Tissue contact assessment with combined mapping and ablation catheter

A system for ablating cardiac tissue through irreversible electroporation, the system comprising:

• an electroporation and mapping catheter for performing irreversible electroporation, the catheter comprising:
• a shaft having a proximal end and an opposite distal end;
• and
• an electrode assembly extending distally from the distal end of the shaft, the electrode assembly defining a distally located central hub portion and a plurality of splines each including a distal end portion extending from the central hub portion, and a proximal end portion attached to and constrained by the outer shaft, the electrode assembly having an expanded configuration and a collapsed configuration, the electrode assembly comprising a plurality of electrodes including:
• a distal ablation electrode including an ablation electrode hub portion located on the distal hub portion, and a plurality of radial segments integrally formed with the ablation electrode hub portion, each of the radial segments extending proximally along a portion of a respective one of the splines and terminating in a proximal end;
• and
• a set of spline sensing electrodes including a plurality of sensing electrodes located on each spline;
• a graphical display;
• and
• a controller coupled to the graphical display and the catheter, the controller configured to:
• determine an impedance from a four-terminal configuration, wherein a current is injected to a current carrying pair of the plurality of electrodes and a voltage is measured across a sensing pair of electrodes comprising a plurality of sensing electrodes;
• and
• generate, on the graphical display, a graphical representation of a model of the impedance of that spline, wherein the graphical representation includes a color from a plurality of colors representative of impedance associated with each of the sensing electrodes of the plurality of sensing electrodes.

A system for ablating cardiac tissue through irreversible electroporation, the system comprising:

• an electroporation and mapping catheter for performing irreversible electroporation, the catheter comprising:
• a shaft having a proximal end and an opposite distal end;
• and
• an electrode assembly extending distally from the distal end of the shaft, the electrode assembly defining a distally located central hub portion and a plurality of splines each including a distal end portion extending from the central hub portion, and a proximal end portion attached to and constrained by the outer shaft, the electrode assembly having an expanded configuration and a collapsed configuration, the electrode assembly comprising a plurality of electrodes including:
• a distal ablation electrode including an ablation electrode hub portion located on the distal hub portion, and a plurality of radial segments integrally formed with the ablation electrode hub portion, each of the radial segments extending proximally along a portion of a respective one of the splines and terminating in a proximal end;
• and
• a set of spline sensing electrodes including a plurality of sensing electrodes located on each spline;
• a graphical display;
• and
• a controller coupled to the graphical display and the catheter, the controller configured to:
• determine an impedance from a four-terminal configuration, wherein a current is injected to a current carrying pair of the plurality of electrodes and a voltage is measured across a sensing pair of electrodes comprising a plurality of sensing electrodes;
• and
• generate, on the graphical display, a graphical representation of a model of the impedance of the spline, wherein the graphical representation includes a color from a plurality of colors representative of impedance associated with each of the sensing electrodes of the plurality of sensing electrodes, and wherein the graphical representation includes a vector from a plurality of vectors representative of impedance associated with each of the sensing electrodes of the plurality of sensing electrodes.