| 摘要 |
<p>A dosing means for facilitating the drawing of respective predetermined volumes of two liquids to be injected, in a single injection, into a hypodermic syringe comprises a first positioning element to hold the body of a removable hypodermic syringe, an axially displaceable plunger, and a second positioning element to hold a removable ampoule containing injection liquid. The two positioning elements are arranged so that the tip of the needle of the hypodermic syringe is inside the ampoule when the syringe and ampoule are located in the device. From the first positioning element a pin protrudes axially and carries first and second stops cooperating with the end of the plunger. When liquid is to be drawn in to the hypodermic syringe the plunger is drawn out until its end part meets the first stop. The first ampoule is then replaced by an ampoule containing a different type of liquid. The pin is then turned to move the first stop to leave a free passage for the end of the plunger, after which the plunger is drawn out further until its end comes into contact with the second stop. The hypodermic syringe now contains a correct mixture of the two liquids and is ready for injection.</p> |
