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The following MPEG files are three-dimensional electrical impedance image sequences taken using 32 electrodes in four layers of eight each around the chest of a healthy subject.

The movie labeled Static is a static three dimensional image of the thorax. Regions with low conductivity are shown in blue, higher conductivity regions are in green to red. The initial view is from the front of the subject somewhat above the electrode array. The movie then "flies around" the subject to show greater details in the image. The highly conductive heart is clearly distinguished from the lower conductivity lungs.

The Pulmonary movie depicts the impedance changes observed while the subject is ventilating normally. A reference image is made at end-expiration. As the subject inspires a normal sized breath, the changes in conductivity are displayed on a scale in which decreases in conductivity are shown in green. Thus, lung regions become an opaque green as air enters the lungs. The image sequence for one breath is displayed once from a point behind and to the left of the subject. It is then repeated as the viewpoint "flies around" the subject, to show greater detail.

The Cardiac movie demonstrates the ability to monitor perfusion of blood through the pulmonary circulation. During breatholding, a reference image was chosen at end-diastole. The movie displays the changes that occurred in the three-dimensional reconstructed images during the next several cardiac cycles. For the color scale chosen, decreases in conductivity are shown in blue, increases in conductivity are shown in green to red. The movie shows the thorax as viewed initially from above the subject's left side, so that the heart (which becomes blue, or less conductive, in systole, is in the foreground. The lungs, predominantly the right lung, is in the background. It becomes more conductive in systole as its blood volume increases. The movie then displays these data a second time as the viewing perspective rotates around the subject.


©Rensselaer Polytechnic Institute, Created by Alexander S. Ross