Sökning: "ventilation perfusion distribution"

Visar resultat 6 - 10 av 19 avhandlingar innehållade orden ventilation perfusion distribution.

  1. 6. Regional ventilation, pulmonary perfusion and gas exchange in supine and prone positions

    Författare :Margareta Mure; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :ARDS; ALI; CPAP; Gas exchange; Prone position; Regional ventilation; Regional perfusion; Supine position;

    Sammanfattning : The rationale for treating patients with acute lung injury in the prone position springs from a number of observations. Clinical reports have documented improved oxygenation when patients are turned prone. Regional vascular conductance is higher in dorsal lung regions regardless of posture. LÄS MER

  3. 7. Novel computational methods for image analysis and quantification using position sensitive radiation detectors

    Författare :Alejandro Sanchez Crespo; Stig A. Larsson; Magnus Dahlbom; Stockholms universitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; SPET; PET; CMOS; spatial resolution; photon depth of interaction; positron annihilation; positron range; non-collinearity; scatter; attenuation; lung ventilation; lung perfusion; breast tumour; Medicine; Medicin;

    Sammanfattning : The major advantage of position sensitive radiation detector systems lies in their ability to non invasively map the regional distribution of the emitted radiation in real-time. Three of such detector systems were studied in this thesis, gamma-cameras, positron cameras and CMOS image sensors. LÄS MER

  4. 8. Topics in multifractal measures, nonparametrics and biostatistics

    Författare :Attila Frigyesi; Anestesiologi och intensivvård; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; confidence interval; mixed effects; Statistics; operations research; programming; actuarial mathematics; Statistik; operationsanalys; programmering; aktuariematematik; operational model of pharmacological agonism; concentration-response curves; dose-response curves; ventilation perfusion scintigraphy; V Q-scan; pulmonary embolism; automated method; box counting; correlation dimension; Hentschel-Procaccia dimension; Rényi dimension; generalized dimensions; fractal dimension estimation; dimension spectrum; multifractal measures; kernel density estimates; absolute continuity; singular distribution functions;

    Sammanfattning : This thesis consists of four papers. The first two papers, which comprise the main part of the thesis, deal with an unexpected connection between kernel density estimators and dimension spectra for multifractal measures. LÄS MER

  5. 9. The effects of posture, airway pressure and anesthesia on regulation of the regional ventilation and perfusion distribution in healthy humans

    Författare :Sven Nyrén; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Anesthesia; ALI; ARDS; CPAP; Dual isotope; Mechanical ventilation; Nitric oxide; Nuclear medicine; Prone position; Regional ventilation; Regional perfusion; SPECT;

    Sammanfattning : Gas exchange has been observed to vary with posture in adult respiratory distress syndrome (ARDS) patients. In this thesis, the effect of posture on theregional distribution of ventilation (V) and perfusion (Q) in the lungs under normal breathing with and without continuous positive airway pressure (CPAP) and during general anesthesia with mechanical ventilation was studied. LÄS MER

  7. 10. Body posture and gravity as determinants of lung perfusion and ventilation

    Författare :Malin Ax; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Normal lung gas exchange depends on an intimate match between regional ventilation and regional blood flow in the lungs. The beneficial effect of the prone posture in acute respiratory failure is well documented but the mechanisms involved are not completely understood. LÄS MER