Medical IoT (IoMT) devices are left exposed to attacks because of outdated or legacy operating systems which, in many cases, are very easy to hack into and expose a throve of sensitive patient data. The UK Department of Health and Social Care announced that all National Health Service (NHS) computer systems will be transitioned to Windows 10 following more than a third of all NHS trusts being hit by WannaCry, with the attacks leading to the cancellation of roughly 7,000 medical appointments across the UK.
Source: https://www.bleepingcomputer.com/news/security/medical-iot-devices-with-outdated-operating-systems-exposed-to-hacking/

