Patent ID: 7455643

Claim:
A method for maintaining calibration of a continuous non-invasive blood pressure (CNIBP) measurement system, the method comprising: performing a calibration by: obtaining for a subject a reference blood pressure value, reference CNIBP data and reference pulse wave data, the reference pulse wave data corresponding to one or more reference pulse waves of the subject and having a waveform; calculating and storing coefficients of a CNIBP calculation formula based on the reference blood pressure value and the reference CNIBP data; and, storing a template comprising information characterizing a plurality of characteristics of the waveform of the reference pulse wave data; subsequently, obtaining subsequent pulse wave data characterizing one or more subsequent pulse waves of the subject and evaluating a recalibration condition comparing characteristics of a waveform of the subsequent pulse waves to the template; and, if the subsequent pulse wave data and template satisfy the recalibration condition, repeating performing the calibration of the CNIBP measurement system, wherein the recalibration condition comprises a sensitivity parameter and the sensitivity parameter affects whether or not the subsequent pulse wave data and template satisfy the recalibration condition.