There is a long history of healthcare disasters due to incompatible devices and standards. However designed in incompatiblity can aid patient safety. The failure to do this with a host of medical devices used with intrathecal administration is an indictment of the systems of design protection and regulation worldwide. Such equipment should not be compatible with equipment for intravenous and intramuscular injections.
In other medical systems designed to do the same jobs, devices should generally adhere to standards, or copy an existing de facto standard. Again patents can get in the way of what is safe for patients.
Insulin supplies and insulin injectors should fall into no more than a couple of families, regardless of manufacturers. The same applies to the diversity of aerosol pumps and spacers. A recent UK manufacturer organised change in spacer resulted in inappropriate dosage delivery and in this case things have gone back to where they should have been due to regulatory pressure.