• 한국정밀공학회지
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• 제27권6호
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• pp.82-89
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• 2010

Ankle-foot orthosis with an artificial pneumatic muscle which is intended for the assistance of plantarfelxion torque was developed. In this study, power pattern of the device in the various pneumatics and the effectiveness of the system were investigated. The pneumatic power was provided by ankle-foot orthosis controlled by user‘s physiological signal, that is, muscular stiffness in soleus muscle. This pneumatic power can assist plantarflexion torque of ankle joint. The subjects performed maximal voluntary isokinetic plantarflexion motion on a biodexdynamometer in different pneumatics, and they completed three conditions: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under muscular stiffness control. Through these experiments, we confirmed the effectiveness of the orthosis and muscular stiffness control using the analyzing isokinetic plantarflexion torque. The experimental results showed that isokinetic torques of plantarflexion motion of the ankle joints gradually increased in incremental pneumatic. The effectiveness of the orthosis was -7.26% and the effectiveness of the muscular stiffness control was 17.83% in normalized isokinetic plantarflexion torque. Subjects generated the less isokinetic torques of the ankle joints in wearing the orthosis with artificial muscles turned off, but isokinetic torques were appropriately reinforced in condition of wearing the orthosis activated under muscular stiffness control(17.83%) compared to wearing the orthosis(-7.26%). Therefore, we respect that developed powered orthosis is applied in the elderly that has weak muscular power as the rehabilitation equipment.

• Journal of Chest Surgery
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• 제30권3호
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• pp.247-252
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• 1997

심장이식시에 가교 역할을 담당하거나 수술 후 심부전에 빠진 심장을 보조할 공압식 심실보조장치를 개발하여 동물실험을 시행하였다. 실험 에 이용한 심실보조장치는 소아용과 성 인용의 두 가지 종류로서 박동장이 각각 34cc와 70cc이다. 심실 재료는 폴리우레탄으로 제작하여 항혈전성을 높였다. 총 10마리의 동물실험을 시행하였다. 심실보조장치의 혈액펌프는 좌심방과 대동맥에 연결관을 이용하여 이식하였다. 심실보조장치의 평균 박출량은 펌프 박동수가 60회일 때 성 인의 경우 2.38 L/min였고 소아용의 경우 0.41 L/min였다. 생존시간은 최고 26시간이었다. 가장 큰 합병증은 출혈이었고 주 사망원인은 심부전 및 폐부전이었다. 심실보조장치 자체 에 대한 결함때문에 일어난 실패는 없었다. 현재까지의 실험 결과를 토대로 심실보조장치를 발전시키면 임상에서도 사용 가능할 것으로 보인다.

• 대한의용생체공학회:의공학회지
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• 제26권6호
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• pp.393-398
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• 2005

An electromechanical type is the most useful mechanism in the various pumping mechanisms. It, however, requires a movement converting system including a ball screw, a helical cam, or a solenoid-beam spring, which makes the device complex and may lessen reliability. Thus, the authors have hypothesized that an electromagnetic actuator mechanism can eliminate the movement converting system and that thereby enhance the mechanical reliability and operative simplicity of an electro­pneumatic pump. The purpose of this study was to show a novel application of electromagnetic actuator mechanism in pulsatile pump and to provide preliminary data for further evaluations. The electromagnetic actuator consists of stators with a single winding excitation coil and movers with a high energy density neodymium-iron-boron permanent magnet. A 0.5mm diameter wire was used for the excitation coil, and 1000 turns were wound onto the stators core with parallel. A prototype of extracorporeal electro-pneumatic pump was constructed, and the pump performance tests were performed using a mock system to evaluate the efficiency of the electromagnetic actuator mechanism. When forward and backward electric currents were supplied to the excitation coil, the mover effectively moved back and forth. The nominal stroke length of the actuator was 10mm. The actuator dimension was 120mm in diameter and 65mm in height with a mass of 1.4kg. The prototype pump unit was 150mm in diameter, 150mm in thickness and 4.5kg in weight. The maximum force output was 70N at input current of 4.5A and the maximum pump rate was 150 beats per minute. The maximum output was 2.0 L/minute at a rate of 80bpm when the afterload was 100mmHg. The electromagnetic actuator mechanism was successfully applied to construct the prototype of extracorporeal electro­pneumatic pump. The authors provide the above results as a preliminary data for further studies.

• 대한조선학회논문집
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• 제47권3호
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• pp.388-397
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• 2010

A two-dimensional time-domain, potential-theory-based fully nonlinear numerical wave tank (NWT) was developed by using boundary element method and the mixed Eulerian-Lagrangian (MEL) approach for free-surface node treatment. The NWT was applied to prediction of primary wave energy conversion efficiency of a bottom-mounted oscillating water column (OWC) wave power device. The nonlinear free-surface condition inside the chamber was specially devised to represent the pneumatic pressure due to airflow velocity and viscous energy loss at the chamber entrance due to wave column motion. The newly developed NWT technique was verified through comparison with given experimental results. The maximum energy extraction was estimated with various chamber-air duct volume ratios.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.235-236
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• 1998

The purpose of this paper is to develop diaphragm type pneumatic Left Ventricular Assist Device(LVAD) for clinical application and to evaluate its performance through the mock circulation and animal experiment. The blood housing and diaphragm are made by polyurethane. The relations of cardiac output us. beat rate and cardiac output vs. systolic-to-diastolic rate was estimated through the mock test and hemodynamic waves are recorded for the evaluation of VAD. We performed animal experiment and 4 animals survived more than 24hrs. As a result, the hemodynamic data and waves showed this system can be applicable to the animal experiment.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.247-250
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• 1995

The purpose of this paper is to develop diaphragm-type pneumatic ventricular assist device(VAD) for clinical application and to evaluate its performance through the mock circulation system. The blood housing and diaphragm are made by coating pellethane on the metallic mold and the back plate is made by machining process. The relations of cardiac output(CO) vs. beat rate and CO vs. systolic-to-diastolic rate was estimated through the mock test and hemodynamic waves are recorded for the evaluation of VAD. As a result, the volume of blood pump is 70 ml, maximum CO is 5 L/min and CO has a close relation to the input resistance of blood pump. The hemodynamic data and waves showed this system can be applicable to the animal experiment.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2016년도 제53차 동계학술대회논문집 24권1호
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• pp.87-90
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• 2016

현재 한국 군부대에서 사용되고 있는 표적구동장치는 1990년도에 만들어진 재래식 장비로서 노후화 및 부품교체 난제로 인하여 지속적인 시스템의 오류와 이에 따른 장비 가동률 저하 등의 문제로 실전적인 사격 훈련이 어렵다. 이에 본 연구에서는 보다 효과적인 훈련을 진행하고자 복합 구동 표적장치를 개발하였다. 본 연구에서 개발된 복합 구동 표적장치는 Up-down, Swing, Turn, Rotary 방식의 표적 구동을 원격으로 제어하여 다양한 사격 및 전술 훈련 적용 가능하도록 제작되었으며, 또한 사격진행 통제 결과를 통제관 혼자서 총괄 운용이 가능한 모니터링 시스템을 구축하였다. 그리고 현재 각 부대에 설치되어 있는 표적구동장치 및 전술훈련 컨트롤러는 유선을 통한 시리얼통신 및 중앙 분배식 전원공급시스템으로서 운영설비를 위하여 과도한 배관배선 등의 공사가 별도로 시행되어야 하는 문제점이 있다. 따라서 본 연구에서는 이러한 문제점을 해결할 수 있도록 무선 통신시스템방식을 적용하여 다양한 훈련지역에 호환 적용될 수 있는 장비를 개발함으로써 훈련장 시설건립을 위한 부담을 줄이고, 운영의 극대화를 확보할 수 있도록 경제적, 기술적 효과를 추구하였다.

• 한국자동차공학회논문집
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• 제16권1호
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• pp.166-174
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• 2008

Recently, the automotive industry has been developing rapidly. With the progress parts of the automobile components need high quality and the reliability. Among them, braking unit is essential device, and acquire the reliability through the performance test of brake. This study was aimed to design the performance-test-bench to measure the drag torque which has effect on caliper in braking unit. In this progressive technology, it is vital importance to use hydraulic and pneumatic, and to combine test bench with instrumentation engineering technology. This system to construct the design of hydraulic and pneumatic circuit, interface technique between sensors and personal computer, data acquisition and display design, and integrated control are very important technology. Moreover, reliable data are obtained through vacuum system and hydraulic and pneumatic system by using of booster and brake master cylinder which are actually applied to automobile. Then, data signal detector sensors for speed, pressure and torque is attached on this system. Therefore, in this study, we designed a performance-test-bench by and we also made an total control system using personal computer which is more progressive and flexible method than existing PLC control.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.198-205
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• 2005

Reduction of labor hour for cleaning up of the used abrasives after blasting. is attempted by improving the efficiency of abrasive recovery process in the protective coating of ship's block, For this purpose, the theoretical background for pneumatic transport technology in the abrasive recovery system as well as experimental evaluation on the effect of design parameters such as flow pattern, saltation velocity and pressure drop on the efficiency of the abrasive recovery system are employed . By optimizing the operating parameters such as the length and diameter of the suction hose, specification of recovery device and recovery mouth, a new method which can dramatically increase the efficiency of abrasive recovery system, is proposed.

• Journal of Chest Surgery
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• 제32권12호
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• pp.1065-1077
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• 1999

Background : Ventricular assist devices(VADs) are being used for patients in postcvardiotomy cardiogenic shock status bridge to cardiac transplant settings and in post-myocardial infarction cardiogenic shock. The VAD which was developed at the Deparment of medical engineering in Dankook University College of Medicine was a pneumatically driven device and can maintain pulsatile flow. The goal of this study is to develop animal experimental models using the VAD and to clarify the reliability and hemodynamic property adequacy of end organ perfusion durability and severity of thrombotic-hemolytic tendency of the device. Material and Method : The pneumatic VAD was applied to 8 adult female lambs, We examined some hemodynamic parameters such as arterial blood pressure pulmonary capillary wedge pressure(pcwp) pulmonary artery pressure(PAP) left atrial pressure hour urine output cardiac index VAD flow EKG to determine the reliability of the VAD and hemodynamic compatibility of the experimental animals within 24 hours of experiment. We also observed the end organ perfusion durability of the VAD and thrombotic-hemolytic property of the VAD after 24 hours of VAD insertion. Result: We could monitor all hemodynamic parameters including pcwp PAP cardiac index EKG, adn hour urine as true clinical settings. We observed that the reliability of the VAD was excellent and the hemodynamic property of the experimental animal and end organ perfusion were adequate within 24 hours of experiment. In four lambs surviving 24 hours after insertion the reliability of the VAD and end organ perfusion were excellent and no thrombotic-hemolytic tendency was noted. However after 15 days of experiment the diaphragm of the VAD was torn and it was recommende that the durability of the VAD should be extended. Conclusion : e conclude that the pneumatic VAD developed at Dankook University Biomedical Engineering has good hemodynamic property and low thromboembolic tendency and presents adequate end organ perfusion but we noted that the durability of the device should be expanded further. It will be possible to do more reliable experiment in the future according to the animal experimental method developed in this study especially with the heart failure models.