Human Compatibility Testing of a Pressure-Breathing Mask, MBU-12/P.

Subject preference for the MBU-12P mask over the MBU-5P was revealed by results from more than 48 altitude-chamber tests with each of these oxygen pressure-breathing masks. According to subject evaluation, the assets of the MBU-12P mask include more comfort better ability to Valsalva more freedom of movement of the head less redness and marking of the face greater peripheral vision and, at altitude, a tighter seal against loss of oxygen. The responses of both masks at low and high temperatures were similar. Subjective evaluation of communication revealed no apparent difference between the two types of mask. Moderate improvement was measured in tendency of the MBU-12P mask to hold to the face and not leak during exposure to increased gravity fields of 3, 5, and 7 Gz. Author