BACKGROUND

Electrosurgical systems are used during surgical procedures to remove several different tissue types. For example, procedures involving the knee or shoulder may remove portions of cartilage, meniscus, and free floating and/or trapped tissue. In some cases, the removal may be a very slight removal, such as tissue sculpting, and in other cases more aggressive removal of tissue is used. Electrosurgical systems may also operate in a coagulation mode, to seal arterial vessels exposed during tissue removal, and sealing to reduce bleeding.

SUMMARY

There is provided an electrosurgical wand including a handle on a proximal end of the electrosurgical wand. An elongate shaft is coupled to the handle and extends distally from the handle along a longitudinal central axis. An active electrode is disposed at a distal end of the electrosurgical wand and has an outer face and defining an exterior periphery extending thereabout. The active electrode resides within and defines a plane spaced from and extending along and laterally from the longitudinal central axis. A return electrode abuts the elongate shaft and extends along and annularly about the longitudinal central axis. The return electrode has a top side adjacent the active electrode and a bottom side disposed remotely from the active electrode and opposite the top side. At least a portion of the return electrode is disposed proximally to the active electrode. The top side of the return electrode has a first length measured axially from the elongate shaft and the bottom side has a second length measured axially from the elongate shaft being greater than the first length to define a notch enabling the bottom side of the return electrode and the active electrode to overlap along the longitudinal central axis in an overlap region. A support member that is electrically insulative is disposed in the notch between the active electrode and the return electrode and extending axially from the return electrode. The support member is coupled to and supports the active electrode. The support member transitions curvilinearly from the notch of the return electrode axially and tapers to a distal tip adjacent the active electrode to define a front surface extending laterally across and axially from the return electrode. The front surface tapers downwardly from the active electrode to define a first portion disposed adjacent the active electrode and defining a first convex outer surface. The front surface also extends toward the bottom side of the return electrode to define a second portion disposed adjacent the bottom side of the return electrode and defining a second convex outer surface. The support member holds the active electrode a first distance from the longitudinal central axis that is greater than a second distance from the longitudinal central axis to the top side of the return electrode.

In some embodiments, the support member has a mid-section disposed between the first portion and the second portion of the front surface and defining a concave outer surface axially undercutting the active electrode toward the proximal end of the electrosurgical wand.

In some embodiments, the concave section has a member radius of curvature having a center disposed on a side of the longitudinal central axis being the same as the active electrode.

In some embodiments, the notch defines a circuitous edge extending arcuately across the top side of the return electrode between a pair of corners to define an upper segment and from the pair of corners axially toward the distal end to define a pair of horizontal segments laterally opposite one another and each extending axially to end at respective shoulders and from the shoulders extending arcuately around the bottom side of the return electrode to define a lower segment and wherein the support member includes a rear edge extending along and corresponding with the circuitous edge of the return electrode.

In some embodiments, the lower segment of the circuitous edge is angled axially away from the distal end as the circuitous edge extends away from the longitudinal central axis at a lower edge segment angle relative to the longitudinal central axis.

In some embodiments, at least one of the shoulders and the corners is rounded.

In some embodiments, the electrosurgical wand further includes an aspiration channel defined within the elongate shaft and the active electrode further comprises at least one aperture that defines a suction lumen, the at least one aperture is disposed over an opening into the aspiration channel.

In some embodiments, the support member includes at least one shelf extending axially along and disposed below the exterior periphery of the active electrode and extending laterally outwardly from the support member.

In some embodiments, the at least one shelf is angled at a shelf angle relative to the outer face of the active electrode.

In some embodiments, the shelf angle is between 30 and 60 degrees.

There is also provided an electrosurgical wand comprising including a handle on a proximal end of the electrosurgical wand. An elongate shaft is coupled to the handle and extends distally from the handle along a longitudinal central axis. An active electrode is disposed at a distal end of the electrosurgical wand and has an outer face and resides within and defining a plane spaced from and extending along and laterally from the longitudinal central axis. A return electrode abuts the elongate shaft and extends along and annularly about the longitudinal central axis. The return electrode has a top side adjacent the active electrode and a bottom side disposed remotely from the active electrode and opposite the top side. At least a portion of the return electrode is disposed proximally to the active electrode. A support member that is electrically insulative is disposed between the active electrode and the return electrode and extends axially from the return electrode and is coupled to and supports the active electrode. The active electrode has an oblong shape viewed perpendicular to the plane within which the active electrode resides with a wider portion and a narrower portion narrowing with increasing distal distance from the wider portion. The active electrode is disposed distally with respect to the wider portion and defines an exterior periphery extending thereabout including a pair of side edges. The active electrode includes a plurality of protrusions extending away from the outer face of the active electrode in a direction away from the longitudinal central axis.

In some embodiments, the plurality of protrusions includes a pair of rear protrusions spaced from and on opposite sides of the longitudinal central axis in the wider portion and a pair of front protrusions spaced from and on opposite sides of the longitudinal central axis and axially spaced from the rear protrusions in the narrower portion.

In some embodiments, the pair of front protrusions each angles laterally inwardly toward the longitudinal central axis as they extend axially away from the wider portion.

In some embodiments, the pair of side edges each is slightly convex and converges with one another at an active electrode apex in the narrowing portion and connected at a truncated end being linear and extending laterally from the longitudinal central axis in the wider portion.

In some embodiments, the pair of side edges each has an edge radius of curvature having a center on an opposite side of the longitudinal central axis from the respective one of the pair of side edges.

In some embodiments, the longitudinal central axis does not intersect the plane within the periphery of the active electrode.

In some embodiments, the longitudinal central axis is parallel to the plane.

In some embodiments, the electrosurgical wand further includes an aspiration channel defined within the elongate shaft and the active electrode further comprises at least one aperture that defines a suction lumen, the at least one aperture is disposed over an opening into the aspiration channel.

Further features and advantages of at least some of the embodiments of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.

