Spatially multiplexed waveform for selective cell ablation
AssigneeBoston Scientific Scimed, Inc.
InventorsBruce R. Forsyth, Larry D. Canady, Jr., Jonathan Tyler Gorzycki, Timothy A. Ostroot, Hong Cao
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Abstract
Methods and devices for performing ablation using spatially multiplexed waveforms are disclosed. The increased efficacy of monophasic waveforms is combined with the reduced side effects of biphasic waveforms by distributing components of the waveform across multiple electrodes. Charge balancing occurs upon completion of therapy delivery within a time period that avoids muscle stimulation, while allowing unbalanced waveforms to be delivered during stimulation.
Claims18
A method of ablating tissue using a plurality of electrodes comprising at least three electrodes, the method comprising:
- placing the at least three electrodes in or on tissue to be ablated;
- and
- delivering a treatment cycle comprising:
- a first monophasic pulse between a first pair of electrodes chosen among the at least three electrodes;
- a second monophasic pulse between a second pair of electrodes chosen among the at least three electrodes;
- and
- a third monophasic pulse between a third pair of electrodes chosen among the at least three electrodes;
- wherein each first, second and third monophasic pulses uses a unique combination of anode and cathode;
- wherein, at the end of each treatment cycle, the quantity of charge delivered by each electrode is balanced to near zero;
- and
- wherein the treatment cycle is completed within a predefined maximum duration that is less than a time constant of surrounding tissue, wherein the time constant defines a duration of time associated with increased risk of muscle contraction, wherein the predefined maximum duration is less than 1 millisecond, to prevent muscle contraction.
A pulse generator configured for use with a probe having at least three electrodes for delivering ablation therapy to a patient, the pulse generator comprising output circuitry for delivering voltage-based therapy, monitoring circuitry for monitoring characteristics of delivered therapy pulses, and control circuitry comprising a non-volatile memory containing an executable instruction set configured to cause the pulse generator to deliver a treatment cycle comprising:
- a first monophasic pulse between a first pair of electrodes chosen among the at least three electrodes;
- a second monophasic pulse between a second pair of electrodes chosen among the at least three electrodes;
- and
- a third monophasic pulse between a third pair of electrodes chosen among the at least three electrodes;
- wherein each first, second and third monophasic pulses uses a unique combination of anode and cathode;
- wherein, at the end of each treatment cycle, the quantity of charge delivered by each electrode is balanced to near zero;
- wherein the treatment cycle is completed within a predefined maximum duration that is less than a time constant of surrounding tissue,
- wherein the time constant defines a duration of time associated with increased risk of muscle contraction, and
- wherein the executable instruction set is configured such that each treatment cycle is completed in a time period of less than 1 millisecond, to prevent muscle contraction.
Dependencies are inferred from the claim text.