Sökning: "blood velocity estimation"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden blood velocity estimation.

  1. 1. Signal Processing for Spectroscopic Applications

    Författare :Erik Gudmundson; Peter Stoica; Peter Händel; Stoica Stoica; Uppsala universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spectral estimation; spectroscopic techniques; MRI; NMR; NQR; signal detection; parameter estimation; missing data; non-uniform sampling; damped sinusoids; detection of explosives; T1-mapping; relaxometry; brain imaging; skin imaging; blood velocity estimation; medical ultrasound; Signal processing; Signalbehandling; Elektroteknik med inriktning mot reglerteknik; Electrical Engineering with specialization in Automatic Control;

    Sammanfattning : Spectroscopic techniques allow for studies of materials and organisms on the atomic and molecular level. Examples of such techniques are nuclear magnetic resonance (NMR) spectroscopy—one of the principal techniques to obtain physical, chemical, electronic and structural information about molecules—and magnetic resonance imaging (MRI)—an important medical imaging technique for, e. LÄS MER

  2. 2. On perfusion estimation using ultrasound

    Författare :Tomas Jansson; Avdelningen för Biomedicinsk teknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Instrumentation technology; Speckle; Artifacts; Perfusion; Ultrasound; Doppler; Mät- och instrumenteringsteknik;

    Sammanfattning : This thesis has the main focus on ways to improve the blood perfusion estimate, as obtained from a continuous wave Doppler system. Earlier studies have shown large temporal variations in the detected perfusion estimate, due to speckle. LÄS MER

  3. 3. Cardiac surgery and the brain - studies on cerebral blood flow autoregulation and mechanisms of cerebral injury

    Författare :Björn Reinsfelt; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :Cardiac surgery; cerrebral dysfunction; cardiopulmonary bypass; anaesthetics; aortic valve replacement; transcranial Doppler; cerebraospinal fluid; blood-brain barrier;

    Sammanfattning : Cardiac surgery and the brain - studies on cerebral blood flow autoregulation and mechanisms of cerebral injury Björn Reinsfelt Department of Anaesthesiology and Intensive Care, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Sweden Abstract Cerebral dysfunction (CD) occurs frequently after cardiac surgery with cardiopulmonary bypass (CPB). The main causes of CD are thought to be cerebral hypoperfusion, cerebral microembolisation , cerebral inflammation or disruption of the blood brain barrier (BBB). LÄS MER

  4. 4. Ultrasonic Methods for 2D Arterial Wall Movement Measurements

    Författare :Magnus Cinthio; Avdelningen för Biomedicinsk teknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tissue Doppler imaging; Cardiovascular system; Diagnostik; Diagnostics; Kardiovaskulära systemet; arteries; ultrasound; shear stress; axial movement; radial movement; Arterial distension; Arterial lumen diameter; PWV; Arterial longitudinal movement; pulse-wave velocity;

    Sammanfattning : Cardiovascular diseases constitute the major cause of morbidity and mortality in the Western World. To increase our knowledge of cardiovascular diseases, it is important to find methods, preferably non-invasive ones, to study very early manifestations of vascular disease. LÄS MER

  5. 5. Influence of optical properties on Laser Doppler Flowmetry

    Författare :Marcus Larsson; Stefan Andersson-Engels; Linköpings universitet; []
    Nyckelord :MEDICINE; MEDICIN;

    Sammanfattning : Laser Doppler flowmetry (LDF) is based on the principle that a Doppler shift occurs when coherent light is scattered by a moving object, i.e. red blood cell (RBC). The magnitude of these frequency shifts affects the optical beating that occurs w hen shifted and non-shifted light is mixed. LÄS MER