Catheter electrode for measuring potential or ion activity - has channel containing electrolytic fluid surrounding supply lead to provide screening

摘要

The electrode, comprises a circular channel (8) containing an electrolytic fluid extending over almost the full length of the electrode and enclosing the insulated electrical lead (5,6). The interior of the channel (8) communicates with the outside via at least one small aperture (13) near the bottom end of the electrode. An ion selective electrode is used with a metallic end contact (14) enclosed by a sheath (17) of silver chloride for blocking the oxygen effect. The ion selective membrane (16) extends across the front face to cover the edge (17) of the sheath (17). The outer sleeve (7) providing the channel (8) containing the electrolytic fluid is adhered or welded to the outer insulation (6) of the lead (5,6) and coupled to the end contact (14). The electrode provides good screening for the supply lead.