Patent ID: 8386041

Claim:
An implantable medical device comprising: a pulse generator that emits cardiac stimulating pacing pulses; at least one lead comprising electrodes configured to deliver said pulses to cardiac tissue of a heart of a patient; an impedance measuring unit connectable to at least two electrodes to measure cardiac impedance of said heart, said impedance measuring unit generating impedance information corresponding to said measured impedance; an impedance morphology determining unit that receives said impedance information and determines an impedance morphology curve from said impedance information; and a calculation unit that detects an extreme point section of said impedance morphology curve and fits a second degree polynomial to the section of the impedance morphology curve in a time window surrounding said extreme point section of said impedance morphology curve and calculates a measure of a hemodynamic parameter of said heart as a function of a curvature component of the polynomial, and that makes said measure available as an output signal.