| 摘要 |
Improvements in infusion controlling apparatus used in limiting the flow rate of an intravenous solution to a patient. The improvements provide coarse and fine orientations of a casette through which the solution passes relative to a controller which valves the casette's inlet and outlet to provide measured volumes of fluid. The coarse alignment device includes spaced apart metal sections which grasp onto the casette and move it towards the controller's valving members. As the casette reaches the valving members, protuberances on the controller fit into indentations on the casette, as the fine adjustment. The indentations into which the protuberances fit form part of the casette's base section of plastic notwithstanding the location of a cover slip between these two items. The valving members couple to a rocker arm which pivots about a point located at its middle and has magnetic poles at its ends. The rocker arm's pivot point over the center leg of an E-frame electromagnet allows the arm to rotate between two orientations in which one of its magnetic poles contacts a side leg of the E-frame electromagnet. Current passing through a coil located on the center leg of the electromagnet moves the rocker arm between these positions, depending upon the current's direction. With no current in the coil, the arm's magnets and the E-frame provide a bistable magnetic device in which the rocker arm forces one of the valving members to close either the casette's inlet or its outlet. This prevents the uncontrolled passage of fluid through the casette to the patient.
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