Modeling and Testing of a Mechanical Counterpressure Bio-Suit System 2007-01-3172

The Bio-Suit System is a modular spacesuit concept based on mechanical counterpressure (MCP). Considerable experimental work has been conducted in the field of MCP, but there has been no analysis of the hypothetical best pressure production of this type of spacesuit design. Therefore, computer modeling has been undertaken to verify the feasibility of such a design, which is based on not only providing the required pressure on the skin, but also limiting the variation of pressure production across a cross-section of the body. Given the data sets available, which exclusively consists of legs under normal atmospheric pressure, not mechanical counterpressure, the modeling work indicates that an MCP design can meet these requirements.

Using the data gained from this analysis, the team has also set requirements for the fabric and closure mechanism in order to design a working prototype. As part of this design process, the team has further developed the elastic bindings concept, which previously was designed to produce pressure only on the calf. Now the team has extended the design to protect the entire right leg in an underpressurized environment. Of special concern to the team is the knee, since pure mechanical counterpressure may not adequately pressure the concavities around the kneecap, leading to edema. Early tests indicate that the bands are successful at protecting the leg (with the possible exception of the knee) at the desired underpressure (-225 mm Hg).