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Enrolling by Invitation

NCT Number: NCT06476106

Human Research Program Flight Thigh Cuff

Venoconstrictive Thigh Cuffs (VTC) are being evaluated to determine the effectiveness at reversing the headward fluid shift that occurs during weightlessness. If successful, future studies may be done to implement these as a CM to SANS. To support this effort, participants will participate in 2 preflight study sessions consisting of a VTC fit check and a baseline data collection without and with the VTC donned. Participants will also participate in 3 inflight study sessions: a VTC fit check on flight day 30 (FD30) and two separate data collection sessions on flight day 45 (FD45) and 45 days before landing (R-45). During the two in-flight data collection days, participants will be studied before and for up to 6 hours after donning the VTC.

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Key information

Conditions

Healthy

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Johnson Space Center, National Aeronautics and Space Administration

Houston, Texas, 77058, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Astronauts participating in missions that are ≥2 months

Exclusion criteria

  • Having known allergies to proparacaine hydrochloride ophthalmic solution precludes participation in this study
  • Use of ethinyl estradiol Combined Oral Contraceptive (COC) pills precludes participation in this study
  • Having increased risk of venothromboembolism (VTE) based on preflight thrombosis/clotting related biomarkers precludes participation in this study

Treatment and study plan

Venoconstrictive Thigh Cuff (VTC)

Device

The VTC is an adjustable fabric cuff that is worn on the upper thighs to retain some fluid in the legs. It consists of wide straps and a buckle which allow it to be tightened, then velcro to secure the strap in the tightened position. There is also lacing that can be tightened for micro adjustments. Imbedded within the fabric strap is a bladder that is not used for increasing tightness but allows the pressure of the cuff to be measured and tracked.

Other names: Thigh Cuff

Primary outcomes

  1. Internal Jugular Vein (IJV) area

    Time frame: Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return

    Measured using Ultrasound.

  2. IJV pressure

    Time frame: Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return

    Measured using the VeinPres device during Ultrasound.

  3. Intraocular Pressure (IOP)

    Time frame: Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return

    Measured using the Pneumatonometer.

  4. stroke volume

    Time frame: Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return

    Measured from data collected during Ultrasound.

Sponsors and collaborators

Lead sponsor

National Aeronautics and Space Administration (NASA)

Fed

Registry information

Official study title

Mitigating Headward Fluid Shifts With Venoconstrictive Thigh Cuffs During Spaceflight

Important dates

Study start
2023
Primary completion
2028
Study completion
2030
First posted
Jun 26, 2024
Registry last updated
Apr 1, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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