Wildhaber, Reto
Lade...
E-Mail-Adresse
Geburtsdatum
Projekt
Organisationseinheiten
Berufsbeschreibung
Nachname
Wildhaber
Vorname
Reto
Name
Wildhaber, Reto
19 Ergebnisse
Suchergebnisse
Gerade angezeigt 1 - 10 von 19
Publikation Real-time feature extraction from electrocochleography with impedance measurements during cochlear implantation using linear state-space models(IEEE, 2023) Andonie, Raphael R.; Wimmer, Wilhelm; Wildhaber, Reto; Caversaccio, Marco; Weder, Stefan01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Intracoronary ECG ST-segment shift remission time during reactive coronary hyperemia (tau-icECG): a new approach to assess hemodynamic coronary stenosis severity(Oxford University Press, 2023) Kieninger-Graefitsch, Andrea; Bigler, Marius Reto; Waldmann, Frédéric; Wildhaber, Reto; Seiler, ChristianCoronary pressure-derived fractional flow reserve (FFR) measurements are recommended for hemodynamic coronary stenosis assessment. Given temporary paralysis of the coronary microcirculation during hyperemia, pressure is, in theory, directly related to coronary flow. Pressure drop during hyperemia across a coronary stenosis, thus, provides an estimate of its restrictive effect on flow. FFR during reactive hyperemia induced by a proximal, 1-minute coronary artery balloon occlusion has been shown non-inferior to FFR as obtained by adenosine-induced hyperemia. Intracoronary ECG (icECG) is more sensitive in detecting myocardial ischemia than the surface ECG, and can be easily obtained.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Technical characterization of single-lead ECG signals from 4 different smartwatches and its potential clinical implications(Elsevier, 2023) Knecht, Sven; Waldmann, Frédéric; Kuhn, Raffael; Mannhart, Diego; Kühne, Michael; Sticherling, Christian; Badertscher, Patrick; Wildhaber, Reto01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Algorithm for real-time analysis of intracoronary electrocardiogram(Frontiers, 07.09.2022) Bigler, Marius Reto; Kieninger-Gräfitsch, Andrea; Waldmann, Frédéric; Seiler, Christian; Wildhaber, RetoSince its first implementation in 1985, intracoronary (ic) electrocardiogram (ECG) has shown ample evidence for its diagnostic value given the higher sensitivity for myocardial ischemia detection in comparison to surface ECG. However, a lack of online systems to quantitatively analyze icECG in real-time prevents its routine use. The present study aimed to develop and validate an autonomous icECG analyzing algorithm.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Onset detection of pulse-shaped bioelectrical signals using linear state space models(De Gruyter, 02.09.2022) Waldmann, Frédéric; Baeriswyl, Christof; Andonie, Raphael; Wildhaber, RetoBioelectrical signals are often pulse-shaped with superimposed interference signals. In this context, accurate identification of features such as pulse onsets, peaks, amplitudes, and duration is a frequent problem. In this paper, we present a versatile method of rather low computational complexity to robustly identify such features in real-world signals. For that, we take use of two straight-line models fit to the observations by minimizing a quadratic cost term, and then identify desired features by tweaked likelihood measures. To demonstrate the idea and facilitate access to the method, we provide examples from the field of cardiology.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Windowed state space filters for peak interference suppression in neural spike sorting(IEEE, 2022) Wildhaber, Reto; Baeriswil, Christof; Bertrand, Alexander04B - Beitrag KonferenzschriftPublikation Signal analysis using local polynomial approximations(IEEE, 2020) Wildhaber, Reto; Ren, Elizabeth; Waldmann, Frederic; Loeliger, Hans-AndreaLocal polynomial approximations represent a versatile feature space for time-domain signal analysis. The parameters of such polynomial approximations can be computed by efficient recursions using autonomous linear state space models and often allow analytical solutions for quantities of interest. The approach is illustrated by practical examples including the estimation of the delay difference between two acoustic signals and template matching in electrocardiogram signals with local variations in amplitude and time scale.04B - Beitrag KonferenzschriftPublikation Toward a novel semi‐invasive activation mapping tool for the diagnosis of supraventricular arrhythmias from the esophagus(Wiley, 2019) Sweda, Romy; Wildhaber, Reto; Mortier, Simone; Bruegger, Dominik; Niederhauser, Thomas; Goette, Josef; Jacomet, Marcel; Tanner, Hildegard; Haeberlin, AndreasSupraventricular arrhythmia diagnosis using the surface electrocardiogram (sECG) is often cumbersome due to limited atrial signal quality. In some instances, use of esophageal electrocardiography (eECG) may facilitate the diagnosis. Here, we present a novel approach to reconstruct cardiac activation maps from eECG recordings.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Estimation of the cardiac field in the esophagus using a multipolar esophageal catheter(IEEE, 2018) Wildhaber, Reto; Bruegger, Dominik; Zalmai, Nour; Malmberg, Hampus; Goette, Josef; Jacomet, Marcel; Tanner, Hildegard; Haeberlin, Andreas; Loeliger, Hans-AndreaThe rapid progress of invasive therapeutic options for cardiac arrhythmias increases the need for accurate diagnostics. The surface electrocardiogram (ECG) is still the standard of noninvasive diagnostics but lacks atrial signal resolution. By contrast, esophageal electrocardiography (EECG) yields atrial signals of high amplitude and with a high signal-to-noise ratio. Esophageal electrocardiography has become fast and safe, but the mechanical constraints of esophageal measuring catheters and the “random” motion of the catheter inside the subject's esophagus limit the spatial resolution of EECG signals. In this paper, we propose a method to estimate the electrical field projected onto the esophagus with an increased spatial resolution, using commonly available esophageal catheters. In a first step, we estimate the time-varying catheter position, and in a second step, we estimate the projected electrical field with enhanced spatial resolution. The proposed algorithm comprises several consecutive optimization steps, where each intermediate step produces not just a single point estimate, but a cost function over multiple solutions, which reduces the information loss at each processing step. We conclude with examples from a clinical trial, where the fields of cardiac arrhythmias are presented as two-dimensional contour plots.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Windowed state-space filters for signal detection and separation(IEEE, 2018) Wildhaber, Reto; Zalmai, Nour; Jacomet, Marcel; Loeliger, Hans-AndreaThis paper introduces a toolbox for model-based detection, separation, and reconstruction of signals that is especially suited for biomedical signals, such as electrocardiograms (ECGs) or electromyograms (EMGs). The modeling is based on autonomous linear state space models (LSSMs), which are localized with flexible windows. The models are fit to observations by minimizing the squared error while the use of LSSMs leads to efficient recursive error computations and minimizations. Multisection windows enable complex models, and per-sample weights enable multistage processing or adaptive smoothing. This paper is motivated by, and intended for, practical applications, for which several examples and tabulated cost computations are given.01A - Beitrag in wissenschaftlicher Zeitschrift