Novel MRI technique reveals subtypes of paramagnetic rim lesions and predicts 5-year rim disappearance. - In: Multiple sclerosis journal, ISSN 1477-0970, Bd. 29 (2023), 2, P031
https://doi.org/10.1177/13524585231169437
Fast fictitious surface charge method for calculation of torso surface potentials. - In: IEEE Xplore digital library, ISSN 2473-2001, (2023), insges. 4 S.
Well-established forward modeling methods in electrocardiography (ECG) require fine meshes to calculate the electric scalar potential at the body surface with high accuracy. We introduce a fast fictitious surface charge method (FSCM) with local mesh refinement and smart calculations of elements interactions which improves the accuracy of the calculations and, at the same time, preserves the performance speed.
https://doi.org/10.1109/COMPUMAG56388.2023.10411804
Linear versus quadratic detrending in analyzing simultaneous changes in DC-EEG and transcutaneous pCO2. - In: 2023 45th Annual International Conference of the IEEE Engineering in Medicine & Biology Conference (EMBC), (2023), insges. 4 S.
Physiological direct current (DC) potential shifts in electroencephalography (EEG) can be masked by artifacts such as slow electrode drifts. To reduce the influence of these artifacts, linear detrending has been proposed as a pre-processing step. We considered quadratic detrending, which has hardly been addressed for ultralow frequency components in EEG. We compared the performance of linear and quadratic detrending in simultaneously acquired DC-EEG and transcutaneous partial pressure of carbon dioxide during two activation methods: hyperventilation (HV) and apnea (AP). Quadratic detrending performed significantly better than linear detrending in HV, while for AP, our analysis was inconclusive with no statistical significance. We conclude that quadratic detrending should be considered for DC-EEG preprocessing.
https://doi.org/10.1109/EMBC40787.2023.10340855
Entrainment and resonance effects with a new mobile audio-visual stimulation device. - In: 2023 45th Annual International Conference of the IEEE Engineering in Medicine & Biology Conference (EMBC), (2023), insges. 4 S.
Entrainment and photic driving effects triggered by repetitive visual stimulation are long-established in clinical and therapeutic scenarios. Nonetheless, such stimulation patterns are typically bound to stationary clinical and laboratory applications. We investigated the effects of repetitive stimulation with a new dynamic auditory-visual stimulation pattern using a novel consumer-grade stimulation device for home application. Fourteen volunteers (study group) received 16 sessions of combined auditory-visual stimulation during four weeks. An additional control group (seven volunteers) received auditory-only stimulation for two sessions. From 64-channel electroencephalography recordings, we compared individual alpha peak frequencies (iAPF) between week one and week four as well as power values from the time-frequency analysis. The novel stimulation device yielded stable entrainment and resonance effects for all investigated stimulation frequencies. Both groups showed no differences in their iAPFs between weeks one and four. The power comparison suggests that there are similar entrainment and resonance effects in week one and week four within the study group. We conclude that the novel portable consumer-grade stimulation device is suitable for home-based auditory-visual stimulation leading to consistent entrainment and resonance effects over the course of 16 stimulation sessions over four weeks.
https://doi.org/10.1109/EMBC40787.2023.10341051
Optical character recognition for medical records digitization with deep learning. - In: 2023 IEEE International Conference on Image Processing, (2023), S. 3260-3263
The importance of document digitization has increased due to recent technological advancements, including in the medical field. Digitization of medical records plays a vital role in the healthcare sector as it helps expedite emergency treatment. Due to the scarcity of published studies and public German textual resources, a medical records database with German handwriting was collected and digitized. In this study, document digitization was accomplished by implementing deep learning, region of interest (ROI) detection, and optical character recognition (OCR) on a dataset containing medical forms filled with German and English characters. To find the best model for ROI detection, YOLOv5, and SSDResNet50 models were utilized and compared with YOLOv5 producing a better mean average precision (mAP) of 0.91. OCR was then carried out on the output from YOLOv5 with two different methods again for comparison. The Gated-CNN-BLSTM algorithm yielded a character error rate (CER) of 9%, while transformer-based OCR (TrOCR) achieved a CER of 6%. The proposed system could be implemented and further tested in local hospitals, with the OCR dictionary being expandable to include other Roman character-based languages.
https://doi.org/10.1109/ICIP49359.2023.10222038
N˚69 - N-Interval fourier transform analysis of cortical evoked responses - Median and tibial SEPs. - In: Clinical neurophysiology, ISSN 1872-8952, Bd. 150 (2023), S. e93-e94
https://doi.org/10.1016/j.clinph.2023.03.076
Vascular MPI: visualization and tracking of rapidly moving samples. - In: International journal on magnetic particle imaging, ISSN 2365-9033, Bd. 9 (2023), 1, 2303044, S. 1-3
Magnetic Particle Imaging (MPI) is a fast imaging technique for the visualization of the distribution of superparamagnetic iron-oxide nanoparticles (SPIONs) in 3D. For spatial encoding, a field free area is moved rapidly through the field of view (FOV) generating a localized signal. Fast moving samples, e.g., a bolus of SPIONs traveling through the large veins in the human body carried by blood flow with velocities in the order of ˜45 cm/s and higher, cause temporal blurring in MPI measurements using common sequences and reconstruction techniques. This hampers the evaluation of dynamics of rapidly moving samples. In this abstract, initial results of rapidly moving samples in form of SPION boluses visualized within an MPI scanner are shown.
https://doi.org/10.18416/IJMPI.2023.2303044
TMS and fMRI-based localization of the attention network. - In: Brain stimulation, ISSN 1876-4754, Bd. 16 (2023), 1, S. 291-292
Richtiger Name des 4. Verfassers: Jens Haueisen
https://doi.org/10.1016/j.brs.2023.01.517
Closed-loop robotic TMS motor mapping using an online-optimized sampling scheme. - In: Brain stimulation, ISSN 1876-4754, Bd. 16 (2023), 1, S. 320
https://doi.org/10.1016/j.brs.2023.01.593
Magnetic microspheres for MPI and magnetic actuation. - In: International journal on magnetic particle imaging, ISSN 2365-9033, Bd. 8 (2022), 1, 2203006, S. 1-4
Magnetic particle imaging (MPI) systems do not only allow for the visualization of the distribution of magnetic nanoparticles, but the magnetic fields of an MPI scanner can be also used to apply a magnetic force or a torque. This enables the actuation of magnetic particles. Here, we demonstrate that magnetic microspheres (MMS) are well suitable candidates for the actuation and visualization with MPI. By means of magnetic particle spectrometer (MPS) measurements, a promising imaging performance of the MMS for MPI was confirmed. We show that MMS can be actuated by rotating focus fields of a preclinical MPI scanner. Since the used MMS can carry therapeutics, which can be released by means of hyperthermia, this approach paves the way towards an MPI monitored targeted drug delivery.
https://doi.org/10.18416/IJMPI.2022.2203006