0000000000481470

AUTHOR

Marcus Doebrich

showing 3 related works from this author

Analysis of discrete and continuous distributions of ventilatory time constants from dynamic computed tomography.

2005

In this study, an algorithm was developed to measure the distribution of pulmonary time constants (TCs) from dynamic computed tomography (CT) data sets during a sudden airway pressure step up. Simulations with synthetic data were performed to test the methodology as well as the influence of experimental noise. Furthermore the algorithm was applied to in vivo data. In five pigs sudden changes in airway pressure were imposed during dynamic CT acquisition in healthy lungs and in a saline lavage ARDS model. The fractional gas content in the imaged slice (FGC) was calculated by density measurements for each CT image. Temporal variations of the FGC were analysed assuming a model with a continuous…

SwineInformation Storage and RetrievalComputed tomographyModels BiologicalSensitivity and SpecificitySynthetic dataImaging Three-DimensionalImage Interpretation Computer-AssistedmedicineAnimalsRadiology Nuclear Medicine and imagingComputer SimulationLungSimulationMathematicsRadiological and Ultrasound Technologymedicine.diagnostic_testfungiMathematical analysisTime constantReproducibility of ResultsImage EnhancementNoiseKineticsDistribution (mathematics)Continuous distributionsBreathingVentilatory timePulmonary VentilationTomography X-Ray ComputedAlgorithmsPhysics in medicine and biology
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Dynamic computed tomography: a novel technique to study lung aeration and atelectasis formation during experimental CPR

2002

Objective: To develop an image based technique to study the effect of different ventilatory strategies on lung ventilation and alveolar recruitment during cardiopulmonary resuscitation (CPR). Design: (1) Technical development of the following components: (a) construction of an external chest compression device, which does not interfere with CT imaging, and (b) development of a software tool to detect lung parenchyma automatically and to calculate radiological density parameters. (2) Feasibility studies: three strategies of CPR ventilation were performed and imaged in one animal each (pigs, 25 kg): volume-constant ventilation (VCV), no ventilation, or continuous airway pressure (CPAP). One m…

Artificial ventilationPulmonary AtelectasisSwinemedicine.medical_treatmentAtelectasisEmergency NursingIntensive careAnimalsMedicineCardiopulmonary resuscitationMechanical ventilationLungbusiness.industryHemodynamicsmedicine.diseaseCardiopulmonary ResuscitationHeart Arrestmedicine.anatomical_structureAnesthesiaEmergency MedicineBreathingFeasibility StudiesArterial bloodPulmonary VentilationTomography X-Ray ComputedCardiology and Cardiovascular MedicinebusinessResuscitation
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Lung density distribution in dynamic CT correlates with oxygenation in ventilated pigs with lavage ARDS † †This study contains parts of the doctoral …

2003

Background Fast dynamic computed tomography (dCT) has been used to assess regional dynamics of lung inflation and deflation processes. The aim of this study was to relate ventilation-induced changes in lung density distribution, as measured over several respiratory cycles by dCT, to oxygenation and shunt fraction in a lavage acute respiratory distress syndrome model. Methods Six anaesthetized pigs underwent pressure-constant ventilation (F I O2=1.0, inspiratory:expiratory ratio=1:1) before and after induction of lung damage by saline lavage. Mean airway pressure ( P a μ w μ ) was varied (8, 13, 18, 23, 28, 33, and 38 cm H2O) in random order. At each P a μ w μ level, dCT acquisitions were pe…

ARDSPathologymedicine.medical_specialtyLungbusiness.industryAtelectasisOxygenationrespiratory systemMean airway pressureLung injurymedicine.diseaseAnesthesiology and Pain Medicinemedicine.anatomical_structureParenchymamedicineRespiratory systembusinessNuclear medicineBritish Journal of Anaesthesia
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