Static lesion detection in symmetric scenes using dual-frequency electrical impedance tomography

Tissues have characteristic frequency dependent impendence to electrical current. This property is exploited by Electrical Impedance Tomography (EIT), an emerging biomedical imaging technique. In EIT, electrical conductivity maps of the interior of a body of interest can be reconstructed from voltage measurements collected from electrodes placed on the boundary in response to a prescribed pattern of injected electrical current. The ill-posed, poorly conditioned nature of the reconstruction problem has resulted in EIT having most success applied to time difference imaging, while simultaneously challenged by static scenes. Stroke is a biomedical imaging problem featuring a static lesion (a bleed or a clot), with effective treatment only possible once the aetiology is known. It is an application where the low-cost, portable, cheap and hazard free nature of EIT could be used to accelerate the patient treatment path and improve outcomes without the delay for CT or equivalent imaging. Here we present a novel algorithm for lesion detection, identification and location in numerical models of stroke using EIT measurements from two symmetrically equivalent electrode arrays, taken at two different frequencies of current stimulation.peer-reviewe