Temperature control for IRE

A medical apparatus for irreversible electroporation (IRE), comprising:

• a probe, comprising:
• an insertion tube configured for insertion into a body cavity of a patient,
• a distal structure connected distally to the insertion tube and comprising a plurality of electrodes, which are configured to contact tissue within the body, and
• temperature sensors fixed to the distal structure and configured to output signals indicative of a temperature of the tissue adjacent to the distal structure that is contacted by the plurality of the electrodes;
• an electrical signal generator configured to apply a preset series of pulse trains to each of selected pairs of the plurality of the electrodes in turn, each pulse train of each of the preset series of pulse trains including a plurality of bipolar pulses having an amplitude sufficient to cause IRE in the tissue contacted by the selected pairs of the plurality of electrodes;
• and
• a controller programmed to:
• cause a first preset series of pulse trains to be directed to a first pair of the plurality of electrodes while receiving signals from the temperature sensors indicative of a monitored temperature of the tissue adjacent to the distal structure that is contacted by the first pair of the plurality of the electrodes,
• cause, when the monitored temperature of the tissue contacted by the first pair of the plurality of electrodes rises above a preset threshold, the first preset series of pulse trains to be halted and a second preset series of pulse trains to be directed to a second pair of the plurality of electrodes, the second preset series of pulse trains being different than the first preset series of pulse trains, the second preset series of pulse trains continuing until the second preset series of pulse trains is complete or halted when a monitored temperature of the tissue contacted by the second pair of the plurality electrodes rises above the preset threshold, and
• cause, when the monitored temperature of the tissue contacted by the first pair of the plurality of electrodes falls back below the preset threshold and the second preset series of pulse trains to the second pair of the plurality of electrodes is one of:
• i) continuing, ii) completed, or iii) halted in response to the monitored temperature of the tissue contacted by the second pair of the plurality of electrodes rising above the preset threshold, the pulse trains of the first preset series of pulse trains that were not directed to the first pair of the plurality of the electrodes before the first preset series of pulse trains was halted, to be directed to the first pair of the plurality of the electrodes to complete the first preset series of pulse trains.