Waveform generator and control for selective cell ablation

A method of treating a patient using an ablation therapy comprising:

• setting output parameters for a biphasic electrical output comprising a first phase of a first polarity and a second phase of a second polarity opposite the first polarity, with an interpulse period defined between the first and second phases;
• delivering the biphasic electrical output to the patient using the output parameters;
• observing whether a muscle response occurs;
• a) if no muscle response is observed, modifying the output parameters by extending the interpulse period defined between the first and second phases;
• b) if a muscle response is observed, modifying the output parameters by reducing the interpulse period defined between the first and second phases;
• and
• again delivering the biphasic electrical output to the patient using the output parameters as modified in one of steps a) and b).

An ablation device for generating energy for use in electrical ablation of tissue comprising:

• a voltage source;
• a capacitor bank for storing energy from the voltage source to be used in delivery ablation therapy;
• an output stage coupling the capacitor bank to a plurality of output nodes;
• sensing circuitry for receiving a sensed signal from a probe adapted for use with the ablation device;
• and
• a control circuit configured to control the capacitor bank and output stage, using feedback from the sensing circuitry, wherein the control circuitry is configured to perform a method of treating a patient using an ablation therapy comprising:
• setting output parameters for a biphasic electrical output comprising a first phase of a first polarity and a second phase of a second polarity opposite the first polarity, with an interpulse period defined between the first and second phases;
• a) delivering the biphasic electrical output to the patient using the output parameters and observing whether a muscle response occurs;
• b) if no muscle response is observed, modifying the output parameters by extending the interpulse period defined between the first and second phases;
• repeating steps a) and b) until a muscle response is observed or until a predefined maximum interpulse period is used;
• and
• if a muscle response is observed, setting a therapeutic interpulse period as either a fraction of or a reduction of the interpulse period at which muscle response is observed;
• or
• if the maximum interpulse period is used, setting the therapeutic interpulse period at the maximum interpulse period;
• and
• delivering therapy to the patient using a set of therapy parameters including the therapeutic interpulse period.