Abstract: An apparatus for measuring cardiac output designed to prevent measurement errors by eliminating the need for a manufacture step of examining a temperature sensing element during manufacture of the same and, hence, the need for a probe circuit or the like which is a means for effecting correction according to the characteristics of the temperature sensing element.

Abstract: Disclosed are a cardiac output measurement method and a system for the application of the same, which perform the calibration of cardiac output by employing a blood flow velocity measurement method and perform continuous measurement of cardiac output. The system includes a blood temperature sensing element for sensing blood temperature, a blood temperature measurement circuit for generating a blood temperature signal indicative of the sensed blood temperature, an equilibrium temperature obtaining element capable of sensing cooling temperature of blood flow being heated, and an equilibrium temperature measurement circuit for generating an equilibrium temperature signal indicative of the sensed cooling temperature of blood flow heated.