RHYTHM: An Open Source Imaging Toolkit for Cardiac Panoramic Optical Mapping

Christopher Gloschat,Shubham Gupta,Kedar Aras,Igor R Efimov,Roman A Pryamonosov,Jack Rogers,Roman A Syunyaev,Matthew W Kay,N Rokhaya Faye,Hanyu Zhang

doi:10.1038/s41598-018-21333-w

Abstract

Fluorescence optical imaging techniques have revolutionized the field of cardiac electrophysiology and advanced our understanding of complex electrical activities such as arrhythmias. However, traditional monocular optical mapping systems, despite having high spatial resolution, are restricted to a two-dimensional (2D) field of view. Consequently, tracking complex three-dimensional (3D) electrical waves such as during ventricular fibrillation is challenging as the waves rapidly move in and out of the field of view. This problem has been solved by panoramic imaging which uses multiple cameras to measure the electrical activity from the entire epicardial surface. However, the diverse engineering skill set and substantial resource cost required to design and implement this solution have made it largely inaccessible to the biomedical research community at large. To address this barrier to entry, we present an open source toolkit for building panoramic optical mapping systems which includes the 3D printing of perfusion and imaging hardware, as well as software for data processing and analysis. In this paper, we describe the toolkit and demonstrate it on different mammalian hearts: mouse, rat, and rabbit.

Highlights

While many electrophysiological studies can be carried out using a monocular setup, there are some that necessitate a whole surface approach to data acquisition
We developed an open source panoramic optical imaging system suitable for the whole heart imaging of small mammalian hearts
While panoramic imaging was developed over a decade ago, few studies of actual physiology have been performed, and only by groups that developed panoramic methodologies

Summary

Introduction

While many electrophysiological studies can be carried out using a monocular setup, there are some that necessitate a whole surface approach to data acquisition. An increase in the investigation of atrial fibrillation (AF) and ventricular fibrillation (VF) initiation and maintenance using transgenic mouse models[22,23,24] has created the need for panoramic setups that are scalable to accommodate small rodent hearts, such as mouse and rat. In spite of these accomplishments and a growing unmet need, the technical expertise required to design and implement a panoramic imaging system has made it largely inaccessible. The toolkit will be released under the MIT open source software license

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