• Journal of Chest Surgery
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• v.33 no.5
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• pp.385-390
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• 2000

Background: To review the experience that used both ventricular assist device(VAD) and extracorporeal membrane oxygenation(ECMO) for children with congential heart disease requiring postcardiotomy mechanical circulatory support. Material and Method: Between March 1993 and May 1995, we applied mechanical assist device using centrifugal pump to the 16 patients who failed to be weaned from cardiopulmonary bypass(n=15) or had been in cardiogenic shock in intensive care unit(n=1). The diagnosis were all congenital heart diseases and the ages of patients ranged from 20 days to 10 years (mean age=2.5$\pm$3.5 years). Result: The methods of mechanical circulatory support were LVAD(n=13), BVAD (n=1), and ECMO(n=2). The mean assist times were 54.0$\pm$23.7 hours. Post-assist complications were in orders: bleeding, acute renal failure, ventricular failure, respiratory failure, infection, and neurologic complication. It was possible for 9 patients(56.3%) to be weaned from assist device and 5 patients(31.3%) were discharged from hospital. There was no statistical significant between hospital discharged group and undischarged group by age, body weight, cardiopulmonary bypass time, and assist time. Conclusion: The ventricular assist device is an effective modality in salvaging the patient who failed to be weaned from cardiopulmonary bypass, but multiple factors must be considered for improving the results of mechanical circulatory support ; such as patient selection, optimal time of starting the assist device, and prevention and management of the complications.

• Journal of Chest Surgery
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• v.52 no.2
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• pp.105-108
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• 2019

Right heart failure is a relatively common complication after left ventricular assist device (LVAD) implantation. Severe right heart failure can be managed by temporary right ventricular assist device (RVAD) implantation. However, trans-sternal RVAD insertion requires a subsequent third sternotomy for cannula removal. Herein, we present a case of RVAD insertion via a left anterior mini-thoracotomy after LVAD implantation in a patient with alcohol-induced cardiomyopathy.

• Journal of radiological science and technology
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• v.46 no.5
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• pp.395-399
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• 2023

The knee arthritis patients are generally performed standing position radiography. However, patients with pain caused by degenerative diseases or injuries in the knee have difficulty maintaining a standing position. Therefore, this study aims to develop a knee joint standing weight bearing projection assist device to solve these problems when patients undergo knee radiography due to various diseases. The design of the knee joint weight-bearing radiography assist device is carried out with 3D design and drawing production to secure basic data, electric support and frame manufacture. A fixed device for maintaining the patient's knee standing weight-bearing projection, an electric digital height device, a digital protractor, and a safety device were designed. The arm support is made of PVC with a cushion to relieve the impact and make it easier to remove debris. The digital electric device can be moved up and down according to the patient's height, and a remote control is attached. The safety device is made to be adjustable in size by attaching metal hooks on both sides of the frame and to shield the scrotum. A digital protractor was attached to the side frame to set the desired knee angle. When a self-made assist device was used to perform a knee joint standing weight bearing projection, it helped maintain arm support and lower extremities position. In addition, the height could be adjusted using an assist device during standing projections, which helped the patient maintain the position.

• Journal of Drive and Control
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• v.18 no.4
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• pp.72-76
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• 2021

The aim of this study was to establish a breathing assist system for saxophone players with breathing problems. Although the saxophone is a popular wind instrument with a reed in its mouthpiece, it can be difficult for people with breathing problems to play this instrument, as it requires adequate breath support for deep and even long breaths. To solve this problem, the authors propose a breathing assist device, which functions like a pneumatic master-slave amplifier, for saxophone players with breathing problems. First, the proposed device is fabricated. Second, the effectiveness of the breathing assist device as a master-slave amplifier is confirmed through experiments. Third, the dynamic characteristics of the device are tested up to 10 Hz, and they demonstrate that the device responds well for up to approximately 5 Hz.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.79-85
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• 2011

In this paper, we proposed a design of upper-limb rehabilitation device with power-assist function for stroke survivals. The designed upper-limb rehabilitation device has three degrees of freedom； it is possible to perform flexion and extension motions of wrist, index finger and the other fingers except the thumb independently. The power-assist for wrist motion is performed by a pneumatic double-acting cylinder, but the fingers are actuated by electrical linear actuators to assist motions. A prototype upper-limb rehabilitation device and its controller were implemented. The position controller showed 0.8 mm errors in the steady-state. Experimental results showed that the proposed upper-limb rehabilitation device with power-assist function is feasible.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.129-138
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• 2020

Due to the nature of the Rosenberg Method, the patient needs to maintain posture for a certain period of time, and the joint space is observed in various forms depending on the angle of knee flexion, which causes difficulties in examination. In order to solve these problems, Image quality was evaluated in order to evaluate the usefulness of the assistive device by making the assistive device itself. SNR and CNR analysis about the presence or absence of an assistive device using the extremity phantom and the angle of the assistive device itself were not statistically significant(p < 0.05). As a result of measuring the distance between the right and left edges of the medial condyle based on the presence or absence of an assist device, and the absence of assist device (96.00±40.6 mm) and presence of an assist device (134.86±17.68 mm) were statistically significant (p <0.05). To find the aLDFA relationship about the femur and tibia, we measured the right and left aLDFA based on the presence or absence of assist device. As a result, the absence of the right-side aLDFA assist device (74.63°±4.87) and the presence of assist device (79.64°±3.65) were statistically significant (p <0.05). The absence of the left-side aLDFA assist device (76.39°±4.62) and the presence of assist device (79.64°±3.65) were statistically significant (p < 0.05). but, As a result of measuring the distance of the overlapping parts of the right and left proximal tibiofibular joint and the lateral condyle, There were no statistically significant differences between the right and left sides. In conclusion, we confirmed that we can obtain Diagnostically valuable images with a constant knee-to-knee spacing using an assist device we self-created. In addition, we could learn through aLDFA relationship between femur and tibial that the smaller the angle, the more medial condyle overlaps with JSW, We also confirmed the significance by deriving similar values on the normal range values of aLDFA using assist devices. However, it is considered necessary to pay attention to internal and external rotations in order to obtain good quality images by evaluating the distance of overlapping parts between proximal tibiofibular joint and lateral condyle.

• Journal of Biomedical Engineering Research
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• v.17 no.3
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• pp.387-394
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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 circulatory system of Left Ventricular Assist Device(LVAD). This system consists of electronic circuits and pneumatic driving circuits. The initiation 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. Output parameters are preload, afterload which indicate the systemic dynamic characteristics. Consequently, the neural network shows good approximation of nonlinearity, and characteristics of left Ventricular Assist Device. Our results show that the neural network leads to a significant improvement in the modeling of highly nonlinear Left Ventricular Assist Device.

• Membrane Journal
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• v.14 no.1
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• pp.18-25
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• 2004

The purpose of this paper was to find out the proper equation to predict the gas transfer rate for designing intravenous artificial lung assist device. The prepared hollow fiber modules were examined under various experimental conditions through experimental modeling before inserted the artificial lung assist d $\varepsilon$ vice into as venous. As a result, we can estimate the gas transfer as a function of the packing density. The gas transfer obtained from the experiment was similar to that from the equation, confirming the usefulness equation. Therefore, we can conclude the gas transfer of the intravenous artificial lung assist device as a function of the packing density, and this functions are very useful for predicting the gas transfer of the intravenous artificial lung assist device.

• Journal of Chest Surgery
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• v.53 no.2
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• pp.79-81
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• 2020

Treatment options for children with end-stage heart failure are limited. We report the first case of a successful pediatric heart transplantation bridged with a durable left ventricular assist device in Korea. A 10-month-old female infant with dilated cardiomyopathy and left ventricular non-compaction was listed for heart transplantation. During the waiting period, the patient's status deteriorated. Therefore, we decided to provide support with a durable left ventricular assist device as a bridge to transplantation. The patient was successfully bridged to heart transplantation with effective support and without any major adverse events.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.543-546
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• 2021

A 55-year-old woman who had received an implantable left ventricular assist device 3 months earlier presented with dyspnea and a low-flow alarm of the device. Computed tomography and log-file analysis of the device system suggested inflow cannula obstruction. Since the patient had cardiogenic shock due to pump failure, venoarterial extracorporeal membrane oxygenation (ECMO) was initiated. With ECMO, surgical exchange of the pump was considered. However, the obstruction spontaneously resolved without surgical intervention. It turned out that an obstructive thrombus was washed out by rebooting the pump. Moreover, the thrombus was embolized in the patient's left subclavian artery. The patient underwent heart transplantation 4 months after the pump obstruction accident and continued to do well.