F. Schäuble. Auswertung uni - und bipolarer Elektrogramme bei intrakardialen Messungen mittels MiFiTM Ablationskatheter. Institut für Biomedizinische Technik, Karlsruher Institut für Technologie (KIT). Masterarbeit. 2016
Atrial flutter is ranked among the most common cardiac diseases in western civilizations. Although not directly lethal, the evoked functional deficit of the atria increases the risks for both strokes and atrial stenosis . Beside drug therapy, catheter ablation is the golden standard to silence unphysiological patterns of electrical activation . Boston Scientific is one supplier for keyhole surgical equipment to perform such interventions. Recently, the company has released the novel IntellaTip MiFiTM XP Temperature Ab- lation Catheter as part of its innovation program for the RhythmiaTM System. Thereby, the 7 - electrode MiFiTM catheter is advertised to resolve electrophysiological and structural details in high definition due to 3 de - novo microelectrodes integrated in the ablation electrode. Although medical reports are available, a scientific evaluation of its technical capabilities has not been published to date which motivates this thesis. This work intro- duces developed semi-automatic signal preprocessing algorithms to enhance the signal quality of both uni - and bipolar intracardiac electrograms. As signal filtering for these signals is not standardized, a comprehensive filter study was performed from which a set of Butterworth - filters was identified to be the most e↵ective. For subsequent data processing the 12 - channel electrocardiogram signals were considered as well as data from both the 10-electrode coronary sinus and the 64-electrode OrionTM basket catheters. Likewise, structural data was incorporated obtained via impedance and magnetic localization strategies [5, 6]. Signal processing and evaluation used Mathworks Matlab R2016a (Version 9.0) software. Outcomes comprise the development of a program that allows characterization of electrical behavior of intact and ablated regions with respect to signal morphology, amplitude and propagation velocity. Thereby, MiFiTMs distance and orientation against the wall is taken into account. As far as the microelectrodes are concerned, they proofed to record electrical signals with fine spatial sensitivity. This was evaluated based on several well-commented scenarios within the clinical datasets. In conclusion, this work can be regarded as the first step towards an algorithm enabling a semi - automatic evaluation of artificial lesions post ablation therapies. Likewise, it defines a solid base for future work in this regard.
F. Schäuble. Extraktion und Analyse von Aktivierungszeiten aus fluoreszenzoptischen Messdaten. Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT). Bachelorarbeit. 2012