A New Cuffless Device for Measuring Blood Pressure: A Real-Life Validation Study

Abstract

BackgroundCuffless blood pressure (BP) monitoring devices, based on pulse transit time, are being developed as an easy-to-use, more convenient, fast, and relatively cheap alternative to conventional BP measuring devices based on cuff occlusion. Thereby they may provide a great alternative to BP self-measurement.ObjectiveThe objective of our study was to evaluate the performance of the first release of the Checkme Health Monitor (Viatom Technology), a cuffless BP monitor, in a real-life setting. Furthermore, we wanted to investigate whether the posture of the volunteer and the position of the device relative to the heart level would influence its outcomes.MethodsStudy volunteers fell into 3 BP ranges: high (>160 mmHg), normal (130–160 mmHg), and low (<130 mmHg). All requirements for test environment, observer qualification, volunteer recruitment, and BP measurements were met according to the European Society of Hypertension International Protocol (ESH-IP) for the validation of BP measurement devices. After calibrating the Checkme device, we measured systolic BP with Checkme and a validated, oscillometric reference BP monitor (RM). Measurements were performed in randomized order both in supine and in sitting position, and with Checkme at and above heart level.ResultsWe recruited 52 volunteers, of whom we excluded 15 (12 due to calibration failure with Checkme, 3 due to a variety of reasons). The remaining 37 volunteers were divided into low (n=14), medium (n=13), and high (n=10) BP ranges. There were 18 men and 19 women, with a mean age of 54.1 (SD 14.5) years, and mean recruitment systolic BP of 141.7 (SD 24.7) mmHg. BP results obtained by RM and Checkme correlated well. In the supine position, the difference between the RM and Checkme was >5 mmHg in 17 of 37 volunteers (46%), of whom 9 of 37 (24%) had a difference >10 mmHg and 5 of 37 (14%) had a difference >15 mmHg.ConclusionsBP obtained with Checkme correlated well with RM BP, particularly in the position (supine) in which the device was calibrated. These preliminary results are promising for conducting further research on cuffless BP measurement in the clinical and outpatient settings.

Feasibility of a New Cuffless Device for Ambulatory Blood Pressure Measurement in Patients With Hypertension: Mixed Methods Study (Preprint)

“…[20] Other mistakes concerning the use of the Checkme were not observed. This is in contrast to the observation during classic BP measurement, in which various other errors, with respect to cuff usage and position, can occur.…”

“…The SBP with the Checkme was considered comparable to an in-hospital reference monitor, with a mean difference of 2.6 ± 12.1 mmHg. [20] Other studies compared different cuffless SBP measuring devices to a reference monitor. Poon et al [33] described a difference of 0.6 ± 9.8 mmHg and…”

“…[20] This validation protocol may be considered inadequate, since it lacks a consensus about the quality of the BP measurement to be used for calibrating cuffless devices. However, results obtained with the Checkme were promising over a wide range of BP levels.…”

“…However, results obtained with the Checkme were promising over a wide range of BP levels. [20] A recent study showed promising results of vital parameter measurements in an inpatient setting. [21] Since the previous study by Schoot et al was performed under demanded controlled circumstances, we felt the need to evaluate the performance of the Checkme in an uncontrolled home setting.…”

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“…by PPG, piezo, or bioimpedance) the time of arrival of the mechanical pulse wave, e.g. at the radial artery in the wrist (or another well-accessible artery) or (at somewhat reduced accuracy) a fingertip [40]. Note that, because it uses the ECG R-top as a reference, PAT includes the preejection period of the heart which is determined by the ventricular electromechanical delay and isovolemic contraction phase and can vary with contractility and afterload, thus adding additional uncertainty.…”