摘要 |
A syringe for sequentially injecting at least two volumes of liquid with a minimum amount of intermixing prior to and during injection. This is accomplished by means of concentric plunger rods attached, respectively, to adjacent coaxial plungers. A first chamber is filled by drawing back on one plunger, and drawing the liquid through a communicating channel in the other plunger. When the first chamber has been filled to the desired capacity, a second chamber is filled by drawing back on this other plunger. The injection process reverses the previous filling stages, with the most forward plunger being depressed first to inject the fluid in the second chamber adjacent to the tip of the syringe, and the other plunger then being depressed to inject the contents of the first chamber through the communicating channel of the forward plunger and the tip of the syringe.
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