An apparatus for indicating cardiac output comprises means for monitoring a patient's transthoracic impedance and generating a corresponding impedance signal, and signal processing means for (a) deriving a signal S1 which is a measure of the average amplitude of the impedance signal, (b) filtering the impedance signal at a plurality of different wavelengths within a predetermined frequency band, (c) for each filter deriving a signal S2 which is a measure of the average amplitude of the respective filter output, (d) calculating the ratio of the maximum one of the signals S2 derived from step (c) to the signal S1 derived from step (a), and (e) using the ratio from step (d) in a decision tree to provide a signal indicating cardiac output or not.
|Patent number||US9155482 B2|
|Publication status||Published - 13 Oct 2015|
Bibliographical noteCountry: US
Commercialisation Status: assigned
Patent Application Date: 2009-03-04
- Cardiac output
- cardiac arrest