Ring-type CART Monitor Shows it Can Track Blood Pressure in AF and Heart Failure Patients

Sky Labs used ESC Congress 2026 in Munich to present what it says is the first clinical evidence that its ring-type blood pressure monitor, CART, can be used for continuous BP monitoring in patients with atrial fibrillation (AF) and heart failure, two groups that conventional cuff-based devices have historically struggled to measure accurately.

The South Korean company, led by CEO Jack ByungHwan Lee, ran five dedicated sessions at the congress covering new clinical data in these patient groups.

The core problem CART is aimed at

Standard blood pressure cuffs rely on detecting a regular pulse. In patients with atrial fibrillation, the heartbeat is irregular by definition, and in advanced heart failure, pulse variability can also be high. Both scenarios make cuff-based 24-hour ambulatory blood pressure monitoring (ABPM) less dependable, which in turn makes it harder for clinicians to titrate medication or spot dangerous overnight blood pressure patterns.

CART takes a different approach, using PPG (photoplethysmography) sensors and an AI deep learning model built into a finger ring to measure blood pressure continuously over 24 hours without a cuff.

What the new data showed

Professor Ki-Hong Lee of Chonnam National University Hospital presented a 24-hour BP monitoring study in AF patients, reporting an analysable data rate of around 80%. In his words: "Using the CART blood pressure monitor, we achieved an analyzable data rate of approximately 80%, demonstrating the utility of ring-type 24-hour BP testing and enabling continuous observation of nocturnal dipping patterns."

Professor In-Cheol Kim of Keimyung University Dongsan Hospital presented findings in patients with severe heart failure (mean ejection fraction of 29%), comparing CART directly against conventional 24-hour ABPM. He said the comparison

referring to the European Society of Hypertension's validation standard for cuffless devices.

Elsewhere at the congress, Professor Hae-Young Lee of Seoul National University Hospital presented data showing CART met ESH recommendations for cuffless devices across four separate validation protocols: the Static Test, Device Position Test, Awake/Asleep Test and Exercise Test.

Professor Eun-Mi Lee of Dongguk University Ilsan Hospital described a case where CART allowed a patient experiencing cuff-induced pain and stress to have their medication safely reduced based on a more accurate BP reading. Professor Jong-Chan Youn of Seoul St. Mary's Hospital analysed more than 12,000 breathing disorder events across 62 sleep apnea patients, tracking sharp blood pressure surges immediately after breathing resumed.

Commenting on the body of work, Professors Seok-Min Kang of Severance Hospital and George Stergiou of the National and Kapodistrian University of Athens said:

Cuffless blood pressure devices, particularly consumer wearables, have a mixed reputation among clinicians because many haven't been through rigorous, standardised validation. The ESH protocol exists precisely to separate devices with genuine clinical evidence behind them from those relying on marketing claims. CART's inclusion in the 2026 Korean Society of Hypertension Guidelines (6th Edition), which Sky Labs describes as a first for a ring-type cuffless monitor, is a more concrete marker of clinical acceptance than validation testing alone, since guideline committees tend to be conservative about which devices they endorse.

The device already has meaningful uptake behind it. Sky Labs says CART is prescribed in over 2,000 Korean medical institutions, with more than 300,000 cumulative prescriptions to date.

CEO Jack ByungHwan Lee framed the ESC presentations as a step toward wider adoption outside Korea:

Whether European regulators and clinicians respond to that data as positively as the Korean guideline committee did will be the more telling test of CART's claims going forward.