Development of an Integrated Ergometer/Lower Body Negative Pressure System

摘要

The object of the program was to provide prototype equipment for use by the USAF in laboratory studies of physiological deconditioning similar to that which results from space flight. Three successive versions of an integrated Ergometer/Lower Body Negative Pressure (LBNP) System were delivered to AMD. The ergometer consists of a self-powered bicycle type unit with a solid-state electronic control system to maintain constant generator output regardless of pedal rotation speed. Recording capabilities are provided for a tachometer, and a wattmeter. Provisions are made to attach power consuming or power storage devices to the ergometer. Work loads up to one horsepower can be accommodated. The ergometer was calibrated using a dynamometer and speed reducer. The LBNP chamber is fully collapsible and employs circumferential rings to support the side loads. For ground applications longitudinal support members are used to carry the axial loads. The waist seal is a single molded unit and is removable from the chamber. The chamber has provisions for 19 leads of bioinstrumentation. A fail-safe overpressure control system is provided. A design limit of - 80 mm Hg for 15 minutes was demonstrated. Normal operating pressure is - 30 mm Hg. Provisions were made to integrate the ergometer with the LBNP. The two systems were designed to be operated individually, separately, or simultaneously, and in either the vertical or horizontal mode. Development needs were identified for future investigations. The major areas requiring further study are: generator design, weight reduction, material analysis, and flight version design. (Author)