Oscillometric blood pressure devices and simulators: measurements of repeatability and differences between models.
OBJECTIVE
To measure the repeatability and pressure pulse envelope of simulators used for testing oscillometric non-invasive blood pressure (NIBP) devices; to study the effect of different envelopes on NIBP devices, and to measure the difference between NIBP devices due to different oscillometric algorithms.


METHODS
Three different models of NIBP simulator and 18 different patient monitors with NIBP function were studied. We developed a pressure measurement system (accuracy 0.048?mmHg) to measure the repeatability of simulators. The effect of changing the envelope was measured by using three simulators with one NIBP device. Differences between 18 NIBP devices were measured using one simulator at seven blood pressure settings.


RESULTS
Simulators generate repeatable pressure pulse envelopes (< 0.2 mmHg) but the magnitude and shape depends on the model of simulator. Oscillometric NIBP devices are highly repeatable (< 2 mmHg) when presented with a repeatable pressure pulse envelope, but different devices employ different algorithms and give different results. For a simulated standard blood pressure setting of 120/80 mmHg, estimates of systolic pressure ranged from 112.6 to 126.6 mmHg (sd of 3.0 mmHg), and diastolic pressure ranged from 74.8 to 86.9 mmHg (sd of 3.5 mmHg).


CONCLUSIONS
Simulators and NIBP devices are sufficiently repeatable for clinical use, but further systematic clinical studies are required to better characterize the pressure pulse envelope for different patient groups.
Sims
A J
AJ
Regional Medical Physics Department, Freeman Hospital, Newcastlle upon Tyne, UK. a.j.sims@newcastle.ac.uk
Reay
C A
CA
Bousfield
D R
DR
Menes
J A
JA
Murray
A
A
D000465:Algorithms; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000295:instrumentation* / Q000379:methods; D004739:England; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000295:instrumentation* / Q000379:methods*; D009991:Oscillometry / Q000295:instrumentation* / Q000379:methods; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity