Determination of volume blood flow into aortic section over heart beat cycle from impedance curve of cardiogram by derivation of equation from Seifert and Kubieck's equation

摘要

A mathematical equation is derived from an equation of H. Seifert and D. Kubieck for calculation of the heart beat volume from the impedance ( DELTA Z) curve. The derived equation is: SV = =RL2=DZmax/Z02 * (1 - exp (-Ts/ tau 0))/(exp (-T0/ tau 1) - exp (- T0/ tau 0)), where SV is the heart rate volume, rho is the specific blood resistance, L the distance between inner band electrodes, DELTA Zmax the maximum of the DELTA Z curve, Z0 the base impedance in the thorax, Ts time at closure of aortic valve, T0 time until the maximum of the DELTA Z curve, tau 0 is the rising time constant and tau 1 the falling time constant.