Abstract: A tailgate barrier for a pickup truck bed which can be removably located at multiple positions within the truck bed and may be locked by a cotter-key or a padlock for security as the mounting means are brackets suitably mounted in proximity to both sidewalls of the bed. The barrier is made in the form of a membrane which can be wrapped around its support members to accommodate any width of truck bed and can be located forward or rearward of the wheel wells.

Abstract: An improved method and apparatus for controlling the flow of any breathing gas such as oxygen through a cannula or "mask" to a person (patient, aviator, baby, miner, or diver) can be limited to the portion of the breathing cycle when the person breathes inward. This has the effect of reducing the consumption of breathing gas to at least half and possibly less. The result of this reduction of consumption is an extended life of the gas supply and a reduction of the cost per unit time. A bidirectional dynamic mass flow sensor senses the rate of flow of a gas through it and yields an output voltage proportional to mass flow and direction of gas movement. The measured dynamic flow signal is applied to a system controller which operates a flow controller. The system controller provides for indications of operation such as system failure and apnea, rate of flow, duration of flow, and total consumption; in addition, controls are provided to set the duration of gas flow in each breathing cycle.