There are some curiosities that show the IEC60601-1 standard regarding the general requirements for safety and essential performance of medical devices.
For example, medical equipment that is powered by an external power source may be classified as Class I or Class II, depending on whether any electrical part of the developed device comes into contact with the patient. For example, a machine that performs an electrocardiogram on a patient, who has patches attached to the body, has more demanding electrical design requirements than a camera that takes pictures of the skin to check for melanomas.
In the following figures taken from the IEC60601-1 standard, you can see the different electrical circuits that must be made according to the Class (I or II) of the medical device to be designed, the Class II being more complex.