Single-control, accident-proof, manometer tap systems.

,The need has already been discussed for the careful design of control tap arrangements used in the clinical investigation of intravascular pressures (Hepburn, I967). The risk of accidents has been increased by the considerable number of centres introducing such techniques. Because it was considered ,urgently necessary to reduce these risks, an inexpensive tap system was developed (Hep,burn, I967) using a simple arrangement of standard components. Subsequently the need has been felt for more sophisticated tap systems which are not only simpler in use but which may also be operated in parallel and from a distance. Several designs of single-tap control have bPeen produced (e.g. Cambridge Instrument Co., Carle Instruments, Honeywell Controls, Labotron, and St. Thomas' Hospital, London). Unfortunately these units are expensive and not in general use. Moreover, though they achieve the functional requirements to varying degrees, it has been felt in this department that they could be improved tn safety, simplicity, and convenience. Consejuently an eight-position, click-stop, disctype tap was designed and has recently gained enthusiastic clinical acceptance.