Multi-use cannula system

Claim 2

A surgical combination infusion/aspiration cannula comprising an elongated probe member characterized by: (a) a single tubular distal section having a generally cylindrical, axially asymmetrical, hollow interior bore, the asymmetry producing relatively thick and relatively thin sidewall sectors, the interior bore configured to optionally carry a stilette member therein; (b) an insertion tip distally contiguous with the tubular section and of asymmetrically reduced outer cross-section with respect to the tubular section; (c) a transition portion in the form of a gradual arcuate taper, the taper being generally in the relatively thin wall sector of the tubular section; (d) the tip portion further comprising a rounded blunt closed tissue penetration end for atraumatically penetrating subcutaneous tissue and having a generally radially disposed infusion/aspiration opening rearward of the penetration end, the opening being configured with the asymmetry of cross-section so as to be at least partially protected to prevent incursion of foreign material during insertion of the probe; and (e) wherein the edges of the opening have a blunt outward directed surface and sharpened inner edge component configured to cooperate with the cutting surface of a compatible stilette member to excise tissue specimens.

Claim 3

The apparatus of claim 1 wherein the proximal end of the tubular section is adapted to connect to both injection and aspiration devices.

Claim 4

A combination infusion/aspiration cannula comprising an elongated probe member characterized by: (a) a generally cylindrical tubular shaft section having a hollow interior lumen; (b) an insertion tip section at the distal end of the tubular shaft section comprising a relatively blunt, snub-nosed, but gradually curved, tissue penetrating distal tip section having a closed distal tip end of greatly reduced outer cross-section with respect to the cylindrical tubular shaft section for atraumatically penetrating subcutaneous tissue; (c) a transition portion of the cannula between the tubular shaft and the snub-nosed tip describing a slightly convex lower taper shape and a slightly concave recessed upper taper curve shape; (d) an angularly disposed infusion/aspiration port opening accessing the distal end of the interior lumen in the upper shape of the transition section proximal of the closed snub-nosed tip and distal of the cylindrical shaft, the opening being contained within the tapered cross-sectional area and directed at an acute angle with the axis of the cylindrical tubular shaft of the cannula; (e) wherein the edge of the infusion/aspiration port opening is itself further characterized by a dull, curved transition surface; and (f) wherein the diameter of the infusion/aspiration port opening is less than half of the external diameter of the cannula.

Claim 5

A combination infusion/aspiration cannula comprising an elongated probe member characterized by: (a) a generally cylindrical tubular shaft section having a hollow interior lumen; (b) an insertion tip section at the distal end of the tubular shaft section comprising a relatively blunt, snub-nosed, but gradually curved, tissue penetrating distal tip section having a closed distal tip end of greatly reduced outer cross-section with respect to the cylindrical tubular shaft section for atraumatically penetrating subcutaneous tissue; (c) a transition portion of the cannula between the tubular shaft and the snub-nosed tip describing a slightly convex lower taper shape and a slightly concave recessed upper taper curve shape; (d) an angularly disposed infusion/aspiration port opening accessing the distal end of the interior lumen in the upper shape of the transition section proximal of the closed snub-nosed tip and distal of the cylindrical shaft, the opening being contained within the tapered cross-sectional area and directed at an acute angle with the axis of the cylindrical tubular shaft of the cannula; (e) wherein the edge of the infusion/aspiration port opening is itself further characterized by a dull, curved transition surface; and (f) wherein the diameter of the infusion/aspiration port opening is less than half of the external diameter of the cannula.

Claim 6

The apparatus of claim 3 wherein the infusion/aspiration port opening is generally circular.