Lower-body Negative Pressure (LBNP) devices
We are going to have a base on the moon. We are going to send people to mars. That means spending longer periods in microgravity environments. One of the main issues observed in microgravity environments is the headward shift of fluid body which can lead to astronauts’ medical issues that can compromise the space exploration mission.
Lower-body Negative Pressure (LBNP) method is used to draw body fluids to the lower body and thus counter the headward shift observed in microgravity environment, but also generate ground reaction forces to maintain bone and muscle.
A European standard under discussion
Currently, LBNP devices such as standard LBNP chamber or more specifically the Russian “Chibis” LBNP suit have been implemented to counter the headward shift observed in microgravity environment and thus ensure astronaut safety. However, they are not optimal for human spaceflight. Furthermore, there are still no standard LBNP devices available for the astronauts as such in Europe.
How LBNP device works?
There are four main pressures to consider when it comes to implement LBNP device:
- P1: pressure on the upper part of the body
- P2: pressure on the lower part of the body
- P3: pressure inside the LBNP device
- P4: pressure in the International Space Station (ISS)
P1 tends to be higher than P2 due to the absence of weightlessness in space (microgravity) which can cause health issues to the astronauts. The reason for that is because the brain requires a large amount of blood to oxygenate itself, so a lot of fluid go to the upper part of the body. Then, the blood coming from the brain is struggling to get back down because of the absence of weightlessness in space.
P3 is significantly lower than P2 which generates a force that leads to the motion of the fluid from the upper part of the body to the lower part of the body. The molecules inside the lower part of the body try to go from the lower part of the body to outside because of the pressure difference between P2 and P3. They generate a force under the feet (mechanical load) to the ground, resulting in a ground reaction force.
P4 is now bigger than P1 because some molecules (fluid) have travelled from the upper part of the body to the lower part of the body so there is a pressure imbalance between the upper part of the body and the inside of the ISS. Therefore, the pressure difference between P1 and P4 generates a force (mechanical load) to the shoulders.
Results
Benefits: Countering the headward shift observed in microgravity environment, but also generating ground reaction forces to maintain bone and muscle
Limitations: Large, bulky, and usually require the subject to maintain a stationary position.
Ensure the health of space travelers
Ensuring the safety of the astronauts while maintaining crew time for operational and science-related tasks is the key to success of every space exploration mission.
How can the digital engineer assist you?
We will establish the detailed design of a new LBNP device that allows for movement in all dimensions, embed the know-how into our software, and make it accessible to the entire space thermal engineers’ community for free via the web at Digital Engineer®
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