A systematic method for halting, in real time, ablation of body tissue at a current ablation point to achieve a predetermined lesion size upon halting involves registering (S820), with a characteristic curve, one or more values and halting (S825) the ablation based on the registering. The value or values are obtained from monitoring (S820), for the current ablation point, displacement caused by force applied to the body tissue. In one embodiment, halting is performed upon detecting, by the monitoring and after a peak value of the monitored displacement has occurred, an endpoint value of the monitored displacement. In another embodiment, the endpoint value is determined prior to the detecting, and the determining (S820) is performed by the registering.
