3. Hypospray
On Star Trek the hypospray was developed out of necessity the producers wanted to be able to show medicines being applied by Dr McCoy but NBC wouldn't allow for them to show hypodermic syringes on screen. So they applied some inventive thinking and simply removed the needle entirely and in some cases applied a sound effect. That's one of the good things about science fiction is that you can side step problems like that. Star Trek did not inspired the hypospray. So why am I including it here? Because while it didn't inspire it, the series certainly popularised the idea. You see, we know these now as jet injectors. They use a gas powered cartridge to fire the inoculations through the skin and has seen extensive use in Africa against smallpox particularly as there is one such device which is powered by a foot pump and doesn't require an electricity supply to use. In fact Star Trek was probably inspired by the patenting of the device only a few years before The Original Series was made. The problem with jet injectors is that despite the lack of needles, there is still a risk of cross contamination to the extent that since Star Trek first came on, it was properly developed, used and has since stopped. In 1997, the US Department of Defence stopped using jet injectors for mass inoculations due to the possibility of cross contamination. But this doesn't mean that it's necessarily the end of the road for the Star Trek hypospray in the real world someone just needs to come along and resolve the identified issue of cross contamination. Until then, it's confined to single person use. So diabetics of the world rejoice, as you'll soon be make Dr McCoy inspired wise cracks on a daily basis.