Edwards Lifesciences has recently introduced the FloTrac sensor and Vigileo monitor system for monitoring cardiac output continuously. It does not require thermodilution or dye dilution, but rather bases its calculations on arterial waveform characteristics in conjunction with patient demographic data. It is unique among arterial waveform cardiac output systems in that it does not require calibration with another method. Studies thus far indicate that it is robust and accurate over a wide range of cardiac output and clinical conditions. It will be valuable in the care of many patients, such as those with critical illness, cardiovascular dysfunction, trauma or undergoing major surgery.