Provided is a valve element for venting fluids, such as gas or liquids, entrapped in a packaging enclosure. The head-mounted eye tracking assembly comprises a visor having an arcuate shape including a concave surface and an opposed convex surface. The probability of reflection of the adverse influence of the disaster on spatial and temporal movement patterns of an automobile represented by the probe information is high. The dried indicator reagent delivery unit comprises a label zone permeated with a dried indicator reagent which is capable of being placed in transient fluid communication with the reaction zone of the test unit during the assay procedure. According to a further aspect of the present invention, a second technique is employed to locate the left ventricle region. , assuring against collapse of the distal-end half of the softly compliant evacuation tube in the distal region of the mask, such that inflation of the mask does not compromise viability of the evacuation tube by compressing softly compliant material of the evacuation tube during periods of mask inflation.