開發LabVIEW程式輔助三維動態心臟成像和心電圖測量應用於斑馬魚心功能評估

Abstract

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Development of new drugs generally requires the test of cardiotoxicity on animals. Zebrafish has recently been recognized to as a model organism of great potential for high-throughput drug screen because of its various attractive features. In this regard, development of automated, affordable and robust techniques, whichcan enable convenient assessment of the cardiac function of zebrafish,would be an indispensable component towards this end. In this master research, I developed computer codes and systems for (semi) automated determination of the cardiac rhythm, cardiac function and electrocardiogram of zebrafish. First, a LabVIEW code was developed to analyze, either in real time or off-line, video clips, which are acquired with an optical microscope equipped with a low-cost, high frame-rate camera. Through such code, the time-varying contrast in user-defined regions of interest (ROI) of dynamic images was quantified, and the ventricular and arterial rhythms of larval zebrafish, and their temporal offset can be readily determined. Second, another code was developed to sort and process time-lapse images acquired at varied z-depth on a periodically changing three-dimensional object. When applied to zebrafish, this code enables automatic processing of images, reconstruction of pseudodynamic 3D cardiac images, and determination of essential parameters of the cardiac function (such as stroke volume and ejection fraction). This code largely eliminates operator inputs, which are subjective and inevitably introduce errors associated with individual operators, and decreases substantially the time required to complete image analysis from hours to a few minutes. A system, which comprised a perfusion system, electrodes, a bioamplifier, an electrical shielding enclosure, and a LabVIEW code, was developed to acquire electrocardiogram of adult zebrafish. Change in electrophysiological parameters, which areassociated with cardiotoxicity, can be determined and analyzed. In summary, I have achieved the primary goal to develop LabVIEW code aided system to assess the cardiac function and electrophysiological function of zebrafish. The system increases the precision and reduces human errors, and is readily adapted by research groups possessing video microscopes and basic operational skill of LabVIEW code. I anticipate that our system should facilitate research that requires the determination of cardiac function and assessment of the cardiotoxicity of chemicals using zebrafish as a platform.