ARTORG Center for Biomedical Engineering Research

CVE

CVE

Translational Electrophysiology

Heart rhythm disorders are common and may have devastating consequences. The group for translational electrophysiology - a collaboration of the Department of Cardiology, Bern University Hospital, and the ARTORG Cardiovascular Engineering group - aims at developing tools and devices for cardiac rhythm management. 

A main research focus is the development of novel technologies for cardiac pacing. Contemporary pacemakers suffer from limitations. Pacing leads are prone to dislocations and isolation defects. Recently introduced leadless pacemakers overcome this limitations, however, do not allow for dual-chamber pacing. We are implementing ultra low-power communication technology in custom-built leadless pacemakers to allow for multisite pacing. Another limitation of today's pacemakers is their limited longevity due to exhausted batteries. We are looking into methods for intracorporeal energy scavenging which would allow designing lead- and batteryless pacemakers in future. 

A second major research area of our group is the development of tools for arrhythmia diagnosis. Electrophysiologic examinations provide detailed informations but are invasive, time-consuming and costly. We are working on novel minimal-invasive alternatives to perform precise bedside EP examinations. 

Main contact: Andreas Haeberlin, MD, PhD

Leadless multisite pacing

Leadless multisite pacing

In order to avoid the limitations of conventional pacemaker electrodes, leadless pacemakers have recently been introduced. However, these devices do not yet allow for dual-chamber pacing. To synchronize the communication and pacing activity between different leadless devices implanted in the heart, a wireless communication systems is required. We are currently working on the implementation of ultra low-power communication technology in our custom-built leadless pacemakers (see implantation of a prototype in the right ventricle below). The ultimate goal is to equip the leadless multisite pacemaker with a suitable system for energy scavenging which would allow building lead- and batteryless pacemakers.

 

Contact: Lukas Bereuter, Phd / Andreas Haeberlin, MD, PhD

E-harvesting/batteryless pacing

Energy harvesting/batteryless pacing

Different approaches for energy harvesting would allow developing batteryless implantable electronic devices. The MIOG (Mass Imbalance Oscillation Generator) concept focuses on harvesting energy from heartbeat motions. Its mechanism is based on a clockwork of an automatic wristwatch. Similar to the working principle on a person’s wrist, our prototype converts the kinetic energy of a heart motion into electrical energy. Numerical studies and bench tests have been employed to improve the conversion principle. In-vivo experiments have now demonstrated the feasibility of converting enough energy to successfully perform batteryless cardiac pacing (LINK). Another approach uses sunlight as a reliable, ubiquitous energy source. With solar cells, the solar radiation can be transferred into electrical energy to power an active medical implant. Since a part of the light (near infrared) is able to penetrate well into the skin, a solar energy harvester can be implanted subcutaneously (LINK). Recently, we presented the first prototype of a solar powered pacemaker, which was successfully tested in an in-vivo study (LINK). Ongoing research focuses on estimating the energy output of the solar energy harvester module in real life settings to investigate the long-term feasibility of sunlight-powered cardiac pacing.

 

Long-term ECG

Long-term electrocardiography

Long-term electrocardiography is widely used to diagnose intermittent arrhythmias. After several days up to weeks, the ECG is analyzed offline. Due to the large amount of data, software-based ECG analysis is required hepling physicians to reveal arrhythmias. Although semi-automatic software-based ECG analysis may save time, direct analysis of atrial arrhythmias is cumbersome due to the surface ECG's poor signal-to-noise ratio (LINK). Esophageal electrocardiography (eECG) may provide a way out due to the excellent atrial signal quality which may facilitate arrhythmia detection (LINK). In collaboration with the Bern University of Applied Sciences, we develop and validate novel algorithms for improved arrhythmia detection using esophageal as well as conventional surface ECG.

 

Contact: Andreas Haeberlin, MD, PhD

Optical coherence tomography for lesion assessment

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with devastating outcomes such as ischemic strokes. The main initiating mechanism of atrial fibrillation is electrical activity from triggers located mostly in the pulmonary veins (PVs). Pulmonary vein isolation by radiofrequency ablation (RFA) is an effective treatment for atrial fibrillation. Successful PV isolation requires deep and adjacent lesions in the left atrium around the PV ostia. Optical coherence tomography (OCT) is an imaging technique that uses light to capture high-resolution (~10μm) images from optical scattering media. We hypothesize that OCT can directly assess lesion size and provide precise measurement.