| 主权项 |
1. An extravasation tester, comprising:
a frame having a hollow bore for receiving an intravenous infusion delivery tube; a platen on an inner surface of the hollow bore; a manually rotatable wheel having a circumferential outer surface and opposing axial posts; and opposing slots in the frame for receiving the opposing axial posts of the wheel so that the wheel is rotatable about its axis and translatable along the slots in the frame; wherein the slots and the inner surface of the hollow bore are configured so that:
(a) when the wheel is in a free-flow region of the frame, the outer surface of the wheel does not pinch the delivery tube fully closed against the platen, so that a fluid in the delivery tube is allowed to flow in a forward direction,(b) when the wheel is in a tube-pinching region of the frame, the outer surface of the wheel pinches the delivery tube fully closed against the platen at a point of tube closure between the wheel and the platen, so that no flow is allowed in the delivery tube past the point of tube closure, wherein the tube-pinching region comprises a continuous range of more than one positions of the wheel at which the wheel pinches the delivery tube fully closed against the platen,(c) when the wheel is rolled on the delivery tube in the tube-pinching region of the frame, the point of tube closure translates along the delivery tube in conjunction with the rolling of the wheel, so that fluid in the delivery tube translates along the delivery tube in conjunction with the translation of the point of tube closure, whereby when the wheel is rolled in a reverse direction in the tube-pinching region of the frame, opposite the forward direction, the flow of the fluid in the delivery tube reverses with the reverse rolling of the wheel, and(d) wherein in the tube: pinching region, the slots are parallel to the platen, so that there is a constant clearance between the wheel and the platen when the wheel is in the tube-pinching region of the frame. |
