And medical devices cannot just be modified after they are approved for medical use. Any changes must be introduced by the original vendor (or an approved 3rd party vendor) and put through a barrage of tests and certifications needed to release such a device for use on a human. Those include EMC/EMI testing, QC testing, safety testing, RF testing, clinical trials, regulatory compliance, etc.

When you buy a medical device running Windows 3.1, it will run that until it is thrown away or replaced.