Where to B in dZ/dt.

摘要: The B point on the impedance cardiograph waveform corresponds to opening of aortic valve and is an important parameter for calculating systolic time intervals, stroke volume, cardiac output. Identifying location sometimes problematic because characteristic upstroke that serves as a marker this not always apparent. Here presented reliable method identification, based consistent relationship between R interval (RB) R-wave peak dZ/dt function (RZ). polynomial relating RB RZ (RB = 1.233RZ - 0.0032RZ(2) 31.59) accounts 90%-95% variance in across ages gender baseline stress conditions. This relation affords rapid approximation measurement that, noisy or degraded signals, superior visual identification derivative-based estimate.