| 摘要 |
In a hemodialysis system including a dialyzer having a semi-permeable membrane, apparatus for accurately proportioning and mixing fluids comprising a double acting piston/cylinder unit of which the cylinder is divided into two chambers by the piston and the volume of the cylinder swept by the piston at one end of the piston is lesser than that at the other end. An inlet connection for first liquid is made to one chamber, a conduit connects the two chambers and includes a connection to a source of the second liquid. Valve means are associated with the conduits and are effective to cause a charge of first liquid to be delivered to the one chamber and thereafter to be transferred to the other chamber, drawing liquid from the source of the second liquid to make up for the difference in volume. Said valve means then cooperate to cause the mixed liquids to be discharged from the other chamber as said one chamber is again charged with said first liquid. The apparatus is used for accurately establishing the rate of blood waste withdrawal from a patient and for the accurate proportioning and mixing of the liquids, namely, dialysate concentrate and dilution water, which constitute the component parts of dialysate solution. In a variant the piston/cylinder unit is replaced by a receptacle divided by a flexible diaphragm into two chambers, the diaphragm flexing alternately to reduce the volume of one chamber as the other is expanded. |
