| 摘要 |
<p>1468916 Drop-formers for drip-chambers UNITED STATES SURGICAL CORP 3 July 1974 [3 July 1973] 29510/74 Heading A5R A drop former 22, Fig. 3, for use with a drip chamber (not shown) to form drops of a predetermined size is formed of a plastics material e.g. polyethylene, polypropylene, polytetrafluoroethylene, fluorinated ethylene propylene, which absorbs less than 0.03% by weight water so that the size of said drops does not substantially change with time or flow rate. The intermediate portion 40 of the drop-former is tapered outwardly by an angle of 1“ degrees with the vertical so that during the use, it provides a friction-fit between the drop-former and a piercer 12. In a modified drop former (Fig. 7) an annular collar 104 around a tapered portion 100 forms a mechanical lock with adhesive 106 applied on the surface 108 of the fluid discharge opening of the piercer. The piercer 12, formed of a plastics material, e.g. styrene-acrylonitrile. nylon or rigid polyvinyl chloride, is provided with a passage 54, carrying at one end an air filter (not shown) to vent the parenteral fluid container (not shown), and an annular flange 34 which is adhesively attached to the drip chamber. A stainless steel cannula (82) (Figs. 5, 6 not shown) having a diameter slightly larger than the diameter of the cylindrical inlet portion (72) of the drop former may be inserted in the latter to provide more drops e.g. 60 per millilitre of the parenteral fluid.</p> |
