In vitro localization of intracranial haematoma using electrical impedance tomography semi-array

Electrical Impedance Tomography is a non-invasive and portable method that has good potential as an ‎alternative to the conventional modalities for early detection of intracranial haematomas in high risk patients. ‎Early diagnosis can reduce treatment delays and most significantly can impact patient outcomes. Two eight-‎electrode layouts, a standard ring full array (FA) and a semi-array (SA), were investigated for their ability to ‎detect, localise and quantify simulated intracranial haematomas in vitro on ovine models for the purpose of ‎early diagnosis. SA layout speeds up electrode application and avoids the need to move and lift the patient's ‎head. Haematomas were simulated using gel samples with the same conductivity as blood. Both layouts, FA ‎and SA, could detect the presence of haematomas at any location within the skull. The mean of the relative ‎radial position error with respect to the brain radius was 7% for FA and 6% for SA, for haematomas close to the ‎electrodes, and 11% for SA for haematomas far from the electrodes at the back of the head. Size estimation ‎was not as good; the worst size estimation error for FA being around 30% while the best for SA was 50% for ‎simulated haematomas close to the electrodes.