Practical Application of a New Cuffless Blood Pressure Measurement Method

Current blood pressure monitoring relies on cuff-based devices, which can be inconvenient for frequent use. While cuffless alternatives offer convenience, their accuracy remains a concern. Prior research has shown that cuffless methods may introduce variability, especially in diastolic readings. This gap motivated the need to evaluate a new device in real-world conditions. No prior work had resolved whether such devices could meet clinical standards across diverse patient groups. The study aimed to address this uncertainty by testing the CardioQVARK device in a broad sample. It was already known that cuff-based methods remain the gold standard for accuracy. However, the demand for continuous and accessible monitoring has grown. This study sought to determine if the new device could meet these needs without compromising reliability.

The goal was to assess the CardioQVARK device's performance in measuring blood pressure without a cuff. The researchers aimed to compare its readings with those from a standard sphygmomanometer. They focused on evaluating accuracy across different patient groups. The motivation came from the need for a portable and user-friendly BP monitoring solution. The study was designed to test whether the device met IEEE and ESH standards. The researchers wanted to determine if the device could be used for long-term monitoring. They also sought to identify any limitations in diastolic blood pressure readings. The study aimed to provide evidence for the device's potential in clinical settings.

The study included 167 patients with varying blood pressure levels. Each participant underwent three cuff-based measurements using a mercury sphygmomanometer. The average of these readings was used as the reference value. Simultaneously, the CardioQVARK device recorded ECG and photoplethysmocardiogram data. The device was placed on the patient’s body to capture the necessary signals. Two trained observers conducted the cuff-based measurements using a Y-shaped connector. The cuffless device recorded data for three minutes after the final cuff measurement. The researchers followed the IEEE standard for cuffless BP device validation. Bland-Altman plots were used to assess the agreement between the two methods.

The mean difference in systolic blood pressure was 0.31 ± 3.61 mm Hg. For diastolic blood pressure, the mean difference was 0.44 ± 3.76 mm Hg. The mean absolute difference for systolic readings was 3.44 ± 2.5 mm Hg. For diastolic readings, the mean absolute difference was 3.21 ± 2.82 mm Hg. The smallest error was observed in the prehypertension group, below 3 mm Hg. Patients with normal BP and stage 1 hypertension had errors up to 4 mm Hg. The largest errors occurred in stage 2 hypertension, reaching 4–5.5 mm Hg. No single measurement exceeded the 7 mm Hg threshold set by IEEE standards. The mean error remained below 5 mm Hg, meeting ESH guidelines. However, diastolic readings showed a small but consistent bias.

The CardioQVARK device met the IEEE standards for cuffless BP measurement. The study confirmed that the device is suitable for long-term monitoring. However, the diastolic readings showed a small but statistically significant bias. This bias may not affect individual patients but could influence population-level data. The device's portability and ease of use may improve patient adherence to treatment. The researchers propose that the device is not ideal for screening due to the diastolic bias. The study supports the use of the device for tracking BP trends over time. The results suggest that the device has potential for clinical application, especially in monitoring.