Patent ID: 6827689
Filing Date: 2004-12-07
Classification: A61B

Abstract:
A sphygmogram measure method for simultaneously acquiring the information of pulse pressure and blood flow rate, comprising the following steps:step 1: using a upstream pressure sensor and a downstream pressure sensor arranged at a certain distance L in accordance with the bloodstream direction to measure pulse pressures of PO(t) and PL(t) of two adjacent points on radial artery respectively; step 2: using a time delay detecting circuit to determine time lag &tgr; related to the passage time of a pulse wave passing from the upstream pressure sensor to the downstream pressure sensor; step 3: inputting pulse pressure PO(t) at the upstream pressure sensor and time lag &tgr; into a digital signal process unit which takes the values of pulse pressure PO(n) and time lag &tgr; to calculate the value of pulse pressure PL(n) at the downstream pressure sensor; step 4: using an optical displacement sensor to sense the variation of vessel diameter &Dgr;a(n) at the downstream pressure sensor; step 5: calculating the nonlinear vessel compliance in a digital signal process unit, &agr;(n)=&Dgr;a(n)/PL(n); step 6: using a thermal image device to estimate the unstressed vessel's diameter aO at the downstream pressure sensor; step 7: using a viscometer to acquire the blood viscosity coefficient &mgr;; and step 8: taking the above values PO(n), PL(n), L, aO, a(n) and &mgr; to calculate the blood flow rate and other information.