Reddig, M., Tanaka, K., Hargens, A., Webb, P. et al., "Physiological Limits of Underpressure and Overpressure for Mechanical Counter Pressure Suits," SAE Technical Paper 2003-01-2444, 2003, doi:10.4271/2003-01-2444.
The first concept and early experiments of a mechanical counter pressure (MCP) spacesuit were published by Webb in the late 1960's. MCP provides an alternative approach to the conventional full pressure suit that bears some significant advantages, such as increased mobility, dexterity, and tactility. The presented ongoing research provides a thorough investigation of the physiological effect of mechanical counter pressure applied onto the human skin. In this study, we investigated local microcirculatory effects produced with negative and positive ambient pressure on the lower body as a preliminary study for a lower body garment. The data indicates that the positive pressure was less tolerable than negative pressure. Lower body negative and positive pressure cause various responses in skin blood flow due to not only blood shifts but also direct exposure to pressure differentials.