A system, and apparatus for detecting and quantifying circulatory anomalies, including right-to-left cardiac shunts. The apparatus implements a sensor system useful in connection with a circulatory indicator delivery system. The sensor apparatus is preferably configured with a series of emitter/detector pairs to optimize the sensitivity of detection of the circulating indicator. Sensing of the indicator concentration takes place at an arterial vasculature, for example, the pinna of the human ear. A monitor/controller calculates and displays a indicator/dye dilution curve to assess for the presence of a cardiac shunt. The monitor/controller further corrects the indicator/dilution curve displayed for any recirculation phenomena and can quantify any right-to-left shunt calculated conductance associated with detected shunts.
