Non-invasive continuous blood pressure monitoring: a review of current applications

Abstract

Blood pressure monitoring has come a long way from the initial observations made by Reverend Hales in the 18th century. There are none that deny the importance of monitoring perioperative blood pressure; however, the limited ability of the current prevalent technology (oscillometric blood pressure monitoring) to offer continuous blood pressure measurements leaves room for improvement. Invasive monitoring is able to detect beat-to-beat blood pressure measurement, but the risks inherent to the procedure make it unsuitable for routine use except when this risk is outweighed by the benefits. This review focuses on the discoveries which have led up to the current blood pressure monitoring technologies, and especially the creation of those offering non-invasive but continuous blood pressure monitoring capabilities, including their methods of measurement and limitations.

Continuous Blood Pressure Measurement From Invasive to Unobtrusive: Celebration of 200th Birth Anniversary of Carl Ludwig

“…Thus far, the evolution of BP measurement devices has been well documented [11,12]. In this review, we focus on key technological milestones of continuous BP measurement from invasive to unobtrusive techniques.…”

Haemodynamic Monitoring in the Intensive Care Unit

“…Ultrasound detection of arterial wall motion using devices like Puritan Bennett's Infrasonde TM [9] and photometric wave velocity measurement (pulse transit time bears an approximately inverse ratio to systolic blood pressure) has been described [10].…”

Changing trends of hemodynamic monitoring in ICU - from invasive to non-invasive methods: Are we there yet?

“…Both these techniques have been validated. [5] The accuracy and stability of blood pressure recording is maintained by using several concentrically interlocking control loops. [6] Although CNAP has been found to be reliable in patients at risk of hypotensive episodes such as those undergoing caesarean sections under subarachnoid blocks,[7] it is not without its disadvantages which include a lag time of 7.5-10 s,[8] decreased accuracy as compared to invasive techniques[9] and missed blood pressure measurements.…”

“…The pressure required to flatten the artery is then used to derive the systolic, diastolic and mean pressures using an algorithm. [516] T-line TL-200 and TL-200pro are the devices currently available that work on this principle. The studies on tonometry have produced controversial results.…”

“…The systolic blood pressure is inversely proportional to this time. [5] Alternatively, time from the R -wave on the ECG to the time arterial pulse reaches a peripheral site may be measured. Photometry may be used for this purpose.…”