A new proposal for setting servo-control reference for accurate measurement of instantaneous arterial pressure based on the volume-compensation method

Servo-control reference corresponding to arterial unloading volume (r_V₀) is one of the most important parameters when measuring accurately blood pressure (BP) using the volume-compensation method (VCM). We proposed here a new method to set r_V₀ by adjusting it to yield approximately equalized values in systolic and diastolic BP that were determined by a pre-operation procedure of the tube-law based volume-oscillometric method. BP measurements at a finger were made in 10 volunteers by the VCM with r_V₀ settings of both the original (r_V₀_org) and the new value (r_V₀_prp), while measuring simultaneously brachial BP as a reference. Analyses revealed that r_V₀_prp was higher than r_V₀_org, and that the correlation coefficients between systolic/diastolic BP values using the r_V₀_prp and the r_V₀_org settings and those by the brachial BP measurements were 0.97 and 0.83, respectively. These results indicate the effectiveness of this setting method for more practical and accurate BP measurement by the VCM.