Healthy
Conditions
Brief summary
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.
Interventions
DEVICEVenoconstrictive Thigh Cuff (VTC)
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.
Sponsors
National Aeronautics and Space Administration (NASA)
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Internal Jugular Vein (IJV) area | Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return | Measured using Ultrasound. |
| IJV pressure | Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return | Measured using the VeinPres device during Ultrasound. |
| Intraocular Pressure (IOP) | Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return | Measured using the Pneumatonometer. |
| stroke volume | Thigh Cuff Measures 90 days before mission, after 45 days in mission, and 45 days before return | Measured from data collected during Ultrasound. |
Countries
United States
Outcome results
None listed