Peripheral Blood Flow Responses to Electromagnetic Energy

April 27, 2026 updated by: Nicole Lohr, University of Alabama at Birmingham
This study evaluates 670 nm energy in the form of red light to stimulate blood flow changes in healthy adults. All participants will receive red light to their leg. They will also receive a continuous infusion of Definity (octafluoropropane) ultrasound contrast.

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

670 nm energy in the form of red light dilates isolated blood vessels. This study seeks to measure vessel dilation in human subjects exposed to this energy at different irradiance intensities (25 milliwatts (mW)/cm2 and 75 mW/cm2). The intent of this protocol is to measure blood flow in the gastrocnemius muscle before and after exposure to 670 nm light energy. This protocol will be performed in healthy subjects, who do not meet exclusion criteria. The study consists of one visit. Blood flow measurement will be performed using contrast enhanced ultrasound, a method by which ultrasound contrast is continuously infused into the blood stream. Ultrasound records images in the area of interest and flow is related to the intensity of the contrast in each image. After baseline blood flow images are collected, the subject will receive red light energy to the gastrocnemius muscle with concurrent blood flow measurements with contrast ultrasound. The subject will be monitored post procedure and the study will then be completed.

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.
40

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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Nicole L Lohr, MD, PhD
  • Phone Number: 205-996-3504
  • Email: nlohr@uabmc.edu

Study Locations

  • United States
    • Wisconsin
      • Milwaukee, Wisconsin, United States, 53226
        • Recruiting
        • Medical College of Wisconsin
        • Contact:

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

18 years to 59 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Participants will be healthy subjects over the age of 18.
  • Men and women will be recruited for participation.
  • All ethnicities will be included in this study.

Exclusion Criteria:

Exclusionary criteria include:

  • age under 18 years and those over 60 years of age,
  • those who are unable to understand the consent process,
  • those who cannot read or speak English,
  • a history of cancer,
  • peripheral artery disease,
  • diabetes mellitus,
  • active pregnancy,
  • hypersensitivity to perflutren contrast agents,
  • pulmonary hypertension,
  • chronic kidney disease,
  • active tobacco or drug use,
  • blood pressure over 160/90, BMI>30,
  • sickle cell disease, or
  • history of intracardiac shunt.

Additional exclusion criteria include:

  • a history of coronary artery disease,
  • heart failure,
  • the presence of an implanted defibrillator or pacemaker,
  • a history of heart murmur or rhythm disorder (atrial fibrillation, atrial tachycardia, or ventricular tachycardia),
  • neurological diseases such as stroke, and
  • any uncontrolled medical conditions.

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: N/A
  • Interventional Model: Single Group 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: 670 nm light
Subjects will have baseline blood flow measured in the gastrocnemius using octafluoropropane infusion and ultrasound.After baseline flow measurements are obtained, a 670 nm light emitting diode will be placed 1 cm above the gastrocnemius muscle. The diode will not be in direct contact with the skin. Subjects will be exposed to 75 mW/cm2. Contrast images will be obtained up to 5 minutes after the commencement of light.
Device: 670 nm light
670 nm light emitting diode will be placed 1 cm above the gastrocnemius muscle. The diode will not be in direct contact with the skin. Subjects will be exposed to 75 mW/cm2.
Other Names:
  • Red light
Drug: octafluropropane
Octofluoropropane will be administered as a continuous infusion prior to the initiation of 670 nm light in order to measure skeletal muscle blood flow.
Other Names:
  • Definity

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
Change in blood flow (using octafluoropropane infusion and ultrasound)
Time Frame: 10 minutes
Blood flow changes based on ultrasound imaging
10 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.
University of Alabama at Birmingham

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Nicole L Lohr, MD, PhD, Medical College of Wisconsin

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

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.
November 1, 2014

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.
December 31, 2027

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.
December 31, 2027

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).
February 18, 2015

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.
February 23, 2015

First Posted (Estimated)

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.
February 24, 2015

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.
May 1, 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.
April 27, 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.
April 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.
  • 22652

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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