System and method for determining electrode-tissue contact based on amplitude modulation of sensed signal

A method of monitoring contact between a medical probe and tissue, the medical probe having a probe shaft and a first electrode carried by the probe shaft, the method comprising:

• introducing the medical probe into a patient adjacent the tissue;
• measuring an electrical parameter between the first electrode and a second electrode, wherein the electrical parameter is amplitude modulated in response to a physiological cycle of the patient;
• and
• detecting contact between the medical probe and the tissue based on the amplitude modulation of the measured electrical parameter.

A method of monitoring contact between a catheter and heart tissue, the catheter having a catheter shaft and a first electrode carried by the catheter shaft, the method comprising:

• introducing the catheter into a heart chamber of a patient;
• measuring an electrical parameter between the first electrode and a second electrode remote from the first electrode, wherein the electrical parameter is amplitude modulated in response to a physiological cycle of the patient;
• and
• detecting contact between the catheter and the heart tissue based on the amplitude modulation of the measured electrical parameter.

A method of monitoring contact between a medical probe and tissue, the medical probe having a probe shaft and a first electrode carried by the probe shaft, the method comprising:

• introducing the medical probe into a patient adjacent the tissue;
• measuring an electrical parameter between the first electrode and a second electrode, wherein the electrical parameter is amplitude modulated in response to a physiological cycle of the patient;
• and
• detecting contact between the medical probe and the tissue based on whether a signal of the amplitude modulation of the electrical parameter has substantially the same directionality at least temporarily as a measured signal of the physiological cycle of the patient.