Human Research Program Flight Thigh Cuff

Mitigating Headward Fluid Shifts With Venoconstrictive Thigh Cuffs During Spaceflight

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.

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