PD of two kinds of blood pulse wave as an alternative of PAT

Peak Delay (PD) of two different blood pulse waves measured at the same site is intensively studied in this paper. The derived expression, based on Womersley theory and simplified Navier-Stokes equations, implies that PD is closely related to the change of the Young´s modulus of the blood vessel, which is promising in noninvasively BP monitoring. Traditionally, BP is estimated with Pulse Transit Time (PTT) or Pulse Arrival Time (PAT). Experiment results show that PAT and PD are inversely related with correlation coefficient from 0.78 to 0.95 when BP is relatively stable. If BP changes remarkably, calibration should be conducted to better trace PAT with PD. Therefore PTT or PAT can be replaced by PD for continuous and noninvasive BP monitoring, with the convenience that the measuring site is concentrated on fingertip.