Smartphone Blood Pressure Measurement to Screen for Hypertension (Optiscreen)

March 24, 2026 updated by: Patrick Schoettker, Centre Hospitalier Universitaire Vaudois

Assessing the Feasibility of Classifying People Using a Machine-learning Approached Based on Features Derived From Smartphone Video Data Recorded at the Person's Fingertip

The goal of this observational study is to assess the feasibility of classifying people whose blood pressures are within hypertensive range using a machine-learning approach based on features derived from smartphone video data recorded at the patient's fingertips. The main question[s] it aims to answer are:

Is a smartphone a reliable device for high blood pressure screening ? Is a smartphone a reliable device for blood pressure monitoring ? Participants will record their blood pressure with a smartphone at their fingertips and with an approved cuff device, 3 times in the morning and 3 times in the evening for 7 days. There will be two groups, a volunteer presumed healthy, and a volunteer addressed for a Home Blood pressure monitoring with the diagnosis of hypertension suspected.

Researchers will compare the two groups to see if the smartphone can be reliable in terms of diagnosis and monitoring of the blood pressure comparing to a standard cuff device.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a single-center observational pilot study. Data will be collected prospectively on 100 participants (maximum of 120) with, ideally, 50 presumed healthy volunteers and 50 participants with a suspected diagnosis of hypertension. Presumably healthy volunteers will be recruited via flyers and participants presumed to be hypertensive will be recruited by the hypertension unit of the CHUV, where they are referred for the search for a diagnosis of hypertension.

To comply with the International Hypertension Societies guidelines for LMWH, participants will measure their blood pressure for 7 consecutive days, in the morning (before taking medications and food) and in the evening. (before dinner). At each measurement time point, participants will acquire three separate measurements, one minute apart. Participants will record signals by placing a fingertip of the right hand over a smartphone camera, while simultaneously acquiring a baseline blood pressure measurement using a validated cuff device (WatchBP O3 Ambulatory, Microlife, Widnau, Switzerland) on the left arm. Please note that the smartphone and armband will be provided by the site investigator. The data recorded using the smartphone will be processed and directly compared to the values obtained using the inflatable cuff device.

In accordance with international guidelines for LMWH (except those of the American Heart Association), the threshold for hypertension is set at systolic blood pressure values ≥ 135 mmHg and/or diastolic blood pressure values ≥ 85 mmHg.

The aim of this study is to evaluate the feasibility of classifying people whose blood pressure is in the hypertensive range or not, using a method based on machine learning. To do this, optical data will be recorded at the fingertip from a smartphone camera following the HBPM measurement protocol. The optical signals will then be processed by a machine learning method to obtain the classification. In other words, investigators will attempt to evaluate the reliability of the machine learning method compared to the automatic oscillometric brachial cuff and therefore evaluate the feasibility of using the smartphone as a potential future tool for diagnosis, screening and monitoring hypertension.

The methods of screening, diagnosis and monitoring of hypertensive pathologies are precise but require cumbersome equipment and are sometimes poorly available. Investigators hypothesize that smartphones can be used because of their availability and their capacity to generate quality optical signals, as a discriminating classifier in arterial hypertension thanks to the precision of a machine learning model hypothetically greater than a classification carried out by a random level.

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Switzerland
      • Lausanne, Switzerland, 1011
        • Recruiting
        • University Hospital Lausanne CHUV
        • Contact:
    • Canton of Vaud
      • Lausanne, Canton of Vaud, Switzerland, 1011

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

For this study, the aim is to reach balanced classes, with at least 40% of non-hypertensive patients and 40% of hypertensive patients. In order to approach such distributions, both healthy volunteers and patients suspected of hypertension visiting the CHUV Hypertensive Unit for diagnosis confirmation will be recruited.

Description

Inclusion Criteria:

  • Informed consent as documented by signature
  • Men or women older than 18 years old
  • Good understanding of written and oral speaking used at the center where the study will be carried out

Exclusion Criteria:

  • Patients that cannot sign informed consent
  • Patients in emergency situation, are not legally competent, cannot understand the situation or are vulnerable
  • Unable to participate due to pain or stress [12]
  • Known or suspected non-compliance (e.g. drug or alcohol abuse, language problems, psychological disorders, dementia)
  • Patients older than 80 years old [4] [13]
  • Known pregnancy
  • Known unstable cardiac condition (myocardial infarction < 1 week, decompensated heart failure, pulmonary embolism)
  • End-stage renal disease (GFR < 15/min/1.73m2 and/or dialysis) [4] [14] [15] [16]
  • Diabetes mellitus [15] [8]
  • Known (or assessed by recording heart rate and using pulse palpation, as recommended in ESC/ESH guidelines [1]) cardiac arrhythmia (atrial fibrillation, numerous extrasystoles and important bradycardia/bradyarrhythmia, bigeminy, trigeminy, isolated VPB) [4] [1] [7] [15] [17]
  • SBP or DBP difference between two arms >10 mmHg [8] [18]
  • Patient with finger lesions that would alter the correct capture of signals by the mobile phone.
  • Known mobile phone contact dermatitis (caused by metal allergens, notably nickel and chromium
  • Incapacity of properly using the smartphone (i.e. incapacity of obtaining a recording with sufficient signal quality after the dedicated training)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Volunteer presumed healthy
People presumed healthy undergoing blood pressure measurement with a standard cuff device and with a Smartphone
Other: Blood pressure measurement
Blood pressure measurement using a standard cuff device and a smartphone
Volunteer suspected of arterial hypertension
People addressed for a suspected diagnosis of arterial hypertension undergoing a home blood pressure monitoring and measurements with a smartphone
Other: Blood pressure measurement
Blood pressure measurement using a standard cuff device and a smartphone

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Measurement of blood pressure by a smartphone
Time Frame: 7 days
Reliability of blood pressure measure by smartphone to discriminate values within hypertension range compared to standard cuff device
7 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centre Hospitalier Universitaire Vaudois

Investigators

  • Principal Investigator: Patrick Schoettker, PhD, Centre hospitalier universitaire vaudois

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2024

Primary Completion (Estimated)

December 30, 2026

Study Completion (Estimated)

December 30, 2026

Study Registration Dates

First Submitted

August 27, 2024

First Submitted That Met QC Criteria

August 27, 2024

First Posted (Actual)

August 29, 2024

Study Record Updates

Last Update Posted (Actual)

March 27, 2026

Last Update Submitted That Met QC Criteria

March 24, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 2023-00851

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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