Photochromic flow visualization for the investigation of artificial heart valves

A new method for the investigation of hydrodynamics of artificial heart valves is presented. It is a method of flow visualisation. The photochromic flow visualization method is based on activation of color tracers in originally colorless photochromic solutions by pulse laser radiation during 10(-6)-10(-9) seconds. The tracer appears as a straight colored line, which subsequently is deformed by the flow. The methods known so far for the flow visualization give an insight on the general flow but do not provide quantitative data. The method mainly used, the LDA, permits measurements only in one point. The new method combines the precision of the LDA with the clarity of flow visualization.