• Title/Summary/Keyword: Arteries of lower limb

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Computational Study on the Hemodynamic Behaviors of the Human Cardiovascular System with an Acute Arteriovenous Fistula (급성 동정맥루를 포함하는 인체 심혈관계의 혈류역학적 거동에 관한 수치 해석적 연구)

  • 변수영;손정락;심은보;노승탁
    • Journal of Biomedical Engineering Research
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    • v.24 no.4
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    • pp.329-337
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    • 2003
  • Blood in congenital or acquired AY fistula(arteriovenous fistula) flows from arteries directly to veins. detouring peripheral micro-circulation. This makes a great effect on the hemodynamics of human cardiovascular system. In this study, a computational method using lumped parameter mode) was proposed to simulate the cardiovascular hemodynamics of patients with acute AV fistula The cardiovascular system model with a fistula compartment in left lower limb was built using 17 standard lumped compartments. Using fourth order Runge-Kutta method. we solved numerically the unsteady linear set of the ordinary differential equations resulting from application of Kirchhoff's law to the lumped parameter hemodynamic model. The baroreceptor reflex system was implemented to explain the auto-regulation effect of the cardiovascular system with acute AV fistula.

Traumatic Peripheral Arterial Injury with Open Repair: A 10-Year Single-Institutional Analysis

  • Cho, Hoseong;Huh, Up;Lee, Chung Won;Song, Seunghwan;Kim, Seon Hee;Chung, Sung Woon
    • Journal of Chest Surgery
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    • v.53 no.5
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    • pp.291-296
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    • 2020
  • Background: We report our 10-year experience with traumatic peripheral arterial injury repair at an urban level I trauma center. Methods: Between January 2007 and December 2016, 28 adult trauma patients presented with traumatic peripheral arterial injuries. Data were retrospectively collected on demographic characteristics, the mechanism of injury, the type of vascular injury, and physiological status on initial assessment. The analysis also included the Mangled Extremity Severity Score (MESS), Injury Severity Score, surgical procedures, and outcome variables including limb salvage, hospital stay, intensive care unit stay, and postoperative vascular complications. Results: Four (14.3%) patients required amputation due to failed revascularization. MESS significantly differed between patients with blunt and penetrating trauma (8.2±2.2 vs. 5.8±1.3, respectively; p=0.005). The amputation rate was not significantly different between patients with blunt and penetrating trauma (20% vs. 0%, respectively; p=0.295). The overall mortality rate was 3.6% (1 patient). Conclusion: Blunt trauma was associated with higher MESS than penetrating trauma, and amputation was more frequent. In particular, patients with blunt trauma had significantly higher MESS than patients with penetrating trauma (8.2±2.2 vs. 5.8±1.3, respectively; p=0.005), and amputation was performed when revascularization failed in cases of blunt trauma of the lower extremity. Therefore, particular care is needed in making treatment decisions for patients with peripheral arterial injuries caused by blunt trauma.

Clinical Features and Long-Term Outcome in Adult Stroke Patient due to Moyamoya Disease : A Single Subject Study

  • Kwon, Yong Hyun;Kim, Chung Sun
    • The Journal of Korean Physical Therapy
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    • v.25 no.3
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    • pp.126-131
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    • 2013
  • This case report described a single case of adult stoke patient due to Moyamoya disease through long-term follow-up observation, which included his demographics, brain images, and change of motor function and functional activities. The subject was the 54-year-old male diagnosed with left hemiparesis from a stroke due to multifocal encephalomalacia in both hemispheres. At the time of the stroke attack, he took brain surgery intervention including external ventricular drain. Physical and occupational therapy for stroke rehabilitation were admitted including muscle strengthening exercises, functional activity/ADL training, neurofacilitative techniques with bobath or proprioceptive neuromuscular facilitation concepts, and compensatory strategy. Patient's MRI showed that right frontal lobe, right peri-ventricular area, left parietal, and left occipital lobes were damaged, and MRA showed that abnormal collateral vessel was richly developed in both hemispheres by occlusion of proximal internal carotid arteries in both sides. His motor strength was improved from poor to good grade in all of upper and lower limb motions, that MBC was improved from stage 1 to stage 5. In FAC and barthel index, at the initial evaluation, he could not perform any functional movement, but his FAC and barthel index were on 3 and 14 points at present, respectively. During long-term follow-up for approximately 4 years, the subject's functional motor ability was improved, as similar with recovery progression of usual stroke patient. We believe that this single case report will provide clinical information and concern regarding Moyamoya disease with physical therapist, in terms of such as epidemiology, pathogenesis, diagnostic procedures, clinical features, recovery process, and prognosis.

Assessment of Systemic Arterial Thromboembolism with Multi-Slice Spiral CT in a Dog (개에서 다중나선형 CT촬영에 의한 동맥혈전색전증의 평가)

  • Shin, Seung-Ho;Lee, Ki-Chang
    • Journal of Veterinary Clinics
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    • v.24 no.2
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    • pp.208-213
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    • 2007
  • A 15 kg 6-year-old intact male Jindo dog with a history of a respiratory distress, hindlimb paralysis with necrosed skin of dorsal digit for three weeks was referred to Animal Medical Center, Chonbuk National University. Heartworm infection was identified by kit examination. In plain thoracic radiographs, dilated pulmonary arteries reverse D sign and focal interstitial pattern was compatible with heartworm infection and possible pulmonary thromboembolism. Abdominal radiographs showed poor serosal detail indicating fluid accumulation within peritoneal cavity. No evidence of musculoskeletal abnormalities was found. Ultrasonography presented focal wedge-shaped hyperechogenecity on the both poles of left kidney, weak or absent pulse on the distal to the external iliac artery as well as ascites and irregular liver margin. Multi-organ failure was strongly supposed by blood profile including leukocytosis, anemia, hemoglobinuria bililubinemia, hypoalbuminemia, imbalance of electrolytes, and increased hepatic and renal function values. Interestingly, the glucose level is remarkably lower in pelvic limb compared to thoracic limb. Suspected pulmonary thromboembolism, renal infarction and femoral arterial embolization causing hindlimb paralysis and dermatic necrosis were confirmed by 3D reconstructed CT imaging. Prior to taking a consideration of euthanasia, interventional radiology was experimentally attempted but failed due to not recovered from general anesthesia. Early and accurate diagnosis of thromboembolism is valuable and 3D reconstructed CT images might be very useful to show the correct way to treat effectively.

Venous Flaps Applied for New Clinical Indications with using Various Methods (새로운 적응증에 다양한 방법으로 실시한 정맥피판)

  • Kim, Nam Gyun;Choi, Jae Hoon;Choi, Tae Hyun;Lee, Kyung Suk;Kim, Jun Sik;Lee, Hyuk Gu
    • Archives of Plastic Surgery
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    • v.34 no.1
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    • pp.52-59
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    • 2007
  • Purpose: The venous flap is used as an alternative method to the standard free flap for the management of small and thin soft tissue defects. Especially, the venous flap has advantages of being thin, easy harvest and various donor sites, as well as it having lower morbidity. Yet their clinical applications have been limited by their unstable postoperative course and also by their complications such as partial necrosis. The aim of this study is to extend the clinical indications of venous flaps with using various methods. Methods: From May 2005 to March 2006, total of 19 patients(21 cases) underwent various venous flaps for soft tissue defects as a result of trauma(15 cases), facial skin cancer(3 cases), chronic ulcer(1 case) and surgical wound for congenital anomaly(2 cases). The arterialized venous free flap were applied in 18 cases, the pure venous free flap was applied in 1 case and the pure venous pedicled flap were applied in 2 cases. Among them, two flow-through arterialized venous free flaps were applied that used the great saphenous vein to reconstructed major arteries as well as the injured skin and soft tissues in the arm. All the flap were harvested from the volar wrist(11 cases), dorsum of foot(5 cases), thenar(2 cases), and medial thigh(3 cases). Results: The sizes of the flap ranged from $0.75cm^2$ to $264cm^2$(mean size: $40.06cm^2$). The follow-up period ranged from two to twelve months. In the majority of cases, we obtained satisfying results, which was the excellent reconstruction of skin and soft tissue defects and especially in the case of limb salvage, replantation and cancer reconstruction. However, there were 5 cases of partial necrosis and 2 cases of complete failure. The donor sites were closed primarily in 7 cases and wound closure with skin graft were in 14 cases. Conclusion: We conclude that the venous flap will not only be useful for reconstruction of small defect in the hand and foot, but also be useful for various other clinical indications.

THE CURRENT STATUS OF BIOMEDICAL ENGINEERING IN THE USA

  • Webster, John G.
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.27-47
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    • 1992
  • Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

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