Continuous non-invasive measurement of mean blood pressure in fingers by volume-clamp and differential oscillometric method.

The present study compares two different methods for non-invasive beat-to-beat finger arterial blood pressure monitoring. The measurements using the volume clamp method (FINAPRES, Ohmeda, USA) were compared with measurements applying the differential oscillometric method (UT9201 device, University of Tartu). 13 healthy volunteers were studied at rest, during head-up tilt (HUT) and during deep breathing (DB) with a fixed rate of 6 breaths/min. Blood pressure was recorded from adjacent fingers of the right hand. 150 pairs of mean blood pressure values in each subject were included for statistical evaluation. No systematic differences between the two methods were found. The difference between values (FINAPRES-UT9201) at rest was -1.1 mmHg (SD 5.5), during HUT 0.5 mmHg (SD 6.9) and during DB -3.6 mmHg (SD 7.7). The insignificant differences between the results obtained by the two independent methods allow us to conclude that both methods give reliable data on finger mean arterial pressure.