AI-Guided Predictions of Blood Pressure Dysregulation Using Perfusion Index as a Novel Biomarker in Persons With Spinal Cord Injury

August 6, 2026 updated by: Jill M. Wecht, Ed.D., James J. Peters Veterans Affairs Medical Center

The goal of this clinical trial is to determine if perfusion index (PI) can reliably predict changes in systolic blood pressure (SBP) in persons with spinal cord injury (SCI) during a cool temperature challenge. Participants with SCI can be 18-75 years of age, male or female, neurological level of injury C4-T12, ASIA Impairment Scale (AIS: A or B: motor complete) or gender and healthy age-matched able-bodied (AB) controls.

The main question this study aims to answer is: can PI reliably predict change in SBP during a cool temperature challenge? The investigators hypothesize that PI can be used as a biomarker of SBP in persons with SCI.

Researchers will compare the relationship of 1) changes in PI and SBP and 2) relationship of changes in other vital signs to SBP, during the cool temperature challenge. The researchers aim to determine if PI can be used as a biomarker of SBP in persons with SCI during a cool temperature challenge (experimental group/arm). Able-bodied controls (control group/arm) will receive the same intervention (cool challenge) as the experimental group.

During the study, participants will be asked to wear only shorts and a T-shirt so that their skin can be exposed to the warm and cool temperatures of the 2 rooms.

The investigators will put put on non-invasive sensors (taped or attached on the surface of your body) to measure PI, BP, and other vital signs. The investigators will record these measurements while the participant is seated in a wheelchair for 10 minutes in a warm room and up to 90 minutes in a cool room.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Introduction/Background: Persons with spinal cord injury (SCI) may experience impaired control of several autonomic functions, including blood pressure (BP) fluctuations and impaired body temperature regulation in response to exercise, cold exposure, or a full bladder. Hypertension (high BP) is commonly episodic (comes and goes) and without clinical symptoms (the person is unaware). Mechanisms for impaired BP regulation after SCI are not completely understood and contribute to the limited availability of reliable wearable devices for continuous BP monitoring in the community.

Purpose of the Study: By doing this research study, the investigators hope to learn how perfusion index (PI) and the other measured vital signs, respond to moving from the warm to cool room. The investigators will use sophisticated analysis of the data collected, which will include artificial intelligence, to determine how perfusion index can predict changes in systolic blood pressure (SBP).

The investigators have shown that PI can predict SBP (the greater of the 2 BP values, e.g., 120/80 mmHg) with high accuracy in animal studies of monkeys with SCI. Perfusion index can continuously measure (non-stop measuring) the blood flow in the skin using a pulse-oximeter (pulse oxygen meter) and other sensors on your skin. This new tool can help us to better understand why blood pressure is so unstable (goes quickly up and down) after SCI. The findings may also provide necessary information for developing new non-invasive and wearable devices to monitor blood pressure in the community, thereby allowing persons with SCI early detection, safety, and treatment of clinically silent high blood pressure episodes (episodes that you're not aware of).

Study Procedures: When the participant arrives, the investigators will take the their temperature with an ear thermometer to make sure they don't have a fever. If the participant is having a urinary tract infection (UTI), please call before traveling to the Center. Once at the Center, the investigators will use about 30 minutes in a mildly warm room (75-80 deg F) to tape temperature sensors to the participant's forehead (to measure their body temperature). The investigators will put oxygen meters on the participant's ear, finger and toe to measure perfusion index (PI: a ratio or percentage of blood flowing in your arteries compared to blood not flowing very much in your veins and tissues). The investigators will place a device on another finger that measures beat-to-beat BP device (your BP of every heartbeat).

Once the instrument setup is complete, the participant will remain seated in the wheelchair (or the investigators will provide them with one if they are an AB control) and will take the above measures for 10 minutes. Then, the investigators will move the participant into a cool room (64 deg F) for 90 minutes and continue the same measurements.

Impact: Our studies may provide the scientific community with a novel biomarker and tool to better understand mechanisms for unstable blood pressure control after SCI. The findings may also provide the scientific rationale for development of next-generation non-invasive and accurate and reliable wearable devices to monitor SBP in the community, thereby allowing persons with SCI early detection, safety, and treatment of clinically silent hypertensive episodes (autonomic dysreflexia: AD).

Study Aim: To determine the feasibility of PI as a novel non-invasive biomarker to predict SBP in persons with SCI during a cool temperature challenge.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
24

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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

  • United States
    • New York
      • The Bronx, New York, United States, 10468
        • Recruiting
        • James J Peters VA Medical Center
        • Principal Investigator:
          • Jill M Wecht, EdD
        • Contact:
        • Contact:
        • Sub-Investigator:
          • John P Handrakis, PT, DPT, EdD

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • The participant had a spinal cord injury (SCI: C4-T12) for more than one year and the SCI was graded as ASIA Impairment Scale (AIS) A or B (unable to voluntarily move your legs)
  • The participant can also be a gender and age-matched (±5 years) able-bodied (AB) control subject (similar gender and age to a subject with SCI).
  • Subjects with SCI and AB controls must be between 18 and 75 years of age.
  • If the participant are going to do the study, they must avoid caffeine and alcohol, maintain normal salt and water intake, and avoid strenuous exercise for 24 hours prior to the study visit.

Exclusion Criteria:

  • The participant has cardiovascular, kidney, or untreated thyroid disease
  • The participant has had a traumatic brain injury (TBI)
  • The participant has diabetes mellitus
  • The participant has an acute illness or infection
  • The participant is dehydrated
  • The participant smokes
  • The participant is pregnant
  • The participant has broken, inflamed, or otherwise fragile skin
  • The participant's Body Mass Index (BMI) is more than 30 kg/m2

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

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Participants with SCI: Cool temperature challenge
Participants with SCI will be transferred from a thermoneutral room (27°C) to a cool thermal chamber (18°C) for up to 90 minutes to determine change in 1) perfusion index and 2) systolic blood pressure.
Other: Controlled Cool Thermal Challenge (18°C)
Participants with SCI will undergo a controlled, non-invasive cool thermal challenge of 18°C (64.4°F) in a climate-controlled chamber for up to 90 minutes. Participants will remain seated in their wheelchair while wearing a standard T-shirt and shorts to ensure uniform skin exposure. Continuous non-invasive monitoring of perfusion index and blood pressure will be performed throughout the baseline of 27°C (80°F) and cool challenge 18°C (64.4°F) phases to evaluate their relationship.
Other: Controlled Cool Thermal Challenge (18°C)

Able-bodied participants will undergo a controlled, non-invasive cool thermal challenge of 18°C (64.4°F) in a climate-controlled chamber for up to 90 minutes. Participants will remain seated in a wheelchair that will be provided while wearing a standard T-shirt and shorts to ensure uniform skin exposure.

Continuous non-invasive monitoring of perfusion index and blood pressure will be performed throughout the baseline of 27°C (80°F) and cool challenge 18°C (64.4°F) phases to evaluate their relationship.
Active Comparator: Able-bodied participants (Control): Cool temperature challenge
Able-bodied participants will be transferred from a thermoneutral room (27°C) to a cool thermal chamber (18°C) for up to 90 minutes to determine change in 1) perfusion index and 2) systolic blood pressure.
Other: Controlled Cool Thermal Challenge (18°C)
Participants with SCI will undergo a controlled, non-invasive cool thermal challenge of 18°C (64.4°F) in a climate-controlled chamber for up to 90 minutes. Participants will remain seated in their wheelchair while wearing a standard T-shirt and shorts to ensure uniform skin exposure. Continuous non-invasive monitoring of perfusion index and blood pressure will be performed throughout the baseline of 27°C (80°F) and cool challenge 18°C (64.4°F) phases to evaluate their relationship.
Other: Controlled Cool Thermal Challenge (18°C)

Able-bodied participants will undergo a controlled, non-invasive cool thermal challenge of 18°C (64.4°F) in a climate-controlled chamber for up to 90 minutes. Participants will remain seated in a wheelchair that will be provided while wearing a standard T-shirt and shorts to ensure uniform skin exposure.

Continuous non-invasive monitoring of perfusion index and blood pressure will be performed throughout the baseline of 27°C (80°F) and cool challenge 18°C (64.4°F) phases to evaluate their relationship.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Perfusion Index (PI)
Time Frame: Continuously recorded during 10 minutes of the baseline thermoneutral (27°C) phase and throughout the cool thermal challenge (18°C) phase for up to 90 minutes.
Perfusion index (PI: ranging from 0.02 to 20) reflects the ratio of pulsatile (arterial) blood flow to non-pulsatile static blood flow. PI will be continuously collected using Masimo Radical-7 pulse oximeters (Masimo Corp., Irvine, CA) attached to three sites: an ear, a finger, and a toe. This multi-site data will serve as the primary independent predictor variable of SBP in the AI/machine learning models.
Continuously recorded during 10 minutes of the baseline thermoneutral (27°C) phase and throughout the cool thermal challenge (18°C) phase for up to 90 minutes.
Systolic Blood Pressure (SBP)
Time Frame: Continuously recorded during 10 minutes of the baseline thermoneutral (27°C) phase and throughout the cool thermal challenge (18°C) phase for up to 90 minutes.
Beat-to-beat systolic blood pressure (SBP: mmHg) will be continuously collected via a finger-cuff sensor using the VitalStream-CM wireless hemodynamic monitor (CareTaker Medical LLC, Charlottesville, VA). SBP will serve as the primary target dependent variable that the investigators are trying to predict to evaluate sympathetic/vascular reactivity and to train the non-invasive machine learning prediction algorithms.
Continuously recorded during 10 minutes of the baseline thermoneutral (27°C) phase and throughout the cool thermal challenge (18°C) phase for up to 90 minutes.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
James J. Peters Veterans Affairs Medical Center

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 7, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 7, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 13, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 10, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 6, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 1930980
  • RFA # 20465 (Other Grant/Funding Number: New York State Department of Health)
  • SFS # PART72025 (Other Grant/Funding Number: New York State Spinal Cord Injury Research Board Projects to Accelerate Research Translation (PART))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The investigators have an approved Data Use Agreement (DUA) with Dr. Leif Havton of the VA Puget Sound Health Care System. Transferring data to our subaward site, the VA Puget Sound Health Care System, will allow Dr Leif Havton to perform analysis of the de-identified data, which will include artificial intelligence (AI)/machine learning (ML) to determine best surrogate biomarkers for blood pressure predictions.

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings