Blood pressure is typically taken with a cuff wrapped around the arm, providing a reading in one moment in time. These fleeting snapshots may not always reflect a person’s average blood pressure, and even simple factors like the stress of being at a doctor’s appointment can drive up the numbers. Continuous monitoring offers a broader picture, but many wearable devices still require calibration with a standard blood pressure cuff reading – until now.
Happy Health’s new smart ring – the Happy Ring – is designed to measure blood pressure continuously, without a cuff or invasive device, and without the requirement for external calibration that many other wearable blood pressure devices require. The Austin, Texas-based digital health company announced last week that Happy Ring’s blood pressure measurement capabilities have received FDA clearance and is available for consumers to buy directly or access via referral from their own doctor or a physician from Happy Health’s network. The company claims it is the first BP-measurement device requiring no external calibration. The blood pressure monitoring capability is an add-on feature to the Happy Ring, which is primarily used to track sleep.
The company raised $75 million in August 2026 from ARCH Venture Partners and OpenLoop to build out its platform for home-based care. Their devices focus on assessing sleep quality and other health measurements, providing both patients and physicians data that can help support medical care.
“This is blood pressure’s CGM moment,” said Dustin Freckleton, MD, founder and CEO of Happy Health in a news release last week, referring to continuous glucose monitoring devices for patients with diabetes. “High blood pressure is the most prevalent and modifiable risk factor for heart disease, stroke, dementia and all-cause mortality, which makes seeing it in real life incredibly powerful. Just as CGMs freed glucose monitoring from the finger stick, we’ve freed blood pressure from the cuff, turning an occasional measurement into a passive signal that can reveal risk throughout everyday life, including overnight.”
The ring combines two technologies to provide its cuffless, continuous blood pressure measurements: photoplethysmography (PPG) and bioimpedance. PPG is an optical sensing method in which various wavelengths of light measure how blood volume changes with each heartbeat. Bioimpedance uses an electrical signal to measure the properties of the surrounding tissue, which helps to determine how much blood is present.
Freckleton explained that, “We then use physics-based models of how blood vessels expand and contract to translate those measurements into an absolute blood pressure in mmHg. Because factors like hydration, temperature, medication, vascular tone, etc. can influence these signals, the system also evaluates the physiological state in which each measurement is taken. If those conditions fall outside the ranges we’ve validated, the ring can withhold the measurement rather than report a blood pressure that may not be reliable. This is what allows the Happy Ring to measure blood pressure without an inflatable cuff and, importantly, without requiring a cuff measurement for calibration.”
Happy Health is not the only company with a cuffless BP device. Biobeat, which makes the Biobeat chest patch, offers 24-hour, cuffless, ambulatory blood pressure monitoring combined with a mobile app and automated physician report. However, unlike Happy Health’s device which does not require calibration against a traditional cuff measurement, Biobeat’s does.
Happy Health validated its technology against invasive arterial line measurements, which is the clinical standard for continuous blood pressure measurements. They also tested the device in people with varying BMIs, skin tones, and health conditions, as these variables can also impact blood pressure readings. The company claims that the mean difference was less than 1 mmHg for both systolic and diastolic blood pressure.
Freckleton discussed the clinical implications of being able to monitor blood pressure continuously, particularly overnight.
“Sleep apnea is a good example of what that additional context can reveal. It can repeatedly stress the cardiovascular system overnight and contribute to hypertension,” he said. “When a physician can see blood pressure alongside what is happening with a patient’s sleep and breathing, they can begin to understand those relationships rather than looking at each measurement in isolation.”
For Happy Health, the longer-term challenge is establishing how continuous blood pressure measurements should inform diagnosis and treatment. Translating those patterns into clinical decisions will require further evidence, but for now, Freckleton is hopeful that the device will help patients to smoothly integrate at-home blood pressure monitoring into their routine.
“Our vision is much simpler: put on a ring when you go to bed, take it off when you wake up, and automatically get the health measurements that matter to you and your doctor without having to remember to measure anything,” he said. Instead of asking patients to become better at monitoring their blood pressure, we can make the monitoring fit naturally into their lives.”
Photo: Waldemarus, Getty Images