Oscillometric blood pressure devices and simulators: measurements of repeatability and differences between models

Area of Science:

• Biomedical Engineering
• Medical Device Technology
• Clinical Measurement

Background:

• Oscillometric non-invasive blood pressure (NIBP) devices are widely used for patient monitoring.
• The accuracy and reliability of NIBP devices depend on the simulators used for their testing.
• Understanding the characteristics of pressure pulse envelopes generated by simulators is crucial for accurate NIBP device evaluation.

Purpose of the Study:

• To assess the repeatability and pressure pulse envelope characteristics of NIBP simulators.
• To investigate the impact of different pressure pulse envelopes on NIBP device performance.
• To quantify the variability in NIBP measurements arising from different oscillometric algorithms.

Main Methods:

• Evaluated three NIBP simulator models and 18 patient monitors with NIBP functionality.
• Developed a high-accuracy pressure measurement system (0.048 mmHg) to quantify simulator repeatability.
• Measured the effect of envelope variations using three simulators with one NIBP device and algorithm differences using one simulator across 18 devices.

Main Results:

• NIBP simulators consistently generate repeatable pressure pulse envelopes (< 0.2 mmHg), though magnitude and shape vary by simulator model.
• Oscillometric NIBP devices demonstrate high repeatability (< 2 mmHg) with consistent envelopes but show significant result differences due to distinct algorithms.
• Simulated 120/80 mmHg readings varied: systolic pressure estimates ranged from 112.6 to 126.6 mmHg (sd 3.0 mmHg), and diastolic from 74.8 to 86.9 mmHg (sd 3.5 mmHg).

Conclusions:

• Both NIBP simulators and NIBP devices exhibit sufficient repeatability for clinical applications.
• Differences in oscillometric algorithms contribute to measurement variability across NIBP devices.
• Further clinical research is necessary to define pressure pulse envelopes for various patient populations.