1
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Netaev A, Schierbaum N, Seidl K. Artificial Neural Network (ANN)-Based Determination of Fractional Contributions from Mixed Fluorophores using Fluorescence Lifetime Measurements. J Fluoresc 2024; 34:305-311. [PMID: 37212979 PMCID: PMC10808714 DOI: 10.1007/s10895-023-03261-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/04/2023] [Indexed: 05/23/2023]
Abstract
Here we present an artificial neural network (ANN)-approach to determine the fractional contributions Pi from fluorophores to a multi-exponential fluorescence decay in time-resolved lifetime measurements. Conventionally, Pi are determined by extracting two parameters (amplitude and lifetime) for each underlying mono-exponential decay using non-linear fitting. However, in this case parameter estimation is highly sensitive to initial guesses and weighting. In contrast, the ANN-based approach robustly gives the Pi without knowledge of amplitudes and lifetimes. By experimental measurements and Monte-Carlo simulations, we comprehensively show that accuracy and precision of Pi determination with ANNs and hence the number of distinguishable fluorophores depend on the fluorescence lifetimes' differences. For mixtures of up to five fluorophores, we determined the minimum uniform spacing Δτmin between lifetimes to obtain fractional contributions with a standard deviation of 5%. In example, five lifetimes can be distinguished with a respective minimum uniform spacing of approx. 10 ns even when the fluorophores' emission spectra are overlapping. This study underlines the enormous potential of ANN-based analysis for multi-fluorophore applications in fluorescence lifetime measurements.
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Affiliation(s)
- Alexander Netaev
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstr. 61, 47057, Duisburg, Germany.
| | - Nicolas Schierbaum
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstr. 61, 47057, Duisburg, Germany
| | - Karsten Seidl
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstr. 61, 47057, Duisburg, Germany
- Department of Electronic Components and Circuits and Center for Nanointegration Duisburg-Essen (CENIDE), University Duisburg-Essen, 47057, Duisburg, Germany
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2
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Cibir Z, Hassel J, Sonneck J, Kowitz L, Beer A, Kraus A, Hallekamp G, Rosenkranz M, Raffelberg P, Olfen S, Smilowski K, Burkard R, Helfrich I, Tuz AA, Singh V, Ghosh S, Sickmann A, Klebl AK, Eickhoff JE, Klebl B, Seidl K, Chen J, Grabmaier A, Viga R, Gunzer M. ComplexEye: a multi-lens array microscope for high-throughput embedded immune cell migration analysis. Nat Commun 2023; 14:8103. [PMID: 38081825 PMCID: PMC10713721 DOI: 10.1038/s41467-023-43765-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 11/17/2023] [Indexed: 12/18/2023] Open
Abstract
Autonomous migration is essential for the function of immune cells such as neutrophils and plays an important role in numerous diseases. The ability to routinely measure or target it would offer a wealth of clinical applications. Video microscopy of live cells is ideal for migration analysis, but cannot be performed at sufficiently high-throughput (HT). Here we introduce ComplexEye, an array microscope with 16 independent aberration-corrected glass lenses spaced at the pitch of a 96-well plate to produce high-resolution movies of migrating cells. With the system, we enable HT migration analysis of immune cells in 96- and 384-well plates with very energy-efficient performance. We demonstrate that the system can measure multiple clinical samples simultaneously. Furthermore, we screen 1000 compounds and identify 17 modifiers of migration in human neutrophils in just 4 days, a task that requires 60-times longer with a conventional video microscope. ComplexEye thus opens the field of phenotypic HT migration screens and enables routine migration analysis for the clinical setting.
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Affiliation(s)
- Zülal Cibir
- Institute for Experimental Immunology and Imaging, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Jacqueline Hassel
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Justin Sonneck
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
- Faculty of Computer Science, Ruhr-Universität Bochum, 44801, Bochum, Germany
| | - Lennart Kowitz
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Alexander Beer
- Institute for Experimental Immunology and Imaging, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Andreas Kraus
- Institute for Experimental Immunology and Imaging, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Gabriel Hallekamp
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Martin Rosenkranz
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Pascal Raffelberg
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Sven Olfen
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Kamil Smilowski
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Roman Burkard
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Iris Helfrich
- Department of Dermatology and Allergology, Medical Faculty of the Ludwig Maximilian University of Munich, Munich, Germany
| | - Ali Ata Tuz
- Institute for Experimental Immunology and Imaging, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Vikramjeet Singh
- Institute for Experimental Immunology and Imaging, University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Susmita Ghosh
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, 44801, Bochum, Germany
- Department of Chemistry, College of Physical Sciences, University of Aberdeen, AB24 3FX, Aberdeen, UK
| | | | | | - Bert Klebl
- Lead Discovery Center GmbH, Dortmund, Germany
| | - Karsten Seidl
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Jianxu Chen
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany
| | - Anton Grabmaier
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany
| | - Reinhard Viga
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg, Germany.
| | - Matthias Gunzer
- Institute for Experimental Immunology and Imaging, University Hospital, University of Duisburg-Essen, Essen, Germany.
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Dortmund, Germany.
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3
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Vora K, Kordas N, Seidl K. Label-Free, Impedance-Based Biosensor for Kidney Disease Biomarker Uromodulin. Sensors (Basel) 2023; 23:9696. [PMID: 38139542 PMCID: PMC10747639 DOI: 10.3390/s23249696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 11/27/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
We demonstrate the development of a label-free, impedance-based biosensor by using a passivation layer of 50-nm tantalum pentoxide (Ta2O5) on interdigitated electrodes (IDE). This layer was fabricated by atomic layer deposition (ALD) and has a high dielectric constant (high-κ), which improves the capacitive property of the IDE. We validate the biosensor's performance by measuring uromodulin, a urine biomarker for kidney tubular damage, from artificial urine samples. The passivation layer is functionalized with uromodulin antibodies for selective binding. The passivated IDE enables the non-faradaic impedance measurement of uromodulin concentrations with a measurement range from 0.5 ng/mL to 8 ng/mL and with a relative change in impedance of 15 % per ng/mL at a frequency of 150 Hz (log scale). This work presents a concept for point-of-care biosensing applications for disease biomarkers.
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Affiliation(s)
- Kunj Vora
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany; (N.K.); (K.S.)
| | - Norbert Kordas
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany; (N.K.); (K.S.)
| | - Karsten Seidl
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany; (N.K.); (K.S.)
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Forsthausweg 2, 47057 Duisburg, Germany
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4
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Alić B, Zauber T, Wiede C, Seidl K. Current methods for contactless optical patient diagnosis: a systematic review. Biomed Eng Online 2023; 22:61. [PMID: 37330551 DOI: 10.1186/s12938-023-01125-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/08/2023] [Indexed: 06/19/2023] Open
Abstract
Many countries around the world face a shortage of medical personnel, leading to work overload or even burnout. This calls for political and scientific solutions to relieve the medical personnel. The measurement of vital signs in hospitals is still predominately carried out manually with traditional contact-based methods, taking over a substantial share of the medical personnel's workload. The introduction of contactless methods for vital sign monitoring (e.g., with a camera) has great potential to relieve the medical personnel. This systematic review's objective is to analyze the state of the art in the field of contactless optical patient diagnosis. This review distinguishes itself from already existing reviews by considering studies that do not only propose the contactless measurement of vital signs but also include an automatic diagnosis of the patient's condition. This means that the included studies incorporate the physician's reasoning and evaluation of vital signs into their algorithms, allowing an automated patient diagnosis. The literature screening of two independent reviewers resulted in a total of five eligible studies. The highest number of studies (three) introduce methods for the risk assessment of infectious diseases, one study introduces a method for the risk assessment of cardiovascular diseases, and one study introduces a method for the diagnosis of obstructive sleep apnea. Overall, high heterogeneity in relevant study parameters is reported among the included studies. The low number of included studies indicates a large research gap and emphasizes the demand for further research on this emerging topic.
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Affiliation(s)
- Belmin Alić
- Department of Electrical Engineering and Information Technology, University of Duisburg-Essen, Bismarckstr. 81, 47057, Duisburg, Germany.
| | - Tim Zauber
- Department of Electrical Engineering and Information Technology, University of Duisburg-Essen, Bismarckstr. 81, 47057, Duisburg, Germany
| | - Christian Wiede
- Department of Embedded Software and Embedded AI, Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstr. 61, 47057, Duisburg, Germany
| | - Karsten Seidl
- Department of Electrical Engineering and Information Technology, University of Duisburg-Essen, Bismarckstr. 81, 47057, Duisburg, Germany
- Business Unit Health, Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstr. 61, 47057, Duisburg, Germany
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5
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Ackermann J, Stegemann J, Smola T, Reger E, Jung S, Schmitz A, Herbertz S, Erpenbeck L, Seidl K, Kruss S. High Sensitivity Near-Infrared Imaging of Fluorescent Nanosensors. Small 2023; 19:e2206856. [PMID: 36610045 DOI: 10.1002/smll.202206856] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Biochemical processes are fast and occur on small-length scales, which makes them difficult to measure. Optical nanosensors based on single-wall carbon nanotubes (SWCNTs) are able to capture such dynamics. They fluoresce in the near-infrared (NIR, 850-1700 nm) tissue transparency window and the emission wavelength depends on their chirality. However, NIR imaging requires specialized indium gallium arsenide (InGaAs) cameras with a typically low resolution because the quantum yield of normal Si-based cameras rapidly decreases in the NIR. Here, an efficient one-step phase separation approach to isolate monochiral (6,4)-SWCNTs (880 nm emission) from mixed SWCNT samples is developed. It enables imaging them in the NIR with high-resolution standard Si-based cameras (>50× more pixels). (6,4)-SWCNTs modified with (GT)10 -ssDNA become highly sensitive to the important neurotransmitter dopamine. These sensors are 1.7× brighter and 7.5× more sensitive and allow fast imaging (<50 ms). They enable high-resolution imaging of dopamine release from cells. Thus, the assembly of biosensors from (6,4)-SWCNTs combines the advantages of nanosensors working in the NIR with the sensitivity of (Si-based) cameras and enables broad usage of these nanomaterials.
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Affiliation(s)
- Julia Ackermann
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstrasse 61, 47057, Duisburg, Germany
- Department EBS, University Duisburg-Essen, Bismarkstrasse 81, 47057, Duisburg, Germany
| | - Jan Stegemann
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstrasse 61, 47057, Duisburg, Germany
- Department of Chemistry, Ruhr-University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Tim Smola
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstrasse 61, 47057, Duisburg, Germany
- Department EBS, University Duisburg-Essen, Bismarkstrasse 81, 47057, Duisburg, Germany
| | - Eline Reger
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstrasse 61, 47057, Duisburg, Germany
- Department EBS, University Duisburg-Essen, Bismarkstrasse 81, 47057, Duisburg, Germany
| | - Sebastian Jung
- ZEMOS Center for Solvation Science, Ruhr-University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Anne Schmitz
- Department of Dermatology, University Hospital Münster, Von-Esmarch-Strasse 58, 48149, Münster, Germany
| | - Svenja Herbertz
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstrasse 61, 47057, Duisburg, Germany
| | - Luise Erpenbeck
- Department of Dermatology, University Hospital Münster, Von-Esmarch-Strasse 58, 48149, Münster, Germany
| | - Karsten Seidl
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstrasse 61, 47057, Duisburg, Germany
- Department EBS, University Duisburg-Essen, Bismarkstrasse 81, 47057, Duisburg, Germany
- Center for Nanointegration Duisburg-Essen (CENIDE), Carl-Benz-Strasse 199, 47057, Duisburg, Germany
| | - Sebastian Kruss
- Fraunhofer Institute for Microelectronic Circuits and Systems, Finkenstrasse 61, 47057, Duisburg, Germany
- Department of Chemistry, Ruhr-University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
- Center for Nanointegration Duisburg-Essen (CENIDE), Carl-Benz-Strasse 199, 47057, Duisburg, Germany
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6
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Hoyer I, Utz A, Lüdecke A, Kappert H, Rohr M, Antink CH, Seidl K. Design of Hardware Accelerators for Optimized and Quantized Neural Networks to Detect Atrial Fibrillation in Patch ECG Device with RISC-V. Sensors (Basel) 2023; 23:2703. [PMID: 36904905 PMCID: PMC10007562 DOI: 10.3390/s23052703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Atrial Fibrillation (AF) is one of the most common heart arrhythmias. It is known to cause up to 15% of all strokes. In current times, modern detection systems for arrhythmias, such as single-use patch electrocardiogram (ECG) devices, have to be energy efficient, small, and affordable. In this work, specialized hardware accelerators were developed. First, an artificial neural network (NN) for the detection of AF was optimized. Special attention was paid to the minimum requirements for the inference on a RISC-V-based microcontroller. Hence, a 32-bit floating-point-based NN was analyzed. To reduce the silicon area needed, the NN was quantized to an 8-bit fixed-point datatype (Q7). Based on this datatype, specialized accelerators were developed. Those accelerators included single-instruction multiple-data (SIMD) hardware as well as accelerators for activation functions such as sigmoid and hyperbolic tangents. To accelerate activation functions that require the e-function as part of their computation (e.g., softmax), an e-function accelerator was implemented in the hardware. To compensate for the losses of quantization, the network was expanded and optimized for run-time and memory requirements. The resulting NN has a 7.5% lower run-time in clock cycles (cc) without the accelerators and 2.2 percentage points (pp) lower accuracy compared to a floating-point-based net, while requiring 65% less memory. With the specialized accelerators, the inference run-time was lowered by 87.2% while the F1-Score decreased by 6.1 pp. Implementing the Q7 accelerators instead of the floating-point unit (FPU), the silicon area needed for the microcontroller in 180 nm-technology is below 1 mm2.
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Affiliation(s)
- Ingo Hoyer
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany
| | - Alexander Utz
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany
| | - André Lüdecke
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany
| | - Holger Kappert
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany
| | - Maurice Rohr
- KIS*MED (AI Systems in Medicine), Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Christoph Hoog Antink
- KIS*MED (AI Systems in Medicine), Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Karsten Seidl
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany
- Department of Electronic Components and Circuits, University of Duisburg-Essen, 47057 Duisburg, Germany
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7
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Wichum F, Wiede C, Seidl K. Depth-Based Measurement of Respiratory Volumes: A Review. Sensors (Basel) 2022; 22:9680. [PMID: 36560048 PMCID: PMC9785978 DOI: 10.3390/s22249680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/25/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
Depth-based plethysmography (DPG) for the measurement of respiratory parameters is a mobile and cost-effective alternative to spirometry and body plethysmography. In addition, natural breathing can be measured without a mouthpiece, and breathing mechanics can be visualized. This paper aims at showing further improvements for DPG by analyzing recent developments regarding the individual components of a DPG measurement. Starting from the advantages and application scenarios, measurement scenarios and recording devices, selection algorithms and location of a region of interest (ROI) on the upper body, signal processing steps, models for error minimization with a reference measurement device, and final evaluation procedures are presented and discussed. It is shown that ROI selection has an impact on signal quality. Adaptive methods and dynamic referencing of body points to select the ROI can allow more accurate placement and thus lead to better signal quality. Multiple different ROIs can be used to assess breathing mechanics and distinguish patient groups. Signal acquisition can be performed quickly using arithmetic calculations and is not inferior to complex 3D reconstruction algorithms. It is shown that linear models provide a good approximation of the signal. However, further dependencies, such as personal characteristics, may lead to non-linear models in the future. Finally, it is pointed out to focus developments with respect to single-camera systems and to focus on independence from an individual calibration in the evaluation.
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Affiliation(s)
| | | | - Karsten Seidl
- Fraunhofer IMS, 47057 Duisburg, Germany
- Department of Electronic Components and Circuits, University of Duisburg-Essen, 47047 Duisburg, Germany
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8
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Wichum F, De Lazzari N, Götte M, David C, Wiede C, Seidl K, Tewes M. Development of an AI-supported exercise therapy for advanced cancer patients. Current Directions in Biomedical Engineering 2022. [DOI: 10.1515/cdbme-2022-1044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Exercise therapy is able to reduce symptom burden in advanced cancer patients (ACP). However, ACP daily form differs between days e.g. tumor and therapy induced. We included five ACP to classify individual exercise capacity due to cardiovascular parameters. Features are extracted from the electrocardiogram and then processed with a neural network after feature selection. Results indicate a high classification quality with an F1 score up to 0.95 ± 0.05. Including neuronal networks for training control can potentially help to manage exercise intensity ideal.
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Affiliation(s)
| | - Nico De Lazzari
- Westdeutsches Tumorzentrum, Universitatsklinikum Essen, Essen , Germany
| | - Miriam Götte
- Westdeutsches Tumorzentrum, Universitatsklinikum Essen, Essen , Germany
| | | | | | - Karsten Seidl
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg , Germany
| | - Mitra Tewes
- Westdeutsches Tumorzentrum, Universitatsklinikum Essen, Essen , Germany
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9
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Wuerich C, Wichum F, El-Kadri O, Ghantawi K, Grewal N, Wiede C, Seidl K. Blood Pressure Estimation based on Electrocardiograms. Current Directions in Biomedical Engineering 2022. [DOI: 10.1515/cdbme-2022-1015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
To overcome limitations of currently used blood pressure measurement devices in accuracy, continuity and comfort, we propose an approach for blood pressure estimation from electrocardiogram (ECG) signals only. Thereby, statistical signal features are extracted from the ECG which, eventually, serve as input to a random forest regression. The method is trained and tested on MIMIC III waveform data with a large range of blood pressure values. It obtains a mean absolute error ± standard deviation of 3.73 ± 5.19 mmHg for diastolic blood pressure (DBP) and 5.92 ± 7.23 mmHg for systolic blood pressure (SBP), with Pearson coefficients ΥDBP=0.92 and ΥSBP=0.91 respectively.
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Affiliation(s)
| | | | - Omar El-Kadri
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg , Germany
| | - Kusay Ghantawi
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg , Germany
| | - Navraj Grewal
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg , Germany
| | | | - Karsten Seidl
- Fraunhofer IMS, Duisburg , Germany
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg , Germany
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10
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Netaev A, Schierbaum N, Seidl K. Advantages and Limitations of Fluorescence Lifetime Measurements Using Single-Photon Avalanche Diode (SPAD) Array Detector: A Comprehensive Theoretical and Experimental Study. Sensors (Basel) 2022; 22:3822. [PMID: 35632231 PMCID: PMC9144122 DOI: 10.3390/s22103822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 02/01/2023]
Abstract
Fast fluorescence lifetime (FL) determination is a major factor for studying dynamic processes. To achieve a required precision and accuracy a certain number of photon counts must be detected. FL methods based on single-photon counting have strongly limited count rates because of the detector's pile-up issue and are suffering from long measurement times in the order of tens of seconds. Here, we present an experimental and Monte Carlo simulation-based study of how this limitation can be overcome using array detectors based on single-photon avalanche diodes (SPADs). We investigated the maximum count rate per pixel to determine FL with a certain precision and accuracy before pile-up occurs. Based on that, we derived an analytical expression to calculate the total measurement time which is proportional to the FL and inversely proportional to the number of pixels. However, a higher number of pixels drastically increases data rate. This can be counteracted by lowering the time resolution. We found that even with a time resolution of four times the FL, an accuracy of 10% can be achieved. Taken all together, FLs between 10 ns and 3 ns can be determined with a 300-pixel SPAD array detector with a measurement time and data rate less than 1 µs and 700 Mbit/s, respectively. This shows the enormous potential of SPAD array detector for high-speed applications requiring continuous data read out.
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Affiliation(s)
- Alexander Netaev
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany; (N.S.); (K.S.)
| | - Nicolas Schierbaum
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany; (N.S.); (K.S.)
| | - Karsten Seidl
- Fraunhofer Institute for Microelectronic Circuits and Systems, 47057 Duisburg, Germany; (N.S.); (K.S.)
- Department of Electronic Components and Circuits, University of Duisburg-Essen, 47057 Duisburg, Germany
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11
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Wichum F, Wiede C, Seidl K. Vital Signs and Sensors for Post-Exertional Malaise Prevention. Current Directions in Biomedical Engineering 2021. [DOI: 10.1515/cdbme-2021-2094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
| | | | - Karsten Seidl
- Fraunhofer IMS, 47057 Duisburg, Germany and Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg , Germany
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12
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Hegel L, Kauth A, Seidl K, Ingebrandt S. Self-Assembling Flexible 3D-MEAs for Cortical Implants. Current Directions in Biomedical Engineering 2021. [DOI: 10.1515/cdbme-2021-2091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Flexible Multi Electrode Arrays (MEAs) for neural interfacing reduce the mechanical mismatch between the soft brain tissue and the electrode arrays allowing accurate signal recordings and neural stimulation while reducing inflammatory responses. Many standard manufacturing processes of MEAs are designed for planar structures and the production of three-dimensional structures is challenging. In the present study, shaft structures with one to two circular gold microelectrodes (10 - 20 μm), each on a base polyimide (PI) substrate, were investigated. We describe a fabrication method, with which shafts made from bi-layer PI flip into the third dimension, which is a first step towards spontaneous assembly of electrodes in flexible 3D MEAs for neuroelectronic applications. A lift-up of the shafts was achieved by the contraction of a second PI layer and a steady nitrogen flow during polycondensation. This shrinking PI was structured in pits with a width of 5 - 600 μm. We achieved liftup angles of up to 42 degrees. The shaft structures can be hardened and later be used for neural implantation experiments.
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Affiliation(s)
- Lena Hegel
- Institute of Materials in Electrical Engineering 1 (IWE1), RWTH Aachen University, Aachen , Germany
| | | | - Karsten Seidl
- Fraunhofer Institute for Microelectronic Circuits and Systems, Duisburg, Germany and Department of Electronic Components and Circuits and Center for Nanointegration Duisburg- Essen (CENIDE), University of Duisburg-Essen, Duisburg , Germany
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Dogan O, Schierbaum N, Weidenmuller J, Baum M, Schroder T, Wunsch D, Gortz M, Seidl K. Miniaturized Multi Sensor Implant for Monitoring of Hemodynamic Parameters .. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2019:3823-3826. [PMID: 31946707 DOI: 10.1109/embc.2019.8856571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
t a novel miniaturized multi sensor implant for monitoring hemodynamic parameters in cardiovascular regions. Pressure measurements are performed with a highly accurate capacitive pressure sensor. An additional acceleration and temperature sensor allows compensating the impact of patient's inclination and temperature variations on the pressure measurement, respectively. A multi-functional transponder application-specific integrated circuit (ASIC) manages sensor signal processing, storage of ID, sensor calibration data, telemetric energy, and data transmission with an extracorporeal reading unit. Each component of the implant is assembled on a low temperature co-fired ceramics (LTCC) circuit board with an integrated antenna coil enabling an inductive near-field coupling at a frequency of 13.56 MHz. For a streamlined shape and reduction of thrombogenicity, the implant is encapsulated by biocompatible polymers.
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Gembaczka P, Heidemann B, Bennertz B, Groeting W, Norgall T, Seidl K. Combination of sensor-embedded and secure server-distributed artificial intelligence for healthcare applications. Current Directions in Biomedical Engineering 2019. [DOI: 10.1515/cdbme-2019-0008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
The application of artificial intelligence (AI) in the areas of health, care and social participation offers great opportunities but also involves great challenges. Extensive regulatory, ethical and data-security related requirements exist for data recording, storage and processing of respective personalized and patient-related data. “Artificial Intelligence as a Service” (AIaaS) is pushed for consumer applications by global players, which implies data storage on external database server. However, the available solutions do not meet the requirements. Moreover, small and medium-sized enterprises (SMEs) in the field of healthcare fear the loss of data sovereignty and information outflow. In this paper, we propose a secure and resource-efficient approach by embedding AI directly close to the sensor in combination with secure and distributed data processing on local server or certified “Trusted Data Center”. For this purpose, we have developed the Artificial Intelligence for Embedded Systems (AIfES) platform-independent machine learning library in C programming language. It contains a fully configurable deep artificial neural network with feedforward structure. The library can be run directly on a microcontroller and even allows to train the neural network. Possible healthcare applications include direct (pre-) processing of sensor data, sensor calibration, pattern recognition and classification.
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Affiliation(s)
- Pierre Gembaczka
- Fraunhofer Institute for Microelectronic Circuits and Systems (IMS), Duisburg , Germany
| | - Burkhard Heidemann
- Fraunhofer Institute for Microelectronic Circuits and Systems (IMS), Duisburg , Germany
| | - Bernhard Bennertz
- Fraunhofer Institute for Microelectronic Circuits and Systems (IMS), Duisburg , Germany
| | - Wolfgang Groeting
- Fraunhofer Institute for Microelectronic Circuits and Systems (IMS), Duisburg , Germany
| | - Thomas Norgall
- Fraunhofer Institute for Integrated Circuits (IIS), Erlangen , Germany
| | - Karsten Seidl
- Department of Electronic Components and Circuits, University of Duisburg-Essen, Duisburg , Germany
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Walk C, Wiemann M, Görtz M, Weidenmüller J, Jupe A, Seidl K. A Piezoelectric Flexural Plate Wave (FPW) Bio-MEMS Sensor with Improved Molecular Mass Detection for Point-of-Care Diagnostics. Current Directions in Biomedical Engineering 2019. [DOI: 10.1515/cdbme-2019-0067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
A piezoelectric FPW-sensor has been developed for a point of care device in this work. The Bio- MEMS FPW-sensor consists of an electrode configuration termed as an interdigital transducer (IDT) placed on a membrane. An input IDT excites and an output IDT detects the propagating acoustic waves through a PZT layer. Design optimizations and fabrication improvements of the FPW-sensor led to significantly reduced attenuation of the wave signal and the damping of the propagating waves between the IDTs. The working principle of mass loading is shown using different low-viscous liquids. A densitydependent sensitivity of -0.39 MHz/g/cm³ was evaluated. After the membrane was functionalized, the Bio-MEMS FPW-sensor was used to measure a specific chemokine in complex solution. By design improvements, the resolution was significantly increased from 0.7 Hz/nM to 14 Hz/nM.
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Affiliation(s)
- Christian Walk
- Fraunhofer Institute for Microelectronic Circuits and Systems (IMS), Finkenstrasse 61, Duisburg , Germany
| | | | | | | | | | - Karsten Seidl
- University of Duisburg-Essen, Dep. of Electronic Components and Circuits, Duisburg , Germany
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Christow S, Seidl K, Diener HC, Huisman MV, Lip GYH, Rauch-Kroenert U, Schuster S, Brachmann J, Muegge A, Schwimmbeck PL, Teutsch C, Senges J. 1669Increased rate of previous stroke in asymptomatic/minimally symptomatic versus symptomatic patients with newly detected atrial fibrillation in western Europe - results from the GLORIA-AF registry. Europace 2017. [DOI: 10.1093/ehjci/eux159.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Dombovári B, Fiáth R, Kerekes BP, Tóth E, Wittner L, Horváth D, Seidl K, Herwik S, Torfs T, Paul O, Ruther P, Neves H, Ulbert I. In vivo validation of the electronic depth control probes. ACTA ACUST UNITED AC 2015; 59:283-9. [PMID: 24114890 DOI: 10.1515/bmt-2012-0102] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 08/30/2013] [Indexed: 11/15/2022]
Abstract
In this article, we evaluated the electrophysiological performance of a novel, high-complexity silicon probe array. This brain-implantable probe implements a dynamically reconfigurable voltage-recording device, coordinating large numbers of electronically switchable recording sites, referred to as electronic depth control (EDC). Our results show the potential of the EDC devices to record good-quality local field potentials, and single- and multiple-unit activities in cortical regions during pharmacologically induced cortical slow wave activity in an animal model.
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Spieth S, Schumacher A, Trenkle F, Brett O, Seidl K, Herwik S, Kisban S, Ruther P, Paul O, Aarts AAA, Neves HP, Rich PD, Theobald DE, Holtzman T, Dalley JW, Verhoef BE, Janssen P, Zengerle R. Approaches for drug delivery with intracortical probes. ACTA ACUST UNITED AC 2015; 59:291-303. [PMID: 24101367 DOI: 10.1515/bmt-2012-0096] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 08/21/2013] [Indexed: 11/15/2022]
Abstract
Intracortical microprobes allow the precise monitoring of electrical and chemical signaling and are widely used in neuroscience. Microelectromechanical system (MEMS) technologies have greatly enhanced the integration of multifunctional probes by facilitating the combination of multiple recording electrodes and drug delivery channels in a single probe. Depending on the neuroscientific application, various assembly strategies are required in addition to the microprobe fabrication itself. This paper summarizes recent advances in the fabrication and assembly of micromachined silicon probes for drug delivery achieved within the EU-funded research project NeuroProbes. The described fabrication process combines a two-wafer silicon bonding process with deep reactive ion etching, wafer grinding, and thin film patterning and offers a maximum in design flexibility. By applying this process, three general comb-like microprobe designs featuring up to four 8-mm-long shafts, cross sections from 150×200 to 250×250 µm², and different electrode and fluidic channel configurations are realized. Furthermore, we discuss the development and application of different probe assemblies for acute, semichronic, and chronic applications, including comb and array assemblies, floating microprobe arrays, as well as the complete drug delivery system NeuroMedicator for small animal research.
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Albrecht V, Orth M, Kinzel L, Seidl K, Winssinger N, Friedl A, Belka C, Lauber K. OC-0619: Targeting HSP90 with the small-molecule inhibitor NW457 sensitizes human glioblastoma cells to ionizing radiation. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40611-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kinzel L, Seidl K, Winssinger N, Friedl A, Belka C, Lauber K. PD-0428: Targeting HSP90 with the novel inhibitor NW457 attenuates radioresistance of human glioblastoma cells. Radiother Oncol 2014. [DOI: 10.1016/s0167-8140(15)30533-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Seidl K, Kastner S. Exploring the contents of the category-specific attentional search template. J Vis 2012. [DOI: 10.1167/12.9.802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Seidl K, Torfs T, De Mazière PA, Van Dijck G, Csercsa R, Dombovari B, Nurcahyo Y, Ramirez H, Van Hulle MM, Orban GA, Paul O, Ulbert I, Neves H, Ruther P. Control and data acquisition software for high-density CMOS-based microprobe arrays implementing electronic depth control. ACTA ACUST UNITED AC 2012; 55:183-91. [PMID: 20441537 DOI: 10.1515/bmt.2010.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This paper presents the NeuroSelect software for managing the electronic depth control of cerebral CMOS-based microprobes for extracellular in vivo recordings. These microprobes contain up to 500 electronically switchable electrodes which can be appropriately selected with regard to specific neuron locations in the course of a recording experiment. NeuroSelect makes it possible to scan the electrodes electronically and to (re)select those electrodes of best signal quality resulting in a closed-loop design of a neural acquisition system. The signal quality is calculated by the relative power of the spikes compared with the background noise. The spikes are detected by an adaptive threshold using a robust estimator of the standard deviation. Electrodes can be selected in a manual or semi-automatic mode based on the signal quality. This electronic depth control constitutes a significant improvement for multielectrode probes, given that so far the only alternative has been the fine positioning by mechanical probe translation. In addition to managing communication with the hardware controller of the probe array, the software also controls acquisition, processing, display and storage of the neural signals for further analysis.
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Affiliation(s)
- Karsten Seidl
- Department of Microsystems Engineering (IMTEK), Microsystem Materials Laboratory, University of Freiburg, Georges-Koehler-Allee 103, Freiburg, Germany.
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Gurses AP, Xiao Y, Seidl K. Imapct of systems ambiguity on guideline compliance in intensive care units. BMC Proc 2011. [PMCID: PMC3239461 DOI: 10.1186/1753-6561-5-s6-o48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Frey O, van der Wal PD, Spieth S, Brett O, Seidl K, Paul O, Ruther P, Zengerle R, de Rooij NF. Biosensor microprobes with integrated microfluidic channels for bi-directional neurochemical interaction. J Neural Eng 2011; 8:066001. [DOI: 10.1088/1741-2560/8/6/066001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Torfs T, Aarts AAA, Erismis MA, Aslam J, Yazicioglu RF, Seidl K, Herwik S, Ulbert I, Dombovari B, Fiath R, Kerekes BP, Puers R, Paul O, Ruther P, Van Hoof C, Neves HP. Two-dimensional multi-channel neural probes with electronic depth control. IEEE Trans Biomed Circuits Syst 2011; 5:403-412. [PMID: 23852173 DOI: 10.1109/tbcas.2011.2162840] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This paper presents multi-electrode arrays for in vivo neural recording applications incorporating the principle of electronic depth control (EDC), i.e., the electronic selection of recording sites along slender probe shafts independently for multiple channels. Two-dimensional (2D) arrays were realized using a commercial 0.5- μm complementary-metal-oxide-semiconductor (CMOS) process for the EDC circuits combined with post-CMOS micromachining to pattern the comb-like probes and the corresponding electrode metallization. A dedicated CMOS integrated front-end circuit was developed for pre-amplification and multiplexing of the neural signals recorded using these probes.
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von Scheidt W, Seidl K. [What is new in the 2009 ESC guidelines?]. Herzschrittmacherther Elektrophysiol 2011; 22:113-117. [PMID: 21523455 DOI: 10.1007/s00399-011-0133-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Accepted: 02/02/2011] [Indexed: 05/30/2023]
Abstract
The 2009 ESC guideline emphasizes active risk stratification and the diagnostic strategy of prolonged ECG monitoring using an implantable loop recorder. The initial evaluation aims at establishing a prima vista diagnosis or at least a diagnostic hypothesis and risk stratification according to ECG criteria and clinical findings. Carotid sinus massage as a diagnostic procedure remains controversial. Electrophysiological study for evaluation of suspected arrhythmogenic syncope is of decreasing relevance. The loop recorder enables documentation of the rhythm during a subsequent syncope. Neurological work-up is not routinely recommended. A standardized evaluation minimizes the rate of unexplained syncopes. Therapeutic decisions include ICD or pacemaker, as indicated in cases of arrhythmogenic syncope or carotid sinus syncope, and mostly general measures in case of other reflex syncopes.
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Affiliation(s)
- W von Scheidt
- I. Medizinische Klinik, Klinikum Augsburg, Herzzentrum Augsburg-Schwaben, Deutschland.
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Biffi M, Exner D, Crossley G, Ramza B, Coutu B, Tomassoni GF, Kranig W, Voss F, Teo KM, Stuart AG, Tomassoni G, Baker J, Corbisiero R, Love C, Martin D, Niazi I, Sheppard R, Worley S, Jurkuvenas P, Sedlacek K, Malek I, Hoskova L, Kautzner J, Landolina M, Lunati M, Gasparini M, Santini M, Giannola G, Ammirati F, Ricci R, Valsecchi S, Folino AF, Vaccari D, Zanotto G, Marras E, Bertaglia M, Chiusso F, Buja G, Veneto Region HMSG, Strunk-Mueller C, Meyer Zu Vilsendorf D, Stellbrink C, Senges J, Schwab JO, Gordon BJ, Fazal IA, Plummer CJ, Mccomb JM, Kleemann T, Strauss M, Hochadel M, Seidl K, Zahn R. Hot topics: CRT and ICD therapy. Europace 2011. [DOI: 10.1093/europace/eur219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Seidl K, von Scheidt W, Pfafferott C. [Reflex syncope : diagnosis and therapy]. Herzschrittmacherther Elektrophysiol 2011; 22:93-98. [PMID: 21491128 DOI: 10.1007/s00399-011-0130-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 02/23/2011] [Indexed: 05/30/2023]
Abstract
Reflex-mediated syncope is a common cause for syncope. The first step in evaluating the cause of syncope is to assess the risk of a life-threatening cause for syncope, e.g., ventricular arrhythmias. Reflex-mediated syncope has to be differentiated from orthostatic syncope. In orthostatic syncope, there is an insufficient autonomic response. In contrast to a reflex-mediated syncope, in which the autonomic nervous system acts inappropriately, reflex-mediated syncope is classified into the classical vasovagal form, the situational form, or due to carotid sinus hypersensitivity. In the elderly, often a mixed form is present. Treatment is difficult. Most important is educating the patient and avoiding precipitating factors. Physical maneuvers, e.g., counter pressure maneuvers, are more effective than drug treatment. Permanent pacing is rarely needed. However, before indicating a pacemaker, a correlation between bradycardia and syncope should be documented. This is often only possible by implanting a monitoring device at an early stage.
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Affiliation(s)
- K Seidl
- Medizinische Klinik IV, Kardiologie mit Schwerpunkt Elektrophysiologie, Ingolstadt, Deutschland.
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Horváth D, Fiáth R, Kerekes BP, Dombovári B, Acsády L, Seidl K, Herwik S, Paul O, Ruther P, Neves HP, Ulbert I. High channel count electrode system to investigate thalamocortical interactions. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.procs.2011.09.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Patients who survive out-of-hospital cardiac arrest or symptomatic ventricular tachyarrhythmias are at considerable risk of recurrence of these events and ultimately death. The implantation of an implantable cardioverter defibrillator (ICD) in patients with previous sustained ventricular tachyarrhythmias (VT) is considered secondary prevention of sudden cardiac death. The purpose of this review is to summarize the most important trials on secondary prevention with an ICD. The results from a meta-analysis showed a relative-risk reduction of 28% in overall mortality. Compared with amiodarone, an ICD provided maximal benefit for those patients with an ejection fraction between 20% and 35%. The results of the ICD trial demonstrate that there is clear evidence for the effectiveness of an ICD in patients with unstable VT; however, for patients with stable VT the results are less clear. Data on older patients are scant, and whether the survival benefit observed in the middle aged and younger-old also extend to older elderly patients with a more limited life span is less clear. Therefore, as the population becomes older, it is important to evaluate the safety, effectiveness, and the cost effectiveness of ICD implantation in this population. Guidelines are important and helpful to guide clinical decisions, but the indication for an ICD still remains an individual decision after evaluation of the risks and benefits for the individual patient. However, the patient needs to be involved, which emphasizes the importance of dialogue between the patient and physician.
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Affiliation(s)
- K Seidl
- Zentrum für Herzrhythmusstörungen Ludwigshafen, Bremserstr. 79, 67063, Ludwigshafen, Deutschland.
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Kleemann T, Becker T, Strauss M, Dyck N, Weisse U, Saggau W, Burkhardt U, Seidl K. Prevalence of bacterial colonization of generator pockets in implantable cardioverter defibrillator patients without signs of infection undergoing generator replacement or lead revision. Europace 2009; 12:58-63. [DOI: 10.1093/europace/eup334] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Toquero Ramos J, Monivas Palomero V, Castro Urda V, Mariona Montero VA, Fernandez Lozano I, Nombela Franco L, Sufrate Sorzano E, Pulpon L, Gadler F, Noelker G, Kranig W, Seidl K, Brandt J, Holmstrom N, Sperzel J, Mont I Girbau J, Lemke B, Merkely B, Zhang Y, Kayser T, Averina V, Wold N, Bloch Thomsen P, Braunschweig F, Vanderheyden M, Houben R, Verstreken S, Stahlberg M, Reiters P, Miranda R, Alvarenga C, Almeida AR, Celeiro M, Almeida S, Brandao Alves L, Cotrim C, Carrageta M. Poster session 3: Device and heart failure monitoring. Europace 2009. [DOI: 10.1093/europace/euq226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Zahn R, Schuster S, Schiele R, Seidl K, Voigtländer T, Hauptmann KE, Gottwik M, Berg G, Kunz T, Gieseler U, Senges J. Differences in patients with acute myocardial infarction treated with primary angioplasty or thrombolytic therapy. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group. Clin Cardiol 2009; 22:191-9. [PMID: 10084061 PMCID: PMC6655809 DOI: 10.1002/clc.4960220307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Little is known about the differences in patients with acute myocardial infarction (AMI) treated with primary angioplasty or intravenous thrombolysis in clinical practice. METHODS In all, 5,906 patients with AMI were registered by the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) study. Of these, 491 (8.3%) patients were treated with primary angioplasty and 2,817 (47.7%) with intravenous thrombolysis. RESULTS There were only minor differences in baseline characteristics between the two groups. Prehospital delay time (median) was longer in the angioplasty group than in the thrombolysis group (161 vs. 120, p = 0.001), as was door-to-treatment time (88 vs. 30 min; p = 0.001). Patients treated with primary angioplasty more often had contraindications for thrombolytic therapy (12.9 vs. 6%, p = 0.001) and received beta blockers (65 vs. 58.1%, p = 0.004), heparin (98.2 vs. 91.6%, p = 0.001), angiotensin-converting enzyme (ACE) inhibitors (64.8 vs. 50%, p = 0.001) and "optimal" concomitant medication (56.4 vs. 42.9%, p = 0.001) more often. Univariate analysis showed a significant lower incidence of heart failure (5.3 vs. 16.5%, p = 0.001), postinfarct angina (7.3 vs. 16.4%, p = 0.001), in-hospital death (7.9 vs. 11.7%, p = 0.015) and the combined end point (21.6 vs. 40.3%, p = 0.001) in these patients. Stepwise logistic regression analysis revealed optimal concomitant medication [odds ratio (OR) = 0.94, 95% confidence interval (CI): 0.89-0.98) and the type of revascularization (OR = 0.65, 95% CI: 0.58-0.73) to be associated with a significant reduction in the incidence of the combined end point. Similar results were obtained in all predefined subgroups. CONCLUSIONS In clinical practice, patients treated with primary angioplasty are more often treated with beta blockers and ACE inhibitors than patients treated with intravenous thrombolysis. Thus, the selection of patients and the type of revascularization contributes to the reduction in mortality, overt heart failure, and postinfarct angina in these patients.
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Affiliation(s)
- R Zahn
- Herzzentrum Ludwigshafen, Kardiologie, Ludwigshafen, Germany
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Kleemann T, Becker T, Strauss M, Schneider S, Seidl K. Prevalence and clinical impact of left atrial thrombus and dense spontaneous echo contrast in patients with atrial fibrillation and low CHADS2 score. European Journal of Echocardiography 2009; 10:383-8. [DOI: 10.1093/ejechocard/jen256] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Spieth S, Schumacher A, Seidl K, Hiltmann K, Haeberle S, McNamara R, Dalley JW, Edgley SA, Ruther P, Zengerle R. Robust microprobe systems for simultaneous neural recording and drug delivery. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/978-3-540-89208-3_582] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Kisban S, Herwik S, Seidl K, Rubehn B, Jezzini A, Umilta MA, Fogassi L, Stieglitz T, Paul O, Ruther P. Microprobe Array with Low Impedance Electrodes and Highly Flexible Polyimide Cables for Acute Neural Recording. ACTA ACUST UNITED AC 2007; 2007:175-8. [DOI: 10.1109/iembs.2007.4352251] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Kleemann T, Becker T, Dönges K, Vater M, Gut B, Schneider S, Senges J, Seidl K. The prognostic impact of successful cardioversion of atrial fibrillation in patients with organic heart disease. Clin Res Cardiol 2006; 96:103-8. [PMID: 17115325 DOI: 10.1007/s00392-006-0466-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Accepted: 10/02/2006] [Indexed: 11/26/2022]
Abstract
The aim of the study was to evaluate the prognostic impact of successful cardioversion (CV) compared to failed CV in patients with atrial fibrillation (AF) and organic heart disease. A total of 471 consecutive patients with organic heart disease from the prospective single center anticoagulation registry ANTIK who underwent CV of AF or atrial flutter were analyzed. 417 patients (89%) could be successfully cardioverted. In 54 patients (11%) CV failed, these patients remained in AF. After 5 years there were 92 (24%) deaths among patients with restored sinus rhythm at index admission and 20 (38%) deaths among those who remained in AF after CV (unadjusted OR 1.9, 95% CI 1.1-3.6). After adjustment for age, gender and ejection fraction, successful CV was not associated with a beneficial effect on mortality (OR 0.72, 95% CI 0.43-1.21). Thus, successful CV is not an independent predictor of mortality on multivariate analysis. However, it remains a marker for a better prognosis in patients with organic heart disease as these patients have a lower unadjusted longterm mortality.
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Affiliation(s)
- T Kleemann
- Herzzentrum Ludwigshafen, Klinikum Ludwigshafen, Medizinische Klinik B, Germany.
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Seidl K, Schuchert A, Tebbenjohanns J, Hartung W. [Commentary on the guidelines the diagnosis and the therapy of syncope--the European Society of Cardiology 2001 and the update 2004]. ACTA ACUST UNITED AC 2005; 94:592-612. [PMID: 16142520 DOI: 10.1007/s00392-005-0230-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- K Seidl
- Herzzentrum Ludwigshafen, Medizinische Klinik B (Kardiologie, Pneumologie, Angiologie), Bremserstr. 79, 67063 Ludwigshafen, Germany.
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Zahn R, Vogt A, Zeymer U, Gitt AK, Seidl K, Gottwik M, Weber MA, Niederer W, Mödl B, Engel HJ, Tebbe U, Senges J. In-hospital time to treatment of patients with acute ST elevation myocardial infarction treated with primary angioplasty: determinants and outcome. Results from the registry of percutaneous coronary interventions in acute myocardial infarction of the Arbeitsgemeinschaft Leitender Kardiologischer Krankenhausarzte. Heart 2005; 91:1041-6. [PMID: 16020592 PMCID: PMC1769038 DOI: 10.1136/hrt.2004.045336] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
OBJECTIVE To determine the predictors of time between presentation and primary angioplasty and the influence of this delay time on in-hospital mortality in clinical practice. DESIGN Analysis of data from the registry of percutaneous coronary interventions in acute myocardial infarction of the Arbeitsgemeinschaft Leitender Kardiologischer Krankenhausärzte (ALKK). PATIENTS Data of 4815 patients registered at 80 hospitals between 1994 and 2000 were analysed. RESULTS Mean age of the patients was 61.4 (12.5) years. Cardiogenic shock was present in 14.1%. Mean time from admission to primary angioplasty ("door to angiography" time) was 83 (122) minutes. Logistic regression analysis showed the presence of a bundle branch block (odds ratio (OR) 1.95, 95% confidence interval (CI) 1.15 to 3.29), prior coronary artery bypass grafting (OR 1.67, 95% CI 1.08 to 2.59), pre-hospital delay > 3 hours (OR 1.61, 95% CI 1.37 to 1.89), and female sex (OR 1.21, 95% CI 1.01 to 1.45) to be independently associated with longer door to angiography times, whereas a higher hospital volume of performing primary angioplasty (OR 0.53, 95% CI 0.46 to 0.62) and the year of the investigation (OR 0.96, 95% CI 0.92 to 1.00) were independently associated with shorter door to angiography times. Independent predictors of in-hospital mortality were cardiogenic shock (41.6% v 4.0% without cardiogenic shock, p < 0.0001), technical success (29.2% with TIMI (thrombolysis in myocardial infarction) flow < 3 v 6.5% with TIMI flow 3, p < 0.0001), age (16.5% > or = 70 years v 6.6% < 70, p < 0.0001), three vessel disease (16.5% v 6.8% with < 3 vessel disease, p < 0.0001), anterior location of infarction (12% v 7.4% without anterior infarction, p < 0.0001), year of inclusion (adjusted OR 0.92 per year, p = 0.011), and volume of primary angioplasty at the hospital (11% for < 20 angioplasty procedures/year v 8.3% for > or = 20/year, p = 0.027) but not the door to angiography time (adjusted OR 1.14 per tertile, p = 0.397). CONCLUSIONS In current clinical practice in Germany median door to angiography time is quite short (83 (122) minutes). Some patients and hospital factors are independently associated with a longer door to angiography time. Within the observed short in-hospital delays door to angiography time did not influence in-hospital mortality. However, efforts to keep them as short as possible should be continued.
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Affiliation(s)
- R Zahn
- Herzzentrum, Kardiologie, Ludwigshafen, Germany.
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Seidl K. Trial finds that enoxaparin may be the preferred drug for initiating anticoagulation in atrial fibrillation. Evid Based Cardiovasc Med 2004; 8:206-7; discussion 208. [PMID: 16379934 DOI: 10.1016/j.ebcm.2004.06.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
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Mark B, Schneider S, Schiele R, Taubert G, Kilkowski C, Seidl K, Nagel D, Seiler D, Senges J, Zahn R. Comparison of different cardiac markers in monitoring percutaneous coronary interventions with frequent use of stents and gpIIbIIIa-antagonists. ACTA ACUST UNITED AC 2003; 92:1018-24. [PMID: 14663612 DOI: 10.1007/s00392-003-1020-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2003] [Accepted: 09/08/2003] [Indexed: 10/26/2022]
Abstract
Studies from the early 1990s found elevations of creatine kinase (CK) and its isoform CK-MB in 5-30% of patients after PCI, indicating minor myocardial damage. Less is known about the influence of modern improved PCI-techniques on the frequency of elevated cardiac markers and the correlation between different commonly used markers, especially cardiac troponins. From 1997 to 2001, 1486 patients undergoing PCI during the regular working hours were included in the prospective "Ludwigshafen Infarctlet Registry". Myocardial infarction in the past 48 hours was an exclusion criterion. Clinical and procedural data were documented. Follow-up data were obtained from discharge up to one year. PCI-related elevations of troponin T were found in 18%, of total-CK in 11%, of CK-MB in 33% and of myoglobin in 23% of cases. The correlation between the different markers was poor. Compared with troponin T, other markers showed low sensitivity (total-CK 58%, CK-MB 27%, myoglobin 22%) and, especially total-CK, low specificity. Stenting, side branch occlusion or major dissection, complex lesion morphology, gpIIbIIIa-antagonist application, proximal stenosis and unstable angina were independent predictors of an elevated troponin T in multivariate analysis. Due to this weak correlation between more specific and sensitive troponins and the other markers, troponins are preferred in monitoring after PCI. In addition to lesion characteristics, particularly stenting is associated with an increased rate of elevated troponin.
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Affiliation(s)
- B Mark
- Herzzentrum Ludwigshafen, Kardiologie, Klinikum der Stadt Ludwigshafen, Bremserstrasse 79, 67073 Ludwigshafen, Germany.
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Drögemüller A, Schultz H, Senges J, Seidl K. Kathetertechnische Bergung der Innenwendel einer separierten Schrittmacher-Elektrode in der Arteria pulmonalis. ACTA ACUST UNITED AC 2003; 92:884-8. [PMID: 14579054 DOI: 10.1007/s00392-003-0980-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2003] [Accepted: 06/11/2003] [Indexed: 11/25/2022]
Abstract
This case report describes a successful catheter-based rescue of a split pacemaker lead in the pulmonary artery-as an unusual reason for pleural effusion. Hemorrhagic pleural effusion was diagnosed 7 months after pacemaker exchange due to battery depletion and lead replacement due to an increase of the stimulation threshold. The reason for the pleural effusion was a splitting of the inactive electrode lead into shaft and inner fragment which was dislocated into the pulmonary artery and micro-perforated. The dislocated lead was retrieved using biopsy forceps and a gooseneck snare. Finally it was capped and fixed. Even in an anatomically difficult position, catheter-based rescue is feasible. Not in all pacemaker lead types is cutting the adapter of the inactive pacemaker leads recommendable.
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Affiliation(s)
- A Drögemüller
- Herzzentrum Ludwigshafen, Kardiologie, Bremserstr. 79, 67063 Ludwigshafen, Germany.
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Seidl K, Drögemüller A, Rameken M, Schneider S, Zahn R, Senges J. Two year follow-up in 643 patients with non-invasively unexplained syncope and therapy guided by electrophysiologic study. ACTA ACUST UNITED AC 2003; 92:852-61. [PMID: 14579050 DOI: 10.1007/s00392-003-0969-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2002] [Accepted: 05/22/2003] [Indexed: 10/26/2022]
Abstract
AIM Although it has become standard practice to perform electrophysiologic studies in patients with unexplained syncope, limited information exists on prognosis after therapy guided by electrophysiologic studies. METHODS AND RESULTS Electrophysiologic studies were performed in 643 patients with unexplained syncope. Electrophysiologic studies revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. An ejection fraction </= 40%, a PR-interval > 2 s and injury are helpful parameters in predicting a positive electrophysiologic study. There was no difference regarding cumulative 2-year survival rate after therapy guided by positive electrophysiologic study compared to patients with negative electrophysiologic study. The cumulative 2-year survival free-of-syncope rate was significantly higher after therapy guided by electrophysiologic study compared to patients with negative electrophysiologic findings-for patients with organic heart disease (71.3% vs 48.5%, p < 0.001) and patients without disease (91.3% vs. 65.2%, p < 0.001). Using a logistic regression model, a positive electrophysiologic study was associated with a favorable outcome; multiple syncopal events or organic heart disease were associated with an unfavorable outcome. CONCLUSION The cumulative overall 2-year surival free-of-syncope rate is significantly higher in patients after therapy guided by electrophysiologic study compared to patients with negative electrophysiologic findings.
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MESH Headings
- Adult
- Aged
- Arrhythmias, Cardiac/diagnosis
- Arrhythmias, Cardiac/mortality
- Arrhythmias, Cardiac/physiopathology
- Arrhythmias, Cardiac/therapy
- Cardiac Catheterization
- Cardiac Pacing, Artificial
- Diagnosis, Differential
- Disease-Free Survival
- Echocardiography
- Electrocardiography, Ambulatory
- Female
- Follow-Up Studies
- Heart Conduction System/physiopathology
- Heart Diseases/diagnosis
- Heart Diseases/mortality
- Heart Diseases/physiopathology
- Heart Diseases/therapy
- Humans
- Male
- Middle Aged
- Prognosis
- Stroke Volume/physiology
- Syncope/etiology
- Tilt-Table Test
- Ventricular Dysfunction, Left/diagnosis
- Ventricular Dysfunction, Left/mortality
- Ventricular Dysfunction, Left/therapy
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Affiliation(s)
- K Seidl
- Herzzentrum Ludwigshafen, Kardiologie, Bremserstr. 79, 67063 Ludwigshafen, Germany.
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Zahn R, Fraiture B, Siegler KE, Schneider S, Gitt AK, Seidl K, Gandjour A, Wendland G, Vogt S, Lauterbach KW, Senges J. Effectiveness of the glycoprotein IIb/IIIa antagonist abciximab during percutaneous coronary interventions (PCI) in clinical practice at a single high-volume center. Z Kardiol 2003; 92:438-44. [PMID: 12819992 DOI: 10.1007/s00392-003-0928-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Randomized controlled trials (RCTs) showed that the glycoprotein (GP) IIb/IIIa antagonist abciximab is able to reduce ischemic complications during percutaneous transluminal coronary interventions (PCIs). Its effectiveness in daily clinical practice in unselected patients remains to be determined. DESIGN, SETTING AND PATIENTS From 7/1997 until 12/2000, 3310 PCIs were performed at the Heart Center Ludwigshafen. Out of them, 1076 (32.5%) patients were nonrandomly treated with a GP IIb/ IIa antagonist. Patients who were treated with abciximab were matched with patients not treated with abciximab. The matching procedure resulted in 590 pairs of patients. RESULTS Patients treated with abciximab were more likely to have a history of former PCI (13.7% versus 8.8%, p=0.008) or coronary artery bypass surgery (19.2% versus 12.8%, p=0.003). There were no differences in concomitant diseases, left ventricular function, number of vessels diseased or target vessel. However, patients treated with abciximab had a higher rate of more complex stenosis (> or =B2; 94.4% versus 80.7%, p<0.001) and a longer x-ray exposition (median 486 s versus 422 s, p<0.001). Treatment with abciximab was associated with a significantly lower incidence of the combined endpoint of death, reinfarction or stroke during the hospital stay (2.4% versus 4.4%, p=0.039). This was confirmed after adjustment for confounding parameters (p=0.034). There was no increase in the rate of severe bleeding in the abciximab group (p=0.347). After one year the rates for the combined endpoint were 8.5% in the control group and 6.2% in the abciximab group (univariate analysis, p=0.134; multivariate analysis, p=0.143). CONCLUSION Treatment with abciximab during PCI in daily clinical practice at a high volume center in patients with a high rate of acute coronary syndromes seems to be as effective as shown in RCTs.
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Affiliation(s)
- R Zahn
- Herzzentrum Ludwigshafen, Kardiologie, Bremserstrasse 79, 67063 Ludwigshafen, Germany.
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Seidl K, Drögemüller A, Rameken M, Zahn R, Schneider S, Senges J. Usefulness of a non-invasive scoring system in predicting the outcome of electrophysiologic studies in non-invasively unexplained syncope. Z Kardiol 2003; 92:147-54. [PMID: 12596076 DOI: 10.1007/s00392-003-0897-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND An electrophysiologic study is a useful method to clarify the cause of non-invasively unexplained syncope in 18-60% of patients. However, it is invasive with possible procedure-related complications. Therefore, it would be helpful to identify patients in whom an electrophysiologic study is useful for diagnosis of syncope. METHODS Patients with unexplained syncope were prospectively enrolled in a registry, if an electrophysiologic study was performed. The study group comprised of 643 consecutive patients. RESULTS The electrophysiologic study revealed conduction abnormalities and tachyarrhythmias accounting for syncope in 35% of patients. Using a logistic regression model, history of injury during syncope (p<0.001), ejection fraction < or =40% (p=0.03), and PR interval >0.2 s (p=0.001) were independent predictors of an abnormal electrophysiologic study. These three clinical and easily measurable variables were entered into a scoring system. The maximal score consisted of 3 points. A score of >1 predicts a positive electrophysiologic study result in more than 70% of patients with non-invasively unexplained syncope. CONCLUSION Electrophysiologic abnormalities were detected in 35% of patients with unexplained syncope. A history of injury, ejection fraction < or =40% and a PR interval >200 ms were independent predictors for a positive electrophysiologic study.
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Affiliation(s)
- K Seidl
- Herzzentrum Ludwigshafen, Kardiologie, Bremserstr. 79, 67063 Ludwigshafen, Germany.
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Drögemüller A, Seidl K, Schiele R, Schneider S, Gitt A, Gottwik M, von Leitner ER, Poppe C, Rettig-Stürmer G, Senges J. Prognostic value of non-sustained ventricular tachycardias after acute myocardial infarction in the thrombolytic era: importance of combination with frequent ventricular premature beats. Z Kardiol 2003; 92:164-72. [PMID: 12596078 DOI: 10.1007/s00392-003-0890-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE of this study was to re-evaluate the association between ventricular arrhythmias and long-term mortality after acute myocardial infarction (AMI) in the thrombolytic era. METHODS MITRA (maximal individual therapy in patients with AMI) is a multicenter registry of 54 hospitals in Germany investigating patients with AMI. RESULTS 2420 patients received Holter ECG. Positive Holter ECG was defined: > or =10 ventricular premature beats (VPB)/h, or > or =4 couplets/d, or > or =1 non-sustained ventricular tachycardia (nsusVT)/d, or their combination. Mortality rates (median 17 months) were 6.5% without ventricular arrhythmias, with > or =10 VPB/h 15.2% and with the combination of > or =10 VPB/h plus either > or =4 couplets/d or > or =1 nsusVT/d 23.4%. In multivariate analysis, none of the ventricular arrhythmias alone correlated with mortality. There was a significant association between mortality and the combination of > or =10 VPB/h plus > or =4 couplets/d (OR 2.3) or > or =10 VPB/h plus > or =1 nsusVT/d (OR 2.8). CONCLUSION Non-sustained VTs are only associated with poor prognosis if combined with frequent VPBs.
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Affiliation(s)
- A Drögemüller
- Herzzentrum Ludwigshafen, Kardiologie, Bremserstr. 79 67063 Ludwigshafen, Germany.
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Fox D, Morita Y, Gupta R, Seidl K, Mcdonagh K. Arthritis Res Ther 2003; 5:12. [DOI: 10.1186/ar813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
Despite the demonstrated efficacy of implantable cardioverter defibrillators (ICDs) in reducing sudden and total mortality in selected patients, their implantation rates vary greatly between countries. In the United States, implantation rate is 228 implants per million inhabitants compared to only 45 implants per million in Western Europe. The differences in the ICD use may be explained by following factors: manner in which sudden cardiac death is perceived by politicians and physicians (sudden cardiac death is perceived as a "nice way of dying"); differences in indications; physicians' information; prevalence of coronary artery disease; sudden cardiac death survival rates; perceived reliability of alternative treatment (namely antiarrhythmics including amiodarone); economic backgrounds; and health care politics. Furthermore, the cost of this treatment strategy must be considered. This issue has been raised because generalization of ICD use in patients matching clinical characteristics of patients enrolled in the primary prevention trials may represent a significant economic burden to be added to the already overloaded health care system. This low acceptance may not be entirely related to budget constraint but also to the perceived efficacy of ICDs by physicians and health authorities.
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Affiliation(s)
- K Seidl
- Herzzentrum Ludwigshafen, Department of Clinical Electrophysiology, Ludwigshafen, Germany. seidlk@ klilu.de
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Schwacke H, Brandt A, Rameken M, Vater M, Fischer F, Senges J, Seidl K. [Long-term outcome of AV node modulation in 387 consecutive patients with AV nodal reentrant tachycardia]. Z Kardiol 2002; 91:389-95. [PMID: 12132285 DOI: 10.1007/s00392-002-0792-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
UNLABELLED Aim of this study was to assess the long-term results of AV-node modulation in patients with AV nodal reetrant tachycardia. METHODS From December 1991 until September 1999, AV node modulation (ablation of the fast pathway or ablation/modification of the slow pathway) was performed in 387 consecutive patients with clinically apparent AV nodal reentrant tachycardia. Follow-up data was available in 95% of patients with a mean of 41 +/- 26 months after ablation. RESULTS Acute success rate was 97%. During long-term follow-up recurrence rate was 7.4% without any difference between fast and slow pathway ablation. Recurrence occurred in 23% of patients with persistent dual AV node physiology after ablation (modification of the slow pathway) in contrast to 3% without dual AV node physiology (ablation of the slow pathway) (p = 0.002). The presence of a dual AV node physiology after slow pathway modulation was the only predictor of recurrence during long-term follow-up. The complication rate was 5.7%. The incidence of complete heart block was 1% without any difference between fast and slow pathway ablation. CONCLUSIONS Catheter modulation of the AV node for the treatment of AV nodal reentrant tachycardia is effective and safe. During long-term follow-up, the recurrence rate was low. Modulation of the slow pathway is associated with a significantly higher recurrence rate than ablation of the slow pathway.
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Affiliation(s)
- H Schwacke
- Herzzentrum Ludwigshafen Bremserstr. 79 67063 Ludwigshafen, Germany.
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Drögemüller A, Kilkowski A, Senges J, Seidl K. [Catheter ablation of ventricular tachycardia in the left ventricular outflow tract beyond the aortic valve]. Z Kardiol 2002; 91:410-5. [PMID: 12132288 DOI: 10.1007/s00392-002-0775-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This case report describes successful catheter ablation of an ectopic focus in the left ventricular outflow tract just beyond the aortic valve. Extended pace-mapping revealed a focus about 1 cm beneath the origin of the left coronary artery--above the base of the left coronary cusp. During a follow-up of 1 year no further spontaneous episode of ventricular tachycardia was documented. This case report describes an unusual localization of an idiopathic ventricular tachycardia and it demonstrates that radiofrequency catheter ablation can be done even in a critical position.
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Affiliation(s)
- A Drögemüller
- Herzzentrum Ludwigshafen, Kardiologie Bremserstr. 79 67063 Ludwigshafen, Germany.
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