Method of artifact rejection for noninvasive blood-pressure measurement

Abstract

For use in performing non-invasive blood-pressure measurement (NIBP), an artifact rejection method for predicting expected data values from acquired data, and for adjusting previously acquired data based on the relationship of actually measured data values to their corresponding predicted values. The method is practiced in a system comprising an inflatable, occluding cuff, a pump and a valve coupled to the cuff, and monitoring apparatus coupled to the cuff adapted to measure cuff pressure and recurring blood-pressure pulsations occurring in the cuff that are caused by each heart contraction occurring in a measurement cycle. Cuff pressure is raised to a level above the patient's systolic pressure, and progressively reduced in a stepwise fashion to an ending cuff pressure. A fixed number of pulsations are measured and processed at a first and second cuff-pressure step, and a generally lesser number of pulsations are measured and processed at a third and subsequent cuff-pressure steps. The method includes, at the second cuff-pressure step, generating a prediction curve for predicting a next, expected-to-be-stored pulsation data value for a next, lower cuff-pressure step. The method also includes repeatedly smoothing the prediction curve based on the difference between a pulsations's calculated data value and its respective predicted data value. A final, smoothed curve is generated reflecting a final pulsation data value for each cuff-pressure step. From the final curve, the desired blood pressure parameters are derived and displayed in the form of arabic numerals by means of an LCD read-out.