During the second mission you'll unlock the ability to upgrade certain machines in rooms; the EZ scans, the Extract-A-Pan, etc. You can either just build 25 rooms and then upgrade 25 of the machines afterwards, or continue playing, where you should reach a large enough hospital to achieve this organically. It'll cost around 18k/room if you decide to build a bunch of diagnosis rooms and upgrade the EZ scanners, other rooms will cost more. I'd also recommend hiring multiple janitors if you can to speed the process up, it takes 30 ingame days for each machine to upgrade.