An electrode device adapted for use in medical devices, such as tissue ablation apparatus, includes a sheet of flexible fabric including at least one surface electrode formed as part of the fabric. More particularly, the sheet is made from a plurality of filaments. At least some of the filaments are made at least partially from an electrically conductive material and cooperate so as to form the electrode. The filaments are formed into a plurality of yarns which are interwoven to form the sheet.