A kind of method, it includes the distal end be inserted into flexible probe (22) and enter living body positioning probe core subject, this distally includes the position for being configured to generate position sensor (36) the instruction distal end of position signal, electrode (32), for transmitting the electric signal from heart. This method further comprises that the first instruction of the variation of mean place is formulated in response to the position signal, and heart exports the electric signal of the second instruction variation in the living body. The method also includes the heart of new mean place is determined in response to first instruction and the second instruction.
