Simultaneous Panoramic Optical Mapping and Multi-channel Stimulation System for Validation of Adaptive Antitachycardia Pacing

Abstract

To achieve low-energy defibrillation for ventricular tachycardia (VT) and fibrillation (VF), an experimental system is essential to investigate appropriate point stimulation protocols. In this study, we developed an experimental system integrating 3D panoramic optical mapping (POM) with an adaptive multi-channel stimulation (AMS) system based on electrocardiogram (ECG) signals. A validation experiment was conducted using an ex vivo rabbit heart. We fabricated patch-shaped transparent bipolar electrodes made of polydimethylsiloxane (PDMS) for measurement and stimulation purposes. In the AMS system, we measured the ECG signals with these electrodes at sampling rate of 1 kHz using an amplifier. These potentials were analyzed using an embedded computer system, which then triggered a multi-channel stimulator for adaptive point stimulations. Reconstruction of the heart shape model and estimation of camera position were achieved using structure from motion and the multi-view stereo algorithm. The 3D POM was obtained by optically projecting captured images acquired from three cameras and calculating membrane potentials. By evaluating the adaptive stimulation delay of the AMS system, we identified a latency of approximately 1.41 ± 0.23 ms (n = 21). We stimulated an ex vivo rabbit heart using the AMS system combined with the 3D POM. The adaptive stimulation was confirmed to be executed at the intended timing, as indicated by the measured ECG. Additionally, we attempted VT termination by adaptive point stimulations and observed their effect on the original VT using 3D POM. We successfully constructed an experimental system to evaluate various adaptive point stimulation defibrillation protocols.