• Journal of Korea Society of Industrial Information Systems
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• v.14 no.2
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• pp.51-58
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• 2009

In this paper, a system which uses Bluetooth and Zigbee wireless communication and mobile device is designed. The temperature within vehicle and the distance betweeen the vehicle and the obstacle is measured by ultrasonic sensor system. The measured data is sent to the mobile PDA and displayed to assist safe driving.

• Journal of Biomedical Engineering Research
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• v.27 no.4
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• pp.143-153
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• 2006

The purpose of this work was to assess and quantify the beneficial effects of gas exchange, while testingto the various frequencies of the sinusoidal wave that was excited by the PZT actuator, for patients suffering from acute respiratory distress syndrome (ARDS) or chronic respiratory problems. Also, this paper considered a simulator to design a hollow type artificial lung, and a mathematical model was used to predict a behavior of blood. This simulation was carried out according to the Montecarno's simulation method, anda fourth order Runge-Kutta method was used to solve the equation. The experimental design and procedure are then applied to the construction of a new device to assess the effectiveness of the membrane vibrations. As a result, the vibration method is very effective in the increase of gas transport. The gas exchange efficiency for the vibrating intravascular lung assist device can be increased by emphasizing the following design features: consistent and reproducible fiber geometry, and most importantly, an active means of enhancing convective mixing of water around the hollow fiber membranes. The experimental results showed the effective performance of the vibrating intravascular lung assist device. Also, we concluded that important design parameters were blood flow rates, fiber outer diameter and oxygen pressure drop. Based on the present results, it was believed that the optimal level of blood flow rates was 200$cm^3$/min.

• Journal of Korean Physical Therapy Science
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• v.29 no.1
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• pp.41-46
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• 2022

Background: The purpose of this study was to develop a sit-to-stand transfer assistive device, and to conduct a feasibility test. Design: A technical note. Methods and results: In this study, we developed a sit-to-stand transfer assistive device for the elderly and the disabled who have difficulty standing up independently from sitting positions. The sit-to-stand transfer assistive device allows the user to transfer the weight from a sitting position to a standing position while shifting the weight forward by grabbing and pulling a support stand. Ten healthy adults participated in the feasibility test of the device. Each participant used the developed sit-to-stand transfer assistive device and investigated supplementation through a brief interview. As a result of the feasibility test, the opinion was that the device could assist the sit-to-stand transfer to some extent. There were opinions that it needed a function to adjust the height of the knee protective plate in the sitting position according to the user's physical characteristics. Because of the inconvenience of operating the lock device for fixing the position and adjusting inclination, there was an opinion that the improvement for a locking device is needed. There were opinions that it would be better to reduce the size of the device due to its inconvenience of portability. Conclusion: In this study, we developed the sit-to-stand transfer assistive device for the elderly and the disabled who have difficulty standing up independently from sitting positions. In addition, it is considered that the upgrade of the device is necessary for the future since there are supplementary opinions on some points.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.439-448
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• 2001

This paper considers the acoustical characteristics of the closing click sounds of the mechanical valves employed in an implantable biventricular assist device (BYAD) and their re1evance to the Physical states of the valved. Bj rk Shiley Convexo Concave tilting disk valve was chosen for the study and acoustic measurement was made for the BYAD operated in a mock circulatory system as well as implanted in an animal (sheep). In the BYAD operated in the mock circulatory system. three different states of the valve were examined, ie. normal. mechanically damaged. pseudo-thrombus attached. Microphone measurement for the BVAD implanted in the animal was carried out for five days at a regular time interval from one day after implantation. Characteristic spectrum of the sound from the valve was estimated using Multiple Signal Classification (MUSIC) in which the optimal order was determined according to Bayesian Information Criterion (BIC) . It was observed that the mechanical damage of the valve resulted in changes of the structure of the acoustic spectrum. In contrast. the thrombus formed on the valve did not change much the basic structure of the spectrum but brought about altering the spectral Peak frequencies and energies. Maximum spectral Peak (MSP) with the greatest energy was seen at 2 kHz for the normal valve and it was shifted to 3 kHz for the calve attaching the Pseudo-thrombus. Unlike the normal valve, strong spectral Peak appeared around 7 kHz in the sound from the valve mechanically damaged. In the case of the BYAD implanted in the animal. as the thrombus grew, acoustic energy was reduced relatively more in the low frequency components (〈 2 kHz) and the frequencies of the 1st, 2nd and 3rd MSP were increased little. The thrombus formation would result in reduction in both the variability of the 1st, 2nd and 3rd MSP and the value of the BIC optimal order.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.9
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• pp.739-745
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• 2014

Although medication is given to heart disease patients, conventional medication alone is not sufficient to treat heart disease. However, it has been reported that left ventricular assist device (LVAD) transplantation is an effective bridge to heart transplantation by assisting cardiac function. This study used long-term animal testing and emergency situations with a bovine model (Holstein) and canine model (Labrador-retriever) to evaluate the biocompatibility of LibraHeart-I (LH-1), which is a bent-tube type of LVAD that was developed in a previous study. In the long-term animal testing with the bovine model, the subjects survived for 49 days with no irregularities observed in their complete blood cell counts or the vital sign tests that were carried out during the test period. In short-term animal testing with the canine model, it was observed that blood did not remain inside the LH-I even without power support from an external drive source. In this study, the biocompatibility of the LH-I that was developed in a previous study was verified by the ejection performance during long-term animal testing and emergency situations.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1205-1211
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• 2011

In this paper, we developed a pacemaker that can increase the efficacy of a left ventricular assist device (LVAD) and increase the survival rate for patients suffering end-stage heart failure. Because LVAD patients can experience arrhythmia, the pacemaker incorporated into the LVAD has the important role of sustaining sufficient blood circulation during arrhythmia. The electrode of the pacemaker is located at the apex of the left ventricle, where the VAD's inlet cannula is connected. This is efficient placement, in that the electrode can transmit electrical stimulation directly to the Purkinje fibers of the myocardium. The pacemaker can change the stimulation rate from 0 bpm to 191.4 bpm when a button is pressed on the external control module, and the pacemaker normally stimulates the heart at 60 bpm with 0.25 J of energy. We performed animal experiments to evaluate the performance and reliability of the combination of the LVAD and pacemaker. At pacemaker stimulation rates of 86.4 bpm, 100.2 bpm, 126.6 bpm, we recorded the ECGs, aortic pressures, and flow rates to analyze the heart loads.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1457-1458
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.346-350
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• 1996

This paper presents a Neural Network Identification (NNI) method for modeling of highly complicated nonlinear and time varing human system with a pneumatically driven mock circulation system of Left Ventricular Assist Device(LVD). This system consists of electronic circuits and pneumatic driving circuits. The initation of systole and the pumping duration can be determined by the computer program. The line pressure from a pressure transducer inserted in the pneumatic line was recorded. System modeling is completed using the adaptively trained backpropagation learning algorithms with input variables, Heart Rate(HR), Systole-Diastole Rate(SDR), which can vary state of system, and preload, afterload, which indicate the systemic dynamic characteristics and output parameters are preload, afterload.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.643-647
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• 1986

A new type of motor-driven Total Artificial Heart (TAH) system with rolling-ball mechanism has been developed. To test its performance as a Left Ventricular Assist Device (LVAD), LVAD is controlled to bypass blood for impaired heart triggered by the R-wave in ECG. Results of the test with a Mock Circulation System (MCS) and an animal experiment with a dog are also included. More powerful system using a brushless DC motor has been developed and its control scheme is represented.

• Proceedings of the KTCVS Conference
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• 1998.10a
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• pp.4-4
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• 1998