Methods And Apparatus For Determining Cuff Blood Pressure

Abstract

A method is provided for determining blood pressure for a subject using a sphygmomanometer. The method includes: measuring an oscillometric cuff pressure waveform of the subject using the sphygmomanometer; representing the measured waveform with a physical model accounting for mechanics of the cuff, an artery and coupling between the cuff and the artery; determining the model unknowns from the measured waveform; and determining blood pressure for the subject using the determined model.

1 .- 23 . (canceled) 
     
     
         24 . A method for determining blood pressure for a subject using an oscillometric cuff device, comprising:
 measuring cuff pressure using an oscillometric cuff device by inflating and deflating a cuff placed over an artery of the subject;   deriving an oscillogram from the measured cuff pressure, where the oscillogram is an amplitude of oscillations in the measured cuff pressure as a function of the measured cuff pressure;   determining an envelope difference between an upper envelope of the oscillogram and a lower envelope of the oscillogram;   representing the envelope difference as a difference in a parametric model, where the parametric model is defined in terms of parameters with unknown values and specifies a nonlinear area-pressure relationship of the artery underneath a cuff of the oscillometric cuff device at systole and diastole;   estimating values for the parameters of the parametric model simultaneously by fitting the parametric model to the envelope difference; and   determining blood pressure for the subject from the values of the parameters of the parametric model.   
     
     
         25 . A method for determining blood pressure for a subject using an oscillometric cuff device, comprising:
 measuring cuff pressure using an oscillometric cuff device by inflating and deflating a cuff placed over an artery of the subject;   measuring volume of air pumped into and out of the cuff during inflation and deflation of the cuff;   representing the measurements with a parametric model, where the parametric model is defined in terms of parameters with unknown values and specifies (a) a nonlinear area-pressure relationship for the artery of the subject, (b) a relationship between the arterial area of the subject and the cuff pressure and volume of air pumped into and out of the cuff during inflation and deflation of the cuff, and (c) the blood pressure waveform;   estimating values for the parameters of the parametric model by fitting the parametric model to the measurements; and   determining blood pressure for the subject from the values of the parameters of the parametric model.   
     
     
         26 . A method for continuously determining blood pressure for a subject using a finger cuff device, comprising:
 a) measuring cuff pressure using a finger cuff device by inflating and deflating the finger cuff device while the finger cuff device is placed over a finger artery of the subject;   b) representing the measured cuff pressure with a physical model, where the model accounts for a nonlinear area-pressure relationship for the artery of the subject;   c) determining unknowns of the model using the measured cuff pressure;   d) determining blood pressure of the subject using the determined physical model;   e) maintaining the cuff pressure of the finger cuff device at a constant cuff pressure; and   determining when to repeat steps a)-e) using the amplitude of the cuff pressure oscillation at the constant cuff pressure and the determined physical model.