the improvement plans for using AEC by measuring the exposure dose and evaluating the image quality according to whether the AEC is used or not, and to provide basic data for AEC research. In the present study, images were acquired while varying tube voltage and test distance according to the use of AEC in chest radiography. The radiation dose was measured by placing the dosimeter in front of the chest phantom, and the CNR and SNR of acquired images were analyzed using Image J. The t-test was conducted for the statistical analysis and the significance was determined at the level of 95%(p<.05). As a result of this study, in the inspection distance (100cm, 140cm, 180cm) according to the use of AEC, high doses were observed when the AEC was used and there was statistically significant difference(p<.05). In the t-test to determine the difference between CNR and SNR depending on whether AEC was used or not, there was no significant difference according to the use of AEC(p>.05). Therefore, when performing chest radiography, if the radiologist establishes the appropriate examination conditions and conducts the examination by not just relying solely on AEC, it may be possible to reduce unnecessary radiation exposure to the patient.

• The Journal of Korean Society for Radiation Therapy
• /
• v.29 no.2
• /
• pp.83-91
• /
• 2017

Objectives: The purpose of this study was to evaluate the error of the leaf position accuracy of the MLC due to the gravity effect according to the gantry angle by using picket fence test using EPID and GafChromic EBT3 film. Materials and Methods: A 5 cm solid phantom was placed on the table and the SAD was set to 100 cm. The EBT3 film was placed exactly over the solid phantom and covered a 1.5 cm solid phantom and the picket fence test was performed. The EPID was measured under the same conditions as the EBT3 film at SID 100 cm. The gantry angles were measured at $0^{\circ}$, $90^{\circ}$, $180^{\circ}$ and $270^{\circ}$ in order to evaluate the position of the MLC according to the gantry angle. For the geometric evaluation of the MLC, the leaf position accuracy of the MLC was analyzed using the analysis program. Results: In case of EPID, when the gantry angle was changed to $0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, the difference of the position errors of the leaves was 0.18 mm, 0.31 mm, 0.20 mm, 0.26 mm on the average and the maximum values of the errors were respectively 0.44 mm, 0.54 mm, 0.34 mm, 0.44 mm. In case of EBT3 film, when the gantry angle was changed to $0^{\circ}$, $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, the difference of the position errors of the leaves was 0.19 mm, 0.21 mm, 0.19 mm, 0.31 mm on the average and the maximum values of the errors were respectively 0.35 mm, 0.45 mm, 0.36 mm, 0.48 mm. Conclusion: In this study, we analyzed the position error of the leaf of the MLC according to the gantry angle, and confirmed the position error of the leaf by gravity effect. As a result of comparing the leaf position accuracy using EPID and EBT3 film according to the variation of gantry angle, a larger error occurred in the error analysis method using EPID than that of EBT3 film. Therefore, in the case of IMRT based on MLC, as well as verification of accurate dosimetry should be conducted, it is considered that the quality control and verification for the precise operation of the MLC will be needed. and it is necessary to compare and verify the method of analysis.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.29B no.11
• /
• pp.16-21
• /
• 1992

The validity of the application of the second-order Born equation to the ultrasound tomography algorithm is studied by comparing the scattered fields computed using the first-order Born equation, the first-order Rytove equation, and the second-order Born equation. The second-order Born equation turns out to provide more desirable results than the other two equations for a certain group of test objects. Phantom images with resolutions upto 1 pixel$\times$1 pixel are satisfactorily reconstructed using the second-order Born equation. It is shown that when the view angle is limited, good resonstruction results are also obtained using multi-frequency incident fields.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.17 no.3
• /
• pp.20-25
• /
• 1980

A singular value decomposition (SVD) pseudo-inversion method has been applied to the image reconstruction from projections. This approach is relatively unknown and differs from conventionally used reconstructioll methods such as the Foxier convolution and iterative techniques. In this paper, two SVD pseudo-inversion methods have been discussed for the search of optimum reconstruction and restoration, one using truncated inverse filtering, the other scalar Wiener filtering. These methods partly overcome the ill-conditioned nature of restoration problems by trading off between noise and signal quality. To test the SVD pseudo-inversion method, simulations were performed from projection data obtained from a phantom using truncated inversefiltering. The results are presented together with some limitations particular to the applications of the method to the general class of 3-D image reconstruction and restoration.

• Journal of Yeungnam Medical Science
• /
• v.28 no.2
• /
• pp.145-152
• /
• 2011

Background: To evaluate the changes in the radiation dose and temperature distribution on irradiated egg albumin and nanoparticle ($Fe_3O_4$) powder mixed egg albumin. Methods: A new type of phantom was designed by fabricating a $30{\times}30{\times}30cm$ acryl square inside a $3{\times}3{\times}3cm$ small square and dividing it into two parts. In the control group, only egg albumin was irradiated, and in the test group, 25 nm 20 mg/cc, 25 nm 40 mg/cc, and 1 um 40mg/cc nanoparticles with egg albumin were irradiated. The radiation isodose distributions and temperature changes were then observed. Results: No significant changes were observed in the radiation dose and temperature distribution. Conclusion: The nanoparticles were considered not to have had any effect on the radiation dose and temperature distribution under the experimental conditions. Further studies can be conducted based on the changes in the mixture material.

• Journal of radiological science and technology
• /
• v.21 no.2
• /
• pp.57-63
• /
• 1998

AEC was designed to assist in the production of radiographs of equal density and to aid in the production f consistently high quality radiographs. Many improvements have been made in the AEC and these have helped to increase it's acceptance. Newer system (Falling load) control kVp and mA as well as exposure time. Authors have had experiments about the characteristics of AEC by Zone System. Zone System is the method to detection of photographic image qualify by control the photo print from Fred Archer and Ansel Adams. With the Zone System theory the experiments of density control, characteristics of phantom thickness and reproducibility of occupation rate of contrast media could make quality control of X-ray photography effectively in falling load system.

• Journal of the military operations research society of Korea
• /
• v.13 no.1
• /
• pp.19-27
• /
• 1987

This paper deals with the development of an expert system modeling by constructing a knowledge-based system of the dive recovery for anticrash on the ground or sea during the task of fighter aircraft. In an IBM PC / XT computer, a prototype dive recovery expert system is constructed using mu LISP-86 programming language, and is interconnected to the SAM SUNG RM-501 robot arm to test and simulate this model. The knowledge base of this model is composed of the dive recovery charts and the V-N envelope charts of F-4 D Phantom fighter aircraft. It is shown that the prototype expert system woks well and the feasibility of practical realization is valid.