Publications on Hans Dierckx' Research Page

Feynman-like diagrams in the heart!

Fri, 22 Nov 2024 00:00:00 +0000

Electrical patterns in the heart drive its mechanical contraction and therefore the pumping of blood. Since the cardiac muscle cells can transmit the electrical signal themselves, this pattern can go wild, leading to dangerous arrhythmias.

To understand and control complexity of excitation patterns is still challenging. In our paper, we asked ourselves: “What are the most fundamental building blocks of such a pattern, as seen on the heart’s surface?”

We started by considering that elementary (topological) building blocks are the regions of excited and unexcited tissue and the borders between them. Additionally, there are conduction blocks, i.e. zones where the next wave cannot yet propagate. Now, if one colors the medium in according to these 3 regions (excited, unexcited, local block), there are special points where these regions meet: heads (end points of wave fronts) and tails (end points of wave backs). These points should always be pairwise created or annihilated (with opposite chirality). Also, if one supposes that conduction blocks are thin, its end points should also appear in pairs.

The three sets of points are therefore akin to elementary particles in physics (say the 3 flavours of quarks). We propose to call these cardions, in analogy to baryons, fermions, twistons etc.

To our own surprise, we found that during ’normal’ evolution of patterns, the cardions bind together into `core particles’, which could explain why they were not observed before. During more ‘violent’ events, such as arrhythmia formation and termination, the cardions recombine.

To keep track of the topological changes during arrhythmia formation, we propose a diagrammatic way, see above. Presently, this is a schematic drawing reminiscent of the famous Feynman diagrams in physics; however, in our case there is (not yet) a deeper meaning such as the path integrals or cross-section calculations in particle physics.

Nonetheless, we show that heads, tails and pivots all have their own topological charge ($\pm$ 1/2), which constrains the possible interactions.

We are currently developing automated pipelines for cardion detection and analysis, which will enable to perform statistical analysis and systematically investigate arrhythmia initiation mechanisms.

Figure adapted from Arno et al., Scientific Reports volume 14, 28962 (2024), licensed under a Creative Commons Attribution (CC BY) license

New publication by Kabus et al. 2024

Thu, 25 Jan 2024 00:00:00 +0000

They introduce a fast and efficient data-driven methodology for creating reliable mathematical models of cardiac excitation using recorded videos at the tissue level.

In a nutshell, the paper demonstrates that recorded movies at the tissue level can be used to swiftly generate reliable mathematical models for cardiac tissue excitation. By leveraging exponentially weighed moving averages and polynomial regression, a rapid and efficient pipeline for creating in-silico models is unlocked. This method takes just a few minutes!

Congratulations to Desmond and his co-authors from the Leiden University Medical Center, Tim De Coster, Antoine de Vries and Daniel Pijnappels.

The full paper can be found here:
https://doi.org/10.1016/j.compbiomed.2024.107949

New publication by Cloet et al. 2023

Fri, 17 Nov 2023 00:00:00 +0000

The general topic is excitable systems: Think of the spread of rumor, flow of information in the brain or electrical activation of cardiac tissue. These can all be modeled on a network, and by studying excitation patterns in the network, we can learn more about the behavior of news in social networks, brain cells and cardiac activation.

“Scroll Waves and Filaments in Excitable Media of Higher Spatial Dimension” is the result of research during Marie’s master’s thesis.

The published version can be consulted on the Physical Review Letters website:
https://doi.org/10.1103/PhysRevLett.131.208401

The paper is also available on arXiv:
https://doi.org/10.48550/arXiv.2304.14861

Cover image generated by Dall-E 3.

New publication by Li et al. 2023 including Hans Dierckx

Wed, 06 Sep 2023 00:00:00 +0000

Read the article here: https://doi.org/10.1103/PhysRevE.108.034218

Cover image generated by Dall-E 3.

New publication by Leenknegt et al. 2023

Mon, 10 Jul 2023 00:00:00 +0000

Read the article here: https://doi.org/10.3389/fphys.2023.1213218

Cover image generated by Dall-E 3.

New publication by Kabus et al. 2022

Tue, 12 Jul 2022 00:00:00 +0000

Desmond Kabus has published this paper with Louise Arno, Lore Leenknegt, Alexander Panfilov, and Hans Dierckx.

The full paper can be found here:
https://doi.org/10.1371/journal.pone.0271351

Cover image generated by Dall-E 3.