System and method for estimating cardiac output

摘要

Cardiac output CO is separately estimated in a local estimator and a trend estimator to provide CO values. A thermal signal is injected preferably according to a pseudo-random binary sequence signal profile at an upstream position in a blood flow region of a patient's body and is sensed as an indicator output signal at a downstream position. Low-frequency noise is preferably removed from the sensed indicator output signal. The local and trend estimations are based on measured frequency-domain transfer function values between the sensed and input indicator signal in relation to a pre-determined transfer function model, which is preferably a lagged normal model. The trend estimator is preferably a Kalman filter. The local estimator preferably forms its estimate based on non-recursive optimization of a cost function. The local estimator preferably provides initial values to start the trend estimator.