such that these do not have to be specified in greater detail at this juncture fig3 a 3b show two configurations of electrode line arrangements that can be provided with shaping parts of the above described type fig3 a shows an electrode line arrangement 50 with an electrode line electrode 50 1 which has a tip electrode 50 2 and a ring electrode 50 3 as electrode poles and is deformed so as to be v shaped in the end portion by a shaping part 50 4 shrunk fit on the line between the two electrode poles 50 2 50 3 the electrode line arrangement 50 thus tenses between the opposite walls of a vessel which in turn leads in a desirable manner due to the fact that the electrode poles 50 2 and 50 3 have reliable wall contact and can thus reliably performed their stimulation and or sensing task in a durable manner fig3 b shows as a modification of this configuration a further electrode line arrangement 50 u2032 which comprises a three pole electrode line 50 1 u2032 with the electrode poles 50 2 u2032 50 3 u2032 and 50 4 u2032 and two shaping parts 50 5 u2032 50 6 u2032 both shaping parts are each placed between the three electrode poles around the corresponding portions of the electrode 50 1 u2032 and are tightly glued there to the electrode it can be seen that the electrode line in this embodiment has assumed a form that is.