RF ablation apparatus and method using amplitude control

A system for delivering energy to biological tissue associated with a biological site, said system comprising:

• a catheter carrying an electrode system having a plurality of electrodes at its distal end, the electrode system adapted to be positioned proximal to the biological tissue;
• a backplate adapted to be positioned proximal to the biological site so that the biological tissue is interposed between the electrode system and the backplate;
• a power control system adapted to:
• during a first period of time, provide a first peak-to-peak amplitude signal to at least one electrode defining a first electrode set and a second peak-to-peak amplitude to at least one electrode defining a second electrode set, wherein the first amplitude is greater than the second amplitude of,
• during a second period of time, provide a third peak-to-peak amplitude signal to the first electrode set and a fourth peak-to-peak amplitude signal to the second electrode set, wherein the third amplitude of the third power is less than the fourth amplitude;
• and
• during at least one of the first and second time periods, establishing a voltage potential between the backplate and either of the first and second electrode sets.

A power control system for delivering energy to a biological tissue interposed between a plurality of electrodes, said power control system comprising:

• a power generator adapted to provide power signals to the electrodes;
• a processor programmed to control the power generator such that:
• during a first period of time, a first peak-to-peak amplitude signal is provided to at least one electrode defining a first electrode set and a second peak-to-peak amplitude signal is provided to at least one electrode defining a second electrode set, wherein the first amplitude is greater than the second amplitude;
• and
• during a second period of time, a third peak-to-peak amplitude signal is provided to the first electrode set and a fourth peak-to-peak amplitude signal is provided to the second electrode set, wherein the third amplitude is less than the fourth amplitude.

A method of delivering energy to biological tissue associated with a biological site, said method comprising:

• positioning a catheter having a plurality of electrodes proximal to the biological tissue;
• during a first period of time providing a first peak-to-peak amplitude signal to at least one electrode defining a first electrode set and a second peak-to-peak amplitude signal to at least one electrode defining a second electrode set, wherein the first amplitude is greater than the second amplitude;
• and
• during a second period of time, providing a third peak-to-peak amplitude signal to the first electrode set and a fourth peak-to-peak amplitude signal to the second electrode set, wherein the third amplitude is less than the fourth amplitude.

An ablation system comprising:

• a catheter having a plurality of electrode pairs;
• a power control system adapted to:
• during a first period of time, establish a voltage potential between a first electrode pair by providing a first power signal to one of the electrodes while maintaining the other electrode at a reference potential;
• and
• during a second period of time, establish a voltage potential between a second electrode pair by providing the first power signal to one of the electrodes while maintaining the other electrode at the reference potential.

A method of delivering energy to biological tissue associated with a biological site, said method comprising:

• positioning a catheter having a plurality of electrodes pairs proximal to the biological tissue;
• during a first period of time establishing a voltage potential between a first electrode pair by providing a first power signal to one of the electrodes while maintaining the other electrode at a reference potential;
• and
• during a second period of time establishing a voltage potential between a second electrode pair by providing the first power signal to one of the electrodes while maintaining the other electrode at the reference potential.