Register for free to
view the full innovation profile.
The method is currently being applied to cardiovascular waveforms such as arterial blood pressure (ABP), ECG and pulse oximetry, but may be used to analyse any approximately periodic signal.
About
The cardiovascular system is complex, showing both non-linear (chaotic) and periodic behaviour. Cardiovascular data such as ABP are most commonly viewed as a time trace in which, due to the density of the data, the most obvious component to the eye is the increase or decrease of the average pressure. Our method differs fundamentally from this approach in the following ways; (i) the input signal is reconstructed in 3-dimensional (3D) phase space using Takens’ delay coordinate method, (ii) the motion corresponding to baseline changes is factored out by visualising the attractor in the x=y=z plane, (iii) the resulting 2D attractor is adjusted to maintain rotational symmetry by changing the time delay (?), and (iv) scalar measures of the 2D attractor (which have a 1:1 relationship to input waveform shape) are used as novel physiological readouts.