• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1330-1338
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• 2011

Social activities of the elderly have been increasing as our society progresses toward an aging society. As their activities increase, so does the occurrence of falls that could lead to fractures. Falls are serious health hazards to the elderly. Therefore, development of a device that can detect fall accidents and prevent fracture is essential. In this study, we developed a portable fall detection system for the fracture prevention system of the elderly. The device is intended to detect a fall and activate a second device such as an air bag deployment system that can prevent fracture. The fall detection device contains a 3-axis acceleration sensor and two 2-axis tilt sensors. We measured acceleration and tilt angle of body during fall and activities of daily(ADL) living using the fall detection device that is attached on the subjects'. Moving mattress which is actuated by a pneumatic system was used in fall experiments and it could provide forced falls. Sensor data during fall and ADL were sent to computer and filtered with low-pass filter. The developed fall detection device was successful in detecting a fall about 0.1 second before a severe impact to occur and detecting the direction of the fall to provide enough time and information for the fracture preventive device to be activated. The fall detection device was also able to differentiate fall from ADL such as walking, sitting down, standing up, lying down, and running.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.203-212
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• 2016

This study examined the prevention of deep vein thrombosis and skin response after the application of boots or calf intermittent pneumatic compression (IPC) devices in immobile patients with intracranial surgery. The subjects of this study included 60 patients in a surgical intensive care unit after receiving intracranial surgery from May to November in 2015. The blood flow velocity was measured daily to assess the deep vein thrombosis for 7 days, and the skin response of the legs was observed regularly. As a result, the boots IPC group showed an increased blood flow velocity over time compared to the calf IPC group. A significant statistical difference was observed in both the boots IPC group and calf IPC group over time (Right side; F=64.41, p<.001, Left side; F=58.21, p<.001). The dorsum circumference over time and the correlations between two groups (Right side; F=9.13, p <.001, left side; F=9.29, p<.001) also showed a significant difference. In addition, the boots IPC group showed no skin complications. In conclusion, the boots type IPC is a more effective method for preventing deep vein thrombosis for immobile patients with intracranial surgery.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.204-209
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• 2005

The respiration measurement method using the ultrasound sensor hardly gets an influence of an error of inertia and pressure and it is a respiratory detection device available semi-permanently. This device measures the amount and flow of respiration through using a delivery speed difference of the ultrasound waves that are a return format by the pneumatic stream that is a flogging of ultrasound waves during transmission and receipt as having used a characteristic of ultrasound waves. In this paper, it improved sensitivity of a signal to happen during transmission and receipt of a sensor because measurement must be performed with a patient to the center and measurement was played in a weak breathing so that it was possible.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.207-212
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• 1996

We developed pneumatic blood pump and its driving system as a pediatric ventricular assist device. The blood pump is diaphragm type system and its blood contacting area is coated with Bio-Span. The driving unit Is consists of dual pumps, valves for the reliable blood pumping and its controller uses 80C196(Intel) as a main processor. The acute animal experiment was performed with dogs and its body weight is about 20 kg. The maximum cardiac output is about 2.1 l/min and the pressure and flow curves showed reliable operation as assist device.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1379-1385
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• 2014

Even the rough prediction of the product test time before the lifetime test of mechanical component begins would be of use in estimating cost and deciding how to keep up with the test. The reliability predictions of mechanical components are difficult because failure or degradation mechanisms are complicated, and few plausible databases are available for lifetime prediction. Therefore, this study conducted lifetime predictions of elastomeric U seals that were respectively installed in a hydraulic actuator and a pneumatic actuator using lifetime models and a field database based on failure physics and an actual test database obtained from the NSWC handbook. To validate the results, the predicted failure rates were compared with the actual lifetime test results acquired in the lab durability tests. Finally, this study discussed an engineering procedure to determine the coefficients in the failure rate models and analyzed the sensitivity of each influential parameter on the seal lifetime.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.303-311
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• 2013

This research deals with the analysis and design of a driving mechanism for an automatic pneumatic drug injector, which can precisely control the injection volume using a relatively simple friction-driven mechanism, without any complicated control system. Through a dynamic analysis, the effects of the design parameters of the driving mechanism associated with the geometry, spring stiffness, and fiction are analyzed, and the results are reflected in a proto-type drug injector design, which is under development for mass production. A test is performed to assess the durability of the mechanism for up to one million operations, and comparison of its displacement after one million operations, verifies the mechanism's durability.

• Journal of Engineering Education Research
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• v.20 no.4
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• pp.61-66
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• 2017

Automatic flow control system composed by hardware and software was designed and fabricated to be used as teaching tool of feedback control theory in university experimental class. This system includes hardwares like data acquisition board, flow measuring device, transmitters, and the pneumatic valve, and software like LabView program for the monitoring and control of flow rates. The system was designed as the student can see the control effect of not only set point but also disturbance changes. Also the LabView program was composed for the calculation of controller parameters of both Ziegler-Nichols and Cohen-Coon tuning. The students can apply both tuning constants and compare the control performances. This system will provide the easy way for the students to understand the function and specification of control hardwares, and to raise the programing ability of control software.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.779-790
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• 1993

A prototype of the feeding-milking robot was developed in the Hungarian Institute of Agricultural Engineering in 1988-89. Before starting with the operation tests the cleaning system had to be elaborated . The cleaning system has two parts. Those are the complete cleaning of the system, producing a practically sterile state, as well as flushing through the milking device between milking of two cows. Separate electronic sensor development was necessary for both system which can connect to the control system of the robot. To clean the system pneumatic air input was applied. As an effect of the local adjustment of the electronic control system optimal flow conditions can be formed what is more favourable comparing to the earlier solutions of cleaning due to the mechanical effect. In the flushing through overpressure air is applied. The air and the cleaning liquid input duration can be adjusted to the local conditions. The electronic control unit can be connected to the electric ircuits of robot.

• Journal of Biomedical Engineering Research
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• v.3 no.1
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• pp.43-48
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• 1982

Ventricular assist device(VAD) has been clinically applied as a temporary circulatory sup- porting system in the patients with severe heart failure, but small sized VAD for infant is not available. The purpose of this paper is to introduce small sized VAD and presents the result of in vitro test. Sejong VAD is diaphragmatic type of pneumatic pump and stroke volume is 11cc. Cardiac outputs of the Sejong VAD were measured by overflow tank under variable conditions of driving parameters. The cardiac output was 1.3 1/min at the heart rate of 120 per minute, left atrial pressure of 15cmH2O, percent systole of 43%, driving pressure of 240 mmHg, vacuum pressure of -40 mmHg, and mean aortic pressure of 70 mmHg. No mechanical problem was developed during the continuous in vitro test for 3 months.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.166.1-166
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• 2001

Anti-lock Braking System(ABS) is a device which prevents the wheels form locked up under emergency braking of a vehicle. So it helps the vehicle to maintain the steerability and shortens the braking distance by maintaining optimal frictional force during braking since the tire road slip is controlled in acceptable range. Recently, ABS is accepted as a standard equipment in vehicles, especially in commercial vehicles(bus and trucks). Commercial vehicles don´t use hydraulic lines but use pneumatic lines for braking system mostly. In this paper, ECU(Electronic Control Unit) for the anti-lock braking system of a commercial vehicle which is equipped with a full-air brake system and its control algorithms are presented. In this algorithm wheel speed acceleration flags and wheel slip flags are defined ...