Rockley Photonics completes trial of wearable blood pressure monitoring device

Recently, Rockley Photonics, a developer of silicon photonics technology for healthcare applications, announced the results of trials using their wearable device to monitor blood pressure. These trials, approved by an Institutional Review Board (IRB), build upon preliminary pilot studies completed in 2022, marking progress in the commercialization of Rockley Photonics' first-generation Alpha device.

In the first study, 30 participants were tracked using Rockley Photonics' wearable device to monitor blood pressure within the body, and the measurements were compared to blood pressure measurements obtained using arterial pressure sensors (the gold standard for continuous blood pressure monitoring during surgeries and in the intensive care unit, ICU).

The company stated that, based on the ISO 81060-2 and IEEE 1708 standards recognized by the U.S. Food and Drug Administration (FDA), using signals based on Rockley Photonics' laser measurements and single-point blood pressure calibration, blood pressure variations ranging from -10 mmHg to +25 mmHg were within the target accuracy range.

In the second study, participants who had their blood pressure calibrated were tracked over 34 days with repeated measurements using Rockley Photonics' wearable device, and the measurements were compared to traditional cuff and stethoscope blood pressure measurements.

Rockley Photonics noted that while there were individual variations in how the wearable devices were worn, participants used multiple devices, and there was a higher reference error, the study results are expected to meet the accuracy goals of ISO 81060-2 and IEEE 1708.

"Reliably obtaining blood pressure is necessary to help diagnose early and monitor the management of various cardiovascular diseases," said Dr. Richard Kuntz, a medical doctor and scientific advisor to Rockley Photonics. "Our wearable device has the potential to achieve the accuracy of traditional medical device measurements, which can greatly enhance patient compliance and overall case management."

Rockley Photonics' first-generation Alpha device is designed with sensors in both the radial artery and dorsal wrist positions, allowing for direct comparison of measurements between the two locations. Each sensor module includes

(1) a laser sensor,

(2) an inertial measurement unit (IMU) with MEMS accelerometers and gyroscopes, 

(3) green, red, and near-infrared LEDs

(4) two photodiodes.

These trial results are good news for Rockley Photonics, which announced in June 2023 that it had completed a comprehensive financial restructuring after filing for Chapter 11 bankruptcy protection in the first quarter of the same year. The 46-day relief provided under Chapter 11 was achieved with an additional $35 million in funding raised from stakeholders.

Rockley Photonics will now engage with the FDA to discuss the next-generation Alpha device, with a focus on improving the convenience of wearing it on the user's wrist and the stability of measurement signals. Dr. Zahi Fayad of the Mount Sinai Health System in New York commented, "Measuring blood pressure using wearable devices has been a challenge for a long time. The emergence of this cuffless blood pressure measurement technology is very exciting, as it allows for frequent blood pressure measurements and provides a seamless and easy experience for both doctors and patients."