A wearable ultrasound patch for continuous and non-invasive blood pressure monitoring has been created by a team of researchers at the University of California San Diego.

Source: David Baillot/UC San Diego Jacobs School of Engineering

“Traditional blood pressure measurements with a cuff, which are limited to providing one-time blood pressure values, can miss critical patterns. Our wearable patch offers a continuous stream of blood pressure waveform data, allowing it to reveal detailed trends in blood pressure fluctuations,” the researchers explained.

Worn on the forearm, the sensor reportedly offers precise, real-time readings of blood pressure deep within the body. The patch is comprised of a silicone elastomer that sandwiches piezoelectric transducers between stretchable copper electrodes.

Those tightly packed transducers, the team explained, transmit and receive ultrasound waves that track alterations in the diameter of blood vessels, which are subsequently converted into blood pressure values.

Building on a previously developed patch, the researchers re-engineered its design to improve performance for continuous blood pressure monitoring. They achieved this by positioning the piezoelectric transducers closer together, ensuring broader coverage and more precise targeting of smaller, clinically significant arteries. Additionally, they incorporated a backing layer to dampen redundant vibrations from the transducers, enhancing signal clarity and improving the accuracy of arterial wall tracking.

The team concluded that the results of the patch when compared to the results of a blood pressure cuff and an arterial line, which is a sensor inserted into an artery to continuously monitor blood pressure, were comparable.

“Blood pressure can be all over the place depending on factors like white coat syndrome, masked hypertension, daily activities or use of medication, which makes it tricky to get an accurate diagnosis or manage treatment,” the researchers added.

An article detailing the patch, “Clinical validation of a wearable ultrasound sensor of blood pressure,” appears in the journal Nature Biomedical Engineering.