Comparing Accuracy Between Cuffless Wrist Worn and Cuffed Ambulatory BP Monitoring Devices

A Single Centre Randomised Prospective Cross-over Study to Assess Agreement Between Blood Pressure Measurements Taken Using Cuffless Wearable and Cuffed, Ambulatory Blood Pressure Monitoring Devices.

Wrist worn devices can help record Blood Pressure (BP) throughout the day. As such devices are becoming increasingly affordable, they could help improve awareness, early diagnosis, and treatment of high and uncontrolled BP.

The goal of Continuum BP is to evaluate how BP readings from two different types of wrist-worn cuffless devices available on the market (Aktiia and Healthstats BPro Evo) compare with BP taken using an ambulatory BP monitor which records readings over 24h using a standard upper arm cuff. This interventional study will recruit balanced numbers of male and female participants within different age group, who will sequentially wear the Aktiia Bracelet and the Heathstats BPro Evo for a period of 24h, alongside the cuffed ambulatory BP monitor.

If wrist worn devices are found to measure BP reliably, future research will assess if artificial intelligence can use continuous BP readings from these devices to learn patterns and changes in BP; and develop digital twin models to guide better, more precise BP management for individuals.

Inclusion Criteria:

1. Participant is aged ≥21 years and <85 years at the time of screening visit.
2. Able to speak and understand English.
3. Able and willing to give informed consent.
4. Independent and mobile.
5. Willing and able to wear devices/no upper limb restrictions.

Exclusion Criteria:

1. Individuals who are or have been involved in interventional research within a period of 3 months.
2. Vulnerable individuals including those with mental ill-health or who are care dependant.
3. Individuals with serious comorbidities or end organ damage (e.g., previously diagnosed heart failure with New York Heart Association class III/IV, verbal or documented evidence of renal failure or history of dialysis, stroke or myocardial infarction within the last 1-year, previous stroke with residual deficit); and doctor diagnosed hyperthyroidism.
4. Individuals with arterio-venous fistula; or reduced peripheral perfusion identified by a history of Raynaud's syndrome or a pulse pressure of <30mmHg or a capillary refill time of >3s in the dominant arm.
5. Individuals with heart rhythm disorders e.g., persistent Atrial Fibrillation and those who have tachycardia > 120 after 5 minutes of rest.
6. Individuals with skin irritation injury or damage.
7. Self-reported pregnancy. Participation will be withdrawn in the event of pregnancy following enrolment.
8. Life threatening or terminal illness with limited lifespan of <12months.
9. Obesity (Body Mass Index 35kg/m2 or higher) or arm/wrist circumferences outside the range highlighted in each device's specification.
10. Those with very high office BP (greater than Stage 3 hypertension).
11. Interarm difference >15mmHg in Systolic BP and >10mmHg in Diastolic BP.
12. Where the PI thinks that it would be technically difficult to obtain or interpret blood pressures measurements.