초록 ▼

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 indica

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.

대표청구항 ▼

A method for estimating blood output through a flow region of a patient\s body, comprising the following steps: A) injecting an indicator as an indicator input signal having an input signal profile and a period into an upstream position in the flow region; B) sensing the presence of the indicator at

A method for estimating blood output through a flow region of a patient\s body, comprising the following steps: A) injecting an indicator as an indicator input signal having an input signal profile and a period into an upstream position in the flow region; B) sensing the presence of the indicator at a downstream position in the flow region to determine an indicator output signal; C) estimating as a predetermined function of the input signal profile and the indicator output signal both a local blood output value over a local estimation time, and a trend blood output value over a trend estimation time, in which the trend estimation time is longer than the local estimation time, thereby providing estimated blood output values corresponding to both relatively fast and slow changes in blood output.