Method for determining a position of a catheter tip of a catheter

A method for inserting a catheter tip of a catheter into a patient, the method comprising the steps of:

• locating a plurality of electrodes on a body surface of a body of the patient;
• inserting the catheter tip into the body of the patient;
• and
• advancing the catheter tip in the body of the patient based on determining a movement path of the catheter tip by:
• a) detecting at least one first electrical voltage between a first pair of the plurality of electrodes and detecting at least one second electrical voltage between a second pair of the plurality of electrodes, wherein the first pair of the plurality of electrodes are spaced apart from one another along a first coordinate axis of the body of the patient and the second pair of the plurality of electrodes are spaced apart from one another along a second coordinate axis of the body of the patient, and generating a first ECG signal that represents a first time curve of the at least one first electrical voltage that is assigned to the first coordinate axis, and generating a second ECG signal that represents a second time curve of the at least one second electrical voltage that is assigned to the second coordinate axis;
• b) detecting a first electrical reference voltage between a catheter electrode assigned to the catheter tip and a first reference electrode of the plurality of electrodes on the body surface of the patient, detecting a second electrical reference voltage between the catheter electrode and a second reference electrode of the plurality of electrodes on the body surface of the patient, and generating a first ECG reference signal that represents a time curve of the first electrical reference voltage and generating a second ECG reference signal that represents a time curve of the second electrical reference voltage;
• c) determining a plurality of transformed first ECG signals and transformed second ECG signals for a plurality of different transformation angles using the first ECG signal and the second ECG signal;
• d) determining a first transformation angle of the plurality of different transformation angles, for which a deviation between the corresponding transformed first ECG signal and the first ECG reference signal is minimal, and a second transformation angle of the plurality of different transformation angles, for which a deviation between the corresponding transformed second ECG signal and the second ECG reference signal is minimal;
• and
• e) determining a position of the catheter tip in relation to a coordinate system formed by the first coordinate axis and the second coordinate axis as a function of the first transformation angle and a position of the first reference electrode and the second transformation angle and a position of the second reference electrode;
• wherein the at least one first electrical voltage, the second electrical voltage, the first electrical reference voltage and the second electrical reference voltage result from electrical activity of cardiac muscle cells of the patient.