What is a needleless injector?

Question

what is a needleless injector and how does it work?

Answer 1

In military, when they give the immunization to the recruits (say, in basic training), that is what they use. No needle is used, so it just squirted right into the muscle (deeply). If the patient moves it "cuts" him.

Can be seen in the movie (1971) The Andromeda Strain. The character Dr. Hall goes through the body analyzer and at the end, he's given a booster shot.

Answer 2

Until the 1960s we had to take cars to the garage to be lubricated. The grease guns were pressurized and shot a thin stream of grease into the fitting. Some novice mechanics would invariably put the guns against their skin and pull the trigger, injecting themselves with a few milliliters of grease that was difficult to remove.

The needleless injectors that I am familiar with work on the same principle. You hold the gun firmly against the skin and pull the trigger. A measured super-fine pressurized stream of vaccine penetrates the skin and subcutaneous tissues, entering the muscle layer if so desired by adjusting the pressure. Judging from the yelps of the kids, it wasn't painless.

Answer 3

It's a bit ambiguous... For example an IV or any sort of IV delivery system, suppose it's hooked up to a power injector in an angio suite for run offs or a CT suite for contrast enhanced imaging.  There's only a catheter inside a vein, there's no needle, per se.

Answer 4

usually you have a pressure injector straight into the skin, just like a very strong water spray. The stuff goes sub cutaneous and is absorbed without needle holes

obviously its only for intra dermal substances