• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.916-921
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• 2016

It is possible for humans to breathe underwater using dissolved oxygen. However, unlike fish, humans need large amounts of oxygen to breathe underwater. Water generally contains small amounts of dissolved oxygen. To get enough dissolved oxygen from water, great volumes of it should be supplied into a separation device. If exhalation gases are used, the amounts of water supplied into the membrane can be decreased. However, the characteristics of exhalation gases after passage through the separation device need to be investigated. To reuse the exhalation gases, the concentration of carbon dioxide should be decreased. A compressor is needed to supply the exhalation gases because of the high pressure generated in the membrane inlet. However, compressors require a lot of power and are heavy, so it is not proper to get the portable separation device. A system without the compressor is needed. If the pressure of the position mixed from the exhalation is less than atmosphere, the compressor is not needed. In this thesis, characteristics of the gases which are mixed with exhalation gases and separated from water after passing the membrane are investigated. The compositions of carbon dioxide, oxygen, and nitrogen are measured with the gas chromatography. The effects of water and exhalation gas flow rates on characteristics of gases separated from water after the membrane are showed.

• Journal of Advanced Marine Engineering and Technology
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• 제40권9호
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• pp.842-846
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• 2016

물속의 용존산소를 이용하면 물고기가 아가미를 이용하여 호흡하듯이 사람이 수중에서 호흡이 가능하지만, 물속에 포함된 용존산소의 양이 적기 때문에 필요한 산소량을 확보하는 문제가 해결되어야 한다. 우선 물의 유량을 증가시켜 분리되는 산소량을 증가하는 것이 가능하지만, 필요한 펌프와 멤브레인 그리고 주변기기의 용량 증가로 분리장치의 부피와 무게 그리고 소요비용도 함께 증가하게 된다. 이러한 문제를 효과적으로 해결하기 위해 많은 양의 산소를 포함하는 날숨의 특성을 이용하면 필요한 산소량을 효과적으로 확보할 수 있다. 일반적으로 날숨에 포함된 산소량은 공기보다 낮고, 이산화탄소 량은 공기보다 많은 것으로 알려져 있다. 본 연구에서는 용존기체 분리장치의 입력 단에 날숨을 혼합한 후, 용존기체 분리장치에서 산소를 포함하는 용존기체를 재분리하는 과정을 거치며, 이때, 입력단에 설치된 수중펌프의 동작으로 수압이 증가하므로, 이러한 수압을 갖는 물에 날숨을 혼합하기 위해서는 압축기가 요구되므로 분리장치의 무게와 부피 그리고 소비 전력이 증가하게 된다. 본 연구에서는 입력단의 압력을 감소시킴으로써 압축기를 사용하지 않고도 날숨을 물에 혼합하는 구조를 갖는 것이 특징이다. 실험을 통해 압축기를 사용하지 않고 날숨이 입력단의 물에 혼합되는 것이 가능함을 제시하였으며, 날숨이 입력단에 공급된 후 분리장치를 통해 분리된 기체의 분리특성을 제시하였다. 날숨을 사용함으로써 용존기체의 분리량이 크게 증가하였으며, 공급되는 날숨의 유량이 증가하면 분리되는 용존 기체의 양도 증가하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1347-1353
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• 2014

It's possible for a human to breathe under water, if dissolved oxygen is effectively used. Fish can stay under water using the gill which extracts dissolved oxygen from water. Water includes small amounts of oxygen, so a human needs larger amounts of water to acquire oxygen enough for underwater breathing. The exhalation gas from a human is another method to get higher amounts of oxygen under water. It mainly composes of oxygen, nitrogen and carbon dioxide. So, if only carbon dioxide is decreased, the exhalation gas has good characteristics for breathing of a human under water. In this paper, composition of the exhalation gas from a human was analyzed using GC. Based on these results, the synthesized gas was prepared and mixed into water which was used for experimental devices to analyze separation characteristics of dissolved gases from water. Experimental devices included a water pump, a hollow fiber membrane module and a vacuum pump. The effects of pressure and water flow on separation characteristics of synthesized gas were investigated. The compositions of gases separated from water using synthesized gas were investigated using GC. These results expect to be applied to the development of underwater breathing technology for a human.

• 센서학회지
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• 제20권5호
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• pp.300-304
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• 2011

Exhaled breath gases include gases generated in the body. When there is disease in the body, exhalation can include gas components from the disease. If we can find these specific elements through analysis of the exhalation gases, this can be an effective way to diagnose the disease. The lung has a close relationship with exhalation. Lung cancer refers to malignant tumors which originate in the lungs. Exhalation from the lung causes direct jets of gas to be ejected through the mouth and nose, so by analyzing these jets it may be possible to diagnose lung cancer. In our study we attempt to diagnose lung cancer from patient's exhaled gases. Exhalation of lung cancer patients was analyzed using gas chromatography-mass spectroscopy(GC-MS) and the expiratory gas was also measured using a sensor system. The system was designed to use a metal oxide sensor and solid phase micro extraction(SPME) fiber. The GC-MS analysis of the healthy subject's and cancer patient's exhalation gases both showed the presence of decane in the breath of patients with lung cancer. In addition, the results from the sensor system showed significant difference between the lung cancer patients and the healthy subjects.

• 센서학회지
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• 제22권3호
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• pp.219-222
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• 2013

The exhaled breath contains gases generated from human body. When disease occurs in the body, exhaled breath may include gas components released from disease metabolism. If we can find specific elements through analysis of the exhaled gases, this approach is an effective way to diagnose the disease. The lung function has a close relationship with exhalation. Exhaled gases from COPD (Chronic Obstructive Pulmonary Disease) patients can be analyzed by gas chromatography-mass spectroscopy (GC-MS) and a gas sensor system. The exhaled breath for healthy person and COPD patients had different components. Significantly more benzendicarboxylic acid was detected from COPD patients than in healthy persons. In addition, patients had a variety of decane. Phosphorous compounds with different isomers were detected from patients. The results obtained by gas sensor system were processed by PCA (Principal Component Analysis). The PCA results revealed distinct difference between the patients and healthy people.

• 로봇학회논문지
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• 제16권4호
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• pp.291-298
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• 2021

In this study, we present a multi-sensor module for snake robot searching survivors in a narrow space. To this end, we integrated five sensor systems by considering the opinions of the first responders: a gas sensor to detect CO₂ gases from the exhalation of survivors, a CMOS camera to provide the image of survivors, an IR camera to see in the dark & smoky environment, two microphones to detect the voice of survivors, and an IMU to recognize the approximate location and direction of the robot and survivors. Furthermore, we integrated a speaker into the sensor module system to provide a communication channel between the first responders and survivors. To integrated all these mechatronics systems in a small, compact snake head, we optimized the positions of the sensors and designed a stacked structure for the whole system. We also developed a user-friendly GUI to show the information from the proposed sensor systems visually. Experimental results verified the searching function of the proposed sensor module system.

• 센서학회지
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• 제16권5호
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• pp.331-336
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• 2007

In this study, we have fabricated an infrared optical fiber based sensor which can monitor the respiration of a patient. The design of a chalcogenide optical fiber based sensor is suitable for insertion into a high electro-magnetic field environment because the sensor consists of low cost and compact mid-infrared components such as an infrared light source, a chalcogenide optical fiber and a thermopile sensor. A fiber-optic respiration sensor is capable of detecting carbon dioxide ($CO_{2}$) in exhalation of a patient using the infrared absorption characteristics of carbon gases. The modulated infrared radiation due to the presence of carbon dioxide is guided to the thermopile sensor via a chalcogenide receiving fiber. It is expected that a mid-infrared fiber-optic respiration sensor which can be developed based on the results of this study would be highly suitable for respiration measurements of a patient during the procedure of an MRI.