| US 7,491,191 B2 | ||
| Keep vein open method and injector with keep vein open function | ||
| Gary S. Wagner, Independence, Ky. (US); and Frank Fago, Mason, Ohio (US) | ||
| Assigned to Liebel-Flarsheim Company, Cincinnati, Ohio (US) | ||
| Filed on Feb. 13, 2004, as Appl. No. 10/779,285. | ||
| Prior Publication US 2005/0182371 A1, Aug. 18, 2005 | ||
| Int. Cl. A61M 37/00 (2006.01); A61M 5/315 (2006.01); A61M 5/00 (2006.01) | ||
| U.S. Cl. 604—228 [604/235; 604/6.11] | 3 Claims |
| 1. An injector for injecting fluids from a syringe into a patient, the injector comprising:
a plunger drive ram;
a drive motor for moving the drive ram;
a syringe for holding and injecting a fluid, the syringe having a plunger in operable contact with the drive ram,
wherein the plunger has an elastic head distally positioned from the drive ram and a stretcher rod positioned between and
in operable contact with the head and the drive ram, the head adapted to elastically expand as the drive ram advances against
the stretcher rod and elastically contract as the drive ram retracts from the stretcher rod without sliding in the syringe;
and
a controller connected to the drive motor, the controller controlling the drive motor to advance and retract the drive ram.
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