S-58-4: ARE CUFFLESS BLOOD PRESSURE MEASURING DEVICES READY FOR CLINICAL USE?

Abstract

Several cuffless BP measuring devices are currently available on various markets claiming that they provide accurate measurements, and few have some regulatory approval. These technologies may provide numerous BP readings in different settings and activ ities of daily life without using a disturbing cuff. Thus, they have considerable potential to improve the awareness, treatment, and management of hypertension by. The crucial question is whether thjey can provide accurate measurement of BP. Microsoft Research recently published a major engineering paper presenting results of the Aurora Project assessing the accuracy of several PWA and PWA-PAT devices using radial tonometry, photoplethysmography, electrocardiography, and accelerometry signals in 1,125 participants, including younger and older individuals with low or high BP. The overall results were negative. Smaller recent studies also showed negative results. In a recent study, finger PPG waveform analysis and PAT explored during several interventions inducing BP changes the test device had some value in predicting changes in auscultation SBP but not DBP. Another study of a cuff-calibrated wristband device tested against standard 24-h ambulatory BP showed that the cuffless device was unable to track the BP drop during nighttime sleep. In a third study, a cuff-calibrated smartwatch device showed a systematic bias towards the cuff BP at calibration and could not accurately measure BP compared to standard 24-h ambulatory monitoring. On the other hand, two recent studies showed positive results. The first showed that a cuff-calibrated device could almost perfectly predict average ambulatory BP, and the second showed that a demographics-calibrated device could predict invasive BP. Although the scientific community, patients, and the public are eager to adopt cuffless BP devices in routine use, further research is needed to bring these technologies to primetime. A recent statement by the ESH Working Group on BP Monitoring recommended not to use cuffless BP devices for the diagnosis and management of hypertension. These technologies and devices require further development and proper testing in independent studies. In addition, there is an urgent need for establishing protocols which are specific for validating cuffless devices, as the Universal Standard (AANMI/ESH/ISO) for testing automated cuff devices is not applicable to cuffless devices. Developing such protocols is challenging, and the current ones require further vetting (IEEE 2014 and ISO under development). Thus, fundamental research questions need to be carefully addressed before cuffless BP devices can be recommended for clinical use.