According to IEC 60601-1, manufacturers of medical devices must ensure that their medical devices do not allow currents to flow through the patient's body. If the medical device is network compatible, it is advisable to consider a network isolator during development. The network interface (cores and shield) is supplied with 250 VAC as part of the mandatory type examination of an ME device. If current > 100µA flows at one point of the housing during device testing under standard conditions (NC), the device will not be approved.
As the manufacturer, you are not obliged to install or supply a network insulator. It is sufficient if you note in the accompanying documents that the use of a network isolator is necessary when your medical device is connected to a non-medical device or the hospital network. You thus transfer the responsibility for the safe electrical connection of your device to the operator.
Another possibility is to allow the network interface of your medical device exclusively for the connection with other medical devices. If the interface is marked accordingly, it does not have to be electrically isolated, but may not be used for connection to the Ethernet network.