News on Hans Dierckx' Research Page

Publication in Chaos

Tue, 02 Dec 2025 00:00:00 +0000

When electrical waves do not propagate coherently through the heart, a dangerous arrhythmia can form.

Due to the apparent complexity of these patterns, it is challenging to see what is going on, and to devise appropriate intervention. Especially the chaotic phase during which wave breaks form and either vanish or organise into spirals, is hard to grasp.

Recently, we found that in complex excitation patterns, special points exist: heads (end points of fronts), tails (end points of wave backs) and pivots (end points of conduction blocks). We showed that these points persist over time and space as they possess topological charge.

In our paper in Chaos, resulting from the Master’s thesis of Aaron Gobeyn, we design and implement fast algorithms for the detection of head and tail quasiparticles.

Figure reprinted from Gobeyn et al., Chaos 35, 123105 (2025), licensed under a Creative Commons Attribution (CC BY) license

Outreach story in LUMC newsletter

Tue, 21 Oct 2025 00:00:00 +0000

Following our recent publication in Physical Review Letters, the LUMC press office translated the results into an accessible story, which you can read here.

Publication in Physical Review Letters

Thu, 18 Sep 2025 00:00:00 +0000

There are many open questions on how the patterns of electrical activity are organized inside the cardiac wall. Our paper in Physical Review Letters sheds new light on this: the conduction blocks that create and sustain arrhythmia can be quite general surfaces, with handles and side branches. The special points (quasi-particles, cardions) that we identified in surface recordings, now become three types of closed curves.

We also got two mathematical bonuses: the twiston seen in simulations by Fenton and Karma (Chaos, 1998) is a cardion of co-dimension 3, and one can create an untwisted scroll wave that rotates around a M"obius strip!

In view of future applications, we present a mathematically consistent way to classify and analyse three-dimensional patterns in excitable media.

Desmond defends his PhD

Tue, 10 Jun 2025 00:00:00 +0000

After four years of intense research, Desmond Kabus received his dual PhD degree from KU Leuven and Leiden University Medical Centre. Congratulations on behalf of your promoters Hans Dierckx and Daniel Pijnappels!

Lecture on digital innovation in healthcare

Thu, 22 May 2025 00:00:00 +0000

I was invited by colleague Dr. Edris Mahtab to give a talk about digital innovation for the Innovation Day of the Cardiothoracic Surgeons from the University Medical Centers of Amsterdam and Leiden.

Moving to LUMC

Thu, 16 Jan 2025 00:00:00 +0000

Here I am even closer to experimental data and clinicians. I am part of the Experimental Cardiology Laboratory, working closely with Prof. Daniel Pijnappels, Dr. Twan de Vries and Dr. Vincent Portero.

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

LUMC Fellowship awarded

Tue, 19 Nov 2024 00:00:00 +0000

I received the 2024 LUMC fellowship, a competitive grant that will enable me to build my own research line at the Leiden University Medical Center. The topic of this grant is Creation of predictive in silico models from cardiac tissues and patient recordings to unravel arrhythmia mechanisms.

Attending CINC and Cardiac Physiome Conferences

Fri, 13 Sep 2024 00:00:00 +0000

I traveled to Germany to speak at two consecutive conferences: Computing in Cardiology (CINC, Karlsruhe) and the Cardiac Physiome Meeting (Freiburg)

SIAM-UQ24 conference

Tue, 27 Feb 2024 00:00:00 +0000

Within the BICEPS project, we want to incorporate uncertainty quantification into cardiac modeling. This conference was a perfect opportunity to present our first results. Being part of a mini-symposium about …, two presentations uncovered our work on the project so far. Marie Cloet gave a talk about … . Maarten Volkaerts, member of the NUMA research team and also part of the BICEPS project, presented his results on … .

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

Junior College 2024

Tue, 23 Jan 2024 00:00:00 +0000

Video from a previous edition:

Seminar talk by Dylan Vermoortele

Mon, 11 Dec 2023 00:00:00 +0000

In his talk he elucidated how Sudden Cardiac Death is a complex interplay of different systems. Dylan demonstrated the methods he developed to study these systems in an experimental setting.

Many thanks to Dylan for coming over to Kortrijk and to the physics group at Kulak, with specifically Dr. Wouter Deleersnyder for organizing this seminar.

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.

Lecture of Hans Dierckx at the Bio Dynamics Days 2023

Wed, 21 Jun 2023 00:00:00 +0000

Are you doing research in mathematical biology? Here are five ideas that can be helpful along the way.

Analytical solutions are still valuable
Biology exhibits non-linear structures whose slow drift can be found via perturbation theory
Geometric principles are out there
Break free from old concepts if they don’t work
Can we spot overarching ideas?

5th OpenCARP user meeting

Fri, 26 May 2023 00:00:00 +0000

Check out this event

SIAM-DS23 conference

Mon, 15 May 2023 00:00:00 +0000

Visit of Thorrez' Lab

Fri, 28 Apr 2023 00:00:00 +0000

Junior College 2023

Tue, 10 Jan 2023 00:00:00 +0000

Video from last year’s edition:

Day of Science 2022

Sun, 27 Nov 2022 00:00:00 +0000

Saturday, 27th of November was a day attributed to science in Flanders. Here at kulak, many groups organised or workshop, show or exhibition to promote science and let the general public have a taste of the wonderful science that is done. HeartKOR was present as well with a presentation on the basics of the heart and cardiac arrhythmia, some posters and some interactive simulations both in 2D and 3D (By Fenton and Abouzar Kaboudian) so people could play with adding obstacles in a cardiac medium and generate electrical patterns in the heart connected to arrhythmia like spiral waves.

More info…

Look here as well…

Research stay in Bordeaux

Thu, 13 Oct 2022 00:00:00 +0000

“An amazing experience and amazing people! Liryc is a place where modeling meets the clinic every day. Inspiring! I look forward to working with them on phase defects during arrhythmia.”

Louise

Scientist@School

Wed, 12 Oct 2022 00:00:00 +0000

In January, Lore went to Sint-Paulus College in Wevelgem to give a lecture about some of our research done here at HeartKOR! They learned how mathematics and physics can be used to help solve cardiac arrhythmias.

The fifth grade students of this high school, together with their teacher, Lore Seynhaeve, tried to recreate a spiral wave!

Not only the Sint-Paulus College will be able to enjoy our lectures. Lore is also going to the Broederschool in Roeselare, and Louise will present our research to the young minds of school Atheneum Bellevue Izegem . This is all part of the program Scientist@School, organized by KU Leuven. Pictures of these event can be found in the foto album.

Louise went to Atheneum Bellevue in Izegem to give the same lecture about some of our research done here at HeartKOR! They learned how mathematics and physics can be used to help solve cardiac arrhythmias.

Mathematics exhibition "Imaginary"

Fri, 07 Oct 2022 00:00:00 +0000

More info

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.

Summer School in Bordeaux

Sun, 03 Jul 2022 00:00:00 +0000

Experiments in the Gasthuisberg hospital

Wed, 01 Jun 2022 00:00:00 +0000

Lab visit in Leiden

Thu, 07 Apr 2022 00:00:00 +0000

Desmond is doing a joint PhD with LUMC in Leiden. Louise joined him for two days and visited the lab there! There, she could see the very thin slab of cardiac cell cultures and how they are contracting while electrical pulses were passing through them. A very exciting and interesting visit! We hope to go there soon to visit Desmond and the lab there with the entire team!

EHRA conference 2022

Tue, 05 Apr 2022 00:00:00 +0000

Desmond Kabus and Lore Leenknegt have presented e-posters at the EHRA conference in Copenhagen in April!

Desmond showed how to reliably detect phase defect lines in the centres of spiral waves. These lines can be used to get additional information about the electrical properties of heart muscle tissue. Lore presented on the effect of the wall thickness on the properties of the electrogram signal and how this can be analytically approximated.

Luckily, Nathan and Louise joined them at the conference, making it a very interesting, educational and fun experience!

DAE meets HeartKOR and KULAK

Thu, 31 Mar 2022 00:00:00 +0000

Your browser doesn't support HTML5 video. Here is a link to the video instead.

Project by Judith Verdonck

The electrical waves controlling the heart beat behave much like forest fires, just on completely different time scales. Video by Judith Verdonck for her graduation project at Digital Arts and Entertainment:

Project by Robbe Casier

If trees would regrow faster, forest fires could travel in never-ending spiral waves. Terrifying! This is much like spiral waves that form in the heart during cardiac arrhythmias. Video by Robbe Casier for his graduation project at Digital Arts and Entertainment:

Junior College 2022

Thu, 03 Mar 2022 00:00:00 +0000

This month, the online lectures of junior college are published! Prof. Hans Dierckx, teamleader of heartKOR gave a lecture on cardiac arrhythmias and how this very hot and relevant research area needs mathematics and physics! Check out this lecture here.

This is an initiative that allows students in third grade to check out different subjects and get acquainted with scientific research and teaching style.

Children's university

Wed, 03 Nov 2021 00:00:00 +0000

Tell me more…

Research Day

Wed, 15 Sep 2021 00:00:00 +0000

More about this event…

Can we solve heart problems with math?

Wed, 03 Mar 2021 00:00:00 +0000

Link to Article

News on Hans Dierckx' Research Page

Publication in Chaos

Outreach story in LUMC newsletter

Publication in Physical Review Letters

Desmond defends his PhD

Lecture on digital innovation in healthcare

Moving to LUMC

Feynman-like diagrams in the heart!

LUMC Fellowship awarded

Attending CINC and Cardiac Physiome Conferences

SIAM-UQ24 conference

New publication by Kabus et al. 2024

Junior College 2024

Seminar talk by Dylan Vermoortele

New publication by Cloet et al. 2023

New publication by Li et al. 2023 including Hans Dierckx

New publication by Leenknegt et al. 2023

Lecture of Hans Dierckx at the Bio Dynamics Days 2023

5th OpenCARP user meeting

SIAM-DS23 conference

Visit of Thorrez' Lab

Popular science article about digital twins

Junior College 2023

Day of Science 2022

Research stay in Bordeaux

Scientist@School

Mathematics exhibition "Imaginary"

New publication by Kabus et al. 2022

Summer School in Bordeaux

Experiments in the Gasthuisberg hospital

Lab visit in Leiden

EHRA conference 2022

DAE meets HeartKOR and KULAK

Project by Judith Verdonck

Project by Robbe Casier

Junior College 2022

Children's university

Research Day

Can we solve heart problems with math?