Why were new medical treatments and inventions developed during world war i?

The World War I was a time of a lot of injuries - and many of them similar to each other. This gave a lot of opportunities to try out treatment- and see what led to a higher survival rate of the soldiers. If some treatment led to more saved lives- the doctors knew it worked (outside of war time they would need to wait long till they can try it out).

Acase involving the laws of a single state.