Patent ID: 7887491

Claim:
A method for non-invasively measuring blood pressure of a patient, the method comprising: (a) attaching a pressure cuff to an extremity of the patient; (b) attaching a plethysmographic device to the extremity at a distal location relative to the pressure cuff: (c) inflating and deflating the cuff; (d) taking a series of waveforms representing blood pulsations by using the plethysmographic device; (e) deriving, using a processor, a mathematical parameter from a combination of successive ones of the waveforms taken in step (d) and measuring the blood pressure from the mathematical parameter; and (f) outputting the blood pressure measured in step (e); wherein step (e) comprises multiplying corresponding points in groups of the waveforms to produce product waveforms and measuring the blood pressure from the product waveforms.