Development of methods for electrical impedance tomography of epileptic seizures.
Doctoral thesis, UCL (University College London).
In this thesis a method for Electrical lmpedance lmaging (EIT) during epileptic activity is developed. The first chapter provides an introduction to the impedance properties of the tissues of the head, to epilepsy and related conditions and how bioimpedance changes with these. In the second chapter a method for simultaneous recording of EIT and EEG is developed, as the latter may be corrupted by the current injected by the former, to permit clinical reporting and correlation between the two methods. The work in the third chapter analyzes fully a pilot clinical study with EIT during seizures, to see if any significant changes could be measured. In the event, this analysis proved negative, so the fourth and fifth chapters re-examine the engineering aspects of the problem and specify an improved system. In particular their aim was to examine the feasibility of undertaking EIT during seizured with scalp electrodes: a detailed finite element model of the head was used in order to estimate the likely amplitude of scalp potentials, and these were considered in relation to the baseline noise of three available EIT systems. The purpose of this was to determine if EIT appeared feasible, suggest optimal recording conditions (such as optimal applied frequency) and choose the best available system for a clinical study. In the sixth and seventh chapter new measuring protocols were devised and a study was undertaken in saline filled tanks to determine if indeed the performance of the two best systems appeared sufficient for a clinical study. I then summarize the finding of the work in this thesis, discuss their overall significance and propose future work required for EIT in epilepsy.
|Title:||Development of methods for electrical impedance tomography of epileptic seizures|
|Additional information:||Permission for digitisation not received|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science > Medical Physics and Bioengineering|
Archive Staff Only