Agenda

PhD Thesis Defence

Modelling and analysis of atrial epicardial electrograms

Miao Sun

Atrial fibrillation (AF) is a frequently encountered cardiac arrhythmia characterized by rapid and irregular atrial activity, which increases the risk of strokes, heart failure and other heart-related complications. The mechanisms of AF are complicated. Although various mechanisms were proposed in previous research, the precise mechanisms of AF are not clear yet and the optimal therapy for AF patients are still under debated. A higher success rate of AF treatments requires a deeper understanding of the problemof AF and potentially a better screening of the patients.

In order to study AF, instead of using human body surface ECGs, we use the epicardial electrograms (EGMs) obtained directly from the epicardial sites of the human atria during open heart surgery. This data is measured using a high-resolution mapping array and exhibits irregular properties during AF. Although different studies have analyzed electrograms in time and frequency domain, there remain many open questions that require alternative and novel tools to investigate AF.

Experience in signal processing suggests that incorporating the spatial dimension into the time-frequency analysis on the multi-electrode electrograms may provide improved insights on the atrial activity. However, the electrophysiologcial models for describing spatial propagation are relatively complex and non-linear such that conventional signal processing methods are less suitable for a joint space, time, and frequency domain analysis. It is also difficult to use very detailed electrophysiologcial models to extract tissue parameters related to AF fromthe high-dimensional data.

In this dissertation, we propose a radically different approach to study and analyze the EGMs from a higher abstraction level and from different perspectives to get more understanding of the characteristics of AF. We also develop a simplified electrophysiological model that can capture the spatial structure of the data and propose an efficient method to estimate the tissue parameters, which are helpful to analyze the electropathology of the tissue, e.g., cell activation time or conductivity. 

Additional information ...

Overview of PhD Thesis Defence

Agenda

Dr. Taekwang Jang

Circuits Crossing the Border

Circuit designers are entering an exciting era in which circuit innovations will be the key enablers of future innovation. Emerging trends such as Machine Learning, the Internet-of-Everything, Brain-Machine Interfaces, Autonomous Driving, 6G Communication and Quantum Computing will drive the design of novel circuits with drastically improved accuracy, speed, and energy efficiency.

MSc ME Thesis Presentation

Leonardo di Paola

Wafer-scale fabrication of transfer-free graphene-based condenser microphones

PhD Thesis Defence

Krishnaprasad Nambur Ramamohan

Direction of Arrival estimation and Self-Calibration techniques using an array of Acoustic Vector Sensors

PhD Thesis Defence

Miao Sun

Modelling and analysis of atrial epicardial electrograms

PhD Thesis Defence

Tarik Kazaz

Multiband channel estimation for precise localization in wireless networks

Can we reach decimeter accuracy on wireless localization?

Seminar on Wide-bandgap semiconductor technology and industry

This seminar will highlight the state of the art of technology and industry of wide bandgap semiconductors (WBS), which are becoming the cornerstones of future power electronics, communication (5G and beyond) and optoelectronics.