CONTINUOUS, ONLINE, REAL-TIME SPECTRAL-ANALYSIS OF SYSTEMIC ARTERIAL-PRESSURE SIGNALS

We present in this communication an algorithm that offers continuous, on-line, real-time analysis of the power spectrum (CORAPS) of systemic arterial pressure (SAP) signals. Based on direct fast Fourier transfo rm of raw SAP signals into power spectral density, it is suitable for the delineation of acute SAP spectral changes over time after physiolo gical or pharmacological perturbations. Thus it is an improvement over most current methods, which only generate the spectra off-line or fro m intermittent data. Furthermore, all executions can be accomplished e conomically with a general-purpose personal computer. We demonstrated and quantified vivid sequential alterations in the low-frequency compo nents (<3 Hz) of the SAP spectrum, which purportedly reflect the influ ence of vasomotor, baroreceptor, and respiratory activity on SAP durin g pentobarbital administration or transient hypertension. Three window options incorporated into the algorithm further improved the frequenc y or temporal resolution and discrimination of the spectral changes du ring abrupt hypertension or hypotension. Thus our CORAPS algorithm may be useful as an on-line monitor for acute hemodynamic changes.