Applying Electrical Impedance Tomography Techniques for Detection of Decay Inside Trees

Trees play a critical role in creating green spaces in public areas such as streets, parks, schools,offices. Over time, the trees often get pests and diseases, and then rotten trees can break. To care for andconserve the trees, it is necessary to determine the condition inside the trunk, especially the possibility ofhaving a hollow or not. Wood decay, modifications of moisture and ion content, density due to biotic andabiotic stress agents of water extremity, salinity, and infection strongly change (di-) electrical propertiesof wood. Hence, we propose to use electrical impedance tomography to detect the change in electricalproperties inside the trees that can link to wood decay. In electrical impedance tomography, an array ofelectrodes is attached around the tree trunk, and small alternating currents are injected via these electrodes,so the resulting voltages are measured. Processing the data, we can construct the spatial distribution ofimpedance (or resistivity) of the object. In this work, we will present the preliminary results of our groupresearch. We will show theoretical forward modeling results, followed by laboratory experiments and realdata application. The results illustrate that electrical impedance tomography can be useful to define severaldecay scenarios inside the trees.