Open-Source Low-Cost Cardiac Optical Mapping System

Abstract

Fluorescent imaging with voltage- or calcium-sensitive dyes, i.e. optical mapping, is one of the indispensable modern techniques to study cardiac electrophysiology, unsurpassed by temporal and spatial resolution. High-speed CMOS cameras capable of optical registration of action potential propagation are in general very costly. We present a complete solution priced below US$ 1,000 (including camera and lens) at the moment of publication with an open-source image acquisition and processing software. We demonstrate that the iDS UI-3130CP rev.2 camera we used in this study is capable of 200x200 977 frames per second (FPS) action potential recordings from rodent hearts. The signal-to-noise-ratio of a conditioned signal was 16 {+/-} 10 for rodent hearts. A comparison with a specialized MiCAM Ultimate-L camera has shown that signal-to-noise ratio (SNR) is sufficient for accurate measurements of AP waveform, conduction velocity ({+/-} 0.04 m/s) and action potential duration ({+/-} 7ms) in mouse and rat hearts. We measured the action potential prolongation during 4-aminopyridine administration in mouse heart, showing that proposed system signal quality is adequate for drug studies.