Oscillometric blood pressure measurement: the methodology, some observations, and suggestions

Most noninvasive blood pressure (NIBP) devices use the oscillometric method. Published studies of oscillometric methodology introduced varied algorithmic approaches for determination of systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressures. While there is a general agreement about MAP determination, controversy exists about the determination of SBP and DBP Accuracy of oscillometric devices has been questioned and validation studies have revealed problems. Several validation protocols have been developed but they are expensive and time consuming to conduct and they have their own limitations. Instruments for bench testing of NIBP devices are useful for some device functions, but they cannot perform dynamic accuracy tests. The issue of accuracy is becoming very important as health care professionals increasingly rely on electronic NIBP devices. The authors developed a compact system for acquisition of NIBP waveforms. Some representative oscillometric waveforms are introduced here to demonstrate the oscillometric method and its shortcomings. A finger photoplethysmograph (PPG) was used to demonstrate a potential improvement of SBP determination. The concept and significance of an oscillometric blood pressure waveform database is introduced and its applications are discussed.