IEEE transactions on bio-medical engineering
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IEEE Trans Biomed Eng · Aug 1996
A mathematical study of some biomechanical factors affecting the oscillometric blood pressure measurement.
A mathematical lumped parameter model of the oscillometric technique for indirect blood pressure measurement is presented. The model includes cuff compliance, pressure transmission from the cuff to the brachial artery through the soft tissue of the arm, and the biomechanics of the brachial artery both at positive and negative transmural pressure values. The main aspects of oscillometry are simulated i.e., the increase in cuff pressure pulsatility during cuff deflation maneuvers, the existence of a point of maximum pulsations (about 1.5 mmHg) at a cuff pressure close to mean arterial pressure, and the characteristic ratios for cuff pressure pulsatility at systole and diastole (0.52 and 0.70, respectively, with this model, using basal parameters and an individual set of data for the arterial pressure waveform). ⋯ Evaluation of mean arterial pressure through a characteristic ratio is not robust and may lead to misleading results. Mean arterial pressure may be better evaluated as the lowest pressure at which cuff pulse amplitude reaches a plateau. The obtained results may help to explain the nature of errors which usually limit the reliability of arterial pressure measurement (for instance in the elderly).