Zhanqi Zhao

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INTRODUCTION Lung protective ventilation requires low tidal volume and suitable positive end-expiratory pressure (PEEP). To date, few methods have been accepted for clinical use to set the appropriate PEEP. The aim of this study was to test the feasibility of PEEP titration guided by ventilation homogeneity using the global inhomogeneity (GI) index based on(More)
PURPOSE To evaluate the plausibility, stability, and interindividual comparability of the global inhomogeneity index (GI) based on electrical impedance tomography (EIT). METHODS The lung area in an EIT image was identified by using the lung area estimation method, which mirrors the lung regions in the functional EIT image and subsequently subtracts the(More)
The electrical impedance tomography (EIT)-based global inhomogeneity (GI) index was introduced to quantify tidal volume distribution within the lung. Up to now, the GI index was evaluated for plausibility but the analysis of how it is influenced by various physiological factors is still missing. The aim of our study was to evaluate the influence of(More)
Potential harmful effects of ventilation therapy could be reduced by model-based predictions of the effects of ventilator settings to the patient. To obtain optimal predictions, the model has to be individualized based on patients' data. Given a nonlinear model, the result of parameter identification using iterative numerical methods depends on initial(More)
Up to now, the impact of electrode positioning on electrical impedance tomography (EIT) had not been systematically analyzed due to the lack of a reference method. The aim of the study was to determine the impact of electrode positioning on EIT imaging in spontaneously breathing subjects at different ventilation levels with our novel lung function(More)
BACKGROUND The feasibility of electrical impedance tomography (EIT) as an alternative examination tool in cystic fibrosis (CF) was examined. METHODS 14 CF patients and 14 healthy volunteers were studied. Spirometry and EIT measurements were performed simultaneously. The global inhomogeneity (GI) index was applied to assess the degree of ventilation(More)
Electrical impedance tomography (EIT) is a functional imaging modality capable of tracing continuously regional pulmonary gas volume changes. The aim of our study was to determine if EIT was able to assess spatial and temporal heterogeneity of ventilation during pulmonary function testing in 14 young (37 ± 10 yr, mean age ± SD) and 12 elderly (71 ± 9 yr)(More)
PURPOSE To evaluate a novel method for lung area estimation (LAE method) in electrical impedance tomography (EIT) images as a prerequisite of quantitative analysis of ventilation inhomogeneity. METHODS The LAE method mirrors the lung regions in the functional EIT (fEIT) image and subsequently subtracts the cardiac related areas. In this preliminary study,(More)
Electrical impedance tomography (EIT) is able to deliver regional information to assess the airway obstruction in patients with cystic fibrosis (CF). In the present study, regional obstruction in CF patients measured by EIT was compared with high resolution computed tomography (HRCT). Five CF patients were routinely scheduled for HRCT examination. EIT(More)
Patients with obstructive lung diseases commonly undergo bronchodilator reversibility testing during examination of their pulmonary function by spirometry. A positive response is defined by an increase in forced expiratory volume in 1 s (FEV1). FEV1 is a rather nonspecific criterion not allowing the regional effects of bronchodilator to be assessed. We(More)