摘要 |
1,247,368. Intravenous injection apparatus. MILLIPORE CORP. 16 Dec., 1968 [5 March, 1968], No. 5962368. Heading A5R. [Also in Divisions Bl and B2] A filter unit, adapted to be secured to a patient's wrist to filter a solution just before it is fed into his vein, comprises two housing parts 3, 4 of transparent polystyrene or polymethylmethacrylate which sandwich a filter membrane 2 of cellulose nitrate and cellulose acetate mixture therebetween and which are welded together by melting one of the peripheral flanges 8, 15 and causing it to penetrate and fill the pores of the membrane and bond to the other flange. This renders the otherwise opaque membrane locally transparent, giving a visual indication of weld quality. The housing parts have respective inlet and outlet ports 5, 18 to which tubes are connected leading to a gravity feed and to a hollow needle respectively. Housing part 4 has upstanding ribs 16 to support the membrane, and part 3 has a dependent skirt 10 with flanges (11) to which a strap (13) securing the skirt to the patient's wrist is attached (Figs. 1, 4, not shown). The membrane 2 is 150 microns thick, with a pore size between 0.5 and 5 microns and porosity 40-85%. The welding is achieved by ultrasonics at 20 kc/s and amplitude 0.0001 to 0.005 inches. |