Battery, plug-in and laptop ECGs: which need a body-protected area?

It turns on one thing: whether the patient is connected to something plugged into the wall while the leads are on. New Zealand’s RNZCGP scenarios (June 2026) work through the common cases.

• A device that only runs on batteries and cannot be plugged in: no body-protected area needed.
• A battery device that can also be plugged in, as many ECGs can: a body-protected area is preferred. Until there is one, the minimum is a 10 mA Type 1 medical-grade RCD and a sign on the device such as “Unplug me before connecting to the patient”.
• A mains-only ECG, even plugged in through a 10 mA in-line medical-grade RCD: a certified body-protected area is needed. The in-line RCD does not replace it.
• Any of these on an electric examination bed in a treatment room: a body-protected area is needed.
• Off site, at an outreach clinic or marae: a risk-based approach, showing how electrical risk is reduced, what equipment is used (battery or mains) and what advice was obtained.

An ECG that runs from a laptop follows the same test: if the laptop is on its charger while the leads are on the patient, the patient is connected to mains-powered equipment. In Australia the same principle works through the room’s classification: the moment mains-powered equipment is applied to the patient there, the room is a patient area.