and you might be pumping it in continuously over a long period time,

药物滴注过程可能会持续相当长一段时间
maybe over hours or over days.

也许超过几小时或者几天
Sometimes this is done--you've seen on TV shows

有时是这样使用的在电视上你见过
a bag of a solution hanging up on a pole

满是溶液的袋子挂在支架上
and a tube going into a patient's arm.

一根管子伸到病人的手臂里
So, this is an infusion where the infusion is driven

这种注入方式是由
by the gravity flow of fluid

液体的重力所驱动的
through the tube into the patient's blood vessel,

药液通过输液管进入病人的血管
that's one example of an infusion.

这是注射的一个例子
Other examples are there might be pump involved at some point.

其他时候可能还需要泵
You have a pump in between the bag of fluid

在药液袋和刺入手臂的针之间
and the needle that goes into the arm.

有一个泵