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Introduction
Publications
Publications (64)
Background/Objectives: Chronic nausea and vomiting (N/V) disorders are common in clinical practice. Our primary aim was to compare total and segmental gastrointestinal transit times as well as gastric contraction patterns in patients with chronic N/V syndrome to those of healthy volunteers (HVs). In the patient group, our secondary aim was to explo...
Characteristics of electrograms depend on the electrode design and distance to the electric source. Our aim was to assess the impact of electrode design and distance from the myocardial electric source on the unipolar and bipolar electrograms to deduce a far-field cut-off. We retrospectively analyzed left atrial electroanatomical maps of 25 patient...
Introduction
Cardiac autonomic dysfunction has been linked to an increased risk of mortality (1), stroke and silent brain lesions (2) and cognitive impairment (3) in patients with atrial fibrillation (AF). However, the impact of AF on cardiac autonomic function is poorly understood.
Purpose
We aimed to explore the impact of AF on cardiac autonomic...
Background
Sex-specific differences in cardiac autonomic tone have not been thoroughly investigated in patients with atrial fibrillation (AF) but may play a relevant role.
Purpose
We aimed to investigate cardiac autonomic function of female compared to male AF patients by means of short-term heart rate variability (HRV) analysis.
Methods
In this...
Background
Outcome prediction after catheter ablation for atrial fibrillation (AF) based on electronic health records (EHR) using machine learning (ML) is not yet established.
Purpose
The aim of the study was to assess the value of ML methods to predict the risk of AF recurrence after catheter ablation based on easily accessible EHR.
Methods
We a...
Background
The characteristics of intracardiac unipolar and bipolar voltage electrograms (EGM) acquired by electrophysiological catheters depend on the electrical source and on the electrode design and configuration.
Purpose
The aim of the study was to assess the impact of the electrode configuration and their distance from the myocardial tissue (...
Background
Cardiac autonomic dysfunction after brain infarcts is a strong predictor of adverse outcome.
Purpose
The aim of this study was to investigate the association of large cortical or non-cortical brain infarcts (LNCCI) with multiscale (MSE) and sample entropy (SE), which characterize the complexity of RR interval time series in atrial fibri...
Background
The characteristics of intracardiac unipolar and bipolar voltage electrograms (EGM) acquired by electrophysiological catheters depend on the electrode design and configuration.
The aim of the study was to assess the impact of electrode design and distance from the myocardial electric source on the unipolar and bipolar intracardiac electr...
Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): The study was supported by an investigator sponsored grant (Boston Scientific).
Background
Bipolar voltage electrograms (BVE) for left atrial (LA) substrate characterization strongly depend on the catheter design and electrode configuration.
Purpose
The aim...
Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): Swiss National Science Foundation, Swiss Heart Foundation
Background
Emerging evidence indicates that a high atrial fibrillation (AF) burden is associated with adverse outcome. However, AF burden is not routinely measured in clinical practice. An artificial intel...
Background:
Bipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration.
Aims:
The aim of the study was to investigate the relationship between the BV amplitude (BVA) using four catheters with different electrode design and to identify their specific LA cutoffs for scar...
Background
Superimposition of farfield (FF) and nearfield (NF) bipolar voltage electrograms (BVE) complicates the confirmation of pulmonary vein (PV) isolation after catheter ablation of atrial fibrillation. Our aim was to develop an automatic algorithm based on a single-beat analysis to discriminate PV NF from atrial FF BVE from a circular mapping...
Background:
Emerging evidence indicates that a high atrial fibrillation (AF) burden is associated with adverse outcome. However, AF burden is not routinely measured in clinical practice. An artificial intelligence (AI)-based tool could facilitate the assessment of AF burden.
Objective:
We aimed to compare the assessment of AF burden performed ma...
Background
Bipolar voltage (BV) electrograms for left atrial (LA) substrate characterization depend on catheter design and electrode configuration. The aim of the study was to investigate the relationship between the BV amplitude (BVA) using four different catheters and to identify their specific LA cutoffs for scar and healthy tissue.
Methods
Cons...
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation
Introduction
Despite the broad use of oral anticoagulants, stroke remains one of the most serious complications in atrial fibrillation (AF) patients. Stroke has been linked to disturbances of the auton...
Funding Acknowledgements
Type of funding sources: None.
Introduction
Magnetic interference of portable electronic devices (PEDs), such as state-of-the-art mobile phones, with cardiovascular implantable electronic devices (CIEDs) has been reported.
Purpose
The aim of the study was to quantify the magnetic fields of latest generation Smartwatches a...
Funding Acknowledgements
Type of funding sources: Public hospital(s). Main funding source(s): “Stiftung für Herzschrittmacher und Elektrophysiologie” Basel, Switzerland
Background
Confirmation of pulmonary vein (PV) isolation (PVI) during ablation of atrial fibrillation can be challenging due to superimposition of nearfield (NF) PV and farfield (F...
Background
The effect of the ventricular repolarization heterogeneity has not been systematically assessed in patients with atrial fibrillation (AF). Aim of this study is to assess ventricular repolarization heterogeneity as predictor of cardiovascular (CV) death and/or other CV events in patients with AF.
Methods
From the multicenter prospective...
Background/aims:
Patients with diabetes mellitus (DM) often suffer from gastrointestinal (GI) symptoms, but these correlate poorly to established objective GI motility measures. Our aim is to perform a detailed evaluation of potential measures of gastric and small intestinal motility in patients with DM type 1 and severe GI symptoms.
Methods:
Tw...
Objective:
To evaluate the safety and use of the 3D-Transit system (Motilis SA, Lausanne, Switzerland) and to describe regional gastrointestinal transit times, segmental colonic transit times and colonic movement patterns in healthy children.
Methods:
21 healthy children (11 girls, median age 10.5 years, range 7-15 years) were included. For eval...
Purpose: Silent brain infarcts (SBI) are frequently detected in patients with atrial fibrillation (AF), but it is unknown whether SBI are linked to autonomic dysfunction. We aimed to explore the association of autonomic dysfunction with SBI in AF patients.
Methods: 1,358 AF patients without prior stroke or TIA underwent brain MRI and 5-min resting...
Precise landslide monitoring with differential global navigation satellite system (GNSS) is well known, but technical or economic reasons limit its application by geotechnical companies. This study demonstrates the reliability and the usefulness of Geomon (Infrasurvey Sàrl, Switzerland), a stand-alone and cost-effective rover network. The system pe...
Background
Impaired heart rate variability (HRV) is associated with increased mortality in sinus rhythm. However, HRV has not been systematically assessed in patients with atrial fibrillation (AF). We hypothesized that parameters of HRV may be predictive of cardiovascular death in patients with AF.
Methods and Results
From the multicenter prospect...
Background
Gastrointestinal (GI) symptoms are common in patients with diabetes mellitus (DM). The electromagnetic 3D‐Transit system allows assessment of regional transit times and motility patterns throughout the GI tract. We aimed to compare GI transit times and detailed motility patterns of the colon in patients with DM and GI symptoms to those o...
Background
The Motilis 3D‐Transit system allows ambulatory description of transit patterns throughout the gastrointestinal tract and offers an alternative method for studying gastric motility. We aimed to establish normative values for gastric motility assessed with the method.
Method
A total of 132 healthy volunteers ingested the 3D‐Transit capsu...
Background
Opioid treatment often causes debilitating constipation. However, it is not well described how opioids affect colonic motility and whether opioid‐induced constipation is due to either a decrease of powerful peristaltic contractions or “uncoordinated” peristalsis. The present study aims to investigate the effect of oxycodone on parameters...
Background
The 3D‐Transit electromagnet tracking system (Motilis Medica, SA, Lausanne, Switzerland) is an emerging tool for the ambulatory assessment of gastrointestinal (GI) transit and motility. Using this tool, we aimed to derive normative values for region‐specific colonic and GI transit times and to assess the influence of age, gender, and bod...
Background
The Motilis 3D‐Transit system tracks electromagnetic capsules as they traverse the gastrointestinal tract. The method is minimally invasive and ambulatory. Analysis has previously been limited to regional gut transit times, but new methods may allow detailed analysis of colonic motility.
Methods
Parameters of colonic motility were analy...
Aim:
We aimed to determine colorectal length with the 3D-Transit system by describing a 'centerline' of capsule movement and compare it to known anatomy, as determined by magnetic resonance imaging (MRI). Further, we aimed to test the day-to-day variation of colorectal length assessed with the system.
Method:
The 3D-Transit system consists of el...
Background:
Gastrointestinal (GI) dysmotility may present secondary to inflammatory bowel disease. The main aim of this study was to investigate GI motility in ulcerative colitis (UC) patients during severe disease activity.
Methods:
Twenty patients with severe UC were studied with a novel telemetric capsule system (3D-Transit) designed for mini...
Studies of gastrointestinal function during sleep are hampered by lack of applicable techniques. Recent development of a novel ambulatory telemetric capsule system, which can be used in conjunction with polysomnography, offers a solution to this problem. The 3D-Transit system consists of ingestible electromagnetic capsules traceable through a porta...
The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not yet been evaluated in any group of patients. We aimed to test the perf...
Background
Gastrointestinal (GI) motor disorders often involve several regions of the GI tract. Therefore, easy and safe assessment of whole gut and regional motility is valuable for more precise diagnosis. 3D-Transit is a novel method for ambulatory evaluation of total and regional gastrointestinal transit times (GITT) based on the anatomical loca...
Introduction
Due to the inaccessibility of the gastrointestinal (GI) tract and lack of proper measurement techniques clinical studies describing gastrointestinal function during sleep are sparse. In the present pilot study we aimed at introducing a novel ambulatory telemetric capsule system (3D-Transit) in conjunction with polysomnography (PSG).
M...
Data on small intestinal transit time in healthy children are lacking, and normal values for gastric emptying and colonic transit time are sparse. Conventional methods, including radiopaque markers, scintigraphy, and PillCam™ involve radiation or require the child to swallow a large pill. The minimally invasive, radiation-free Motility Tracking Sys...
Aim:
Sacral nerve stimulation (SNS) reduces symptoms in up to 80% of patients with faecal incontinence (FI). Its effects are not limited to the distal colon and the pelvic floor. Accordingly, spinal or supraspinal neuromodulation have been suggested as part of the mode of action. The effect of SNS on gastric and small-intestinal motility was studi...
Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system.
A...
Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis and collagen deposits. Gastrointestinal symptoms of SSc, including abdominal pain, bloating and discomfort, are common but diffuse and their pathophysiology remains obscure.
To investigate the pathophysiology of abdominal pain and discomfort in individuals with SSc.
A total...
Diarrhea is part of the carcinoid syndrome and a significant clinical problem in neuroendocrine tumor (NET) patients. Somatostatin analog (SA) treatment usually alleviates carcinoid diarrhea, but little is known about the objective effects of SA on gastrointestinal transport.
To compare gastrointestinal motility in healthy subjects and NET patients...
Many patients with spinal cord injury (SCI) suffer from constipation, abdominal pain, nausea, or bloating, and colonic transit times are prolonged in most. Gastric and small intestinal dysfunction could contribute to symptoms but remain to be described in detail. Also, it is obscure whether the level of SCI affects gastric and small intestinal func...
Although other methods exist for monitoring gastrointestinal motility and contractility, this study exclusively provides direct and quantitative measurements of the forces experienced by an orally ingested pill. We report motive forces and torques calculated from real-time, in vivo measurements of the movement of a magnetic pill in the stomachs of...
Direct electrical stimulation of the colon offers a promising approach for the induction of propulsive colonic contractions by using an implantable device. The objective of this study was to assess the feasibility to induce colonic contractions using a commercially available battery-operated stimulator (maximum pulse width of 1 ms and maximum ampli...
The Magnet Tracking System (MTS) is a minimally-invasive technique of continuous evaluation of gastrointestinal motility. In this study, MTS was used to analyse colonic propulsive dynamics and compare the transit of a magnetic pill with that of standard radio-opaque markers. MTS monitors the progress in real time of a magnetic pill through the gut....
Direct colonic electrical stimulation may prove to be a treatment option for specific motility disorders such as chronic constipation. The aim of this study was to provoke colonic contractions using electrical stimulation delivered from a battery-operated device.
Electrodes were inserted into the caecal seromuscular layer of eight anaesthetized pig...
Digestive motility was studied in the rat using a miniaturized version of the Magnet Tracking system which monitored the progression of a small magnetic pill through the entire digestive tract. The dynamics of movement was followed and three-dimensional (3-D) images of digestive tract were generated. After a retention period in the stomach and rapi...
Fluoroscopic verification of nasogastric (NG) feeding tube placement is inconvenient and involves radiation exposure. We tested whether the position of an NG tube can be assessed reliably by a recently introduced magnet-tracking system.
A small permanent magnet was attached at the end of an NG tube and its position was monitored using an external s...
A new minimally invasive technique allowing for anatomical mapping and motility studies along the entire human digestive system is presented. The technique is based on continuous tracking of a small magnet progressing through the digestive tract. The coordinates of the magnet are calculated from signals recorded by 16 magnetic field sensors located...
We present a new graphical tool to investigate the time evolution of phase-synchronization clusters and apply it to a computer model of the intestine consisting of coupled oscillators. The method estimates the synchronized zones using a covariance analysis of the electrical activity to detect any linear relationship between segments of the intestin...
These Ecole polytechnique federale de Lausanne EPFL, n° 2872 (2003)Section de microtechniqueFaculte des sciences et techniques de l'ingenieurInstitut de microelectronique et microsystemesJury: Patrick J. French, Jean-Jaques Gonvers, Max-Olivier Hongler, Jean-Marc Vesin Public defense: 2003-11-26 Reference doi:10.5075/epfl-thesis-2872Print copy in l...
A tracking system with five degrees of freedom based on a 2D-array of 16 Hall sensors and a permanent magnet is presented in this paper. The sensitivity of the Hall sensors is increased by integrated micro- and external macro-flux-concentrators. Detection distance larger than 20cm (during one hour without calibration) is achieved using a magnet of...
Based on a 2D-array of 16 cylindrical Hall sensors and a permanent magnet, a tracking system with five degrees of freedom is analysed in this paper. The system accuracy is studied, including offset drifts, sensitivity mismatches and the number of sensors. A detection distance as large as 14 cm (during 1 h without calibration) is achieved using a ma...
We have studied the sensitivity of Hall devices using planar magnetic flux concentrators of various lengths. By placing magneto-concentrators (MCs) on Hall device, we obtained sensitivity up to 100 V/T for a bias current of 1 mA and for a length of the MCs of 50 mm. This value is about 1000 times better then that of a conventional silicon Hall devi...