The Lower Body Negative Pressure Box
Lower pressure negative pressure (LBNP) is the application of sub-atmospheric pressure to the lower portion of the body below the iliac crests. The usual purpose of LBNP is to pool blood in veins that normally return it to the heart. Independent of gravity, the negative pressure applied increases the volume of the lower extremities, stresses the cardiovascular system, and contributes to increase the vascular tone of legs.
It has been used extensively over the last 25 years in investigations dealing with blood pressure control and the effects of exercise training, since it can lower both central venous and arterial pressures. LBNP partially reverses the headward shift of blood and body fluids that occur in microgravity, so it may contribute to reduce cardiovascular deconditioning and has been successfully applied as a countermeasure during space flights and for ground based microgravity simulation studies.
The MicroG has developed and built its own LBNP box, together with a trolley system for the smooth loading of the subject into the device, for use in cardiovascular and exercise studies during LBNP exposure.