Patent ID: 8414499
Filing Date: 2013-04-09
Classification: A61B,G16H

Abstract:
1. A plethysmograph variability method comprising: inputting a plethysmograph waveform having pulses corresponding to pulsatile blood flow within a tissue site; deriving a plurality of perfusion values corresponding to the pulses, wherein deriving the plurality of perfusion values comprises: determining a plurality of variability values indicative of the variability of a plurality of series of perfusion values, wherein each variability value is determined by calculating a difference between a first perfusion value of a series of perfusion values and a second perfusion value of the series of perfusion values and normalizing the difference with the first perfusion value; calculating a plethysmograph variability parameter representative of the plurality of variability values; and displaying the plethysmograph variability parameter.