Welcome to EIT 2014

On April 24–26 2014, the 15th International Conference on Biomedical Applications of Electrical Impedance Tomography (EIT 2014) takes place at the Glen House Resort in Gananoque, Canada. Exciting developments are taking place in EIT: developments in hardware, software, and reconstruction algor

An Approach to Extend GREIT Image Reconstruction to 3D

This paper presents a new image reconstruction technique for 3D EIT based on the extension of the 2D GREIT method. Key aspects include the expansion of optimization targets and set of desired images to cover multiple planes. Results show the reduction off-plane interference seen in 2D reconstruction. The selection of target planes is also found to be highly significant to the image

Effective electrode positions and stimulation patterns for head EIT

The objective of this study is to find an effective stimulation and measurement strategy to improve distinguishability for head EIT. To better understand the relationship between distinguishability and various strategies (stimulation/measurement patterns) for a set of electrodes, we evaluated a realistic head model and a range of common strategies

Using real data to train GREIT improves image quality

Image reconstruction in electrical impedance tomography is sensitive to errors in the (forward) model of the measur

GREIT is sensitive to training targets near boundary

It has been observed that the distribution of the training targets used to calculate the GREIT reconstruction matrix has a strong impact on its chief figure of merit, the amplitude response (AR). We found that uniform AR requires a minimum target distance to the domain boundary, and target density gradient toward the centre has less impact on uniform AR

Temporal Reconstructions in EIT

EIT shows potential for monitoring fast changing conductivity profiles, such as heart and lung physiology and chemical processes. In such cases, the measurements which constitute an EIT frame are not taken simultaneously. Several approaches have been proposed to interpret such data, but have not been systematically compared. We formulate and compare temporal EIT solvers on simulation data

Open Electrical Impedance Tomography (OEIT) File Format

Electrical impedance tomography (EIT) creates tomographic images from surface electrical stimulation and measurement. Many research and commercial devices have been made, with correspondingly many data formats, which negatively impacts the ability to share data. To address this issue, we have developed the OEIT data format, an XMLbased flexible container format for EIT data. We describe its features and structure

An individualized approach to sustained inflation duration at birth improves outcomes in newborn preterm lambs

A sustained first inflation (SI) at birth may aid lung liquid clearance and aeration, but the impact of SI duration relative to the volume-response of the lung is poorly understood. We compared three SI strategies: 1) variable duration defined by attaining volume equilibrium using real-time electrical impedance tomography (EIT; SIplat); 2) 30 s beyond equilibrium (SIlong); 3) short 30-s SI (SI30); and 4) positive pressure ventilation without SI (no-SI) on spatiotemporal aeration and ventilation (EIT), gas exchange, lung mechanics, and regional early markers of injury in preterm lambs. Fifty-nine fetal-instrumented lambs were ventilated for 60 min after applying the allocated first inflation strategy. At study completion molecular and histological markers of lung injury were analyzed. The time to SI volume equilibrium, and resultant volume, were highly variable; mean (SD) 55 (34) s, coefficient of variability 59%. SIplat and SIlong resulted in better lung mechanics, gas exchange and lower ventilator settings than both no-SI and SI30. At 60 min, alveolar-arterial difference in oxygen was a mean (95% confidence interval) 130 (13, 249) higher in SI30 vs. SIlong group (two-way ANOVA). These differences were due to better spatiotemporal aeration and tidal ventilation, although all groups showed redistribution of aeration towards the nondependent lung by 60 min. Histological lung injury scores mirrored spatiotemporal change in aeration and were greatest in SI30 group (P < 0.01, Kruskal-Wallis test). An individualized volume-response approach to SI was effective in optimizing aeration, homogeneous tidal ventilation, and respiratory outcomes, while an inadequate SI duration had no benefit over positive pressure ventilation alone

Comparing belt positions for monitoring the descending aorta by EIT

In electrical impedance tomography, the impedance changes stemming from the descending aorta contain valuable information for haemodynamic monitoring. However, the low signal strength necessitates an optimal measurement setup. Among different belt positions investigated in this work, a transversal and low placement is the best choice for detecting signals of the descending aorta