Sensitivity of compliance-based continuous non-invasive blood pressure monitoring to changes in viscoelastic parameters

The apparent arterial compliance observed from noninvasive measurements of arterial blood pressure and cross-sectional area does not directly correspond to the static compliance curve or dynamic pressure-area loop. The accuracy of continuous, non-invasive blood pressure estimates based on calibrated arterial compliance models to convert area to pressure is affected by both changes in the viscoelastic properties of the artery and in the pressure waveform. The relationship of the apparent compliance curve to static compliance and to dynamic pressure-area loop is demonstrated using a simulated linear viscoelastic model, and the sensitivity of blood pressure estimates to changes in the viscoelastic parameters and pressure waveform is investigated. Changes in the elastic component of the viscoelastic model had the largest effect with a 25% change in the modulus of elasticity resulting in a 5.5% error in the systolic blood pressure estimate.