Aims: 

To explore factors influencing the accuracy of oscillometric blood pressure measurement.

Methods: 

The applied computer-based simulator contained a model having arterial pressure pulses as an input signal and cuff volume oscillations as an output signal. There was a possibility to modify the arterial wall parameters to simulate different modalities of arterial stiffness. Thereafter, the oscillation envelopes were drawn and oscillometric estimation of systolic and diastolic pressures was performed using fixed characteristic ratios. Errors were calculated as differences between the oscillometrically estimated blood pressures and corresponding references (true values) measured from the pressure pulses as input signals of the model.

Results: 

For the tested range of affecting factors, the induced errors in systolic and diastolic pressures ranged 15 and 14 mmHg, respectively. Systolic estimates moved towards underestimation and diastolic ones slightly towards overestimation if pulse pressure increased. Arterial wall stiffening induced systematic overestimation of the systolic and over-or underestimation of the diastolic pressure compared to a normal artery, errors depending on the symmetry and steepness indices of the arterial wall pressure/volume curve. A good accordance between simulation and clinical measurements was revealed.

Conclusion: 

We demonstrated that the accuracy of oscillometric blood pressure estimation depended to a great extent on the functional-anatomical aspects of the artery. Relationships were derived to quantitatively assess the errors induced by changes in pulse pressure and in the shape indices (symmetry and steepness) of the arterial wall pressure/volume curve.