• Archives of Plastic Surgery
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• v.46 no.6
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• pp.594-598
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• 2019

Overall complication rates of 9.1% have been reported following implantable cardioverter defibrillator (ICD) placement. Brachial plexus injury is infrequently reported in the literature. We describe a 26-year-old female experiencing left arm nerve pain, a positive Tinel's sign, numbness in the median nerve distribution of the hand and biceps muscle weakness following revision ICD via subclavian vein approach. Nerve conduction studies identified severe partial left brachial plexopathy, which remained incompletely resolved with conservative management. Surgical exploration revealed lateral cord impingement by the ICD generator and a loop of the ICD lead, along with fibrosis, necessitating surgical neurolysis and ICD generator repositioning. As increasing numbers of patients undergo cardiac device implantation, it is incumbent on practitioners to be aware of potential increases in the prevalence of this complication.

• Journal of Biomedical Engineering Research
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• v.38 no.4
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• pp.211-217
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• 2017

During the emergency situation such as cardiac arrest, cardiopulmonary resuscitation(CPR) is the most important treatment to maintain patient's blood circulation. Since the quality of CPR can not be easily measured or evaluated by the eye, an assistive device with an accelerometer can help to assess the pressure depth of CPR. In this study, we propose a single frequency analysis method to reduce the error of the accelerometer by extracting only one frequency component from the Fourier transform process. To verify the effectiveness of the single frequency analysis, acceleration data at CPR conditions were measured at a sampling rate of 50 / sec using a wristband equipped with an acceleration sensor. Then, We compared the existing distance estimation method and the single frequency analysis method using the measured data. The amplitude value proportional to the compression depth was obtained by applying the single frequency analysis method.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.51-53
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• 2006

This paper proposes a portable ECG monitoring system, which integrates uptodate PDA and RF communication technology. The aim of the study is to acquire the subject's biomedical signal without any constraint. It has two types of transmission mode, which are total signal transmission mode and HR(heart rate)/SC(step count) transmission mode. In audition, wireless communication technology uses Zigbee Wireless PAN and can work in low-power mode, which is one of the advantages of ZiBbee communication technology. The developed system is composed of a transmitter and a receiver. The transmitter has three-axial acceleration sensor. ECG amplifier and Zigbee communication controller. In total signal transmission mode, it can send data 50 packets per second whose transmission speed corresponds to 300 ECG samples and 60 acceleration samples. In HR/SG transmission mode, it can calculate heart rate from EEG data with 216 samples per second and step count from acceleration data and send a packet every cardiac cycle. The receiver forwards the received data to PDA, where the data can be stored and displayed. Therefore, the developed device enables to continuous monitoring for Activities of Daily Living(ADL). Also, this method will reduce medical costs in the aged society.

• Clinical and Experimental Pediatrics
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• v.56 no.2
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• pp.90-93
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• 2013

Congenital coronary arteriovenous fistulas (CCAFs) are rare coronary artery abnormalities in which blood is shunted into a cardiac chamber or great vessel. If the fistula itself is large and tortuous, it is generally recommended to occlude the fistula to prevent several complications. In approaches of transcatheter occlusion, the transvenous approach is preferred over the transarterial approach. The transvenous approach would enable the cannulation of a relatively larger catheter or sheath without potential damage to the femoral vessels or normal coronary arteries, which can occur in the transarterial approach. The transvenous approach may also minimize the blind pouch after releasing the devices. Herein, we report the success of transvenous proximal closure of a CCAF using an Amplatzer vascular plug (AVP) in a 3-year-old patient with cardiomegaly. Complete occlusion was achieved by a single AVP and thrombus formation of the distal aneurysmal portion of the fistula. We suggest that this strategy of closing the proximal end with a dilated fistula using a single AVP by the transvenous approach may be a good option in treating CCAFs in a young child.

• Journal of Biomedical Engineering Research
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• v.36 no.6
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• pp.264-270
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• 2015

A mock circulatory loop system has been developed to construct a simulator for trainees in cardiopulmonary bypass systems or to simulate a test environment for cardiac-assist devices. This paper proposes a computerized mock circulatory loop system whose node is modularized by using a servo control flow regulator to simulate dynamic change of the hemodynamic status. To observe the effect of time-varying resistance, one with hemodynamic properties, the proposed system replicates the planned cross-sectional areas of the outlet of a ventricular assist device in terms of voltage input of a servo valve. The experiment is performed (1) for steady-input commands of selected area sizes and (2) for dynamic commands such as monotonous increase and decrease, and oscillatory functions of the voltage input, and a computer program based on LabVIEW (National Instruments, Austin, USA) processes every measured data and control command to the servo valve. The results show that the pressure and flow at the target points with respect to time-varying resistance match intuitive estimation: the pressure at the outlet and the pressure drop between both sides of the valve increased and the flow at the outlet decreased for increased resistance.

• Journal of Oral Medicine and Pain
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• v.43 no.3
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• pp.61-69
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• 2018

Obstructive sleep apnea (OSA) is a relatively common, but greatly underdiagnosed sleep-related breathing disorder, characterized by recurrent collapse of the upper airway during sleep. OSA has been associated with a variety of cardiometabolic disease, such as hypertension, coronary artery disease, cardiac arrhythmia, cerebrovascular disease and metabolic dysfunction. Neurocognitive impairment, including excessive daytime sleepiness, increased risk of motor vehicle accidents, is also related to OSA. Sleep fragmentation and related arousals during sleep lead to intermittent hypoxia, sympathetic activation, oxidative stress, systemic inflammation and metabolic dysregulation which provide biological plausibility to this pathologic mechanism. Extensive studies demonstrated that OSA is a modifiable risk factor for the above mentioned diseases and oral appliances (OAs), although continuous positive air pressure (CPAP) is a first-line therapy of OSA, are not inferior to CPAP at least in mild OSA, and may be an alternative to CPAP in CPAP-intolerant subjects with OSA. The goal of this article is to provide a current knowledge of pathologic link between OSA and cardiovascular disease, focusing on intermittent hypoxia, sympathetic activation, oxidative stress and metabolic dysregulation. Then, previous epidemiologic studies will be reviewed to understand the causal relationship between OSA and cardiovascular disease. Finally, the effects of OAs will be updated via recent metaanalyses compared to CPAP.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.232-234
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• 1996

Cadiac output estimation scheme of LVAD using multi-dimensional interpolation technique was introduced in this paper. This paper also show appropriate input -output data for estimation. Experimental results show our approach is a good one for the estimation of nonlinear hemodynamics.

• Journal of Neurocritical Care
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• v.11 no.2
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• pp.124-128
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• 2018

Background: Secundum atrial septal defect (ASD) is a common congenital heart defect in adults. Patients with ASDs at high risk of cardiovascular complications undergo either surgical repair or percutaneous device closure. Case Report: We report the case of an 85-year-old male with unusual recurrent cerebral infarctions. The patient has undergone repair of secundum ASD 12 years ago. Evaluation by transesophageal echocardiography revealed a mobile mass at the patch repair site in the left atrium. The mass was surgically removed due to recurrent stroke during the anticoagulation. Conclusion: This case emphasizes the importance of regular cardiac checkup and the need to consider cardioembolic source as being part of the etiology of stroke recurrence, even if the event occurs many years after intracardiac shunt closures.

• Journal of Chest Surgery
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• v.29 no.7
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• pp.689-699
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• 1996

An animal experiment was designed for the evaluation of in vivo performance of the newly developed electrohydraulic type ventricular assist device and its influence on the left ventricular function during pal- satile left ventricular assist. Eight adult sheep were incorporated into the study and data were collected from seven sheep. Total as- sist time ranged from 69 minutes to 7 days. The performance of the device was satisfactory both in asyn- chr nous and synchronous mode within the range of given native heart rate. More than 4 liters of device output could be reached within the range of normal left atral pressure without development of negative pressure in the left atrium. Moderate to severe degree of hemolysis was noted as evidenced by significant increase of plasma free hemoglobin level after 3 days of left ventricular support along with the presence of the small amount of thrombi around the floating disc type polymer valve apparatus reflecting that further study and refinement of the device need to be done in regard of biocompatibility and thromboresistance. The hemodynamics showed increase in heart rate (p < 0.05), cardiac output and left ventricular minute work (p < 0.05) after placement of the device at the flow rate of 2.0∼2.5 Llmin. The left atrial pressure, left ventricular pressure and LV dpldt were decreased after the device placement(p < 0.05). The endocardial viability ratio and oxygen contents of the mixed ven us blood and coronary venous blood were all increased (p < 0.05) after the device placement suggesting effective unloading of the left ventricle was accomplished. The myocardial perfusion was thought improved in synchronous counterpulsation as suggested by sig- nificant increase in endocardial viability ratio and coronary venous blood oxygen content in synchronous assist mode comparing with asynchronous mode.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.381-389
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• 2019

Although the development of Drug-eluting stent (DES) improved the ISR significantly more than the Bare metal stent (BMS), the coronary stent restenosis (ISR) treatment still has a high recurrence rate. This study is compared the efficacy of DEB with that of DES implantation in patients with ISR. Among 4,316 patients who underwent coronary stent implantation at the Chonnam National University Hospital between November 2012 and December 2016, 187 patients developed ISR on follow-up coronary angiography ($66.3{\pm}11.0years$, 123 males) were enrolled and divided into two groups according to revascularization method as group I (DEB group; n=127) and group II (DES group; n=60). Primary end point was defined as major adverse cardiac events (MACEs), composite of cardiac death (CD), myocardial infaction (MI), target lesion revascularization (TLR) and stent thrombosis (ST) during two-year follow-up between the two groups. There were no differences in the baseline characteristics and angiographic findings except that prevalence of device length was shorter ($21.1{\pm}5.3$ vs. $25.3{\pm}9.6 mm$, p<0.002) in group I.Two-year MACE were not different in the two groups (8.7%vs.10.0%, p=0.789). The incidences of cardiac death (0%vs.0%, p=1.000), MI (1.6%vs.6.7%, p=0.085), TLR(8.7% vs. 10.0%, p=0.789) and ST (0% vs. 0%, p=1000). DEB demonstrated comparable risk reduction for MACEs compared with DES in patients with ISR during two-year follow-up. DEB might be good alternative for the treatment of ISR in patients with ISR.