The Experts below are selected from a list of 87 Experts worldwide ranked by ideXlab platform
David G Benditt - One of the best experts on this subject based on the ideXlab platform.
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ECG Electrode reversals an opportunity to learn from mistakes
Journal of Cardiovascular Electrophysiology, 2018Co-Authors: Scott Sakaguchi, Jeremy Sandberg, David G BendittAbstract:An ECG with an "odd" appearance may raise the suspicion that ECG recording Electrodes may have been reversed. Odd appearances include unexpected Q-waves or R-waves, markedly isoelectric leads, and abrupt changes from previous ECGs. A few examples of ECG Electrode reversal provide the opportunity to review some fundamental principles of ECG recording. Some ECG Electrode reversals will invert the QRS complex recorded in a lead. Other ECG leads may be affected in a manner that initially may seem unexpected. These patterns may be understood upon reviewing the genesis of the "unipolar" leads, particularly the "augmented" leads. Recording an ECG between Electrodes placed on the two legs will produce a nearly isoelectric tracing. Elucidation of Electrode reversals is often less difficult than it seems, may present an enjoyable intellectual challenge, and provides insight into the process of ECG recording.
Ramun Schmid - One of the best experts on this subject based on the ideXlab platform.
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simulating arbitrary Electrode reversals in standard 12 lead ECG
Sensors, 2019Co-Authors: Vessela Krasteva, Irena Jekova, Ramun SchmidAbstract:Electrode reversal errors in standard 12-lead electrocardiograms (ECG) can produce significant ECG changes and, in turn, misleading diagnoses. Their detection is important but mostly limited to the design of criteria using ECG databases with simulated reversals, without Wilson’s central terminal (WCT) potential change. This is, to the best of our knowledge, the first study that presents an algebraic transformation for simulation of all possible ECG cable reversals, including those with displaced WCT, where most of the leads appear with distorted morphology. The simulation model of ECG Electrode swaps and the resultant WCT potential change is derived in the standard 12-lead ECG setup. The transformation formulas are theoretically compared to known limb lead reversals and experimentally proven for unknown limb–chest Electrode swaps using a 12-lead ECG database from 25 healthy volunteers (recordings without Electrode swaps and with 5 unicolor pairs swaps, including red (right arm—C1), yellow (left arm—C2), green (left leg (LL) —C3), black (right leg (RL)—C5), all unicolor pairs). Two applications of the transformation are shown to be feasible: ‘Forward’ (simulation of reordered leads from correct leads) and ‘Inverse’ (reconstruction of correct leads from an ECG recorded with known Electrode reversals). Deficiencies are found only when the ground RL Electrode is swapped as this case requires guessing the unknown RL Electrode potential. We suggest assuming that potential to be equal to that of the LL Electrode. The ‘Forward’ transformation is important for comprehensive training platforms of humans and machines to reliably recognize simulated Electrode swaps using the available resources of correctly recorded ECG databases. The ‘Inverse’ transformation can save time and costs for repeated ECG recordings by reconstructing the correct lead set if a lead swap is detected after the end of the recording. In cases when the Electrode reversal is unknown but a prior correct ECG recording of the same patient is available, the ‘Inverse’ transformation is tested to detect the exact swapping of the Electrodes with an accuracy of (96% to 100%).
Marcel Fajkus - One of the best experts on this subject based on the ideXlab platform.
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non invasive fetal monitoring a maternal surface ECG Electrode placement based novel approach for optimization of adaptive filter control parameters using the lms and rls algorithms
Sensors, 2017Co-Authors: Radek Martinek, Radana Kahankova, Homer Nazeran, Jaromir Konecny, J Jezewski, Petr Janku, Petr Bilik, Jan Zidek, Jan Nedoma, Marcel FajkusAbstract:This paper is focused on the design, implementation and verification of a novel method for the optimization of the control parameters (such as step size μ and filter order N) of LMS and RLS adaptive filters used for noninvasive fetal monitoring. The optimization algorithm is driven by considering the ECG Electrode positions on the maternal body surface in improving the performance of these adaptive filters. The main criterion for optimal parameter selection was the Signal-to-Noise Ratio (SNR). We conducted experiments using signals supplied by the latest version of our LabVIEW-Based Multi-Channel Non-Invasive Abdominal Maternal-Fetal Electrocardiogram Signal Generator, which provides the flexibility and capability of modeling the principal distribution of maternal/fetal ECGs in the human body. Our novel algorithm enabled us to find the optimal settings of the adaptive filters based on maternal surface ECG Electrode placements. The experimental results further confirmed the theoretical assumption that the optimal settings of these adaptive filters are dependent on the ECG Electrode positions on the maternal body, and therefore, we were able to achieve far better results than without the use of optimization. These improvements in turn could lead to a more accurate detection of fetal hypoxia. Consequently, our approach could offer the potential to be used in clinical practice to establish recommendations for standard Electrode placement and find the optimal adaptive filter settings for extracting high quality fetal ECG signals for further processing. Ultimately, diagnostic-grade fetal ECG signals would ensure the reliable detection of fetal hypoxia.
Sampi Mehta - One of the best experts on this subject based on the ideXlab platform.
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point of technique reducing wrong side errors for endourology procedures
Urology, 2014Co-Authors: Adam Alleemudder, Phil King, Sampi MehtaAbstract:Objective To describe a simple novel technique for reducing the likelihood of wrong-side surgery in endourology. Method A radiopaque adhesive SKINTACT ECG Electrode is placed in the corresponding groin on the side of the intended procedure and provides a visual aid to the surgeon on the fluoroscopy image to ensure the correct side is being performed. Results The Electrode is placed in the groin at the end of the surgical checklist in view of and in collaboration with the whole surgical team before commencing the procedure. The Electrodes are widely available, nonintrusive, and easily removed. Conclusion Wrong-side surgery unfortunately still does occur despite universal precautionary measures put in place to prevent this. Certain surgical specialties are more prone to wrong-side surgery, such as orthopedics and urology. Such an adverse event can have a significant and negative impact both on the surgeon and the patient. It is almost always due to human error and any measure to prevent this should be welcomed. The method described provides an additional safeguard against this occurring.
Gilsoo Cho - One of the best experts on this subject based on the ideXlab platform.
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pu nanoweb based textile Electrode treated with single walled carbon nanotube silver nanowire and its application to ECG monitoring
Smart Materials and Structures, 2019Co-Authors: Eugene Lee, Gilsoo ChoAbstract:This paper is a research on textile Electrodes fabricated by applying single-walled carbon nanotube (SWCNT) and silver nanowire (AgNW) to polyurethane (PU) nanoweb for monitoring electrocardiography (ECG) signals. In order to impart electrical conductivity, PU nanoweb was treated with SWCNT and AgNW. The PU nanoweb was dipped into 15 g of SWCNT dispersion mixed with 5 g of AgNW dispersion, and it was also treated with heat post-treatment and ethanol pre-treatment for enhanced conductivity. The electrical properties were evaluated by electrical linear resistance and impedance. The tensile properties were measured by Instron. By using the treated specimens, the wearable textile sensors were fabricated and verified to properly act as ECG Electrodes via wear-trials compared to the conventional ECG Electrode. To compare the ECG signals between Ag/AgCl Electrode and textile Electrodes, morphology of waveforms was compared and statistical analysis was also conducted. The results of the electrical properties showed that specimens SA1-H, SA1-E, and SA1-HE was much lower than SA1, and especially, SA1-H showed the lowest resistance. It corresponded to the results of impedance that specimen SA1 had the highest and specimen SA1-H had the lowest value. The results of the tensile properties showed that specimen SA1-H had higher tensile strength and elongation at break than the untreated. And, the results of the wear-trials showed that specimen SA1-H had the performance for ECG signals monitoring regardless of rest/stress-states, age, sex, and BMI index of the participants. Thus, it confirmed that the wearable textile sensors fabricated by using the SWCNT/AgNW treated PU nanoweb was suitable for ECG monitoring. Based on the results, it should have approximately 10 Ω cm−1 when applied as the ECG Electrode for long-term bio-monitoring smart clothing.
