Non-Invasive Mapping of Cerebral Autoregulation Using Near Infrared Spectroscopy

NCT05433129 | Recruiting

• 2 other identifiers: HS25527 (B2022:051)RGPIN-2022-03621
• Study Type: interventional
• Target: 250
• Locations: 1 country
• Sites: 1

Brief Summary

The investigators propose to employ advanced multi-channel near non-invasive near infrared spectroscopy (NIRS) system married with entirely non-invasive continuous arterial blood pressure (niABP) monitor to create a new wearable and portable imaging system that derives CA maps of the entire brain with high sampling rates at each point. The objectives of this project are as follows:

1. 1.To perform in vivo testing and optimization of the device using a block-trial design to evaluate the CA mapping system's performance during various perturbations.
2. 2.To explore the impact of aging and sex on regional disparities in CA in a healthy volunteer population using static recording along with perturbation testing.

Conditions

Cerebral Autoregulation Mapping

Keywords

Near Infrared Spectroscopy; Cerebral Mapping; Cerebral Autoregulation

Outcome Measures

Primary Outcomes (2)

• In Vivo testing and optimization of device during various perturbations

  To assess functionality and feasibility of real-time application in humans, in vivo testing will occur on a small population of healthy human volunteers. Such work will investigate feasibility of the combination monitoring setup, optimal NIRS channel placement using the adjustable OxyMon NIRS cap, ability for pipelines to extract, and analyze signals in real time for continuous derivation of NIRS-based CVR metrics at each channel and functionality of CVR map generation in real-time.

  2 years

• Explore impact of aging and sex on regional disparities in Cerebral Autoregulation

  Current understanding of the aging process and sex on continuously assessed CA, and regional disparities, has been hampered by a lack of high-resolution platform. We will evaluate the impact of both age, and sex on CA using the newly developed platform through static CA assessments in healthy volunteers.

  3 years

Study Arms (1)

Block Testing

OTHER

Perturbations to the system will be investigated through a series of testing (block design separated by baseline rest): A. transient hyperemic response testing via carotid compression methods, B. orthostatic challenge responses (lying-to-sit, sit-to-stand),8 C. vascular chemo-reactivity via fast and slow breathing exercises and D. impact of neurovascular coupling through cognitive/Stroop testing. Work here will establish areas for improvement in real time.

Procedure: Transient hyperemic response; Procedure: Orthostatic challenge; Procedure: Vascular chemo-reactivity; Procedure: Neurovascular coupling

Interventions

Orthostatic challenge PROCEDURE

The orthostatic challenge response will be evaluated by lying-to-sit and sit-to-stand methods 5 times where sitting and standing positions will be held for 3 minutes each for a total block time of 35 minutes. A baseline in lying position will be collected at the start of the block, then the position will be changed from lying to sit for 3 minutes and then position will be changed to standing for another 3 minutes.

Block Testing

Neurovascular coupling PROCEDURE

The fourth block will evaluate the neurovascular coupling using Automated Neuropsychological Assessment Metrics (ANAM) General Neuropsychological Screening (GNS) Clinical Toolkit which contains 5 tests explained as follows 1) Standard Continuous Performance test will assess sustained attention, concentration and working memory. 2) Manikin test will assess 3D spatial rotation ability, left-right orientation, problem solving and attention. 3) Pursuit Tracking test will measure the visuo-motor control. 4) Switching test will assess divided attention, mental flexibility, and executive function. 5) Stroop test will assess the processing speed, selective attention, interference, and executive functioning with three trial blocks.

Block Testing

Transient hyperemic response PROCEDURE

The transient hyperemic response will be tested via carotid compression method. This test will consist of 5 carotid compressions lasting 5 seconds each with a 60 seconds interval between each compression to allow normalization of the CBF to precompression levels, and the total time for this block would be 6 minutes. The ipsilateral common carotid artery will be compressed for this method, and the response of the middle cerebral artery (MCA) blood flow velocity will be assessed using transcranial doppler (TCD) probe (EMS-9D, Delica). The carotid compressions will only be accepted when there is no further decrease in blood flow velocity can be achieved and stable conditions remained during the whole period of the compression. Otherwise, the compression will be terminated and repeated again after 60 seconds. Satisfactory compression is typically considered to result in a reduction in MCA velocity of 50%, at a minimum.

Block Testing

Vascular chemo-reactivity PROCEDURE

vascular chemo-reactivity will be assessed by varying CO2 concentrations through slow and fast breathing exercises with Capnostream 35 Portable Respiratory Monitor (Medtronic Canada) to monitor EtCO2 through nose clip. The breathing trials will occur two times and each of them will have fast and slow trials along with an interval of normal breathing. First time, the normal, fast and slow breathing trials will be 2.5 minutes long while the second time, these breathing trials will be 1.5 minutes long. The normal respiratory rate for adults is 12 breaths/minute, the target slow respiratory rate will be 5 breaths/minute and fast respiratory rate will be 25 breaths/minute as set by metronome. It has been shown that the EtCO2 has a 10% increase during hypoventilation and almost 50% decrease during hyperventilation compared to normal breathing.

Block Testing

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy volunteers (male and female)
• Age \> 17

You may not qualify if:

• History of neurological illness
• History of systemic vascular
• History of cerebrovascular disease

Sponsors & Collaborators

• University of Manitoba: lead
• Health Sciences Centre, Winnipeg, Manitoba: collaborator
• Natural Sciences and Engineering Research Council, Canada: collaborator

Study Sites (1)

Health Sciences Centre (HSC)

Winnipeg, Manitoba, R3A 1R9, Canada

RECRUITING

MeSH Terms

Interventions

Neurovascular Coupling

Intervention Hierarchy (Ancestors)

Cerebrovascular Circulation; Blood Circulation; Cardiovascular Physiological Phenomena; Circulatory and Respiratory Physiological Phenomena

Study Officials

• Frederick A Zeiler, MD PhD FRCSC

  University of Manitoba

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Frederick A Zeiler, MD PhD FRCSC

CONTACT

+1 (431) 335-7461; Frederick.Zeiler@umanitoba.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Device optimization and assessment

Study Record Dates

• First Submitted: June 10, 2022
• First Posted: June 27, 2022
• Study Start: July 11, 2023
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: January 6, 2026

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)