- Vital Signals has announced the $399 Signal Ring, a smart ring that claims to measure actual blood pressure readings — including systolic and diastolic numbers — without requiring any baseline calibration from a traditional arm cuff; this directly addresses the key limitation of every existing wearable blood pressure solution: Apple Watch detects hypertension patterns but cannot display actual readings; Samsung Galaxy Watch and Whoop show actual numbers but require initial cuff calibration and periodic manual re-calibration to prevent drift; the Signal Ring’s cuff-free approach, if it delivers on its accuracy claims, would represent the first consumer device to meaningfully challenge the 150-year-old arm cuff as the default blood pressure measurement standard.
- The device is available for preorder now and will ship in October 2026 at $399 with no ongoing subscription — a deliberate positioning decision by CEO Tom Moss, who said “if the cuff doesn’t charge you a subscription, I won’t charge you a subscription,” directly targeting Oura Ring’s subscription model; Vital Signals is not targeting the mainstream fitness wearable market but rather the roughly half of US adults who have hypertension or are at elevated risk — a population that has had no continuous, cuffless blood pressure monitoring option and for whom a one-time $399 purchase for a medically meaningful device represents a different value calculation than a general wellness tracker.
- A medical-grade version of the Signal Ring is currently in clinical trials at four sites including Stanford University, and could eventually be cleared by the FDA to actively diagnose hypertension and alert users to dangerous trends — a capability that is categorically different from the wellness-tracking designation that the consumer version will carry at launch; co-founder Mohammad Usman, who spent over a decade at medical tech company Masimo Corp., said the device has shown accurate readings for thousands of trial participants, with the key engineering challenge being accuracy across diverse physiologies — varying age, BMI, genetics, and arterial stiffness — which the ring’s proprietary algorithms are designed to address.
- The competitive and IP landscape presents meaningful risks: Oura Health, the leading smart ring company, has sued multiple smart ring challengers for patent infringement, and Vital Signals will enter its commercial ramp in Oura’s legal crosshairs; additionally, because the Signal Ring does its data processing in the cloud rather than on-device, blood pressure readings require a data connection, limiting real-time utility in offline environments; Moss acknowledges the technology could eventually be replicated by a larger company with the resources to reverse-engineer the custom circuits and algorithms — his estimate is that would take at least two years, giving Vital Signals a window to establish clinical credibility and customer relationships before Apple, Samsung, or Google moves aggressively into cuffless blood pressure measurement.
What Happened?
Vital Signals, a three-year-old startup founded by CEO Tom Moss after he nearly died from undiagnosed hypertension, launched preorders Thursday for the $399 Signal Ring — a smart ring that claims to measure actual blood pressure readings without any arm cuff calibration. The device ships in October. Unlike Apple Watch (patterns only) and Samsung/Whoop (actual readings but require cuff calibration), the Signal Ring provides systolic and diastolic numbers with no cuff required. A medical-grade version is in clinical trials at Stanford. There is no subscription fee.
Why It Matters?
Hypertension affects nearly half of US adults and is one of the leading preventable causes of cardiovascular disease, stroke, and premature death — yet most hypertensive patients only get blood pressure readings during doctor visits, missing the continuous monitoring that would give early warning of dangerous spikes. The arm cuff has been the standard for 150 years because no portable alternative has matched its accuracy. If Vital Signals’ clinical data holds up at scale, the Signal Ring could meaningfully expand access to continuous blood pressure monitoring for tens of millions of people who currently have no practical way to track one of their most critical health metrics between clinical visits.
What’s Next?
Watch the October shipping launch and whether accuracy claims hold up in real-world user reports — the hands-on demo Bloomberg conducted produced some inaccurate readings, with Moss attributing them to fit; ring sizing and fit consistency will be a key variable at scale. Also watch for Oura’s legal response, which has been aggressive against other smart ring entrants. Most importantly, watch the Stanford clinical trial results: if the medical-grade version achieves FDA clearance as a diagnostic device, the addressable market and pricing power would expand dramatically beyond the current wellness-positioning at $399.
Source: Bloomberg
