July 12, 2024Open Access
Wearable cuffless blood pressure tracking: when will they be good enough?
Key Result
In an N=1 self-test, three cuffless wearable devices showed varying discrepancies in tracking blood pressure during sleep and emotional stress compared to validated cuff-based monitors.
Structured PICO
Do cuffless wearable blood pressure devices accurately track blood pressure changes compared to standard cuff-based ambulatory monitoring?
P
Population
A 24-hour N=1 self-test by a single female participant evaluating three cuffless blood pressure wearables against cuff-based ambulatory monitors during sleep, wakefulness, and emotional stress.
E
Exposure
Three cuffless wearable blood pressure devices (Aktiia wrist-wearable, Biobeat chest patch, and CAR-T ring) worn simultaneously
C
Comparator
Validated left and right arm cuff-based ambulatory blood pressure monitoring (WatchBP O3)
O
Outcome
Accuracy of tracking systolic and diastolic blood pressure and heart rate over 24 hours (awake, asleep, and during emotional stress/watching rugby)surrogate
This N=1 perspective demonstrates that current cuffless blood pressure wearables show significant discrepancies in tracking physiological blood pressure changes compared to standard ambulatory cuffs, underscoring the need for further validation before clinical use.
Limitations
- N=1 study design
- Not a formal clinical trial
- Potential influence of movement or body position on readings
- Cuff inflation itself may cause an anxiety response influencing comparisons
Abstract
Wearable health monitoring is a multibillion-dollar industry. But the holy grail is probably getting it right for blood pressure monitoring without a cuff, because raised blood pressure is very common and the leading cause of death in the world. Many have tried and failed, but industry is persisting: numerous cuffless wearable blood pressure devices are on the market, several technologies have been developed, hundreds of patents are registered every year, and some devices already have regulatory approval. However, to convince the die-hard blood pressure critic is a different ball game. To understand the challenges of currently accepted methods and cuffless devices, I performed a 24-h blood pressure monitoring self-test, including measurements when awake, asleep and watching an intense match of the Rugby World Cup final, with the purpose to demonstrate the challenges and opportunities we face. Blood pressure was monitored using five different devices simultaneously: validated left and right arm cuff blood pressure, and three cuffless wearable devices (wrist-band, chest patch and a ring). Whilst none of these devices proved to be perfect in capturing a physiologically challenging measure, namely blood pressure, it emphasised that our current practice of a single blood pressure measurement in clinical practice should be revisited. It further begs the question of when cuffless measurements will be good enough to incorporate in clinical decision-making.