Cardiac arrhythmia arises from complex and highly dynamic electrical activity in the heart. Medical Delta PhD-candidate Rui Guan (TU Delft, Electrical Engineering, Mathematics and Computer Science) developed microelectronics‑based sensing technologies that allow this activity to be measured with much higher spatial and temporal resolution than conventional devices.
This spring, Guan successfully defended her dissertation, which she wrote as part of the scientific program Medical Delta Cardiac Arrhythmia Lab. Guan is one of the (partially) Medical Delta funded PhD-candidates of Medical Delta’s 2019-2024 program.
By combining advanced chip technology with high‑density microelectrode arrays (MEAs), Guan showed that cardiac electrophysiology can be studied across multiple biological scales and experimental settings. This includes in vivo measurements on the whole heart surface during open‑chest surgery, in vitro recordings from living myocardial slices, and single‑cell‑resolution measurements in cardiac cell cultures. These measurements reveal electrical patterns and mechanisms that cannot be detected using standard tools such as the electrocardiogram (ECG).
To support this, Guan developed a set of integrated MEA systems and complementary metal-oxide semiconductor (CMOS) circuits that enable multichannel biopotential recording, impedance and capacitance measurements, and electrical stimulation. With these special chips and measurement systems, one can simultaneously measure electrical signals from cells and stimulate the cells electrically. Each system is adapted to its biological scale while following a common microelectronics‑driven design approach.
“The research demonstrates that microelectronics can provide new insight into how cardiac arrhythmia forms, spreads, and evolves,” Guan says. “These high‑density platforms can significantly advance cardiac research and are relevant for diagnostics, drug development, and disease modeling, helping to bridge the gap between laboratory studies and clinical practice.”
Why is this important for further research and for the treatment of cardiac arrhythmia?
“Cardiac arrhythmia, including atrial fibrillation, is not just a single-cell electrical problem, but the result of complex interactions across cells, tissue, and the whole heart. However, current diagnostic and research techniques often lack sufficient spatial resolution and large-area sensing coverage to reliably identify the sources of these abnormalities.
This research supports the goals of the Medical Delta Cardiac Arrhythmia Lab by connecting microelectronics innovation directly with cardiology. High‑resolution electrical measurements, combined with information about tissue condition and cell coupling, provide a more complete understanding of how arrhythmia develop.
This research connects microelectronics innovation directly with cardiology
In the long term, this knowledge can lead to more precise and personalized diagnosis and treatment. For example, it can improve guidance during catheter ablation procedures, reduce recurrence, and ultimately help lower the health risks associated with cardiac arrhythmia.”
What impact could this ultimately have on researchers, healthcare providers, and patients?
“For researchers, these technologies enable more detailed and realistic models for studying cardiac arrhythmia, supporting both fundamental research and drug development. For healthcare providers, improved measurement and interpretation of cardiac electrical activity can increase diagnostic accuracy and improve the effectiveness of procedures, especially in complex cases. For patients, the expected impact is better care, including more accurate diagnosis, more effective treatment, and fewer repeat interventions. This contributes to more personalized and efficient management of cardiac arrhythmia.”
How did the interdisciplinary set-up of the Medical Delta program contribute to your research?
“Interdisciplinary collaboration was not optional, but essential for this healthcare chip development work. A clear example is the development of a single‑cell‑resolution CMOS microelectrode array chip, which required close interaction between engineering, biology, and clinical expertise.
At TU Delft, I worked with my technology promotor prof. dr. ir. Frans Widdershoven to translate biological and clinical needs into microelectronic architectures capable of ultra-low-power, low‑noise biopotential recording, impedance measurements, and stimulation in conductive biological environments. At NXP Semiconductors, in collaboration with professor Widdershoven and dr. Robert van Veldhoven, I applied industrial‑grade analog and mixed‑signal design techniques to ensure the system was scalable and robust, enabling its use both in clinical settings and in laboratory research, including drug screening and disease modeling. And at Erasmus MC, under the guidance of my biomedical promotor prof. dr. Natasja de Groot, clinicians and researchers provided biological insight and clinically relevant questions to ensure that the technology addressed real medical needs.
This continuous interaction ensured that the technology matched biological reality, that experiments were supported by optimized electronics, and that the results were relevant for real applications.
The success of the project relied on ongoing collaboration rather than separate work in different fields. Medical Delta provided the structure and environment that made this collaboration possible. Through the Medical Delta Cardiac Arrhythmia Lab program, engineers, clinicians, and industry partners worked together on shared challenges. This ensured that the technology development remained closely linked to real clinical questions, while providing access to the necessary expertise and facilities. Medical Delta played an important role in keeping the research both scientifically strong and relevant for society.”
What did you personally learn from this PhD process?
“It taught me how to work at the intersection of technology, science, and real‑world application. I learned how to connect cutting‑edge semiconductor technology with real medical needs through collaboration across industry and academia, helping to push the boundaries of chip technology to improve diagnosis, enable better health monitoring, and support more advanced treatment.
I also developed strong skills in communicating across disciplines, translating complex problems into clear engineering solutions, and designing technology not only for performance, but also for the reliability, safety, and scalability of medical devices. Most importantly, I developed a mindset focused on taking real social responsibility to improve human life beyond the laboratory.
As I continue my career as an Analog Circuit Engineer in the healthcare segment at NXP Semiconductors, this experience shapes how I approach collaboration, impact, responsibility, and leadership in healthcare chip technology, and will guide me throughout my career.”
