NCT07699094 · James J. Peters Veterans Affairs Medical Center
AI-Guided Predictions of Blood Pressure Dysregulation Using Perfusion Index as a Novel Biomarker in Persons With Spinal Cord Injury
What this study is about
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.
View original scientific description
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? We 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. We will put put on non-invasive sensors (taped or attached on the surface of your body) to measure PI, BP, and other vital signs. We will record these measurements while you are seated in a wheelchair for 10 minutes in a warm room and up to 90 minutes in a cool room.
Interventions
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.
Primary outcome measures
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.
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- You have 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)
- You 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 you are going to participate, you 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
- You have cardiovascular, kidney, or untreated thyroid disease
- You have a traumatic brain injury (TBI)
- You have diabetes mellitus
- You have an acute illness or infection
- You are dehydrated
- You are pregnant
- You have broken, inflamed, or otherwise fragile skin
- Your Body Mass Index (BMI) is more than 30 kg/m2
Where
- The Bronx, New York
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 10, 2026 · Source of record for eligibility and locations