Comparing blood pressure measurements between a photoplethysmography-based and a standard cuff-based manometry device

Abstract

Repeated blood pressure (BP) measurements allow better control of hypertension. Current measurements rely on cuff-based devices. The aim of the present study was to compare BP measurements using a novel cuff-less photoplethysmography-based device to a standard sphygmomanometer device. Males and females were recruited from within the general population who arrived at a public BP screening station. One to two measurements were taken from each using a sphygmomanometer-based and the photoplethysmography-based devices. Devices were considered equal if the mean difference between paired measurements was below 5 mmHg and the Standard Deviation (SD) was no greater than 8 mmHg. Agreement and reliability analyses were also performed. 1057 subjects were included in the study analysis. There were no adverse events during the study. The mean (± SD) difference between paired measurements for all subjects was -0.1 ± 3.6 mmHg for the systolic and 0.0 ± 3.5 mmHg for the diastolic readings. We found 96.31% agreement in identifying hypertension and an Interclass Correlation Coefficient of 0.99 and 0.97 for systolic and diastolic measurements, respectively. The photoplethysmography-based device was found similar to the gold-standard sphygmomanometer-based device with high agreement and reliability levels. The device might enable a reliable, more convenient method for repeated BP monitoring.

Figure 1

The Biobeat BB-613WP device. This PPG-based wearable provides non-invasive, cuffless, wireless and repeated measurement of blood pressure, heart rate, saturation, respiratory rate, stroke volume, cardiac output, cardiac index, systemic vascular resistance, pulse pressure, heart rate variability, mean arterial pressure, skin temperature, sweat, movement, and calories. Data is transmitted in real-time to a user App and to a medical management system. (A) The face side. (B) The back side with integrated sensors.

Figure 2

Percentage of measurements with a delta of less than 5, 5–7, 7–10 or above 10 mmHg between the reference device and the BB-613WP systolic measurements. Sys1 first systolic measurement. Sys2 second systolic measurement.

Figure 3

Bland Altman agreement plot of the first blood pressure measurement (n = 1057). (A) Systolic blood pressure. (B) Diastolic blood pressure.

Figure 4

Bland Altman agreement plot of the second blood pressure measurement (n = 491). (A) Systolic blood pressure. (B) Diastolic blood pressure.

Figure 5

ROC curves analysis illustrating the diagnostic ability of the BB-613WP device in comparison to the standard reference method (sphygmomanometer device).

Figure 6

Description of the different stages of the study.