Lower body negative pressure box for +Gz simulation in the upright seated position.

The cost of purchasing and operating a human centrifuge is substantial. Lower body negative pressure (LBNP) is considered an acceptable experimental substitute for the +Gz stress of the centrifuge. Since civil aviation pilots are usually subjected to +Gz stress in an upright seated position, an upright seated version of the supine LBNP box was developed. In this version, a negative pressure of -40 torr is considered the equivalent of a 2 +Gz stress. This box has successfully withstood a test pressure of -120 torr. Pedal ergometry within the box is easily accomplished. The box was anthropometrically engineered to accommodate a human height range of 160-195 cm. Locating the box within an altitude chamber allows the application of LBNP at any level of chamber altitude. The total cost of fabrication is approximately $500.