Rockley Photonics completes trials of wearable blood pressure monitor

16 Aug 2023

Clinical study indicates commercial potential as company emerges from Chapter 11.

Rockley Photonics, developer of silicon photonics technology for healthcare, has announced the results of trials using its wearable laser-based device to monitor blood pressure.

Completion of two Institutional Review Board (IRB)-approved trials builds on the findings of an initial pilot study completed in 2022, and is a further step towards commercialization of the company's Alpha device.

The first of the new studies used 30 subjects and successfully demonstrated intra-subject tracking of blood pressure compared to measurements using an intra-arterial pressure transducer, which is the gold-standard method to continuously monitor blood pressure during surgery and in the ICU.

Utilizing only the Rockley laser-based signal and a single-point blood pressure calibration, blood pressure changes from -10 mmHg to +25 mmHg were within target accuracy according to both FDA recognized consensus standards, ISO 81060-2 and IEEE 1708, said the company.

A second longitudinal study followed subjects with repeat visits up to 34 days post calibration, and compared Rockley device predictions with measurements made using traditional cuff and stethoscope.

Despite real-world variability in device placement, the use of multiple devices per subject, and higher reference error, the longitudinal study results were "within sight of meeting the ISO 81060-2 and IEEE 1708 accuracy targets," noted Rockley.

"Reliable acquisition of blood pressure is necessary to aid in the early diagnosis and continued monitoring of patients that require management of a variety of cardiovascular conditions," said Richard Kuntz, MD and Rockley scientific advisor. "Rockley’s device shows promise that it will perform with the accuracy expected from traditional medical devices, which can vastly improve patient compliance and overall case management."

FDA discussions to follow for next-generation device

Rockley's Alpha device is designed with duplicate sensors at the radial artery and dorsal wrist positions, for direct comparison of results at the two locations. Each sensing module includes the laser sensor; an inertial measurement unit with accelerometer and gyroscope; green, red, and near-IR LEDs; and two photodiodes.

The trials are good news for Rockley, which in June 2023 announced that it had completed a comprehensive financial restructuring after filing for bankruptcy protection in Q1 of the year. Emergence from 46 days under Chapter 11 relief was enabled by $35 million of additional funding raised from stakeholders.

That episode followed the company going public in 2021 through merger with SC Health, a listed special purpose acquisition company. The deal was closed in August 2021, at which point it was said to have yielded $167.8 million in gross proceeds for the commercial launch of Rockley's sensing platform.

Rockley will now engage with the FDA on discussions about a next-generation Alpha device, as the company works on improving the ease of placement on the wrist and on signal stability.

"Blood pressure measurements using wearables have long been a challenge," commented Zahi Fayad from New York's Mount Sinai Health System. "It is very exciting to see this cuffless technology becoming available, as it enables frequent measurements and can provide a seamless and easy practitioner and patient experience."