title: Effect of Electrode Belt and Body Positions on Regional Pulmonary Ventilation- and Perfusion-Related Impedance Changes Measured by Electric Impedance Tomography.
abstract: Ventilator-induced or ventilator-associated lung injury (VILI/VALI) is common and there is an increasing demand for a tool that can optimize ventilator settings. Electrical impedance tomography (EIT) can detect changes in impedance caused by pulmonary ventilation and perfusion, but the effect of changes in the position of the body and in the placing of the electrode belt on the impedance signal have not to our knowledge been thoroughly evaluated. We therefore studied ventilation-related and perfusion-related changes in impedance during spontaneous breathing in 10 healthy subjects in five different body positions and with the electrode belt placed at three different thoracic positions using a 32-electrode EIT system. We found differences between regions of interest that could be attributed to changes in the position of the body, and differences in impedance amplitudes when the position of the electrode belt was changed. Ventilation-related changes in impedance could therefore be related to changes in the position of both the body and the electrode belt. Perfusion-related changes in impedance were probably related to the interference of major vessels. While these findings give us some insight into the sources of variation in impedance signals as a result of changes in the positions of both the body and the electrode belt, further studies on the origin of the perfusion-related impedance signal are needed to improve EIT further as a tool for the monitoring of pulmonary ventilation and perfusion.
authors.affiliation: Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Elin
authors.initials: E
authors.lastname: Ericsson
authors.affiliation: Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.|Department of Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Tesselaar
authors.affiliation: Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.|Department of Hand and Plastic Surgery and the Burn Clinic, Linköping University, Linköping, Sweden.
authors.forename: Folke
authors.initials: F
authors.lastname: Sjöberg
mesh_terms: D017097:Electric Impedance; D004566:Electrodes; D064368:Healthy Volunteers; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D010477:Perfusion / Q000009:adverse effects; D011187:Posture / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D014054:Tomography; D055397:Ventilator-Induced Lung Injury / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology