Seals and Sealing Methods for a Surgical Instrument Having an Articulated End Effector Actuated by a Drive Shaft

A seal for a minimally-invasive surgical instrument having an internal drive shaft, the seal comprising:

• a substantially rigid portion having an outer perimeter shaped to interface with an instrument shaft of the surgical instrument, the instrument shaft defining a shaft axis and the rigid portion is configured to receive an internal drive shaft mounted axially there through for rotation within the instrument shaft;
• and
• a first slot oriented laterally to the shaft axis and first and second apertures configured to receive the internal drive shaft axially there through, the first and second apertures disposed on opposing sides of the first slot and opening to the first slot, the first slot open at a first radially perimeter location of the seal and configured to receive a first o-ring seal via the first perimeter opening, the first slot having opposing internal sides oriented laterally to the shaft axis and spaced to simultaneously interface with opposed axial surfaces of the first o-ring seal, the first and second apertures being larger than the internal drive shaft passing through the first and second apertures, respectively, so as to accommodate lateral displacement of the internal drive shaft relative to the instrument shaft while the internal drive shaft rotates and the first o-ring seal inhibits axial transmission of at least one of an insufflated gas or bodily fluids within the instrument shaft.