Methods and apparatus for selective tissue ablation

Abstract

Catheter systems and methods for the selective and rapid application of DC voltage to drive irreversible electroporation are disclosed herein. In some embodiments, an apparatus includes a voltage pulse generator and an electrode controller. The voltage pulse generator is configured to produce a pulsed voltage waveform. The electrode controller is configured to be operably coupled to the voltage pulse generator and a medical device including a series of electrodes. The electrode controller includes a selection module and a pulse delivery module. The selection module is configured to select a subset of electrodes from the series of electrodes. The selection module is configured identify at least one electrode as an anode and at least one electrode as a cathode. The pulse delivery module is configured to deliver an output signal associated with the pulsed voltage waveform to the subset of electrodes.

1 . An apparatus, comprising:
 a voltage pulse generator configured to produce a pulsed voltage waveform; and   an electrode controller configured to be operably coupled to the voltage pulse generator and a medical device including a plurality of electrodes, the electrode controller implemented in at least one of a memory or a processor, the electrode controller including a selection module and a pulse delivery module, the selection module configured to select a subset of electrodes from the plurality of electrodes, the selection module configured identify at least a first electrode from the subset of electrodes as an anode and at least a second electrode from the subset of electrodes as a cathode, the pulse delivery module configured to deliver an output signal associated with the pulsed voltage waveform to the subset of electrodes.   
     
     
         2 . The apparatus of  claim 1 , wherein the electrode controller includes an input/output module, the selection module configured to select the subset of electrodes based on input received from the input/output module. 
     
     
         3 . The apparatus of  claim 1 , wherein the selection module is configured to select the subset of electrodes based on a predetermined schedule of the plurality of electrodes. 
     
     
         4 . The apparatus of  claim 1 , wherein the selection module is configured to select the subset of electrodes automatically based on at least one of an impedance associated with the subset of electrodes, a distance between the first electrode and the second electrode, and a characteristic associated with a target tissue. 
     
     
         5 . The apparatus of  claim 1 , wherein the electrode controller includes a feedback module configured to determine an impedance between the first electrode and the second electrode, the selection module configured to select the subset of electrodes automatically based the impedance. 
     
     
         6 . The apparatus of  claim 1 , wherein the electrode controller includes a feedback module configured to determine an impedance map associated with the plurality of electrodes, the selection module configured to select the subset of electrodes automatically based the impedance map. 
     
     
         7 . The apparatus of  claim 1 , wherein the electrode controller includes an input/output module configured to produce a signal associated with a graphical map of the plurality of electrodes and the subset of electrodes. 
     
     
         8 . The apparatus of  claim 1 , wherein the subset of electrodes includes a plurality of anode/cathode pairs, a first anode/cathode pair including the first electrode and the second electrode, the pulse delivery module configured to deliver the output signal to the plurality of anode/cathode pairs in a sequential pattern. 
     
     
         9 . The apparatus of  claim 8 , wherein the selection module is configured to determine the sequential pattern based on at least one of an impedance associated with the plurality of anode/cathode pairs, a distance between the plurality of anode/cathode pairs, and a characteristic associated with a target tissue. 
     
     
         10 . The apparatus of  claim 1 , wherein:
 the medical device is a first medical device;   the plurality of electrodes is a first plurality of electrodes;   the electrode controller is configured to be operably coupled to a second medical device different from the first medical device, the second medical device including a second plurality of electrodes, the selection module is configured to select the subset of electrodes such that a first portion of the subset of electrodes is from the first plurality of electrodes and a second portion of the subset of electrodes is from the second plurality of electrodes.   
     
     
         11 . The apparatus of  claim 1 , wherein the pulse delivery module configured to deliver the output signal having a predetermined voltage pulse amplitude. 
     
     
         12 . The apparatus of  claim 1 , wherein:
 the electrode controller configured to be operably coupled to a pacing lead; and   the electrode controller includes a pacing module and a feedback module, the pacing module configured to produce a pacing signal to the pacing lead to electrically pace a heart, the feedback module configured to receive an electrocardiograph signal associated with a function of the heart, the pulse delivery module configured to deliver the output signal to the subset of electrodes during a time window associated with at least one the pacing signal or the electrocardiograph signal.   
     
     
         13 . The apparatus of  claim 12 , wherein the feedback module is configured to determine an impedance between the first electrode and the second electrode, the selection module configured to select the subset of electrodes automatically based the impedance. 
     
     
         14 . The apparatus of  claim 1 , wherein the voltage pulse generator is configured to produce a biphasic waveform including a pre-polarizing pulse followed by a polarizing pulse, the pre-polarizing pulse being generated by utilizing voltage spikes generated from switching on the discharge of a capacitor bank. 
     
     
         15 . An apparatus, comprising:
 a voltage pulse generator configured to produce a pulsed voltage waveform; and   an electrode controller configured to be operably coupled to the voltage pulse generator and a medical device including a plurality of electrodes, the electrode controller implemented in at least one of a memory or a processor, the electrode controller including a selection module and a pulse delivery module, the selection module configured to select a plurality of anode/cathode pairs, each anode/cathode pair of the plurality of anode/cathode pairs including at least one anode electrode and at least one cathode electrode, the pulse delivery module configured to deliver an output signal associated with the pulsed voltage waveform to the plurality of anode/cathode pairs according to a sequential pattern.   
     
     
         16 . The apparatus of  claim 15 , wherein the selection module is configured to select the at least one anode electrode from a first anode/cathode pair as the anode electrode and the at least one cathode electrode from the first anode/cathode pair as the cathode electrode. 
     
     
         17 . The apparatus of  claim 15 , wherein the selection module is configured to select the plurality of anode/cathode pairs automatically based on at least one of an impedance associated with the plurality of anode/cathode pairs, a distance between a first electrode and a second electrode, and a characteristic associated with a target tissue. 
     
     
         18 . The apparatus of  claim 15 , wherein the electrode controller includes a feedback module configured to determine an impedance between a first electrode from the plurality of electrodes and a second electrode from the plurality of electrodes, the selection module configured to select the plurality of anode/cathode pairs automatically based the impedance. 
     
     
         19 . The apparatus of  claim 15 , wherein the medical device is a multi-electrode catheter configured to be inserted into the coronary sinus. 
     
     
         20 . The apparatus of  claim 15 , wherein the selection module is configured to determine the sequential pattern based on at least one of an impedance associated with the plurality of anode/cathode pairs, a distance between the plurality of anode/cathode pairs, and a characteristic associated with a target tissue. 
     
     
         21 . A method, comprising:
 identifying, via a selection module of an electrode controller, a plurality of anode/cathode pairs from a plurality of electrodes of a multi-electrode catheter, the multi-electrode catheter configured to be disposed about a portion of a heart, at least one anode/cathode pair including at least one anode electrode and at least one cathode electrode;   conveying a pacing signal to a pacing lead configured to be operatively coupled to the heart;   receiving, at a feedback module of the electrode controller, an electrocardiograph signal associated with a function of the heart; and   delivering, via a pulse delivery module of the electrode controller, a pulsed voltage waveform to the plurality of anode/cathode pairs according to a sequential pattern.   
     
     
         22 . The method of  claim 21 , wherein the identifying is based on an input received from an input/output module of the electrode controller. 
     
     
         23 . The method of  claim 21 , wherein the identifying is based on a predetermined schedule of the plurality of electrodes. 
     
     
         24 . The method of  claim 21 , further comprising:
 determining an impedance between the at least one anode electrode and at least one cathode electrode,   the identifying being performed automatically by the selection module based at least in part on the impedance.   
     
     
         25 . The method of  claim 21 , further comprising:
 determining the sequential pattern based on at least one of an impedance associated with the plurality of anode/cathode pairs, a distance between the plurality of anode/cathode pairs, and a characteristic associated with the heart.   
     
     
         26 . The method of  claim 21 , wherein:
 the multi-electrode catheter is a first catheter;   the plurality of electrodes is a first plurality of electrodes; and   the identifying includes identifying at least one anode/cathode pair including at least one anode electrode from the first catheter and at least one cathode electrode from the second catheter, the second catheter distinct from the first catheter.   
     
     
         27 . A non-transitory processor readable medium storing code representing instructions to be executed by a processor, the code comprising code to cause the processor to:
 identify a plurality of anode/cathode pairs from a plurality of electrodes of a multi-electrode catheter, the multi-electrode catheter configured to be disposed about a portion of a heart, at least one anode/cathode pair including at least one anode electrode and at least one cathode electrode;   convey a pacing signal to a pacing lead configured to be operatively coupled to the heart;   receive an electrocardiograph signal associated with a function of the heart; and   deliver a pulsed voltage waveform to the plurality of anode/cathode pairs according to a sequential pattern.   
     
     
         28 . An apparatus, comprising:
 a signal generator for the generation of DC voltage pulses, the signal generator configured to produce a biphasic waveform having a pre-polarizing pulse followed by a polarizing pulse, the pre-polarizing pulse being generated by utilizing voltage spikes generated from switching on a discharge of a capacitor bank.   
     
     
         29 . The apparatus of  claim 28 , wherein the signal generator is configured to customize the pre-polarizing pulse by tuning component parameters in transient control circuitry. 
     
     
         30 . An apparatus, comprising:
 a catheter shaft having an outer side and an inner side;   a cathode electrode coupled to a distal end portion of the catheter shaft such that a cathode surface is exposed on the outer side of the catheter shaft; and   an anode electrode coupled to the distal end portion distal relative to the cathode electrode, the anode electrode being recessed within the catheter shaft and coupled to the catheter shaft such that an anode surface is exposed on the inner side of the catheter shaft.   
     
     
         31 . The apparatus of  claim 30 , wherein a ratio of an anode electrode length to a cathode electrode length is larger than three. 
     
     
         32 . The apparatus of  claim 30 , wherein the anode electrode is in the form of an annular cylinder. 
     
     
         33 . The apparatus of  claim 30 , wherein the anode electrode is in the form of cylinder with a distribution of channels configured to receive a fluid flow. 
     
     
         34 . The apparatus of  claim 30 , wherein the catheter shaft defines an inner lumen through which ionic fluid is pumped for delivery to the distal end portion of the catheter. 
     
     
         35 . The apparatus of  claim 30 , further comprising;
 at least one ultrasonic transducer configured to generate ultrasound waves through a fluid disposed within the catheter shaft.   
     
     
         36 . An apparatus, comprising:
 a catheter shaft having a distal end portion;   an inflatable balloon coupled to the distal end portion, an outer surface of the balloon being an electrical insulator;   a first electrode coupled to a proximal side of the balloon; and   a second electrode coupled to a distal side of the balloon.   
     
     
         37 . The apparatus of  claim 36 , wherein the first electrode is a cathode and the second electrode is an anode. 
     
     
         38 . The apparatus of  claim 36 , wherein the balloon is configured to displace collateral anatomical structures when in an expanded configuration. 
     
     
         39 . The apparatus of  claim 36 , further comprising:
 an ultrasound transducer disposed on a portion of the shaft inside the balloon, the balloon being inflatable with a liquid, with at least a portion of the wall of the balloon being filled with a gas, where the balloon is configured to reflect at least a portion of the ultrasound energy from the ultrasound transducer to a kinetic energy focusing zone in a target tissue to cause an increase in temperature.   
     
     
         40 . An apparatus, comprising:
 a catheter shaft having a distal end portion;   an expandable basket structure coupled to the distal end portion;   a first electrode coupled to a proximal side of the expandable basket structure;   a second electrode coupled to a distal side of the expandable basket structure; and   a plurality of spherical electrodes coupled to a corresponding plurality of rounded corners of the expandable basket structure.   
     
     
         41 . The apparatus of  claim 40 , wherein the catheter shaft defines an inner lumen configured to receive a guide wire such that the catheter shaft can be delivered by the guide wire to a desired target location in a subject anatomy.