Correlation Between the R-R Interval of the Electrocardiogram and the Intracranial Pulse Wave Interval Assessed by a Noninvasive Method in Healthy People

May 27, 2026 updated by: Gisele Sampaio Silva, Federal University of São Paulo
Heart rate variability (HRV) is a well-established cardiovascular and autonomic health metric in the medical literature. However, its applicability is limited by the difficulty of analysis and interpretation in clinical practice. Given that the intracranial pressure (ICP) waveform is the manifestation of the vascular pulse wave that originates from cardiac muscle contraction, we will evaluate whether the interval between ICP pulse waves assessed noninvasively with Brain4care technology is the same as the R-R interval assessed by electrocardiography in healthy patients, in an attempt to universalize autonomic analysis in clinical practice.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Actual)

103

Contacts and Locations

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

Study Locations

  • Brazil
    • São Paulo
      • São Paulo, São Paulo, Brazil, 04024-002
        • São Paulo Hospital

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

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Healthy adults from 18 to 60 years old.

Description

Inclusion Criteria:

  • Healthy adults from 18 to 60 years old.

Exclusion Criteria:

  • The exclusion criteria were as follows: (1) diagnosed cardiovascular disease, including arrythmia (2) symptoms of illness during the recruitment time, (3) restriction in physical activity, and (4) restriction on using wearable devices.

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
Health adults
Simultaneous EKG measurements, ICP waveform measurements, and Photoplethysmography.
Diagnostic test: Evaluate the correlation between R-R interval and R-R equivalent on the noninvasive intracranial compliance monitor (BRV) and evaluate their correspondence considering the Time domain (HR, NN, NN50, R
Simultaneous Autonomic measures using ECG, noninvasive ICP wave monitor and photoplethysmography (oximeter)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Evaluate the correlation between R-R interval and R-R equivalent on the noninvasive intracranial compliance monitor and evaluate their correspondence considering the Time domain (HR, NN, NN50, RMSSD, SDNN, pNN50) in health patients.
Time Frame: "From enrollment to the end of recruitment at 8 weeks"
The participants will be asked to wear the noninvasive ICP waveform monitor band, an EKG and finger oximeter (photoplethysmography) monitor for 15 minutes in supine position with an 15-degree head elevation. All recordings were performed in a bright and quiet room.
"From enrollment to the end of recruitment at 8 weeks"

Collaborators and Investigators

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

Sponsor

Federal University of São Paulo

Investigators

  • Study Director: Gisele Sampaio Silva, PhD, Federal University of São Paulo

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

June 1, 2025

Primary Completion (Actual)

December 15, 2025

Study Completion (Actual)

May 27, 2026

Study Registration Dates

First Submitted

September 10, 2025

First Submitted That Met QC Criteria

May 27, 2026

First Posted (Actual)

June 1, 2026

Study Record Updates

Last Update Posted (Actual)

June 1, 2026

Last Update Submitted That Met QC Criteria

May 27, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 83670224.6.0000.5505

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Anonymous autonomic data (EKG, ICP waveform monitor, Photoplethysmography).

IPD Sharing Time Frame

from 2026 after article publication.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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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