Ring-Type Blood Pressure Monitor Integrated Into Official Hypertension Guidelines

Sky Labs’ ring-type cuffless blood pressure monitor, CART BP pro, has achieved an important milestone, having been integrated for the first time into official hypertension treatment guidelines.

Publication in the “2026 Korean Society of Hypertension Guidelines for the Management of Hypertension (6th Edition)” is considered a world-first for a ring-type blood pressure monitor, according to the company. The decision makes Korea the first country to incorporate cuffless blood pressure measurement technology into mainstream clinical practice.

“The inclusion of CART BP pro in the KSH guidelines demonstrates that Korea is leading the global clinical standard for cuffless blood pressure technology,” Sky Labs CEO Jack ByungHwan Lee said. “Leveraging this unparalleled clinical evidence and our successful domestic adoption, we will now accelerate overseas regulatory approvals to establish a new global standard in hypertension management.”

Through this revised guideline, the Korean Society of Hypertension explicitly stated the “first inclusion of cuffless blood pressure measuring devices in clinical practice” and presented them as products that may be considered for out-of-office blood pressure monitoring. In the guideline, the recommendation class for cuffless blood pressure monitors was Class IIb.

This inclusion in the treatment guidelines is also a change drawing attention from the global hypertension academic community. Until now, major academic societies in the United States and Europe had maintained a cautious stance on introducing cuffless devices due to reasons such as the lack of standardized validation protocols and differences in accuracy among devices. Even amid such concerns, Sky Labs’ ring-type blood pressure monitor not only showed favorable correlation with office blood pressure measured by the traditional auscultatory method, but also demonstrated high accuracy comparable to standard 24-hour ambulatory blood pressure monitoring (ABPM) values. Based on such clinical evidence, the Korean Society of Hypertension made the world’s first official recommendation.

The Korean Society of Hypertension (KSH) formalized the clinical protocols for out-of-office blood pressure measurement for patients with prehypertension and high-risk groups requiring intensive blood pressure control. First, it set the target blood pressure for patients with diabetes, chronic kidney disease, cerebral infarction (accompanied by stroke), and high-risk hypertension at a more stringent level below 130/80 mmHg than before and presented risk-based drug treatment guidelines. In addition, for the pre-hypertension patient group, which is highly likely to progress to hypertension, it also specified the recommendation to actively consider ambulatory blood pressure monitoring (ABPM) or home blood pressure measurement to determine whether masked hypertension is present.

As the need for 24-hour monitoring is thus expanding to patients with prehypertension, the wearable ring-type cuffless blood pressure monitor, which can be worn without interfering with daily life, is emerging as a practical alternative in clinical settings. It can precisely track the risks of nocturnal hypertension and morning hypertension, which are difficult to detect through one-time office measurements alone, as well as resistant hypertension, which is difficult to treat.

According to a domestic study cited in the guideline, the frequency of nocturnal hypertension, defined as blood pressure of 120/70 mmHg or higher during sleep, reaches about 18% to 23% of the general population. In particular, 92.6% of patients with nocturnal hypertension were classified as having masked hypertension, appearing to have normal blood pressure in everyday circumstances, and were found to have a higher risk of cardiovascular disease, including increased arterial stiffness and left ventricular hypertrophy, compared with the normotensive group. In addition, morning hypertension, defined as morning blood pressure of 135/85 mmHg or higher, was also reported at 15.9% in a domestic study of patients with hypertension and was pointed out as a major risk factor for cardiovascular events.

To more precisely evaluate high‑risk conditions such as nocturnal and morning hypertension, the Society recommends 24‑hour ambulatory blood pressure monitoring and presents ring‑type cuffless blood pressure monitors as a clinical tool for out‑of‑office blood pressure monitoring. In particular, the Society noted the ring-type cuffless monitor as an innovative alternative to overcome the longstanding clinical limitations of conventional cuff-type ABPMs—such as the inconvenience of 24-hour wear, repetitive compression pain, and resulting sleep disturbances, which often disrupted effective nighttime readings.

According to research cited in the guidelines, the ring‑type cuffless blood pressure monitor met the accuracy requirements of the international standard (ISO 81060‑2:2018) in comparative clinical trials against standard 24‑hour ambulatory blood pressure monitoring (ABPM), maintaining a mean error within 5 mmHg and a standard deviation within 8 mmHg during both day and night, and thus demonstrated its clinical usefulness.

Sky Labs’ CART BP pro analyzes blood pressure data collected through photoplethysmography (PPG) using artificial intelligence (AI) deep learning technology, enabling 24-hour measurement during daily life or sleep with minimal discomfort. Thus, it is regarded as an alternative that can precisely evaluate a patient’s blood pressure variability and improve hypertension diagnosis and treatment accuracy.

Based on such clinical evidence, CART BP pro became the first ring-type blood pressure monitor to receive national health insurance reimbursement under South Korea’s National Health Insurance (NHI) system in June 2024. Since its reimbursement entry, it has been prescribed more than 250,000 times in frontline medical settings up to now and is being actively used at 1,920 hospitals and clinics nationwide, including tertiary general hospitals.

Founded in September 2015, Sky Labs is a healthcare company that develops and operates CART, a ring-type medical device and platform for monitoring chronic disease patients. Since the first CART was developed in 2020 for atrial fibrillation monitoring using cardiac signals from optical sensors, the company has expanded its capabilities. In 2023, Sky Labs received medical device approval for CART BP pro, a ring-type monitor designed for 24-hour blood pressure measurement. In 2024, CART BP pro was recognized by the Health Insurance Review and Assessment Service (HIRA) under the existing medical procedure of 24-hour ambulatory blood pressure monitoring (reimbursement code E6547), and is currently being prescribed in hospitals and clinics across Korea. Furthermore, in September 2025, the company launched CART BP, a consumer-grade ring-type blood pressure monitor.