Patent ID: 6955653

Claim:
Apparatus for retrieving a tissue volume, comprising: a delivery member having an interior channel extending from a proximal portion along a longitudinal axis to a forward region having a distal end; a capture component positioned at said delivery member forward region, having a forward portion extending to a forwardly disposed tip region and pursing cable assembly energizable to define an electrosurgical cutting leading portion, said cable assembly including one or more tensionable cables extending from said forward portion along said interior channel to a cable terminator, said forward portion being drivably extendable from an initial position outwardly from said axis and forwardly at a tip region initial angle of attack toward an intermediate position while drawing said cables forwardly, said electrosurgical cutting leading portion defining a cutting profile of maximum effective diametric extent in correspondence with said intermediate position, and subsequently being drivably extendable while being drawn in contraction toward said axis at tip region inwardly directed full pursing angles of attack by pursing stress at said cable assembly to a capture position; and a control assembly having a drive portion in driving engagement with said capture component and actuable to drive said capture component forward portion from said initial position into said capture position, said control assembly effecting the electrosurgical energization of said pursing cable assembly, and being configured to effect a loading of said one or more tensionable cables to derive a said pursing stress which progressively increases toward a higher value to establish corresponding tip region transition pursing angles of attack which commence prior to attainment of said intermediate position and prior to commencement of said tip region full pursing angles of attack.