Abstract: Detection of fetal brain signals in fetal magnetoencephalographic recordings is - due to the low signal to noise ratio - challenging for researchers in this field. Up to now, state of the art is a manual evaluation of the signal. To make the evaluation more reproducible and less time consuming, an approach using Principal Component Analysis is introduced. Locations of the channels of most importance for the first three principal components are taken into account and their possibility of resembling brain activity evaluated. Data with auditory stimulation are taken for this analysis and trigger averaged signals from the channels selected as brain activity (manually & automatically) compared. Comparisons are done with regard to their average baseline activity, activity during a window of interest and timing and amplitude of their highest auditory event-related peak. The number of evaluable data sets showed to be lower for the automated compared to manual approach but auditory event-related peaks did not differ significantly in amplitude or timing and in both cases there was a significant activity change following the tone event. The given results and the advantage of reproducibility make this method a valid alternative.

@inproceedings{moser2019automated, title = {Automated Detection of Fetal Brain Signals with Principal Component Analysis}, author = {Moser, Julia and Sippel, Katrin and Schleger, Franziska and Preißl, Hubert}, booktitle = {2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)}, pages = {6549–6552}, year = {2019}, doi = {10.1109/EMBC.2019.8857283}, organization = {IEEE} }

Abstract: Fetal magnetoencephalography (fMEG) is a method to record human fetal brain signals in pregnant mothers. Nevertheless the amplitude of the fetal brain signal is very small and the fetal brain signal is overlaid by interfering signals mainly caused by maternal and fetal heart activity. Several methods are used to attenuate the interfering signals for the extraction of the fetal brain signal. However currently used methods are often affected by a reduction of the fetal brain signal or redistribution of the fetal brain signal. To overcome this limitation we developed a new fully automated procedure for removal of heart activity (FAUNA) based on Principal Component Analysis (PCA) and Ridge Regression. We compared the results with an orthogonal projection (OP) algorithm which is widely used in fetal research. The analysis was performed on simulated data sets containing spontaneous and averaged brain activity. The new analysis was able to extract fetal brain signals with an increased signal to noise ratio and without redistribution of activity across sensors compared to OP. The attenuation of interfering heart signals in fMEG data was significantly improved by FAUNA and supports fully automated evaluation of fetal brain signal.

@inproceedings{sippel2019fullz, title = {Fully Automated Subtraction of Heart Activity for Fetal Magnetoencephalography Data}, author = {Sippel, Katrin and Moser, Julia and Schleger, Franziska and Escalona-Vargas, Diana and Preissl, Hubert and Rosenstiel, Wolfgang and Spüler, Martin}, booktitle = {2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)}, pages = {5685–5689}, year = {2019}, doi = {10.1109/EMBC.2019.8856603}, organization = {IEEE} }

Abstract: Background and objective: Fetal magnetoencephalography (fMEG) is a method for recording fetal brain signals, fetal and maternal heart activity simultaneously. The identification of the R-peaks of the heartbeats forms the basis for later heart rate (HR) and heart rate variability (HRV) analysis. The current procedure for the evaluation of fetal magnetocardiograms (fMCG) is either semi-automated evaluation using template matching (SATM) or Hilbert transformation algorithm (HTA). However, none of the methods available at present works reliable for all datasets. Methods: Our aim was to develop a unitary, responsive and fully automated R-peak detection algorithm (FLORA) that combines and enhances both of the methods used up to now. Results: The evaluation of all methods on 55 datasets verifies that FLORA outperforms both of these methods as well as a combination of the two, which applies in particular to data of fetuses at earlier gestational age. Conclusion: The combined analysis shows that FLORA is capable of providing good, stable and reproducible results without manual intervention.

@article{sippel2019fully, title = {Fully automated r-peak detection algorithm (flora) for fetal magnetoencephalographic data}, author = {Sippel, Katrin and Moser, Julia and Schleger, Franziska and Preissl, Hubert and Rosenstiel, Wolfgang and Spüler, Martin}, journal = {Computer methods and programs in biomedicine}, volume = {173}, pages = {35–41}, year = {2019}, doi = {10.1016/j.cmpb.2019.02.016}, publisher = {Elsevier} }

Abstract: urpose On-road testing is considered the standard for assessment of driving performance; however, it lacks standardization. In contrast, driving simulators provide controlled experimental settings in a virtual reality environment. This study compares both testing conditions in patients with binocular visual field defects due to bilateral glaucomatous optic neuropathy or due to retro-chiasmal visual pathway lesions. Methods Ten glaucoma patients (PG), ten patients with homonymous visual field defects (PH), and 20 age- and gender-matched ophthalmologically normal control subjects (CG and CH, respectively) participated in a 40-min on-road driving task using a dual brake vehicle. A subset of this sample (8 PG, 8 PH, 8 CG, and 7 CH) underwent a subsequent driving simulator test of similar duration. For both settings, pass/fail rates were assessed by a masked driving instructor. Results For on-road driving, hemianopia patients (PH) and glaucoma patients (PG) showed worse performance than their controls (CH and CG groups): PH 40%, CH 30%, PG 60%, CG 0%, failure rate. Similar results were obtained for the driving simulator test: PH 50%, CH 29%, PG 38%, CG 0%, failure rate. Twenty-four out of 31 participants (77%) showed concordant results with regard to pass/fail under both test conditions (p > 0.05; McNemar test). Conclusions Driving simulator testing leads to results comparable to on-road driving, in terms of pass/fail rates in subjects with binocular (glaucomatous or retro-chiasmal lesion-induced) visual field defects. Driving simulator testing seems to be a well-standardized method, appropriate for assessment of driving performance in individuals with binocular visual field loss.

@article{ungewiss2018agreement, title = {Agreement of driving simulator and on-road driving performance in patients with binocular visual field loss}, author = {Ungewiss, Judith and Kübler, Thomas and Sippel, Katrin and Aehling, Kathrin and Heister, Martin and Rosenstiel, Wolfgang and Kasneci, Enkelejda and Papageorgiou, Eleni and Group, Simulator/On-road Study and others}, journal = {Graefe’s archive for clinical and experimental ophthalmology}, volume = {256}, number = {12}, pages = {2429–2435}, year = {2018}, doi = {10.1007/s00417-018-4148-9}, publisher = {Springer} }

@inproceedings{WTCKWE092015, author = {Fuhl, Wolfgang and Kübler, Thomas C. and Sippel, Katrin and Rosenstiel, Wolfgang and Kasneci, Enkelejda}, title = {ExCuSe: Robust Pupil Detection in Real-World Scenarios}, booktitle = {16th International Conference on Computer Analysis of Images and Patterns (CAIP 2015)}, year = {2015}, month = {sep}, month_numeric = {9} }

@inproceedings{WTCKWE082015, author = {Fuhl, Wolfgang and Kübler, Thomas C. and Sippel, Katrin and Rosenstiel, Wolfgang and Kasneci, Enkelejda}, title = {Arbitrarily shaped areas of interest based on gaze density gradient}, booktitle = {European Conference on Eye Movements, ECEM 2015}, year = {2015}, month = {aug}, month_numeric = {8} }

@book{TCKWGJRWE2015, author = {Kübler, Thomas C. and Sippel, Katrin and Fuhl, Wolfgang and Schievelbein, G. and Aufreiter, J. and Rosenberg, Raphael and Rosenstiel, Wolfgang and Kasneci, Enkelejda}, title = {Analysis of eye movements with Eyetrace}, publisher = {Biomedical Engineering Systems and Technologies. Communications in Computer and Information Science (CCIS). Springer International Publishing}, year = {2015}, volume = {574}, pages = { 458-471} }

@article{EKKMWUE092014, author = {Kasneci, Enkelejda and Sippel, Katrin and Aehling, Kathrin and Heister, Martin and Rosenstiel, Wolfgang and Schiefer, Ulrich and Papageorgiou, Eleni}, title = {Homonymous Visual Field Loss and its Impact on Visual Exploration - A Supermarket Study}, journal = {Translational Vision Science & Technology}, year = {2014}, month = {sep}, volume = {In Press}, month_numeric = {9} }

@article{KEKMWUE082014, author = {Sippel, Katrin and Kasneci, Enkelejda and Aehling, Kathrin and Heister, Martin and Rosenstiel, Wolfgang and Schiefer, Ulrich and Papageorgiou, Eleni}, title = {Binocular Glaucomatous Visual Field Loss and Its Impact on Visual Exploration - A Supermarket Study}, journal = {PLoS ONE}, year = {2014}, month = {aug}, volume = {9}, number = {8}, pages = { e106089}, month_numeric = {8} }

@article{EKKMWUE022014, author = {Kasneci, Enkelejda and Sippel, Katrin and Aehling, Kathrin and Heister, Martin and Rosenstiel, Wolfgang and Schiefer, Ulrich and Papageorgiou, Eleni}, title = {Driving with Binocular Visual Field Loss? A Study on a Supervised On-road Parcours with Simultaneous Eye and Head Tracking}, journal = {PLoS ONE}, year = {2014}, month = {feb}, volume = {9}, number = {2}, pages = { e87470}, month_numeric = {2} }

@inproceedings{UTCMKKEWE092013, author = {Schiefer, Ulrich and Kübler, Thomas C. and Heister, Martin and Aehling, Kathrin and Sippel, Katrin and Papageorgiou, Eleni and Rosenstiel, Wolfgang and Tafaj, Enkelejda}, title = {Auswirkungen des visuellen Explorationsverhaltens von Patienten mit binokularen Gesichtsfelddefekten auf alltagsrelevante Tätigkeiten - Ergebnisse der TUTOR-Studie}, booktitle = {111. DOG-Kongress}, year = {2013}, month = {sep}, month_numeric = {9} }

@inproceedings{UKMKCKEWE2012, author = {Schiefer, Ulrich and Sippel, Katrin and Heister, Martin and Aehling, Kathrin and Heine, C. and Januschowski, K. and Papageorgiou, Eleni and Rosenstiel, Wolfgang and Tafaj, Enkelejda}, title = {Erste Ergebnisse der TUTOR-Pilotstudie: Binokulare Gesichtsfeldausfälle und deren Auswirkungen auf die visuelle Exploration}, booktitle = {Ophthalmologische Nachrichten, 09.2012}, year = {2012} }