An assembly of a breakaway needle and catheter is provided for injection by the user, using only one hand. The needle and catheter are inserted by the user, and the needle is then retracted from the puncture site leaving the catheter in place. As the needle is retracted, it breaks apart and separates from the catheter. The assembly includes adhesive coated taping wings to which the catheter is attached. Hence, when the taping wings are attached to the user's body following splitting of the needle, the catheter will be secured in place for long term use.

An auxiliary supply system for a portable self-contained breathing apparatus in which an auxiliary source of air is provided to the facepiece which is totally independent of the normal air supply, in order to provide additional air to the user in case the original supply of air runs out or any component of the standard breathing apparatus malfunctions.

A breathing apparatus is provided for use, particularly by divers, in recirculation of a breathing gas. The apparatus has a supply line for supply of gas to a user and a return line for return of exhaust gas from the user to be recirculated. Two gas chambers of variable volume, a first in the supply line and a second in the return line, are capable of changing volume in unison with the user's breathing to accommodate a change in gas volume in the apparatus due to the user's breathing action. The first and second chambers are constrained to operate together in such a way that the variation of volume of either chamber is accompanied by a similar variation in the volume of the other chamber. Thus, both chambers would be full together (maximum operational volume) and empty together (minimum operational volume). Preferably, the variable volume chamber is in the form of a counterlung. For example, a pair of linked counterlungs may be used, or preferably a double counterlung comprising a single body with two separate chambers could be employed.

Work persons, wearing clear hoods supplied with breathable air, performing tasks in contaminated spaces, are provided with an in line personal airflow gage. The breathable air passing through the gage moves through an especially shaped volume or chamber, which centers on a variable curved interior surface of the underside portions of an inner indicia receiving cover of this personal airflow gage. How this surface is varied serves to initially calibrate this gage. Also initially and subsequently, this gage is calibrated by selecting a coiled spring, which provides the resisting and returning force of the airflow indicating arm or pointer. This arm in turn is coupled to a pivotal air blade, also called the flag, which partially rotates, pivots or deflects, within a one hundred and eighty degree range, back and forth within the especially shaped volume, through which the breathing air passes. When desired, an alarm system is included, whereby, when respective low or high airflows occur, an alarm will sound to warn the work person. Preferably a personal airflow control valve will be located adjacent this personal airflow gage giving the work person greater control of his or her own air supply. Moreover, the air supply hoses may incorporate communication wires to complete a two way communication system between all persons connected with the work tasks in the contaminated space.

An air bottle support harness for hand-free carrying a compressed air bottle. The harness includes an arm sling with laterally extending spaced retention loops adapted to encircle the bottle to hold the same on the support harness when the arm sling is supported on a shoulder of the wearer.