Problem Solution and Design

BACKGROUND

Cephalic fluid shifts that occur during long-duration space flight (due to lack of gravitational forces) have been hypothesized to lead to increased intracranial and intraocular pressure. Studies suggest this may be the root cause of visual impairment and other anatomical changes commonly recorded in astronauts.
In order to combat cephalic fluid shifts and their negative effects, our team developed a mobile lower body negative pressure (LNBP) suit to maintain a controlled negative pressure differential. It is designed to be worn with the waist seal at the subject’s iliac crest (ensuring compliance) down to their feet.
Current medical devices to counteract cephalic fluid shifts, such as the Russian Chibis (pictured right), has issues with its utility we want to solve in our improved design.

DESIGN REASONING

Currently, the only LBNP apparatus being used in the ISS (International Space Station) is the Russian Chibis suit, which was first used in 1973 and is still being regularly used today. It was designed to be wall-mounted and immobile. This is an inconvenience for astronauts, as they wish to roam freely around the ISS and engage in their daily routines.
Our design seeks to replicate the same fluid shifts that can be generated from the CHIBIS suit, but in a manner that is not a nuisance to the users. Our design looks like a pair of pants, with rigid rings, spanned by airtight fabric. Bernoulli’s Principle dictates the flow of fluid (in this case blood) is always in the direction towards low pressure, away from high pressure. The suit we create should create a low pressure region in the lower body, that will force fluids to move away from the cranium and into the legs. This device should be able to allow for a standard fluid distribution similar to what is found on Earth.
Additionally, since the suit is not completely rigid, it should be flexible and comfortable enough for an astronaut to wear for prolonged periods of time. The vacuum that creates the negative pressure differential should be portable and attached to the waist, drawing air out from a region near the ankle.

CONSTRUCTION

The final trouser-based design, which was chosen through use of a weighted decision matrix, covers the entire lower body, while still providing mobility and comfort for the user.
The suit was constructed with a docking port system, located at the ankle of the suit. The docking port is equipped with a pressure transducer access attachment, safety relief check valve, pressure fitter, and vacuum attachment nozzle. The vacuum hose connects to the vacuum nozzle, generating negative pressure within the chamber of the suit. The safety relief valve is calibrated to allow air to enter back into the suit should the pressure drop too much. The pressure trasnsducer attachment allow for constant monitoring of the internal negative pressure of the suit

Emily Goble was the editor of this page.