• Journal of the Optical Society of Korea
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• v.14 no.3
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• pp.235-239
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• 2010

In this study, we have fabricated two types of non-invasive fiber-optic respiration sensors that can measure respiratory signals during magnetic resonance (MR) image acquisition. One is a nasal-cavity attached sensor that can measure the temperature variation of air-flow using a thermochromic pigment. The other is an abdomen attached sensor that can measure the abdominal circumference change using a sensing part composed of polymethyl-methacrylate (PMMA) tubes, a mirror and a spring. We have measured modulated light guided to detectors in the MRI control room via optical fibers due to the respiratory movements of the patient in the MR room, and the respiratory signals of the fiber-optic respiration sensors are compared with those of the BIOPAC$^{(R)}$ system. We have verified that respiratory signals can be obtained without deteriorating the MR image. It is anticipated that the proposed fiber-optic respiration sensors would be highly suitable for respiratory monitoring during surgical procedures performed inside an MRI system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.56-62
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• 2010

The purpose of this study was to compare the difference of driving pattern between male and female drivers for a straight driving and unexpected situation using driving simulator and motion data. The participants included total 60 university students; 30 males aged 24.3$\pm$1.4 years and 30 females aged 23.2$\pm$1.9 years with 1~3 years of driving experience. The driving task required participants to keep the constant distance (20m, 25m or 30m) with preceding vehicle running at 55~65km/hr speed using driving simulator which was programed unexpected situation for two minutes. Simulator and motion data were acquired. The acquired data was divided in straight driving block for 40 second and unexpected situation block for 2 second. The coefficient of variation (CV) of lane keeping and jerk-cost (JC) function were analyzed for straight driving and unexpected situation blocks. The results show that CV was smaller in males than females for both straight and unexpected situation blocks (p < .05). JC was smaller in females than males for both straight and unexpected situation blocks. As the distance of vehicles become longer, JC was smaller for both male and female (p < .05).

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.869-874
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• 2010

The purpose of this study was to analyze the skin conductance level (SCL) induced by unexpected situation which reflected the emotional and cognitional responses during driving. The participants included 57 college graduates; 28 males aged $24.5{\pm}1.3$ with $2.3{\pm}1.5$ years of driving experiences and 29 females aged $23.6{\pm}2.6$ with $2.2{\pm}1.7$ years of driving experience. Reaction time of brake, averaged SCL, maximum SCL, and rising time to maximum amplitude were measured. They were analysed according to condition (crash, non-crash) and gender (male, female). The reaction time of brake was more faster and averaged SCL was greater during non-crash condition than during crash condition. There were no significant differences between male and female drivers in the reaction time of brake and averaged SCL whether or not it crash. There were no significant differences between crash and non-crash conditions in the maximum SCL and rising time to maximum amplitude, but there were significant differences between male and female in them. These results support the hypothesis that averaged SCL is more related to cognitional response and maximum SCL and rising time to maximum amplitude are more related to emotional responses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1592-1597
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• 2015

In this study, we developed a fiber-optic temperature sensor (FOTS) based on a silicone oil and an optical time domain reflectometer (OTDR) to apply the measurement of a coolant leakage in the nuclear power plant. The sensing probe of the FOTS consists of a silicone oil, a stainless steel cap, a FC terminator, and a single mode optical fiber. Fresnel reflection arising at the interface between the silicone oil and the single mode optical fiber in the sensing probe is changed by varying the refractive index of the silicone oil according to the temperature. Therefore, we measured the optical power of the light signals reflected from the sensing probe. The measurable temperature range of the FOTS using a Cu-coated silica fiber is from $70^{\circ}C$ to $340^{\circ}C$ and the maximum operation temperature of the FOTS is sufficient for usage at the secondary system in the nuclear power plant.

• Journal of Biomedical Engineering Research
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• v.32 no.4
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• pp.279-284
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• 2011

Biomedical engineering is a discipline where engineering principles and techniques are applied to the medical field. Biomedical engineering lies between traditional engineering and medicine and is an inter-disciplinary field in its nature. Current Korean undergraduate biomedical engineering curriculum is a simple list of traditional engineering courses combined with basic medical/life science courses. There have been efforts to improve biomedical engineering education to reflect its inter-disciplinary nature. Enhanced software course for biomedical engineering is proposed as a part of effort to overhaul the undergraduate biomedical engineering curriculum. In this newly proposed course, students will learn MATLAB and LabVIEW, which are the most widely used software tools in biomedical engineering.

• Journal of Sensor Science and Technology
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• v.17 no.2
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• pp.100-105
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• 2008

The objectives of this study are to measure and to remove Cerenkov lights generated in a fiber-optic radiation sensor by a charge-coupled device. we have fabricated a fiber-optic radiation sensor which comprises an organic scintillator, a plastic optical fiber and a charge-coupled device. Charge-coupled device as a light measuring tool has many advantages which are easy in multi-dimensional measurements, high spatial resolution and relatively low cost.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.332-336
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• 2006

In this study, we have fabricated a fiber-optic radiation sensor using an organic scintillator for high energy electron beam therapy. The intensities of scintillating light from a fiber-optic radiation sensor are measured with different field size, electron beam energy and monitor unit of a clinical linear accelerator. To obtain percent depth dose(PDD), the amount of scintillating light is measured at different depth of polymethylmethacrylate(PMMA) phantom. Also the intensity of Cerenkov light is measured and characterized as a function of incident angle of electron beam and a subtraction method is investigated using a background optical fiber to remove a Cerenkov light.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.4
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• pp.203-207
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• 2009

The purpose of this study was to examine differences between male and female in blood oxygen saturation due to 93% oxygen administration of the three levels (1L/min, 3L/min, 5L/min). Ten healthy male ($25.0{\pm}1.8$ years) and ten female ($23.7{\pm}1.9$ years) college students were selected as the subjects for this study. The experiment consisted of three runs, i.e., the three levels of 93% oxygen administration, respectively. The each run consisted of three phases, i.e., Rest 1 (5 min), Hyperoxia (10 min), and Rest 2 (5 min). Blood oxygen saturation were measured throughout the three phases. By increasing the supply rate of highly concentrated oxygen, rising rate of blood oxygen saturation was increased. Blood oxygen saturation of female was higher than male regardless of supply rate of highly concentrated oxygen and phases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.929-933
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• 2014

The measurement of joint angle is important to evaluate the patient's disability. The modified fiber tip and light propagation of the developed fiber sensor were investigated to increase the range of angle detection. Different shapes of fiber tips were manufactured with a polishing machine to deliver light signal in various patterns. Output signals were analyzed to obtain joint angle change with inverse polynomial models. The measured joint angles were displayed with LabVIEW program and the reliability was tested by comparing with a commercial angle sensor. This method can be used in rehabilitation field to determine patient's progress.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.337-342
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• 2006

We have developed a noncontact temperature sensor using a silver halide optical fiber. The infrared collimator and focus head are connected both ends of a silver halide optical fiber with SMA connectors and used to collimate radiations of a heat source and to focus them to infrared sensors such as a pyroelectric sensor and a thermopile sensor, respectively. The relation ships between the temperatures of a heat source and the output signals of the infrared sensors are determined to measure the surface temperature of a heat source. The measurable temperature range is from 25 to $60^{\circ}C$. It is expected that a noncontact temperature sensor using a silver halide optical fiber can be developed for medical usages such as temperature monitoring during hyperthermia, cryosurgery, laser surgery and diagnostic procedure based on the results of this study.