Defibrillation contact electrode

An electrode comprises a body 3, which makes up the electrode and which is formed as a thin flexible polymeric substance such as urethane foam. The electrode body 3 includes a central inner conductive area 5, which is associated with a first electrode connector 6A. Around the inner conductive area 5 is a non-conductive area 7 formed as a ring around the inner conductive area and there is also an outer conductive area 8 provided as a ring, concentrically arranged around the non-conductive area. Electrode connector 6B is connected to the outer conductive ring 8. The electrode body 3, which has a release tag 4 and is supported on a backing sheet 2 and body 3 can be peeled off the backing sheet using the release tag 4. The condition of the electrode can be evaluated using a test device, which can for example measure electrical impedance across the electrode via electrodes 6A and 6B.