Stefan Pollnow

Stefan Pollnow
Karlsruhe Institute of Technology | KIT · Institute of Biomedical Engineering (IBT)

Dr.-Ing.

About

22
Publications
2,127
Reads
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42
Citations
Citations since 2016
19 Research Items
40 Citations
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20162017201820192020202120220246810
20162017201820192020202120220246810
Additional affiliations
August 2014 - present
Karlsruhe Institute of Technology
Position
  • Scientific Staff
Description
  • Simultaneous fluorescence optical and electrical characterization of atrial tissue
May 2012 - July 2014
Technische Universität Ilmenau
Position
  • Student
Education
August 2014 - July 2018
Karlsruhe Institute of Technology
Field of study
  • Medical measurement technology / Digital signal processing
May 2012 - July 2014
Technische Universität Ilmenau
Field of study
  • Biomedical Engineering
October 2008 - April 2012
Technische Universität Ilmenau
Field of study
  • Biomedical Engineering

Publications

Publications (22)
Article
Full-text available
Conduction velocity (CV) slowing is associated with atrial fibrillation (AF) and reentrant ventricular tachycardia (VT). Clinical electroanatomical mapping systems used to localize AF or VT sources as ablation targets remain limited by the number of measuring electrodes and signal processing methods to generate high-density local activation time (L...
Chapter
Atrial fibrillation (AF) is the most common cardiac arrhythmia seen in the clinical practice, and treatments with antiarrhythmic drugs are of limited effectiveness. Radiofrequency catheter ablation (RFA) has been widely accepted as a strategy to treat AF. In this study, we analyzed the electrophysiological impact of different RFA strategies by vary...
Article
Full-text available
Background Radiofrequency ablation (RFA) is a common approach to treat cardiac arrhythmias. During this intervention, numerous strategies are applied to indirectly estimate lesion formation. However, the assessment of the spatial extent of these acute injuries needs to be improved in order to create well-defined and durable ablation lesions. Metho...
Article
Full-text available
Cardiac arrhythmias such as atrial fibrillation occur frequently in industrialized countries. Radiofrequency ablation (RFA) is a standard treatment if drug therapy fails. This minimally invasive surgery aims at stabilizing the heart rhythm on a permanent basis. However, the procedure commonly needs to be repeated because of the high recurrence rate...
Conference Paper
Full-text available
Today, patients suffering from atrial arrhythmias like atrial flutter (AFlut) or atrial fibrillation (AFib) are examined in the EP-lab (electrophysiology lab) in order to understand and treat the disease. Multichannel catheters are advanced into the atria in order to measureelectric signals at manyintracardiacpositions simultaneously. Complementary...
Article
Optical mapping is widely used as a tool to investigate cardiac electrophysiology in ex vivo preparations. Digital filtering of fluorescence-optical data is an important requirement for robust subsequent data analysis and still a challenge when processing data acquired from thin mammalian myocardium. Therefore, we propose and investigate the use of...
Conference Paper
Full-text available
Hyperthermia during radiofrequency ablation causes reversible and irreversible changes of the electrophysiological properties of cardiac tissue. However, the mechanisms are incompletely understood. We studied changes of conduction velocity (CV) in rat myocardium under hyperthermic conditions from macroscopic to microscopic scale by using simultaneo...
Article
Full-text available
Radiofrequency ablation is the gold standard for treating cardiac arrhythmias. However, the success rate of this procedure depends on numerous parameters. Wet lab experiments provide the opportunity to investigate cardiac electrophysiology under reproducible conditions. To evaluate the electrophysiological changes of ablated myocardium in these stu...
Article
Full-text available
Recent studies about the development of endocardial radiofrequency (RF) ablation lesions (ALs) tried to identify reliable electrogram (EGM) markers for assessment of lesion transmurality. Additional clinically relevant information for physicians can be provided by examining endocardial EGM parameters like signal morphology, amplitude or time points...
Article
Full-text available
Lung ventilation and perfusion analyses using chest imaging methods require a correct segmentation of the lung to offer anatomical landmarks for the physiological data. An automatic segmentation approach simplifies and accelerates the analysis. However, the segmentation of the lungs has shown to be difficult if collapsed areas are present that tend...
Article
Full-text available
Cardiac arrhythmias are a widely spread disease in industrialized countries. A common clinical treatment for this disease is radiofrequency ablation (RFA), in which high frequency alternating current creates a lesion on the myocardium. However, the formation of the lesion is not entirely understood. To obtain more information about ablation lesions...
Article
Full-text available
Radiofrequency ablation has become a first line approach for curative therapy of many cardiac arrhythmias. Various existing catheter designs provide high spatial resolution to identify the best spot for performing ablation and to assess lesion formation. However, creation of transmural and non-conducting ablation lesions requires usage of catheters...
Data
In this scenario, the ablation catheter was initially placed in orthogonal orientation (O) at healthy myocardium (tilting angle 90°). To achieve gentle contact between catheter and myocardium in parallel orientation (P, tilting angle 0°), the distance between myocardium and catheter was set to 0.6 mm in O. We varied the tilting angles between 90° (...
Conference Paper
Full-text available
Radiofrequency ablation (RFA) is a widely used clinical treatment for many types of cardiac arrhythmias. However, nontransmural lesions and gaps between linear lesions often lead to recurrence of the arrhythmia. Intracardiac electrograms (IEGMs) provide real-time information regarding the state of the cardiac tissue surrounding the catheter tip. Ne...
Conference Paper
Full-text available
Radiofrequency ablation (RFA) is a standard clinical procedure for treating many cardiac arrhythmias. In order to increase the success rate of this treatment, the evaluation of lesion development with the help of intracar-diac electrogram (EGM) criteria has to be improved further. We are investigating in-vitro the electrophysiological characteristi...
Article
Transabdominal reflective pulse oximetry can be one solution to determine non-invasivly the oxygen saturation of the fetal arterial blood with minimized risk for mother and fetus. For evaluating algorithms to seperate the fetal and maternal pulse waves a new physical-like phantom with two independent artificial blood circuits and different sensors...
Conference Paper
Arterial oxygen saturation of the fetus is an important parameter for monitoring its physical condition. During labor and delivery the transabdominal non-invasive fetal pulse oximetry could minimize the risk for mother and fetus, compared to other existing invasive examination methods. In this contribution, we developed a physical-like phantom to i...
Conference Paper
Power supply of intelligent implants, as for example, an intraocular pressure sensor, cannot be handled with conven-tional voltage sources due to their limited durability. Energy harvesting on the contrary could be a conceivable solution to this task converting mechanical energy of fast eye movements into electrical energy. In this contribution, we...

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Projects

Project (1)
Project
Measuring the electrical activity of vital cardiac preparations by using simultaneously fluorescence-optical and electrical mapping. The main objective of this research project is to investigate the electrophysiological characteristics of cardiac tissue with ablation lesions.