Design of equipment for intermittent normobaric hypoxia

Abstract

Hypoxifiers are clinical devices producing HGM for delivering INH while providing respiratory comfort for patients. Hypoxifiers vary depending on the system of HGM production, but incorporate practically identical respiratory units for supply of the HGM to the patient. Hypoxifiers may prepare HGM from compressed or condensed gases, or from atmospheric air. Of the first group, the most widespread are ejection-type hypoxifiers utilizing compressed nitrogen to which atmospheric air is added at a 1:1 ratio. Since ejection-type hypoxifiers have uncomplicated design, provide operational comfort, and are reliable in producing HGM of precise and stable composition, they are the best choice where compressed nitrogen is readily available. In all other cases hypoxifiers of the second group, gas-separating membrane devices and autohypoxifiers with semiclosed circulation systems, are preferable. Less market potential of equipment of the second group results from the absence of adequate pumping devices and HGM composition control components. Practical experience of the use of hypoxifiers demonstrates the need for equipment with more precise and stable HGM composition. The most competitive will be designs avoiding consumable materials and accommodating units to monitor the patient's condition.