Fluorescent image-tracking velocimetry algorithms for quantitative flow analysis in artificial organ devices

摘要

A Fluorescent Image Tracking Velocimetry (FITV) system has been developed to produce two-dimensional velocity maps of flow fields. This system is capable of measurements at flow boundaries, such as the blood-biomaterial interfaces in artificial cardiac organs (in-vitro only). Three pulse-coding schemes - a single-pulse code, a dash-dot pulse code, and a constant- frequency pulse code - and associated image analysis algorithms have been developed and tested. These algorithms were applied to analyze flow in three types of artificial cardiac organs: the Novacor Left Ventricular Assist System, the Nimbus AxiPump, and the Hattler Intravenous Membrane Oxygenator. Results are presented and discussed in terms of image recognition. Despite the drawback of time-direction ambiguity, a constant-frequency pulse with a hybrid of constant-frequency and single-pulse analyses was found to provide optimum results for these applications.