BEIJING -- A team of researchers has developed a conformal and stretchable piezoelectric microsystem (CSPM) that integrates device design with algorithmic optimization, offering a new approach for long-term, precise monitoring of cardiovascular health.

The achievement was recently published in the journal Nature Communications.

Frequent recalibration poses a major challenge to the accuracy and reliability of current cuffless blood pressure monitoring devices, particularly during long-term use, the study noted.

The CSPM, developed by researchers from Tianjin University, the Chinese University of Hong Kong, City University of Hong Kong and the Hong Kong Centre for Cerebro-cardiovascular Health Engineering (COCHE), features two core sensing modules and achieves much higher sensitivity than conventional designs. It can accurately capture pulse wave signals and measure vascular diameter and its dynamic changes in real time, with a resolution of up to 4.928 micrometers.

The two sensing modules can operate simultaneously in the same localized vascular area, enabling precise, synchronous measurement of pulse wave velocity and vascular diameter, according to a report by China Science Daily.

This provides comprehensive hemodynamic parameters to support accurate blood pressure calculation.

The CSPM also offers excellent wearability. Measuring less than 450 micrometers in thickness and weighing under one gram, it is encapsulated in low-stiffness silicone rubber and can stretch up to 40 percent, allowing it to conform closely to curved skin surfaces such as the wrist.

Thanks to its hydrophobic, sweat-resistant properties and outstanding biocompatibility, the microsystem can maintain a stable temperature during continuous operation for up to three hours, meeting the demands of long-term, uninterrupted monitoring.

On the algorithmic front, the research team developed a demographics-based adaptive blood pressure model, enabling calibration-free blood pressure measurement.

The team also introduced a time-decay compensation strategy to effectively address measurement deviations caused by minor slippage of the wearable sensor, ensuring long-term stability in blood pressure monitoring.

Tests on 45 subjects showed that the CSPM maintained consistent accuracy across individuals of different genders, ages and skin tones.

It can precisely track blood pressure fluctuations during daily activities over a seven-day period without requiring individual calibration, achieving accuracy comparable to that of professional cuff-based medical devices.

This technology overcomes the long-standing challenges of frequent calibration and population adaptability that have limited cuffless blood pressure monitoring. It holds promise for a wide range of applications, including hypertension screening, early warning of cardiovascular diseases and long-term disease management.