Sensing contact of ablation catheter using differential temperature measurements

A method for treatment, comprising:

• bringing a probe into contact with a target tissue in a body of a subject, the probe having first and second temperature sensors on a distal portion of the probe and an ablation electrode thereon, the first and second temperature sensors being disposed on the distal portion, the second temperature sensor being spaced apart from the first temperature sensor such that when the ablation electrode is operationally engaged with the target tissue, the second temperature sensor is less responsive to heat generated at an ablation site comprising the target tissue than the first temperature sensor;
• applying energy through the ablation electrode to ablate the target tissue in the body;
• reading the first and second temperature sensors in order to compute a temperature difference therebetween;
• and
• determining the contact to be sufficient for the treatment if the temperature difference is greater than a predetermined threshold.