• 대한의용생체공학회:의공학회지
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• 제16권1호
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• pp.61-66
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• 1995

We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane. To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medicals prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volllme and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2006년도 춘계 학술발표회 논문집
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• pp.115-118
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• 2006

• Journal of Trauma and Injury
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• 제21권1호
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• pp.22-27
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• 2008

Purpose: Treatment and prognosis in patients with pelvic bone fracture depend on the characteristics of the fracture and the stability of the pelvic ring. The purpose of this study is to analyze the characteristics of and the relationships between fracture patterns, injury mechanisms, clinical courses, and prognoses according to the hemodynamic pattern. Methods: Between January 2004 and September 2006, 89 patients under diagnosis of pelvic bone fracture were retrospectively analyzed on the basis of medical records and radiologic examinations. Patients with confirmed hemorragic shock with a systolic pressure of less than 90 mmHg were defined as the shock group. Young's classification was used to characterize fracture patterns. Factors relating to the clinical manifestation and to treatments such as transfusion and surgery were analytically compared. Results: The mean age of the patients was $48.8{\pm}18.7$, among which 49 (55.1%) were male. The numbers of shock and non-shock patients were 35 (39.3%) and 54 (60.7%) respectively. Eighteen (51.4%) of the shock patient had injuries resulting from pedestrian accidents (p=0.008). According to Young's classification, lateral impact fractures amounted to 20 and 33, front-rear impact fractures to 9 and 20, and multiple fractures to 6 and 1 among the shock and non-shock patients, respectively (p=0.027). Thirty-nine (39) cases in non-shock injuries were conservatively managed while 18 cases in shock injuries were surgically treated. In the shock group, the liver and the kidney were often damaged, as well. Among the shock patients, the average admission period was $7.5{\pm}8.7days$ in intensive care and $55.1{\pm}47.9days$ in total, which were longer than the corresponding numbers of days for the non-shock patients (p<0.05). No deaths occurred in the non-shock group while 5 deaths (14.2%) occurred in the shock group (p=0.007). Conclusion: The factors affecting hemodynamic instability in patients with pelvic bone fracture are injury mechanism, classification of fracture, and associated injuries.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1987-1992
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• 2004

Hemodynamics behavior of the blood flow is influenced by the presence of the arterial stenosis. If stenosis is present in an artery, normal blood flow is disturbed. In the present study, characteristics of steady and pulsatile flow of non-Newtonian fluid, the effects of stenosised geometry are analyzed by numerical simulation. One interesting point is that non-symmetric solutions were obtained at severity stenosis, although the stenosis and the boundary condition were all axisymmetric.

• Journal of Korean Neurosurgical Society
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• 제59권2호
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• pp.117-121
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• 2016

Objective : Hemorrhagic moyamoya disease (hMMD) is associated with a poor clinical course. Furthermore, poorer clinical outcomes occur in cases of recurrent bleeding. However, the effect of hemodynamic insufficiency on rebleeding risk has not been investigated yet. This study evaluated the prognostic implications of the perfusion status during the clinical course of adult hMMD. Methods : This retrospective study enrolled 52 adult hMMD patients between April 1995 and October 2010 from a single institute. Demographic data, clinical and radiologic characteristics, including hemodynamic status using single photon emission computed tomography (SPECT), and follow up data were obtained via a retrospective review of medical charts and imaging. Statistical analyses were performed to explore potential prognostic factors. Results : Hemodynamic abnormality was identified in 44 (84.6%) patients. Subsequent revascularization surgery was performed in 22 (42.3%) patients. During a 58-month (median, range 3-160) follow-up assessment period, 17 showed subsequent stroke (hemorrhagic n=12, ischemic n=5, Actuarial stroke rate $5.8{\pm}1.4%/year$). Recurrent hemorrhage was associated with decreased basal perfusion (HR 19.872; 95% CI=1.196-294.117) and omission of revascularization (10.218; 95%; CI=1.532-68.136). Conclusion : Decreased basal perfusion seems to be associated with recurrent bleeding. Revascularization might prevent recurrent stroke in hMMD by rectifying the perfusion abnormality. A larger-sized, controlled study is required to address this issue.

• 대한융합한의학회지
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• 제6권1호
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• pp.5-20
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• 2024

Objectives: This study was aimed to evaluate the hemodynamic feasibility using pulse parameters as a way to establish safe dose guidelines for Chunwangbosim-dan, and to provide a foundation for developing evidence-based guidelines for clinical use. Methods: Forty-one volunteers were recruited to participate in a study examining the changes in pulse wave characteristics following the ingestion of Chunwangbosim-dan, over a period of 2 weeks, and pulse wave measurements were taken before and after the administration. Pulse wave parameters were measured in this study using a 3-dimensional radial pulse tonometry device(DMP-Lifeplus). In addition, questionnaire, blood pressure, temperature, and body composition were also measured as secondary measures. Results: Fifteen minutes after administration of Chunwangbosim-dan, the non-adverse event group(non-AE) exhibited a statistically significant increase in several power and pressure-related parameters, including h1, h3, h4, h5, SA, PA and PW, while the adverse event group(AE) showed a trend of decreasing stroke volume and increasing Systemic Vascular Resistance Index(SVRI) and applied pressure. After 2 weeks of administration, non-adverse event group(non-AE) exhibited significant changes in standard deviation of pulse rate and HRV_LH ratio. Notably, there are significant differences between AE group and non-AE group in h4/h1, w/t, applied pressure, SV and pulse rate. Conclusion: These findings suggest that pulse parameters may be a useful way to establish safe dosing guidelines for Chunwangbosim-dan. Further research is needed to confirm these results and to develop evidence-based guidelines for clinical use.

• Journal of Dental Anesthesia and Pain Medicine
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• 제18권3호
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• pp.169-175
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• 2018

Background: The objective of this study was to compare hemodynamic and recovery characteristics of total intravenous anesthesia using propofol target-controlled infusion (TCI) versus sevoflurane for extraction of four third molar teeth. Methods: One hundred patients undergoing extraction of four third molar teeth under general anesthesia were randomized to one of two groups. Group 1 received propofol TCI-oxygen for induction and propofol TCI-oxygen-air for maintenance. Group II received a propofol bolus of 2 mg/kg for induction and sevoflurane-oxygen-air for maintenance. Heart rate, mean arterial pressure (MAP), operating time, time to emergence, nausea and vomiting, and sedation and pain scores were measured in each group. Results: Demographic data, including age, gender, weight, and height, were not significantly different between the two groups. The MAP was significantly higher after intubation (P = 0.007) and injection of anesthesia (P = 0.004) in the propofol group than in the sevoflurane group, with significant reflex bradycardia (P = 0.028). The mean time to emergence from anesthesia using propofol was 25 s shorter than that of sevoflurane (P = 0.02). Postoperatively, the propofol group was less sedated than the sevoflurane group at 30 min (0.02 versus 0.12), but this difference was not significant (P = 0.065). Conclusion: Both propofol TCI and sevoflurane are good alternatives for induction and maintenance of anesthesia for short day-case surgery. However, propofol TCI does not blunt the hemodynamic response to sudden, severe stimuli as strongly as sevoflurane, and this limitation may be a cause for concern in patients with cardiac comorbidities.

• Journal of Chest Surgery
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• 제29권6호
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• pp.655-659
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• 1996

Primary cardiac tumors are known to be rare. Of the benign primary tumors, rhabdomyoma predominates in neonates and infants. Tuberous sclerosis is found in hall of the patients with rhabdomyomas. Rhabdomyomas demonstrate benign pathological characteristics and may regress spontaneously that resection of the intracavitary obstructing portion of these tumors are recommended. We performed resection of intraatrial rhabdomyoma which had been obstructing mitral valve orifice and caused heart failure in a neonate. Postoperatively, fungal endocarditis developed and after 3 days, rapid growth and extension of the vegetation in the aorta obstructed the flow through the ascending aorta and resulted in hemodynamic deterioration.

• 한국전산유체공학회지
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• 제16권4호
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• pp.84-91
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• 2011

Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics through arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.469-476
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• 2011

Hemodialysis is essential for patients with end stage renal failure. It is important to improve the patency rate and to minimize occurrence of the stenosis. Also, the blood flow to the artificial kidney can affect the blood flow characteristics though arteriovenous graft. Thus, the delivered dose are important factors for analyzing hemodynamic characteristics during hemodialysis access. In this study, the numerical analysis was performed for the effect of the delivered dose during hemodialysis access on the blood flow through the graft. As a result, The adverse pressure gradient occurred in case of a larger delivered dose through a catheter than standard dose and the flow instability increased. Also the circulation flow appeared largely at anastomotic site of the vein when the delivered dose was exceeded about half blood flow of inlet blood flow.