Why use Finapres or Portapres rather than intraarterial or intermittent non-invasive techniques of blood pressure measurement?

In the clinic, blood pressure is measured almost exclusively using non-invasive intermittent techniques, of which the auscultatory (Riva-Rocci/Korotkoff; RRK) and the computerized oscillometric method are most often used. However, both methods only provide a momentary value. In addition, the accuracy is hampered by phenomena such as cuff response and white coat hypertension, thus providing artefactually increased values. The vascular unloading technique of Penaz together with the Physiocal criteria of Wesseling provide reliable, noninvasive and continuous estimates of blood pressure. This technique is thus an alternative to the invasive intra-arterial measurements in many cases, without the risks and ethical questions inherent to invasive measurements. Since the pressure waveform is available continuously, computations such as pulse contour and Modelflow cardiac output, spectral analysis and baroreflex sensitivity provide further information on the dynamics of the cardiovascular system on a beat-to-beat basis, similar to intra-arterial measurements.